Science.gov

Sample records for short term variability

  1. Local short-term variability in solar irradiance

    NASA Astrophysics Data System (ADS)

    Lohmann, Gerald M.; Monahan, Adam H.; Heinemann, Detlev

    2016-05-01

    Characterizing spatiotemporal irradiance variability is important for the successful grid integration of increasing numbers of photovoltaic (PV) power systems. Using 1 Hz data recorded by as many as 99 pyranometers during the HD(CP)2 Observational Prototype Experiment (HOPE), we analyze field variability of clear-sky index k* (i.e., irradiance normalized to clear-sky conditions) and sub-minute k* increments (i.e., changes over specified intervals of time) for distances between tens of meters and about 10 km. By means of a simple classification scheme based on k* statistics, we identify overcast, clear, and mixed sky conditions, and demonstrate that the last of these is the most potentially problematic in terms of short-term PV power fluctuations. Under mixed conditions, the probability of relatively strong k* increments of ±0.5 is approximately twice as high compared to increment statistics computed without conditioning by sky type. Additionally, spatial autocorrelation structures of k* increment fields differ considerably between sky types. While the profiles for overcast and clear skies mostly resemble the predictions of a simple model published by , this is not the case for mixed conditions. As a proxy for the smoothing effects of distributed PV, we finally show that spatial averaging mitigates variability in k* less effectively than variability in k* increments, for a spatial sensor density of 2 km-2.

  2. Finding Short-Term Variability in Methanol Masers

    NASA Astrophysics Data System (ADS)

    Bonin, Samuel; Barott, W. C.; Catanach, T.

    2012-05-01

    The Allen Telescope Array (ATA) performed 53 observations of 6.7 GHz methanol masers between July 2010 and January 2011 in an effort to identify short-timescale variability. With the notable exception of Weisberg et al. (2005), few analyses have been performed analyzing variability in masers on timescales of minutes or less. This work is aimed both at providing additional data (including refined positions) on the catalog of observed sources as well as identifying the prevalence and cause of short-term phenomena. Observations utilized both the ATA correlator (for mapping) and beamformer (for recording voltage time series). A combination of Fast-Fourier Transforms and Continuous Wavelet Transforms are applied to channelized power series waterfalls) in this investigation. Wavelet analysis can be thought of as a generalization of Fourier analysis that allows us to examine non-stationary characteristics of the spectra. The survey included both short (10 minute), long (60 minute), and follow-up observations on candidate targets. Analysis so far has identified three variable sources out of 43 distinct objects that were observed. These objects exhibit significant variation on the order of several minutes, are consistent in follow-up observations, and we have ruled out instrumental variation. Future and ongoing work includes identifying the source of this variation as intrinsic to the source or a property of the ISM. Shorter time-scales will be investigated using a combination of techniques, including total power variation, pulse searching (in an attempt to find pulsars), and phase-shift demodulation techniques. The case for SETI analysis of these data is given, for example, by Cordes (1993), who suggested that extraterrestrial intelligences could use masers to amplify interstellar signals.This project was funded by the National Science Foundation Grant AST0852095. [1] Weisberg J. M. et al. (2005) Science, 309, 5731. [2] Cordes J. M. (1993) Astron. Soc. Pacific Conf. Series

  3. Short-term and long-term within-person variability in performance: an integrative model.

    PubMed

    Minbashian, Amirali; Luppino, Daniella

    2014-09-01

    Previous research on within-person variability in performance has largely examined short-term fluctuations and long-term changes in performance separately. The present study proposes a model-based on the cognitive-affective personality system meta--theory (Mischel & Shoda, 1995)--that integrates short-term and long-term performance variability within the 1 framework. Key propositions of the model include that short-term performance fluctuations are contingent on variability in situational cues and that situational cue-performance contingencies change over time. To test the propositions, performance data for 393 professional male tennis players were analyzed using hierarchical linear modeling. The results showed that 2 types of situational cues--resource allocation cues and task complexity--interact in complex ways to account for short-term performance variability. Moreover, as predicted, the contingency of performance on the situational cues changed over time, highlighting the importance of an integrated approach to short-term and long-term performance variability. The implications of these findings are discussed for studies of performance at work and practical applications that managers can employ to increase work performance. Furthermore, parallels are drawn with previous studies from the broader literature on dynamic job performance. PMID:25019419

  4. Short-Term Variability on the Scotian Shelf

    NASA Astrophysics Data System (ADS)

    Greenan, B.; Petrie, B.; Harrison, G.; Oakey, N.; Strain, P.

    2002-12-01

    The traditional view of the production cycle on the continental shelf of Nova Scotia features a spring bloom followed by a period of low production and a less intense fall bloom. The annual cycle of primary productivity thus has a large, low frequency component. However, there is increasing evidence that the production cycle has significant variability on shorter time scales. Physical, chemical and biological variability on the Scotian Shelf is examined on a daily to weekly timescale. This is accomplished through the use of a newly developed mooring platform (SeaHorse) that uses surface wave energy to enable the instrument to climb down the mooring wire and then float upwards while sampling the water column. This provides bi-hourly profiles of temperature, salinity, pressure and chlorophyll at one location over month-long periods. Results from the three-week deployment in October 2000 indicate a subsurface chlorophyll maximum below the pycnocline during the first part of the time series. An event occurred in mid-October during which the temperature, salinity and density iso-surfaces rose approximately 25 m. During this event, a small bloom, with peak chlorophyll concentrations of about 2 mg m-3 and duration of several days, began as nutrients were brought into the upper part of the water column by upwelling-favorable winds. SeaWiFS ocean color satellite images were valuable in providing a spatial context for chlorophyll concentrations, however, the lack of temporal resolution due to poor quality images means that this data set provided limited information for short-term chlorophyll variability. Gradient Richardson Numbers were estimated for 2 m vertical bins using SeaHorse CTD data and nearby ADCP current measurements. A trend of decreasing Ri in the ocean mixed layer with increasing surface wind stress is suggested.

  5. Control group response variability in short-term toxicity tests

    SciTech Connect

    Gast, L.C.; Shimp, C.; Wang, Q.; Shukla, R.; Fulk, F.

    1995-12-31

    The US EPA`s National Reference Toxicant Database (NRTDB) has afforded an excellent opportunity to examine and document variability in responses within control groups (i.e. zero concentration of the toxicant.) The NRTDB has compiled acute and chronic reference toxicant test results for eight species and currently contains results for 32 laboratories and generally eight to ten tests for a species within each laboratory. The Ceriodaphnia dubia Survival and Reproduction test and the Pimephales promelas (fathead minnow) Survival and Growth test are the most frequently represented chronic tests with 331 and 144 sets of test data, respectively. For this presentation, Ceriodaphnia dubia reproduction data, expressed as total numbers of young in the test period, and fathead minnow survival and growth data were analyzed using a variance components model. The information regarding the control population is useful in examining the sources of inter and intralaboratory variability of chronic testing. In addition, this control population response variability information will be valuable for characterizing what can be termed as ``practically equivalent responses`` between a control and an effluent. The preliminary analysis indicates considerable between-test variability; however, this variability is not consistent across laboratories. Results of further exploration on this issue will be presented.

  6. Short-term Variability of Extinction by Broadband Stellar Photometry

    SciTech Connect

    Musat, I.C.; Ellingson, R.G.

    2005-03-18

    Aerosol optical depth variation over short-term time intervals is determined from broadband observations of stars with a whole sky imager. The main difficulty in such measurements consists of accurately separating the star flux value from the non-stellar diffuse skylight. Using correction method to overcome this difficulty, the monochromatic extinction at the ground due to aerosols is extracted from heterochromatic measurements. A form of closure is achieved by comparison with simultaneous or temporally close measurements with other instruments, and the total error of the method, as a combination of random error of measurements and systematic error of calibration and model, is assessed as being between 2.6 and 3% rms.

  7. Acute psychological stress induces short-term variable immune response.

    PubMed

    Breen, Michael S; Beliakova-Bethell, Nadejda; Mujica-Parodi, Lilianne R; Carlson, Joshua M; Ensign, Wayne Y; Woelk, Christopher H; Rana, Brinda K

    2016-03-01

    In spite of advances in understanding the cross-talk between the peripheral immune system and the brain, the molecular mechanisms underlying the rapid adaptation of the immune system to an acute psychological stressor remain largely unknown. Conventional approaches to classify molecular factors mediating these responses have targeted relatively few biological measurements or explored cross-sectional study designs, and therefore have restricted characterization of stress-immune interactions. This exploratory study analyzed transcriptional profiles and flow cytometric data of peripheral blood leukocytes with physiological (endocrine, autonomic) measurements collected throughout the sequence of events leading up to, during, and after short-term exposure to physical danger in humans. Immediate immunomodulation to acute psychological stress was defined as a short-term selective up-regulation of natural killer (NK) cell-associated cytotoxic and IL-12 mediated signaling genes that correlated with increased cortisol, catecholamines and NK cells into the periphery. In parallel, we observed down-regulation of innate immune toll-like receptor genes and genes of the MyD88-dependent signaling pathway. Correcting gene expression for an influx of NK cells revealed a molecular signature specific to the adrenal cortex. Subsequently, focusing analyses on discrete groups of coordinately expressed genes (modules) throughout the time-series revealed immune stress responses in modules associated to immune/defense response, response to wounding, cytokine production, TCR signaling and NK cell cytotoxicity which differed between males and females. These results offer a spring-board for future research towards improved treatment of stress-related disease including the impact of stress on cardiovascular and autoimmune disorders, and identifies an immune mechanism by which vulnerabilities to these diseases may be gender-specific.

  8. Acute psychological stress induces short-term variable immune response.

    PubMed

    Breen, Michael S; Beliakova-Bethell, Nadejda; Mujica-Parodi, Lilianne R; Carlson, Joshua M; Ensign, Wayne Y; Woelk, Christopher H; Rana, Brinda K

    2016-03-01

    In spite of advances in understanding the cross-talk between the peripheral immune system and the brain, the molecular mechanisms underlying the rapid adaptation of the immune system to an acute psychological stressor remain largely unknown. Conventional approaches to classify molecular factors mediating these responses have targeted relatively few biological measurements or explored cross-sectional study designs, and therefore have restricted characterization of stress-immune interactions. This exploratory study analyzed transcriptional profiles and flow cytometric data of peripheral blood leukocytes with physiological (endocrine, autonomic) measurements collected throughout the sequence of events leading up to, during, and after short-term exposure to physical danger in humans. Immediate immunomodulation to acute psychological stress was defined as a short-term selective up-regulation of natural killer (NK) cell-associated cytotoxic and IL-12 mediated signaling genes that correlated with increased cortisol, catecholamines and NK cells into the periphery. In parallel, we observed down-regulation of innate immune toll-like receptor genes and genes of the MyD88-dependent signaling pathway. Correcting gene expression for an influx of NK cells revealed a molecular signature specific to the adrenal cortex. Subsequently, focusing analyses on discrete groups of coordinately expressed genes (modules) throughout the time-series revealed immune stress responses in modules associated to immune/defense response, response to wounding, cytokine production, TCR signaling and NK cell cytotoxicity which differed between males and females. These results offer a spring-board for future research towards improved treatment of stress-related disease including the impact of stress on cardiovascular and autoimmune disorders, and identifies an immune mechanism by which vulnerabilities to these diseases may be gender-specific. PMID:26476140

  9. Short-term vs. long-term heart rate variability in ischemic cardiomyopathy risk stratification

    PubMed Central

    Voss, Andreas; Schroeder, Rico; Vallverdú, Montserrat; Schulz, Steffen; Cygankiewicz, Iwona; Vázquez, Rafael; Bayés de Luna, Antoni; Caminal, Pere

    2013-01-01

    In industrialized countries with aging populations, heart failure affects 0.3–2% of the general population. The investigation of 24 h-ECG recordings revealed the potential of nonlinear indices of heart rate variability (HRV) for enhanced risk stratification in patients with ischemic heart failure (IHF). However, long-term analyses are time-consuming, expensive, and delay the initial diagnosis. The objective of this study was to investigate whether 30 min short-term HRV analysis is sufficient for comparable risk stratification in IHF in comparison to 24 h-HRV analysis. From 256 IHF patients [221 at low risk (IHFLR) and 35 at high risk (IHFHR)] (a) 24 h beat-to-beat time series (b) the first 30 min segment (c) the 30 min most stationary day segment and (d) the 30 min most stationary night segment were investigated. We calculated linear (time and frequency domain) and nonlinear HRV analysis indices. Optimal parameter sets for risk stratification in IHF were determined for 24 h and for each 30 min segment by applying discriminant analysis on significant clinical and non-clinical indices. Long- and short-term HRV indices from frequency domain and particularly from nonlinear dynamics revealed high univariate significances (p < 0.01) discriminating between IHFLR and IHFHR. For multivariate risk stratification, optimal mixed parameter sets consisting of 5 indices (clinical and nonlinear) achieved 80.4% AUC (area under the curve of receiver operating characteristics) from 24 h HRV analysis, 84.3% AUC from first 30 min, 82.2 % AUC from daytime 30 min and 81.7% AUC from nighttime 30 min. The optimal parameter set obtained from the first 30 min showed nearly the same classification power when compared to the optimal 24 h-parameter set. As results from stationary daytime and nighttime, 30 min segments indicate that short-term analyses of 30 min may provide at least a comparable risk stratification power in IHF in comparison to a 24 h analysis period. PMID:24379785

  10. Fetal autonomic brain age scores, segmented heart rate variability analysis, and traditional short term variability

    PubMed Central

    Hoyer, Dirk; Kowalski, Eva-Maria; Schmidt, Alexander; Tetschke, Florian; Nowack, Samuel; Rudolph, Anja; Wallwitz, Ulrike; Kynass, Isabelle; Bode, Franziska; Tegtmeyer, Janine; Kumm, Kathrin; Moraru, Liviu; Götz, Theresa; Haueisen, Jens; Witte, Otto W.; Schleußner, Ekkehard; Schneider, Uwe

    2014-01-01

    Disturbances of fetal autonomic brain development can be evaluated from fetal heart rate patterns (HRP) reflecting the activity of the autonomic nervous system. Although HRP analysis from cardiotocographic (CTG) recordings is established for fetal surveillance, temporal resolution is low. Fetal magnetocardiography (MCG), however, provides stable continuous recordings at a higher temporal resolution combined with a more precise heart rate variability (HRV) analysis. A direct comparison of CTG and MCG based HRV analysis is pending. The aims of the present study are: (i) to compare the fetal maturation age predicting value of the MCG based fetal Autonomic Brain Age Score (fABAS) approach with that of CTG based Dawes-Redman methodology; and (ii) to elaborate fABAS methodology by segmentation according to fetal behavioral states and HRP. We investigated MCG recordings from 418 normal fetuses, aged between 21 and 40 weeks of gestation. In linear regression models we obtained an age predicting value of CTG compatible short term variability (STV) of R2 = 0.200 (coefficient of determination) in contrast to MCG/fABAS related multivariate models with R2 = 0.648 in 30 min recordings, R2 = 0.610 in active sleep segments of 10 min, and R2 = 0.626 in quiet sleep segments of 10 min. Additionally segmented analysis under particular exclusion of accelerations (AC) and decelerations (DC) in quiet sleep resulted in a novel multivariate model with R2 = 0.706. According to our results, fMCG based fABAS may provide a promising tool for the estimation of fetal autonomic brain age. Beside other traditional and novel HRV indices as possible indicators of developmental disturbances, the establishment of a fABAS score normogram may represent a specific reference. The present results are intended to contribute to further exploration and validation using independent data sets and multicenter research structures. PMID:25505399

  11. Do nonlinearities play a significant role in short term, beat-to-beat variability?

    NASA Technical Reports Server (NTRS)

    Choi, H. G.; Mukkamala, R.; Moody, G. B.; Mark, R. G.

    2001-01-01

    Numerous studies of short-term beat-to-beat variability in cardiovascular signals have not resolved the debate about the completeness of linear analysis techniques. This aim of this paper is to evaluate further the role of nonlinearities in short-term, beat-to-beat variability. We compared linear autoregressive moving average (ARMA) and nonlinear neural network (NN) models for predicting instantaneous heart rate (HR) and mean arterial blood pressure (BP) from past HR and BP. To evaluate these models, we used HR and BP time series from the MIMIC database. Experimental results indicate that NN-based nonlinearities do not play a significant role and suggest that ARMA linear analysis techniques provide adequate characterization of the system dynamics responsible for generating short-term, beat-to-beat variability.

  12. Metabolic Syndrome and Short-Term Heart Rate Variability in Adults with Intellectual Disabilities

    ERIC Educational Resources Information Center

    Chang, Yaw-Wen; Lin, Jin-Ding; Chen, Wei-Liang; Yen, Chia-Feng; Loh, Ching-Hui; Fang, Wen-Hui; Wu, Li-Wei

    2012-01-01

    Metabolic syndrome (MetS) increases the risk of cardiovascular events. Heart rate variability (HRV) represents autonomic functioning, and reduced HRV significantly increases cardiovascular mortality. The aims of the present paper are to assess the prevalence of MetS in adults with intellectual disabilities (ID), the difference in short-term HRV…

  13. Using short-term climate variability to infer equilibrium climate sensitivity

    NASA Astrophysics Data System (ADS)

    Dessler, A. E.; Zhou, C.

    2015-12-01

    We provide a constraint on the magnitude of the Earth's equilibrium climate sensitivity (ECS) using observations short-term climate variability between 2000 and 2014 along with short- and long-term climate model simulations. Our best estimate of the ECS from this analysis 2.5°C, with a likely range of 1.5-3.4°C, which falls in the bottom half of the canonical IPCC ECS range of 1.5-4.5°C.

  14. Implications of Wide-Area Geographic Diversity for Short- Term Variability of Solar Power

    SciTech Connect

    Mills, Andrew; Wiser, Ryan

    2010-08-23

    Worldwide interest in the deployment of photovoltaic generation (PV) is rapidly increasing. Operating experience with large PV plants, however, demonstrates that large, rapid changes in the output of PV plants are possible. Early studies of PV grid impacts suggested that short-term variability could be a potential limiting factor in deploying PV. Many of these early studies, however, lacked high-quality data from multiple sites to assess the costs and impacts of increasing PV penetration. As is well known for wind, accounting for the potential for geographic diversity can significantly reduce the magnitude of extreme changes in aggregated PV output, the resources required to accommodate that variability, and the potential costs of managing variability. We use measured 1-min solar insolation for 23 time-synchronized sites in the Southern Great Plains network of the Atmospheric Radiation Measurement program and wind speed data from 10 sites in the same network to characterize the variability of PV with different degrees of geographic diversity and to compare the variability of PV to the variability of similarly sited wind. The relative aggregate variability of PV plants sited in a dense 10 x 10 array with 20 km spacing is six times less than the variability of a single site for variability on time scales less than 15-min. We find in our analysis of wind and PV plants similarly sited in a 5 x 5 grid with 50 km spacing that the variability of PV is only slightly more than the variability of wind on time scales of 5-15 min. Over shorter and longer time scales the level of variability is nearly identical. Finally, we use a simple approximation method to estimate the cost of carrying additional reserves to manage sub-hourly variability. We conclude that the costs of managing the short-term variability of PV are dramatically reduced by geographic diversity and are not substantially different from the costs for managing the short-term variability of similarly sited wind in

  15. Short-term nonmigrating tide variability in the mesosphere, thermosphere, and ionosphere

    NASA Astrophysics Data System (ADS)

    Pedatella, N. M.; Oberheide, J.; Sutton, E. K.; Liu, H.-L.; Anderson, J. L.; Raeder, K.

    2016-04-01

    The intraseasonal variability of the eastward propagating nonmigrating diurnal tide with zonal wave number 3 (DE3) during 2007 in the mesosphere, ionosphere, and thermosphere is investigated using a whole atmosphere model reanalysis and satellite observations. The atmospheric reanalysis is based on implementation of data assimilation in the Whole Atmosphere Community Climate Model (WACCM) using the Data Assimilation Research Testbed (DART) ensemble Kalman filter. The tidal variability in the WACCM+DART reanalysis is compared to the observed variability in the mesosphere and lower thermosphere (MLT) based on the Thermosphere Ionosphere Mesosphere Energetics Dynamics satellite Sounding of the Atmosphere using Broadband Emission Radiometry (TIMED/SABER) observations, in the ionosphere based on Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) observations, and in the upper thermosphere (˜475 km) based on Gravity Recovery and Climate Experiment (GRACE) neutral density observations. To obtain the short-term DE3 variability in the MLT and upper thermosphere, we apply the method of tidal deconvolution to the TIMED/SABER observations and consider the difference in the ascending and descending longitudinal wave number 4 structure in the GRACE observations. The results reveal that tidal amplitude changes of 5-10 K regularly occur on short timescales (˜10-20 days) in the MLT. Similar variability occurs in the WACCM+DART reanalysis and TIMED/SABER observations, demonstrating that the short-term variability can be captured in whole atmosphere models that employ data assimilation and in observations by the technique of tidal deconvolution. The impact of the short-term DE3 variability in the MLT on the ionosphere and thermosphere is also clearly evident in the COSMIC and GRACE observations. Analysis of the troposphere forcing in WACCM+DART and simulations of the Global Scale Wave Model (GSWM) show that the short-term DE3 variability in the MLT is

  16. A Systematic Search for Short-term Variability of EGRET Sources

    NASA Technical Reports Server (NTRS)

    Wallace, P. M.; Griffis, N. J.; Bertsch, D. L.; Hartman, R. C.; Thompson, D. J.; Kniffen, D. A.; Bloom, S. D.

    2000-01-01

    The 3rd EGRET Catalog of High-energy Gamma-ray Sources contains 170 unidentified sources, and there is great interest in the nature of these sources. One means of determining source class is the study of flux variability on time scales of days; pulsars are believed to be stable on these time scales while blazers are known to be highly variable. In addition, previous work has demonstrated that 3EG J0241-6103 and 3EG J1837-0606 are candidates for a new gamma-ray source class. These sources near the Galactic plane display transient behavior but cannot be associated with any known blazers. Although, many instances of flaring AGN have been reported, the EGRET database has not been systematically searched for occurrences of short-timescale (approximately 1 day) variability. These considerations have led us to conduct a systematic search for short-term variability in EGRET data, covering all viewing periods through proposal cycle 4. Six 3EG catalog sources are reported here to display variability on short time scales; four of them are unidentified. In addition, three non-catalog variable sources are discussed.

  17. The Gaia spectrophotometric standard stars survey - III. Short-term variability monitoring

    NASA Astrophysics Data System (ADS)

    Marinoni, S.; Pancino, E.; Altavilla, G.; Bellazzini, M.; Galleti, S.; Tessicini, G.; Valentini, G.; Cocozza, G.; Ragaini, S.; Braga, V.; Bragaglia, A.; Federici, L.; Schuster, W. J.; Carrasco, J. M.; Castro, A.; Figueras, F.; Jordi, C.

    2016-11-01

    We present the results of the short-term constancy monitoring of candidate Gaia Spectrophotometric Standard Stars (SPSS). We obtained time series of typically 1.24 h - with sampling periods from 1-3 min to a few hours, depending on the case - to monitor the constancy of our candidate SPSS down to 10 mmag, as required for the calibration of Gaia photometric data. We monitored 162 out of a total of 212 SPSS candidates. The observing campaign started in 2006 and finished in 2015, using 143 observing nights on nine different instruments covering both hemispheres. Using differential photometry techniques, we built light curves with a typical precision of 4 mmag, depending on the data quality. As a result of our constancy assessment, 150 SPSS candidates were validated against short-term variability, and only 12 were rejected because of variability including some widely used flux standards such as BD+174708, SA 105-448, 1740346, and HD 37725.

  18. Jensen's Inequality and the Impact of Short-Term Environmental Variability on Long-Term Population Growth Rates.

    PubMed

    Pickett, Evan J; Thomson, David L; Li, Teng A; Xing, Shuang

    2015-01-01

    It is well established in theory that short-term environmental fluctuations could affect the long-term growth rates of wildlife populations, but this theory has rarely been tested and there remains little empirical evidence that the effect is actually important in practice. Here we develop models to quantify the effects of daily, seasonal, and yearly temperature fluctuations on the average population growth rates, and we apply them to long-term data on the endangered Black-faced Spoonbill (Platalea minor); an endothermic species whose population growth rates follow a concave relationship with temperature. We demonstrate for the first time that the current levels of temperature variability, particularly seasonal variability, are already large enough to substantially reduce long-term population growth rates. As the climate changes, our results highlight the importance of considering the ecological effects of climate variability and not just average conditions. PMID:26352857

  19. Increased Short-Term Beat-To-Beat Variability of QT Interval in Patients with Acromegaly.

    PubMed

    Orosz, Andrea; Csajbók, Éva; Czékus, Csilla; Gavallér, Henriette; Magony, Sándor; Valkusz, Zsuzsanna; Várkonyi, Tamás T; Nemes, Attila; Baczkó, István; Forster, Tamás; Wittmann, Tibor; Papp, Julius Gy; Varró, András; Lengyel, Csaba

    2015-01-01

    Cardiovascular diseases, including ventricular arrhythmias are responsible for increased mortality in patients with acromegaly. Acromegaly may cause repolarization abnormalities such as QT prolongation and impairment of repolarization reserve enhancing liability to arrhythmia. The aim of this study was to determine the short-term beat-to-beat QT variability in patients with acromegaly. Thirty acromegalic patients (23 women and 7 men, mean age±SD: 55.7±10.4 years) were compared with age- and sex-matched volunteers (mean age 51.3±7.6 years). Cardiac repolarization parameters including frequency corrected QT interval, PQ and QRS intervals, duration of terminal part of T waves (Tpeak-Tend) and short-term variability of QT interval were evaluated. All acromegalic patients and controls underwent transthoracic echocardiographic examination. Autonomic function was assessed by means of five standard cardiovascular reflex tests. Comparison of the two groups revealed no significant differences in the conventional ECG parameters of repolarization (QT: 401.1±30.6 ms vs 389.3±16.5 ms, corrected QT interval: 430.1±18.6 ms vs 425.6±17.3 ms, QT dispersion: 38.2±13.2 ms vs 36.6±10.2 ms; acromegaly vs control, respectively). However, short-term beat-to-beat QT variability was significantly increased in acromegalic patients (4.23±1.03 ms vs 3.02±0.80, P<0.0001). There were significant differences between the two groups in the echocardiographic dimensions (left ventricular end diastolic diameter: 52.6±5.4 mm vs 48.0±3.9 mm, left ventricular end systolic diameter: 32.3±5.2 mm vs 29.1±4.4 mm, interventricular septum: 11.1±2.2 mm vs 8.8±0.7 mm, posterior wall of left ventricle: 10.8±1.4 mm vs 8.9±0.7 mm, P<0.05, respectively). Short-term beat-to-beat QT variability was elevated in patients with acromegaly in spite of unchanged conventional parameters of ventricular repolarization. This enhanced temporal QT variability may be an early indicator of increased liability to

  20. Increased Short-Term Beat-To-Beat Variability of QT Interval in Patients with Acromegaly

    PubMed Central

    Orosz, Andrea; Csajbók, Éva; Czékus, Csilla; Gavallér, Henriette; Magony, Sándor; Valkusz, Zsuzsanna; Várkonyi, Tamás T.; Nemes, Attila; Baczkó, István; Forster, Tamás; Wittmann, Tibor; Papp, Julius Gy.; Varró, András; Lengyel, Csaba

    2015-01-01

    Cardiovascular diseases, including ventricular arrhythmias are responsible for increased mortality in patients with acromegaly. Acromegaly may cause repolarization abnormalities such as QT prolongation and impairment of repolarization reserve enhancing liability to arrhythmia. The aim of this study was to determine the short-term beat-to-beat QT variability in patients with acromegaly. Thirty acromegalic patients (23 women and 7 men, mean age±SD: 55.7±10.4 years) were compared with age- and sex-matched volunteers (mean age 51.3±7.6 years). Cardiac repolarization parameters including frequency corrected QT interval, PQ and QRS intervals, duration of terminal part of T waves (Tpeak-Tend) and short-term variability of QT interval were evaluated. All acromegalic patients and controls underwent transthoracic echocardiographic examination. Autonomic function was assessed by means of five standard cardiovascular reflex tests. Comparison of the two groups revealed no significant differences in the conventional ECG parameters of repolarization (QT: 401.1±30.6 ms vs 389.3±16.5 ms, corrected QT interval: 430.1±18.6 ms vs 425.6±17.3 ms, QT dispersion: 38.2±13.2 ms vs 36.6±10.2 ms; acromegaly vs control, respectively). However, short-term beat-to-beat QT variability was significantly increased in acromegalic patients (4.23±1.03 ms vs 3.02±0.80, P<0.0001). There were significant differences between the two groups in the echocardiographic dimensions (left ventricular end diastolic diameter: 52.6±5.4 mm vs 48.0±3.9 mm, left ventricular end systolic diameter: 32.3±5.2 mm vs 29.1±4.4 mm, interventricular septum: 11.1±2.2 mm vs 8.8±0.7 mm, posterior wall of left ventricle: 10.8±1.4 mm vs 8.9±0.7 mm, P<0.05, respectively). Short-term beat-to-beat QT variability was elevated in patients with acromegaly in spite of unchanged conventional parameters of ventricular repolarization. This enhanced temporal QT variability may be an early indicator of increased liability to

  1. Short term variability in FEV1 and bronchodilator responsiveness in patients with obstructive ventilatory defects.

    PubMed Central

    Tweeddale, P M; Alexander, F; McHardy, G J

    1987-01-01

    Short term variability in FEV1 and responsiveness to inhaled bronchodilator were measured in 150 patients with obstructive ventilatory defects. The range of initial FEV1 was 0.5-4.71 and the natural variability over a 20 minute period when expressed in absolute terms was similar over the entire range, and differed insignificantly from that found in normal subjects. The increase in FEV1 and vital capacity (VC) required to exclude natural variability with 95% confidence in these patients was 160 ml and 330 ml respectively. Natural variability when expressed in percentage terms was negatively correlated with the level of FEV1 recorded. The analysis of changes in FEV1 and VC after administration of bronchodilator used absolute and percentage criteria for response. The number of responders differed considerably according to the criterion used. In those defined by the absolute criterion as responders there was no evidence that size of response was related to level of FEV1. Percentage criteria have traditionally been used to identify responses to bronchodilator that may be clinically useful, while absolute criteria, although statistically valid, have not been favoured. Reappraisal of the criteria used and their limitations and implications is required. PMID:3438892

  2. Ultra-Short-Term Heart Rate Variability is Sensitive to Training Effects in Team Sports Players

    PubMed Central

    Nakamura, Fabio Y.; Flatt, Andrew A.; Pereira, Lucas A.; Ramirez-Campillo, Rodrigo; Loturco, Irineu; Esco, Michael R.

    2015-01-01

    The aim of this study was to test the possibility of the ultra-short-term lnRMSSD (measured in 1-min post-1-min stabilization period) to detect training induced adaptations in futsal players. Twenty-four elite futsal players underwent HRV assessments pre- and post-three or four weeks preseason training. From the 10-min HRV recording period, lnRMSSD was analyzed in the following time segments: 1) from 0-5 min (i.e., stabilization period); 2) from 0-1 min; 1-2 min; 2-3 min; 3-4 min; 4-5 min and; 3) from 5-10 min (i.e., criterion period). The lnRMSSD was almost certainly higher (100/00/00) using the magnitude-based inference in all periods at the post- moment. The correlation between changes in ultra-short-term lnRMSSD (i.e., 0-1 min; 1-2 min; 2-3 min; 3-4 min; 4-5 min) and lnRMSSDCriterion ranged between 0.45-0.75, with the highest value (p = 0.75; 90% CI: 0.55 – 0.85) found between ultra-short-term lnRMDSSD at 1-2 min and lnRMSSDCriterion. In conclusion, lnRMSSD determined in a short period of 1-min is sensitive to training induced changes in futsal players (based on the very large correlation to the criterion measure), and can be used to track cardiac autonomic adaptations. Key points The ultra-short-term (1 min) natural log of the root-mean-square difference of successive normal RR intervals (lnRMSSD) is sensitive to training effects in futsal players The ultra-short-term lnRMSSD may simplify the assessment of the cardiac autonomic changes in the field compared to the traditional and lengthier (10 min duration) analysis Coaches are encouraged to implement the ultra-short-term heart rate variability in their routines to monitor team sports athletes PMID:26336347

  3. Variability of Short-term Precipitation and Runoff in Small Czech Drainage Basins

    NASA Astrophysics Data System (ADS)

    Kavka, Petr; Strouhal, Luděk; Landa, Martin; Neuman, Martin; Kožant, Petr; Muller, Miloslav

    2016-04-01

    The aim of this contribution is to introduce the recently started three year's project named "Variability of Short-term Precipitation and Runoff in Small Czech Drainage Basins and its Influence on Water Resources Management". Its main goal is to elaborate a methodology and online utility for deriving short-term design precipitation series, which could be utilized by a broad community of scientists, state administration as well as design planners. The outcomes of the project will especially be helpful in modelling hydrological or soil erosion problems when designing common measures for promoting water retention or landscape drainage systems in or out of the scope of Landscape consolidation projects. The precipitation scenarios will be derived from 10 years of observed data from point gauging stations and radar data. The analysis is focused on events' return period, rainfall total amount, internal intensity distribution and spatial distribution over the area of Czech Republic. The methodology will account for the choice of the simulation model. Several representatives of practically oriented models will be tested for the output sensitivity to selected precipitation scenario comparing to variability connected with other inputs uncertainty. The variability of the outputs will also be assessed in the context of economic impacts in design of landscape water structures or mitigation measures. The research was supported by the grant QJ1520265 of the Czech Ministry of Agriculture, using data provided by the Czech Hydrometeorological Institute.

  4. A Meta-Analysis of the Impact of Short-Term Sleep Deprivation on Cognitive Variables

    PubMed Central

    Lim, Julian; Dinges, David F.

    2012-01-01

    A substantial amount of research has been conducted in an effort to understand the impact of short-term (<48 hr) total sleep deprivation (SD) on outcomes in various cognitive domains. Despite this wealth of information, there has been disagreement on how these data should be interpreted, arising in part because the relative magnitude of effect sizes in these domains is not known. To address this question, we conducted a meta-analysis to discover the effects of short-term SD on both speed and accuracy measures in 6 cognitive categories: simple attention, complex attention, working memory, processing speed, short-term memory, and reasoning. Seventy articles containing 147 cognitive tests were found that met inclusion criteria for this study. Effect sizes ranged from small and nonsignificant (reasoning accuracy: ḡ = −0.125, 95% CI [−0.27, 0.02]) to large (lapses in simple attention: ḡ = −0.776, 95% CI [−0.96, −0.60], p < .001). Across cognitive domains, significant differences were observed for both speed and accuracy; however, there were no differences between speed and accuracy measures within each cognitive domain. Of several moderators tested, only time awake was a significant predictor of between-studies variability, and only for accuracy measures, suggesting that heterogeneity in test characteristics may account for a significant amount of the remaining between-studies variance. The theoretical implications of these findings for the study of SD and cognition are discussed. PMID:20438143

  5. Modeling short-term variability of α-hexachlorocyclohexane in Northern Hemispheric air

    NASA Astrophysics Data System (ADS)

    Hansen, Kaj M.; Christensen, Jesper H.; Brandt, JøRgen; Frohn, Lise M.; Geels, Camilla; SkjøTh, Carsten Ambelas; Li, Yi-Fan

    2008-01-01

    The POP version of the Danish Eulerian Hemispheric Model (DEHM-POP) is a further development of a 3-D dynamic atmospheric chemistry transport model covering the Northern Hemisphere, which was originally developed to study atmospheric transport of conventional air pollutants and other atmospheric constituents (e.g., SOX, heavy metals, and CO2). Four different surface compartments (soil, ocean water, vegetation, and snow) are introduced in DEHM-POP with each compartment including the most dominant dynamic processes determining the exchange between air and the surface type to account for the consecutive cycles of deposition and reemission of persistent organic pollutants (POPs). This model setup makes it possible to study short-term atmospheric variability of POPs, which is exemplified in this paper by a study of the atmospheric variability of α-hexachlorocyclohexane (α-HCH), the major component of the worldwide most used insecticide: technical HCH. Simulated α-HCH air concentrations are evaluated against measurements from 21 monitoring stations within the model domain, and the model is able to predict the annual average concentration as well as the long-term trend for the 1990s. Significant correlations between simulated and measured short-term atmospheric concentrations of α-HCH are also found at the majority of the investigated monitoring stations, which shows that it is possible to resolve the atmospheric variability of POPs using an atmospheric chemistry transport model. Differences between simulated and measured atmospheric α-HCH variability can arise because the measurements may be influenced by local features that are not accounted for in the model with the relatively coarse horizontal resolution and surface description.

  6. Changing maternity leave policy: short-term effects on fertility rates and demographic variables in Germany.

    PubMed

    Thyrian, Jochen René; Fendrich, Konstanze; Lange, Anja; Haas, Johannes-Peter; Zygmunt, Marek; Hoffmann, Wolfgang

    2010-08-01

    Changes in reproductive behaviour and decreasing fertility rates have recently led to policy actions that attempt to counteract these developments. Evidence on the efficacy of such policy interventions, however, is limited. The present analysis examines fertility rates and demographic variables of a population in Germany in response to new maternity leave regulations, which were introduced in January 2007. As part of a population-based survey of neonates in Pomerania (SNiP), all births in the study region from the period 23 months prior to January 1st, 2007 until 23 months afterwards were examined. Crude Birth Rates (CBR) per month, General Fertility Rates (GFR) per month, parity and sociodemographic variables were compared using bivariate techniques. Logistic regression analysis was performed. No statistically significant difference in the CBR or GFR after Jan. 1st, 2007 was found. There were statistically significant differences in other demographic variables, however. The proportion of mothers who (a) were employed full-time before pregnancy; (b) came from a higher socioeconomic status; and (c) had higher income levels all increased after January 1st, 2007. The magnitude of these effects was higher in multigravid women. Forward stepwise logistic regression found an odds ratio of 1.79 for women with a family income of more than 3000 euro to give birth after the new law was introduced. This is the first analysis of population-based data that examines fertility rates and sociodemographic variables in response to new legal regulations. No short-term effects on birth rates were detected, but there was a differential effect on the subgroup of multigravidae. The focus of this policy was to provide financial support, which is certainly important, but the complexity of having a child suggests that attitudinal and motivational aspects also need to be taken into account. Furthermore, these analyses were only able to evaluate the short-term consequences of the policy

  7. Broadband short term X-ray variability of the quasar PDS 456

    NASA Astrophysics Data System (ADS)

    Matzeu, G. A.; Reeves, J. N.; Nardini, E.; Braito, V.; Costa, M. T.; Tombesi, F.; Gofford, J.

    2016-05-01

    We present a detailed analysis of a recent 500 ks net exposure Suzaku observation, carried out in 2013, of the nearby (z=0.184) luminous (L_bol˜1047 erg s-1) quasar PDS 456 in which the X-ray flux was unusually low. The short term X-ray spectral variability has been interpreted in terms of variable absorption and/or intrinsic continuum changes. In the former scenario, the spectral variability is due to variable covering factors of two regions of partially covering absorbers. We find that these absorbers are characterised by an outflow velocity comparable to that of the highly ionised wind, i.e. ˜ 0.25 c, at the 99.9% (3.26σ) confidence level. This suggests that the partially absorbing clouds may be the denser clumpy part of the inhomogeneous wind. Following an obscuration event we obtained a direct estimate of the size of the X-ray emitting region, to be not larger than 20 R_g in PDS 456.

  8. Short-term spatial and temporal variability in greenhouse gas fluxes in riparian zones.

    PubMed

    Vidon, P; Marchese, S; Welsh, M; McMillan, S

    2015-08-01

    Recent research indicates that riparian zones have the potential to contribute significant amounts of greenhouse gases (GHG: N2O, CO2, CH4) to the atmosphere. Yet, the short-term spatial and temporal variability in GHG emission in these systems is poorly understood. Using two transects of three static chambers at two North Carolina agricultural riparian zones (one restored, one unrestored), we show that estimates of the average GHG flux at the site scale can vary by one order of magnitude depending on whether the mean or the median is used as a measure of central tendency. Because the median tends to mute the effect of outlier points (hot spots and hot moments), we propose that both must be reported or that other more advanced spatial averaging techniques (e.g., kriging, area-weighted average) should be used to estimate GHG fluxes at the site scale. Results also indicate that short-term temporal variability in GHG fluxes (a few days) under seemingly constant temperature and hydrological conditions can be as large as spatial variability at the site scale, suggesting that the scientific community should rethink sampling protocols for GHG at the soil-atmosphere interface to include repeated measures over short periods of time at select chambers to estimate GHG emissions in the field. Although recent advances in technology provide tools to address these challenges, their cost is often too high for widespread implementation. Until technology improves, sampling design strategies will need to be carefully considered to balance cost, time, and spatial and temporal representativeness of measurements.

  9. Short-term variability in the open ocean cycle of dimethylsulfide

    NASA Astrophysics Data System (ADS)

    Simó, Rafel; Pedrós-Alió, Carlos

    1999-12-01

    The marine biogeochemical cycle of dimethylsulfide (DMS), the main natural source of sulfur to the global atmosphere, was studied during a 2-week Lagrangian experiment in the subpolar North Atlantic, at 60°N 21°W. A bloom of coccolithopores, mostly of the species Emiliania huxleyi, dominated the phytoplankton assemblage over the first week. High surface concentrations of dimethylsulfoniopropionate (DMSP, 37-70 nM) were found along with moderate DMS concentrations (3-9 nM) during the entire experiment. Rates of biological DMSP consumption (8-51 nM d-1) and DMS production (1-14 nM d-1) and consumption (0-6 nM d-1) were measured in short-term dark incubations of surface seawater. Rates of DMSP biosynthesis (11-31 nM d-1) and DMS photochemical loss (1-10 nM d-1) were estimated by budgeting concentrations and transformation rates between Lagrangian samplings. Air-sea exchange rates for DMS (0.03-3 nM d-1) were calculated from surface concentrations, seawater temperature, and wind speed. All major processes involved in the DMS cycle showed significant short-term variability in coupling to the variability of solar radiation, wind speed, and mixing. Biotic and abiotic DMS turnover rates were of similar magnitude and very dynamic, with a prompt response to a rapidly changing physical environment. The rapid impact of meteorological forcing factors on DMS cycling provides the basis for a sulfur-mediated, short-term plankton/climate interaction.

  10. Gender plays significant role in short-term heart rate variability.

    PubMed

    Woo, Jong-Min; Kim, Tae-Suk

    2015-12-01

    This study examined the role of gender on short-term heart rate variability (HRV) and the correlation between subjective ratings of stress and HRV in healthy adults. Standardized short-term HRV measurement and self-administered stress response inventory (SRI) were obtained in 441 healthy women and 1440 healthy men. Hierarchical multiple regressions suggested that there was no gender by stress interaction in explaining HRV. However, there were significant gender differences in the associations between stress and HRV (the standard deviation of the NN interval (SDNN), high frequency (HF), low frequency (LF)/HF (F(1, 1878) = 7.706, p < .01; F(1, 1878) = 29.132, p < .01; F(1, 1878) = 49.685, p < .01). In men, only HF (r = -.56, p = .031) showed such an association; whereas in women, the SRI total scores were negatively correlated with SDNN (r = -.103, p = .032), total power (TP) (r = -.104, p = .030), and HF (r = -.129, p = .007), and positively correlated with LF/HF (r = .111, p = .020) when adjusted for age, alcohol drinking, smoking, and caffeine intake. There are gender differences in the association between psychological stress response and HRV. Gender also showed a significant impact on short-term HRV measurement. Given that both clinicians and researchers are increasingly relying on HRV assessment, our work suggest that gender based norms are very important. PMID:26179374

  11. Gender plays significant role in short-term heart rate variability.

    PubMed

    Woo, Jong-Min; Kim, Tae-Suk

    2015-12-01

    This study examined the role of gender on short-term heart rate variability (HRV) and the correlation between subjective ratings of stress and HRV in healthy adults. Standardized short-term HRV measurement and self-administered stress response inventory (SRI) were obtained in 441 healthy women and 1440 healthy men. Hierarchical multiple regressions suggested that there was no gender by stress interaction in explaining HRV. However, there were significant gender differences in the associations between stress and HRV (the standard deviation of the NN interval (SDNN), high frequency (HF), low frequency (LF)/HF (F(1, 1878) = 7.706, p < .01; F(1, 1878) = 29.132, p < .01; F(1, 1878) = 49.685, p < .01). In men, only HF (r = -.56, p = .031) showed such an association; whereas in women, the SRI total scores were negatively correlated with SDNN (r = -.103, p = .032), total power (TP) (r = -.104, p = .030), and HF (r = -.129, p = .007), and positively correlated with LF/HF (r = .111, p = .020) when adjusted for age, alcohol drinking, smoking, and caffeine intake. There are gender differences in the association between psychological stress response and HRV. Gender also showed a significant impact on short-term HRV measurement. Given that both clinicians and researchers are increasingly relying on HRV assessment, our work suggest that gender based norms are very important.

  12. Short-Term Tidal Variability in the Mesosphere/Lower Thermosphere from SABER

    NASA Astrophysics Data System (ADS)

    Oberheide, J.; Pedatella, N. M.; Du, J.; Lieberman, R. S.; Siskind, D. E.

    2015-12-01

    The understanding of migrating and nonmigrating tidal propagation from the troposphere and stratosphere into the mesosphere/lower thermosphere and upper thermosphere has much improved over the past few years. Yet, space-borne diagnostics of tides from single satellites like TIMED are limited to > monthly mean averages because of the slow orbit precession and the resulting local solar time coverage. Ground-based observations and whole atmosphere models on the other hand strongly suggest a short-term tidal variability on the order of a factor of two within a few days. This paper attempts to address this challenge by presenting a different approach than the conventional wavenumber/frequency Fourier fits to the satellite data: tides are diagnosed from the vertical/longitudinal structure of ascending-descending orbit node differences. This so-called "tidal deconvolution" method is applied to SABER temperature observations over one solar cycle. The resulting diurnal amplitudes and phases have an effective time resolution of approximately one week and are compared to short-term tidal diagnostics based on Fourier fits to multiple satellites and results from the NOGAPS-ALPHA, WACCM and eCMAM30 models for various tidal components. Preliminary results suggest that tidal components forced by tropical convection respond strongly to convective precipitation changes associated with the Madden-Julian-Oscillation while other nonmigrating tides show clear signatures of wave-wave interaction.

  13. Visibility graph analysis of very short-term heart rate variability during sleep

    NASA Astrophysics Data System (ADS)

    Hou, F. Z.; Li, F. W.; Wang, J.; Yan, F. R.

    2016-09-01

    Based on a visibility-graph algorithm, complex networks were constructed from very short-term heart rate variability (HRV) during different sleep stages. Network measurements progressively changed from rapid eye movement (REM) sleep to light sleep and then deep sleep, exhibiting promising ability for sleep assessment. Abnormal activation of the cardiovascular controls with enhanced 'small-world' couplings and altered fractal organization during REM sleep indicates that REM could be a potential risk factor for adverse cardiovascular event, especially in males, older individuals, and people who are overweight. Additionally, an apparent influence of gender, aging, and obesity on sleep was demonstrated in healthy adults, which may be helpful for establishing expected sleep-HRV patterns in different populations.

  14. Short-Term Variability and Predictors of Urinary Pentachlorophenol Levels in Ohio Preschool Children

    PubMed Central

    Morgan, Marsha; Jones, Paul; Sobus, Jon

    2015-01-01

    Pentachlorophenol (PCP) is a persistent and ubiquitous environmental contaminant. No published data exist on the temporal variability or important predictors of urinary PCP concentrations in young children. In this further analysis of study data, we have examined the associations between selected sociodemographic or lifestyle factors and urinary PCP concentrations in 115 preschool children over a 48-h period and assessed the 48-hour variability of urinary PCP levels in a subset of 15 children. Monitoring was performed at 115 homes and 16 daycares in Ohio (USA) in 2001. Questionnaires/diaries and spot urine samples were collected from each child. The median urinary PCP level was 0.8 ng/mL (range < 0.2–23.8 ng/mL). The intraclass correlation coefficient for urinary PCP was 0.42, which indicates fairly low reliability for a single sample over a 48-h period. In a multiple regression model, age of home and ln(creatinine levels) were significant predictors and sampling season, time spent outside, and pet ownership were marginally significant predictors of ln(urinary PCP levels), collectively explaining 29% of the variability of PCP in urine. To adequately assess short-term exposures of children to PCP, several spot urine measurements are likely needed as well as information regarding residence age, seasonality, time spent outdoors, and pet ownership. PMID:25594782

  15. Microgravity alters respiratory sinus arrhythmia and short-term heart rate variability in humans

    NASA Technical Reports Server (NTRS)

    Migeotte, P-F; Prisk, G. Kim; Paiva, M.; West, J. B. (Principal Investigator)

    2003-01-01

    We studied heart rate (HR), heart rate variability (HRV), and respiratory sinus arrhythmia (RSA) in four male subjects before, during, and after 16 days of spaceflight. The electrocardiogram and respiration were recorded during two periods of 4 min controlled breathing at 7.5 and 15 breaths/min in standing and supine postures on the ground and in microgravity. Low (LF)- and high (HF)-frequency components of the short-term HRV (< or =3 min) were computed through Fourier spectral analysis of the R-R intervals. Early in microgravity, HR was decreased compared with both standing and supine positions and had returned to the supine value by the end of the flight. In microgravity, overall variability, the LF-to-HF ratio, and RSA amplitude and phase were similar to preflight supine values. Immediately postflight, HR increased by approximately 15% and remained elevated 15 days after landing. LF/HF was increased, suggesting an increased sympathetic control of HR standing. The overall variability and RSA amplitude in supine decreased postflight, suggesting that vagal tone decreased, which coupled with the decrease in RSA phase shift suggests that this was the result of an adaptation of autonomic control of HR to microgravity. In addition, these alterations persisted for at least 15 days after return to normal gravity (1G).

  16. Rotational Properties of the Haumea Family Members and Candidates: Short-term Variability.

    NASA Astrophysics Data System (ADS)

    Thirouin, Audrey; Sheppard, Scott S.; Noll, Keith S.; Moskovitz, Nicholas A.; Ortiz, Jose Luis; Doressoundiram, Alain

    2016-06-01

    Haumea is one of the most interesting and intriguing trans-Neptunian objects (TNOs). It is a large, bright, fast rotator, and its spectrum indicates nearly pure water ice on the surface. It has at least two satellites and a dynamically related family of more than 10 TNOs with very similar proper orbital parameters and similar surface properties. The Haumean family is the only one currently known in the trans-Neptunian belt. Various models have been proposed, but the formation of the family remains poorly understood. In this work, we have investigated the rotational properties of the family members and unconfirmed family candidates with short-term variability studies, and report the most complete review to date. We present results based on five years of observations and report the short-term variability of five family members and seven candidates. The mean rotational periods, from Maxwellian fits to the frequency distributions, are 6.27 ± 1.19 hr for the confirmed family members, 6.44 ± 1.16 hr for the candidates, and 7.65 ± 0.54 hr for other TNOs (without relation to the family). According to our study, there is a possibility that Haumea family members rotate faster than other TNOs; however, the sample of family members is still too limited for a secure conclusion. We also highlight the fast rotation of 2002 GH32. This object has a 0.36 ± 0.02 mag amplitude lightcurve and a rotational period of about 3.98 hr. Assuming 2002 GH32 is a triaxial object in hydrostatic equilibrium, we derive a lower limit to the density of 2.56 g cm-3. This density is similar to Haumea’s and much more dense than other small TNO densities.

  17. Energy Storage on the Grid and the Short-term Variability of Wind

    NASA Astrophysics Data System (ADS)

    Hittinger, Eric Stephen

    profitability of wind farms. We find that market scenarios using existing price signals to motivate wind to reduce variability allow wind generators to participate in variability reduction when the market conditions are favorable, and can reduce short-term (30-minute) fluctuations while having little effect on wind farm revenue.

  18. Investigating Inter-Individual Differences in Short-Term Intra-Individual Variability

    ERIC Educational Resources Information Center

    Wang, Lijuan; Hamaker, Ellen; Bergeman, C. S.

    2012-01-01

    Intra-individual variability over a short period of time may contain important information about how individuals differ from each other. In this article we begin by discussing diverse indicators for quantifying intra-individual variability and indicate their advantages and disadvantages. Then we propose an alternative method that models…

  19. Connectivity clues from short-term variability in settlement and geochemical tags of mytilid mussels

    NASA Astrophysics Data System (ADS)

    Fodrie, F. Joel; Becker, Bonnie J.; Levin, Lisa A.; Gruenthal, Kristen; McMillan, Pat A.

    2011-01-01

    The use of geochemical tags in calcified structures of fish and invertebrates is an exciting tool for investigating larval population connectivity. Tag evaluation over relatively short intervals (weeks) may detect environmental and ecological variability at a temporal scale highly relevant to larval transport and settlement. We collected newly settled mussels ( Mytilus californianus and M. galloprovincialis) weekly during winter/spring of 2002 along the coast of San Diego, CA, USA, at sites on the exposed coast (SIO) and in a protected coastal bay (HI), to investigate temporal patterns of geochemical tags in mussel shells. Analyses of post-settlement shell via LA-ICP-MS revealed statistically significant temporal variability for all elements we examined (Mg, Mn, Cu, Sr, Cd, Ba, Pb and U). Despite this, our ability to distinguish multielemental signatures between sites was largely conserved. Throughout our 13-week study, SIO and HI mussels could be chemically distinguished from one another in 78-87% of all cases. Settlement varied between 2 and 27 settlers gram-byssus -1 week -1 at SIO and HI, and both sites were characterized by 2-3 weeks with "high" settlement. Geochemical tags recorded in early larval shell of newly settled mussels differed between "high" and "low" settlement weeks at both sites (MANOVA), driven by Mg and Sr at SIO (p = 0.013) and Sr, Cd, Ba and Pb at HI (p < 0.001). These data imply that shifts in larval sources or transport corridors were responsible for observed settlement variation, rather than increased larval production. In particular, increased settlement at HI was observed concurrent with the appearance of geochemical tags (e.g., elevated Cd), suggesting that those larvae were retained in upwelled water near the mouth of the bay. Such shifts may reflect short-term changes in connectivity among sites due to altered transport corridors, and influence the demography of local populations.

  20. Short-term heart rate variability in older patients with newly diagnosed depression.

    PubMed

    Ha, Jee Hyun; Park, Soyeon; Yoon, Daehyun; Kim, Byungsu

    2015-04-30

    Dysfunction of the autonomic nervous system has been considered to be a risk factor for major depressive disorder (MDD) and cardiovascular disease (CVD). The aim of this study was to evaluate short-term heart rate variability (HRV) in elderly patients with newly diagnosed MDD. Thirty MDD patients over 60 years old newly diagnosed by a structured interview were enrolled, free from antidepressants. Socio-demographic data, blood tests, and heart rate variability (HRV) obtained from 5-min ECG were gathered. The MDD group showed significantly lower very low frequency power, low frequency power, high frequency power, and total power in frequency domain. In time domain analysis, the MDD group showed a significantly smaller standard deviation of the NN, root mean square of the differences of the successive NN, and NN50/total number of all NNs. These findings demonstrated a lower HRV in older patients who were newly diagnosed with depression without a history of CVD and antidepressants effect, compared with the control subjects. Low HRV may be an important predictor of both MDD and CVD in elderly. The use of HRV in elderly depressive patients could be a meaningful screening method for risk of CVD. PMID:25747680

  1. Broad-band short term X-ray spectral variability of the quasar PDS 456

    NASA Astrophysics Data System (ADS)

    Matzeu, G.; Reeves, J.; Nardini, E.; Braito, V.; Costa, M.; Tombesi, F.

    2015-07-01

    We present an analysis of a recent 500 ks Suzaku observation, carried out in 2013, of the nearby (z=0.184) luminous (L_{bol}˜10^{47} erg s^{-1}) quasar PDS 456 in which the X-ray flux was unusually low. Short term X-ray spectral variability has been detected, which may be caused by two variable coverers of column density log (N_{H,1}/cm^{-2})=22.3±0.1 and log (N_{H,2}/cm(-2) )=23.2±0.1 We find that the partial covering requires an outflow velocity of ˜0.25 c, coincident with the velocity of the highly ionised outflow at the 99.9 % confidence level. Therefore the partial covering clouds could be the denser clumpy part of an inhomogeneous wind. An obscuration event occurs 1250 ks into the observation, where the spectrum becomes totally opaque at Fe K. This implies that the size of the absorber and likewise the X-ray emitter, to be less than 20 Rg. We also analyse the flaring behaviour in the lightcurve. The behaviour of the soft and hard X-ray flux, suggested a corona characterised by an extended "warm" region of ˜20 Rg in size combined with more compact regions of "hot" electrons of ˜8 Rg in size.

  2. EVALUATING SHORT-TERM CLIMATE VARIABILITY IN THE LATE HOLOCENE OF THE NORTHERN GREAT PLAINS

    SciTech Connect

    Joseph H. Hartman

    1999-09-01

    This literature study investigated methods and areas to deduce climate change and climate patterns, looking for short-term cycle phenomena and the means to interpret them. Many groups are actively engaged in intensive climate-related research. Ongoing research might be (overly) simplified into three categories: (1) historic data on weather that can be used for trend analysis and modeling; (2) detailed geological, biological (subfossil), and analytical (geochemical, radiocarbon, etc.) studies covering the last 10,000 years (about since last glaciation); and (3) geological, paleontological, and analytical (geochemical, radiometric, etc.) studies over millions of years. Of importance is our ultimate ability to join these various lines of inquiry into an effective means of interpretation. At this point, the process of integration is fraught with methodological troubles and misconceptions about what each group can contribute. This project has met its goals to the extent that it provided an opportunity to study resource materials and consider options for future effort toward the goal of understanding the natural climate variation that has shaped our current civilization. A further outcome of this project is a proposed methodology based on ''climate sections'' that provides spatial and temporal correlation within a region. The method would integrate cultural and climate data to establish the climate history of a region with increasing accuracy with progressive study and scientific advancement (e. g., better integration of regional and global models). The goal of this project is to better understand natural climatic variations in the recent past (last 5000 years). The information generated by this work is intended to provide better context within which to examine global climate change. The ongoing project will help to establish a basis upon which to interpret late Holocene short-term climate variability as evidenced in various studies in the northern Great Plains, northern

  3. Heart rate variability indices for very short-term (30 beat) analysis. Part 2: validation.

    PubMed

    Smith, Anne-Louise; Owen, Harry; Reynolds, Karen J

    2013-10-01

    Heart rate variability (HRV) analysis over shorter periods may be useful for monitoring dynamic changes in autonomic nervous system activity where steady-state conditions are not maintained (e.g. during drug administration, or the start or end of exercise). This study undertakes a validation of 70 HRV indices that have previously been identified as possible for short-term use. The indices were validated over 10 × 30 beat windows using PhysioNet databases with physiological states of rest, active, exercising, sleeping, and meditating (N from 12 to 20). Baseline 95 % confidence intervals of the median were established with bootstrap resampling (10,000x). Statistical significance was assessed using the overlap of 95 % confidence intervals. Thirty-one indices could differentiate between resting and at least one physiological state using 30 beat windows. All respiratory sinus arrhythmia indices and Poincaré plot indices were strongly correlated to time domain measures (SDNN or RMSSD). Spectral indices using the Lomb-Scargle algorithm were able to correctly identify paradoxical shifts in power with meditation and reduced power in exercise. Some less-known indices gave interesting results: PolVar20 identified the higher sympathetic activity of exercise with the largest positive magnitude. These indices should now be considered for rigorous gold standard tests with pharmacological blockade.

  4. Short-term variability on the surface of (1) Ceres⋆. A changing amount of water ice?

    NASA Astrophysics Data System (ADS)

    Perna, D.; Kaňuchová, Z.; Ieva, S.; Fornasier, S.; Barucci, M. A.; Lantz, C.; Dotto, E.; Strazzulla, G.

    2015-03-01

    Context. The dwarf planet (1) Ceres - next target of the NASA Dawn mission - is the largest body in the asteroid main belt. Although several observations of this body have been performed so far, the presence of surface water ice is still questioned. Aims: Our goal is to better understand the surface composition of Ceres and to constrain the presence of exposed water ice. Methods: We acquired new visible and near-infrared spectra at the Telescopio Nazionale Galileo (La Palma, Spain), and reanalyzed literature spectra in the 3-μm region. Results: We obtained the first rotationally resolved spectroscopic observations of Ceres at visible wavelengths. Visible spectra taken one month apart at almost the same planetocentric coordinates show a significant slope variation (up to 3%/103Å). A faint absorption centered at 0.67 μm, possibly due to aqueous alteration, is detected in a subset of our spectra. The various explanations in the literature for the 3.06-μm feature can be interpreted as due to a variable amount of surface water ice at different epochs. Conclusions: The remarkable short-term temporal variability of the visible spectral slope and the changing shape of the 3.06-μm band can be hints of different amounts of water ice exposed on the surface of Ceres. This would agree with the recent detection by the Herschel Space Observatory of localized and transient sources of water vapor over this dwarf planet. Based on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias.Appendices are available in electronic form at http://www.aanda.org

  5. Multicolor Near-Infrared Intra-Day and Short-Term Variability of the Blazar S5 0716+714

    NASA Astrophysics Data System (ADS)

    Gupta, Alok C.; Cha, Sang-Mok; Lee, Sungho; Jin, Ho; Pak, Soojong; Cho, Seoung-hyun; Moon, Bongkon; Park, Youngsik; Yuk, In-Soo; Nam, Uk-won; Kyeong, Jaemann

    2008-12-01

    In this paper, we report results of our near-infrared (NIR) photometric variability studies of the BL Lacertae (BL Lac) object S5 0716+714. NIR photometric observations were spread over seven nights during our observing run on 2007 April 2-9 at the 1.8 m telescope equipped with the Korea Astronomy and Space Science Institute Near-Infrared Camera System and J, H, and Ks filters at Bohyunsan Optical Astronomy Observatory, South Korea. We searched for intra-day variability (IDV), short-term variability, and color variability in the BL Lac object. We have not detected any genuine IDV in any of the J, H, and Ks passbands in our observing run. Significant short-term variabilities ~32.6%, 20.5% and 18.2% have been detected in the J, H, and Ks passbands, respectively, and ~11.9% in (J - H) color.

  6. A Meta-Analysis of the Impact of Short-Term Sleep Deprivation on Cognitive Variables

    ERIC Educational Resources Information Center

    Lim, Julian; Dinges, David F.

    2010-01-01

    A substantial amount of research has been conducted in an effort to understand the impact of short-term (less than 48 hr) total sleep deprivation (SD) on outcomes in various cognitive domains. Despite this wealth of information, there has been disagreement on how these data should be interpreted, arising in part because the relative magnitude of…

  7. Application of Remote Sensing to Assess the Impact of Short Term Climate Variability on Coastal Sedimentation

    NASA Technical Reports Server (NTRS)

    Moeller, Christopher C.; Gunshor, Mathew M.; Menzel, W. Paul; Huh, Oscar K.; Walker, Nan D.; Rouse, Lawrence J.; Frey, Herbert V. (Technical Monitor)

    2001-01-01

    The University of Wisconsin and Louisiana State University have teamed to study the forcing of winter season cold frontal wind systems on sediment distribution patterns and geomorphology in the Louisiana coastal zone. Wind systems associated with cold fronts have been shown to modify coastal circulation and resuspend sediments along the microtidal Louisiana coast. The assessment includes quantifying the influence of cumulative winter season atmospheric forcing (through surface wind observations) from year to year in response to short term climate variability, such as El Nino events. A correlation between winter cyclone frequency and the strength of El Nino events has been suggested. The atmospheric forcing data are being correlated to geomorphic measurements along western Louisiana's prograding muddy coast. Remote sensing data is being used to map and track sediment distribution patterns for various wind conditions. Transferring a suspended sediment concentration (SSC) algorithm to EOS MODIS observations will enable estimates of SSC in case 2 waters over the global domain. Progress in Year 1 of this study has included data collection and analysis of wind observations for atmospheric forcing characterization, a field activity (TX-2001) to collect in situ water samples with co-incident remote sensing measurements from the NASA ER-2 based MODIS Airborne Simulator (MAS) and the EOS Terra based MODerate resolution Imaging Spectroradiometer (MODIS) instruments, aerial photography and of sediment burial pipe field measurements along the prograding muddy Chenier Plain coast of western Louisiana for documenting coastal change in that dynamic region, and routine collection of MODIS 250 in resolution data for monitoring coastal sediment patterns. The data sets are being used in a process to transfer an SSC estimation algorithm to the MODIS platform. Work is underway on assessing coastal transport for the winter 2000-01 season. Water level data for use in a Geomorphic Impact

  8. Numerical experiments on short-term meteorological effects on solar variability

    NASA Technical Reports Server (NTRS)

    Somerville, R. C. J.; Hansen, J. E.; Stone, P. H.; Quirk, W. J.; Lacis, A. A.

    1975-01-01

    A set of numerical experiments was conducted to test the short-range sensitivity of a large atmospheric general circulation model to changes in solar constant and ozone amount. On the basis of the results of 12-day sets of integrations with very large variations in these parameters, it is concluded that realistic variations would produce insignificant meteorological effects. Any causal relationships between solar variability and weather, for time scales of two weeks or less, rely upon changes in parameters other than solar constant or ozone amounts, or upon mechanisms not yet incorporated in the model.

  9. Application of Remote Sensing to Assess the Impact of Short Term Climate Variability on Coastal Sedimentation

    NASA Technical Reports Server (NTRS)

    Menzel, W. Paul; Huh, Oscar K.; Walker, Nan

    2004-01-01

    The purpose of this joint University of Wisconsin (UW) and Louisiana State University (LSU) project has been to relate short term climate variation to response in the coastal zone of Louisiana in an attempt to better understand how the coastal zone is shaped by climate variation. Climate variation in this case largely refers to variation in surface wind conditions that affect wave action and water currents in the coastal zone. The primary region of focus was the Atchafalaya Bay and surrounding bays in the central coastal region of Louisiana. Suspended solids in the water column show response to wind systems both in quantity (through resuspension) and in the pattern of dispersement or transport. Wind systems associated with cold fronts are influenced by short term climate variation. Wind energy was used as the primary signature of climate variation in this study because winds are a significant influence on sediment transport in the micro-tidal Gilf of Mexico coastal zone. Using case studies, the project has been able to investigate the influence of short term climate variation on sediment transport. Wind energy data, collected daily for National Weather Service (NWS) stations at Lake Charles and New Orleans, LA, were used as an indicator of short term climate variation influence on seasonal time scales. A goal was to relate wind energy to coastal impact through sediment transport. This goal was partially accomplished by combining remote sensing and wind energy data. Daily high resolution remote sensing observations are needed to monitor the complex coastal zone environment, where winds, tides, and water level all interact to influence sediment transport. The NASA Earth Observing System (EOS) era brings hope for documenting and revealing response of the complex coastal transport mosaic through regular high spatial resolution observations from the Moderate resolution Imaging Spectrometer (MODIS) instrument. MODIS observations were sampled in this project for

  10. Ambulatory blood pressure monitoring-derived short-term blood pressure variability is increased in Cushing's syndrome.

    PubMed

    Rebellato, Andrea; Grillo, Andrea; Dassie, Francesca; Sonino, Nicoletta; Maffei, Pietro; Martini, Chiara; Paoletta, Agostino; Fabris, Bruno; Carretta, Renzo; Fallo, Francesco

    2014-11-01

    Cushing's syndrome is associated with high cardiovascular morbility and mortality. Blood pressure (BP) variability within a 24-h period is increasingly recognized as an independent predictor of cardiovascular risk. The aim of our study was to investigate the short-term BP variability indices in Cushing's syndrome. Twenty-five patients with Cushing's syndrome (mean age 49 ± 13 years, 4 males; 21 Cushing's disease and 4 adrenal adenoma patients) underwent 24-h ambulatory BP monitoring (ABPM) and evaluation of cardiovascular risk factors. Cushing patients were divided into 8 normotensive (NOR-CUSH) and 17 hypertensive (HYP-CUSH) patients and were compared with 20 normotensive (NOR-CTR) and 20 hypertensive (HYP-CTR) age-, sex-, and BMI-matched control subjects. Short-term BP variability was derived from ABPM and calculated as the following: (1) standard deviation (SD) of 24-h, daytime, and nighttime BP; (2) 24-h weighted SD of BP; and (3) average real variability (ARV), i.e., the average of the absolute differences between consecutive BP measurements over 24 h. In comparison with controls, patients with Cushing's syndrome, either normotensive or hypertensive, had higher 24-h and daytime SD of BP, as well as higher 24-h weighted SD and ARV of BP (P = 0.03 to P < 0.0001). No difference in metabolic parameters was observed between NOR-CTR and NOR-CUSH or between HYP-CTR and HYP-CUSH subgroups. ABPM-derived short-term BP variability is increased in Cushing's syndrome, independent of BP elevation. It may represent an additional cardiovascular risk factor in this disease. The role of excess cortisol in BP variability has to be further clarified.

  11. Short-term spatial and temporal variability of disinfection by-product occurrence in small drinking water systems.

    PubMed

    Guilherme, Stéphanie; Rodriguez, Manuel J

    2015-06-15

    Disinfection by-products (DBPs) constitute a large family of compounds. Trihalomethanes and haloacetic acids are regulated in various countries, but most DBPs are not. Monitoring DBPs can be delicate, especially for small systems, because various factors influence their formation and speciation. Short-term variations of DBPs can be important and particularly difficult for small systems to handle because they require robust treatment and operation processes. According to our knowledge, for the first time, our study covers the short-term variability of regulated and non-regulated DBP occurrence in small systems in the summer. An intensive sampling program was carried out in six small systems in Canada. Systems in the provinces of Newfoundland and Labrador and Quebec were sampled daily at the water treatment plant and at six different locations along the distribution system. Five DBP families were studied: trihalomethanes, haloacetic acids, haloacetonitriles, halonitromethanes and haloketones. Results show that there were considerable variations in DBP levels from week to week during the month of study and even from day to day within the week. On a daily basis, DBP levels can fluctuate by 22% to 96%. Likewise, the large number of sampling locations served to observe DBP variations along the distribution system. Observations revealed some degradation and decomposition of non-regulated DBPs never before studied in small systems that are associated with the difficulty these systems experience in maintaining adequate levels of residual disinfectant. Finally, this study reveals that the short term temporal variability of DBPs is also influenced by spatial location along the distribution system. In the short term, DBP levels can fluctuate by 23% at the beginning of the system, compared to 40% at the end. Thus, spatial and temporal variations of DBPs in the short term may make it difficult to select representative locations and periods for DBP monitoring purposes in small

  12. Atmospheric Parameter Climatologies from AIRS: Monitoring Short-, and Longer-Term Climate Variabilities and 'Trends'

    NASA Technical Reports Server (NTRS)

    Molnar, Gyula; Susskind, Joel

    2008-01-01

    The AIRS instrument is currently the best space-based tool to simultaneously monitor the vertical distribution of key climatically important atmospheric parameters as well as surface properties, and has provided high quality data for more than 5 years. AIRS analysis results produced at the GODDARD/DAAC, based on Versions 4 & 5 of the AIRS retrieval algorithm, are currently available for public use. Here, first we present an assessment of interrelationships of anomalies (proxies of climate variability based on 5 full years, since Sept. 2002) of various climate parameters at different spatial scales. We also present AIRS-retrievals-based global, regional and 1x1 degree grid-scale "trend"-analyses of important atmospheric parameters for this 5-year period. Note that here "trend" simply means the linear fit to the anomaly (relative the mean seasonal cycle) time series of various parameters at the above-mentioned spatial scales, and we present these to illustrate the usefulness of continuing AIRS-based climate observations. Preliminary validation efforts, in terms of intercomparisons of interannual variabilities with other available satellite data analysis results, will also be addressed. For example, we show that the outgoing longwave radiation (OLR) interannual spatial variabilities from the available state-of-the-art CERES measurements and from the AIRS computations are in remarkably good agreement. Version 6 of the AIRS retrieval scheme (currently under development) promises to further improve bias agreements for the absolute values by implementing a more accurate radiative transfer model for the OLR computations and by improving surface emissivity retrievals.

  13. Novel spectrophotometer for the investigation of short term variability in stellar spectra.

    PubMed

    Stiff, T; Jeffers, S

    1978-06-01

    A variety of astronomical objects (e.g., O(f) stars, B(e) stars, optical counterparts of X-ray sources, etc.) exhibit emission line spectra. For some of these objects the emission line strengths are suspected as being variable (and possibly periodic) over time scales as short as minutes or less. A spectrophotometer has been built whose output signal is a measure of the line strength only. The spectrophotometer is used to look at the emission feature and the adjacent continuum in rapid succession by means of magnetic modulation of the electron image of the optical spectrum in an image tube, thus generating a modulated signal which is detected with a lockin amplifier. This detection technique essentially subtracts off an instrumental dark current signal due to sky background and the signal due to the continuum of the star giving a real time measure of the line strength only. The design of the instrument, its laboratory calibration, and some preliminary observational data are presented. PMID:20198073

  14. Novel spectrophotometer for the investigation of short term variability in stellar spectra.

    PubMed

    Stiff, T; Jeffers, S

    1978-06-01

    A variety of astronomical objects (e.g., O(f) stars, B(e) stars, optical counterparts of X-ray sources, etc.) exhibit emission line spectra. For some of these objects the emission line strengths are suspected as being variable (and possibly periodic) over time scales as short as minutes or less. A spectrophotometer has been built whose output signal is a measure of the line strength only. The spectrophotometer is used to look at the emission feature and the adjacent continuum in rapid succession by means of magnetic modulation of the electron image of the optical spectrum in an image tube, thus generating a modulated signal which is detected with a lockin amplifier. This detection technique essentially subtracts off an instrumental dark current signal due to sky background and the signal due to the continuum of the star giving a real time measure of the line strength only. The design of the instrument, its laboratory calibration, and some preliminary observational data are presented.

  15. Short-term variability of mineral dust, metals and carbon emission from road dust resuspension

    NASA Astrophysics Data System (ADS)

    Amato, Fulvio; Schaap, Martijn; Denier van der Gon, Hugo A. C.; Pandolfi, Marco; Alastuey, Andrés; Keuken, Menno; Querol, Xavier

    2013-08-01

    Particulate matter (PM) pollution in cities has severe impact on morbidity and mortality of their population. In these cities, road dust resuspension contributes largely to PM and airborne heavy metals concentrations. However, the short-term variation of emission through resuspension is not well described in the air quality models, hampering a reliable description of air pollution and related health effects. In this study we experimentally show that the emission strength of resuspension varies widely among road dust components/sources. Our results offer the first experimental evidence of different emission rates for mineral dust, heavy metals and carbon fractions due to traffic-induced resuspension. Also, the same component (or source) recovers differently in a road in Barcelona (Spain) and a road in Utrecht (The Netherlands). This finding has important implications on atmospheric pollution modelling, mostly for mineral dust, heavy metals and carbon species. After rain events, recoveries were generally faster in Barcelona rather than in Utrecht. The largest difference was found for the mineral dust (Al, Si, Ca). Tyre wear particles (organic carbon and zinc) recovered faster than other road dust particles in both cities. The source apportionment of road dust mass provides useful information for air quality management.

  16. [Analysis Methods of Short-term Non-linear Heart Rate Variability and Their Application in Clinical Medicine].

    PubMed

    Chi, Xianglin; Zhou, Jianhua; Shi, Ping; Liu, Chengyu

    2016-02-01

    The linear analysis for heart rate variability (HRV), including time domain method, frequency domain method and time-frequency analysis, has reached a lot of consensus. The non-linear analysis has also been widely applied in biomedical and clinical researches. However, for non-linear HRV analysis, especially for short-term non-linear HRV analysis, controversy still exists, and a unified standard and conclusion has not been formed. This paper reviews and discusses three short-term non-linear HRV analysis methods (fractal dimension, entropy and complexity) and their principles, progresses and problems in clinical application in detail, in order to provide a reference for accurate application in clinical medicine.

  17. Recurring flood distribution patterns related to short-term Holocene climatic variability

    NASA Astrophysics Data System (ADS)

    Benito, Gerardo; Macklin, Mark G.; Panin, Andrei; Rossato, Sandro; Fontana, Alessandro; Jones, Anna F.; Machado, Maria J.; Matlakhova, Ekaterina; Mozzi, Paolo; Zielhofer, Christoph

    2015-11-01

    Millennial- and multi-centennial scale climate variability during the Holocene has been well documented, but its impact on the distribution and timing of extreme river floods has yet to be established. Here we present a meta-analysis of more than 2000 radiometrically dated flood units to reconstruct centennial-scale Holocene flood episodes in Europe and North Africa. Our data analysis shows a general increase in flood frequency after 5000 cal. yr BP consistent with a weakening in zonal circulation over the second half of the Holocene, and with an increase in winter insolation. Multi-centennial length phases of flooding in UK and central Europe correspond with periods of minimum solar irradiance, with a clear trend of increasing flood frequency over the last 1000 years. Western Mediterranean regions show synchrony of flood episodes associated with negative phases of the North Atlantic Oscillation that are out-of-phase with those evident within the eastern Mediterranean. This long-term flood record reveals complex but geographically highly interconnected climate-flood relationships, and provides a new framework to understand likely future spatial changes of flood frequency.

  18. Recurring flood distribution patterns related to short-term Holocene climatic variability.

    PubMed

    Benito, Gerardo; Macklin, Mark G; Panin, Andrei; Rossato, Sandro; Fontana, Alessandro; Jones, Anna F; Machado, Maria J; Matlakhova, Ekaterina; Mozzi, Paolo; Zielhofer, Christoph

    2015-01-01

    Millennial- and multi-centennial scale climate variability during the Holocene has been well documented, but its impact on the distribution and timing of extreme river floods has yet to be established. Here we present a meta-analysis of more than 2000 radiometrically dated flood units to reconstruct centennial-scale Holocene flood episodes in Europe and North Africa. Our data analysis shows a general increase in flood frequency after 5000 cal. yr BP consistent with a weakening in zonal circulation over the second half of the Holocene, and with an increase in winter insolation. Multi-centennial length phases of flooding in UK and central Europe correspond with periods of minimum solar irradiance, with a clear trend of increasing flood frequency over the last 1000 years. Western Mediterranean regions show synchrony of flood episodes associated with negative phases of the North Atlantic Oscillation that are out-of-phase with those evident within the eastern Mediterranean. This long-term flood record reveals complex but geographically highly interconnected climate-flood relationships, and provides a new framework to understand likely future spatial changes of flood frequency. PMID:26549043

  19. Recurring flood distribution patterns related to short-term Holocene climatic variability

    PubMed Central

    Benito, Gerardo; Macklin, Mark G.; Panin, Andrei; Rossato, Sandro; Fontana, Alessandro; Jones, Anna F.; Machado, Maria J.; Matlakhova, Ekaterina; Mozzi, Paolo; Zielhofer, Christoph

    2015-01-01

    Millennial- and multi-centennial scale climate variability during the Holocene has been well documented, but its impact on the distribution and timing of extreme river floods has yet to be established. Here we present a meta-analysis of more than 2000 radiometrically dated flood units to reconstruct centennial-scale Holocene flood episodes in Europe and North Africa. Our data analysis shows a general increase in flood frequency after 5000 cal. yr BP consistent with a weakening in zonal circulation over the second half of the Holocene, and with an increase in winter insolation. Multi-centennial length phases of flooding in UK and central Europe correspond with periods of minimum solar irradiance, with a clear trend of increasing flood frequency over the last 1000 years. Western Mediterranean regions show synchrony of flood episodes associated with negative phases of the North Atlantic Oscillation that are out-of-phase with those evident within the eastern Mediterranean. This long-term flood record reveals complex but geographically highly interconnected climate-flood relationships, and provides a new framework to understand likely future spatial changes of flood frequency. PMID:26549043

  20. Changes in Heart Rate Variability Are Associated with Expression of Short-Term and Long-Term Contextual and Cued Fear Memories

    PubMed Central

    Kuang, Hui; Zhao, Fang; Tsien, Joe Z.

    2013-01-01

    Heart physiology is a highly useful indicator for measuring not only physical states, but also emotional changes in animals. Yet changes of heart rate variability during fear conditioning have not been systematically studied in mice. Here, we investigated changes in heart rate and heart rate variability in both short-term and long-term contextual and cued fear conditioning. We found that while fear conditioning could increase heart rate, the most significant change was the reduction in heart rate variability which could be further divided into two distinct stages: a highly rhythmic phase (stage-I) and a more variable phase (stage-II). We showed that the time duration of the stage-I rhythmic phase were sensitive enough to reflect the transition from short-term to long-term fear memories. Moreover, it could also detect fear extinction effect during the repeated tone recall. These results suggest that heart rate variability is a valuable physiological indicator for sensitively measuring the consolidation and expression of fear memories in mice. PMID:23667644

  1. Molecular Mechanism of Aggravation of Hypertensive Organ Damages by Short-Term Blood Pressure Variability

    PubMed Central

    Kai, Hisashi; Kudo, Hiroshi; Takayama, Narimasa; Yasuoka, Suguru; Aoki, Yuji; Imaizumi, Tsutomu

    2015-01-01

    There is increasing evidence that not only the elevation of systolic and diastolic blood pressure (BP) but also the increase in BP variability (or fluctuation) are associated with hypertensive organ damages and the morbidity and mortality of cerebrovascular and cardiovascular events. However, the molecular mechanism whereby the increase in BP variability aggravates hypertensive organ damages remains unknown. Thus, we created a rat chronic model of a combination of hypertension and large BP variability by performing bilateral sino-aortic denervation in spontaneously hypertensive rat. A series of our studies using this model revealed that large BP variability induces chronic myocardial inflammation by activating local angiotensin II and mineralocorticoid receptor systems and thereby aggravates cardiac hypertrophy and myocardial fibrosis, leading to systolic dysfunction, in hypertensive hearts. In addition, large BP variability induces the aggravation of arteriolosclerotic changes and ischemic cortical fibrosis in hypertensive kidney via local angiotensin II system. PMID:25544288

  2. Short-term variability and predictors of urinary pentachlorophenol levels in Ohio preschool children

    EPA Science Inventory

    Pentachlorophenol (PCP) is a persistent and ubiquitous environmental contaminant. No published data exist on the temporal variability or important predictors of urinary PCP concentrations in young children. In this further analysis of study data, we have examined the associations...

  3. Short term Heart Rate Variability to predict blood pressure drops due to standing: a pilot study

    PubMed Central

    2015-01-01

    Background Standing from a bed or chair may cause a significant lowering of blood pressure (ΔBP), which may have severe consequences such as, for example, falls in older subjects. The goal of this study was to develop a mathematical model to predict the ΔBP due to standing in healthy subjects, based on their Heart Rate Variability, recorded in the 5 minutes before standing. Methods Heart Rate Variability was extracted from an electrocardiogram, recorded from 10 healthy subjects during the 5 minutes before standing. The blood pressure value was measured before and after rising. A mathematical model aiming to predict ΔBP based on Heart Rate Variability measurements was developed using a robust multi-linear regression and was validated with the leave-one-subject-out cross-validation technique. Results The model predicted correctly the ΔBP in 80% of experiments, with an error below the measurement error of sphygmomanometer digital devices (±4.5 mmHg), a false negative rate of 7.5% and a false positive rate of 10%. The magnitude of the ΔBP was associated with a depressed and less chaotic Heart Rate Variability pattern. Conclusions The present study showes that blood pressure lowering due to standing can be predicted by monitoring the Heart Rate Variability in the 5 minutes before standing. PMID:26391336

  4. Effects of short term bioturbation by common voles on biogeochemical soil variables.

    PubMed

    Wilske, Burkhard; Eccard, Jana A; Zistl-Schlingmann, Marcus; Hohmann, Maximilian; Methler, Annabel; Herde, Antje; Liesenjohann, Thilo; Dannenmann, Michael; Butterbach-Bahl, Klaus; Breuer, Lutz

    2015-01-01

    Bioturbation contributes to soil formation and ecosystem functioning. With respect to the active transport of matter by voles, bioturbation may be considered as a very dynamic process among those shaping soil formation and biogeochemistry. The present study aimed at characterizing and quantifying the effects of bioturbation by voles on soil water relations and carbon and nitrogen stocks. Bioturbation effects were examined based on a field set up in a luvic arenosol comprising of eight 50 × 50 m enclosures with greatly different numbers of common vole (Microtus arvalis L., ca. 35-150 individuals ha-1 mth-1). Eleven key soil variables were analyzed: bulk density, infiltration rate, saturated hydraulic conductivity, water holding capacity, contents of soil organic carbon (SOC) and total nitrogen (N), CO2 emission potential, C/N ratio, the stable isotopic signatures of 13C and 15N, and pH. The highest vole densities were hypothesized to cause significant changes in some variables within 21 months. Results showed that land history had still a major influence, as eight key variables displayed an additional or sole influence of topography. However, the δ15N at depths of 10-20 and 20-30 cm decreased and increased with increasing vole numbers, respectively. Also the CO2 emission potential from soil collected at a depth of 15-30 cm decreased and the C/N ratio at 5-10 cm depth narrowed with increasing vole numbers. These variables indicated the first influence of voles on the respective mineralization processes in some soil layers. Tendencies of vole activity homogenizing SOC and N contents across layers were not significant. The results of the other seven key variables did not confirm significant effects of voles. Thus overall, we found mainly a first response of variables that are indicative for changes in biogeochemical dynamics but not yet of those representing changes in pools. PMID:25954967

  5. Effects of Short Term Bioturbation by Common Voles on Biogeochemical Soil Variables

    PubMed Central

    Wilske, Burkhard; Eccard, Jana A.; Zistl-Schlingmann, Marcus; Hohmann, Maximilian; Methler, Annabel; Herde, Antje; Liesenjohann, Thilo; Dannenmann, Michael; Butterbach-Bahl, Klaus; Breuer, Lutz

    2015-01-01

    Bioturbation contributes to soil formation and ecosystem functioning. With respect to the active transport of matter by voles, bioturbation may be considered as a very dynamic process among those shaping soil formation and biogeochemistry. The present study aimed at characterizing and quantifying the effects of bioturbation by voles on soil water relations and carbon and nitrogen stocks. Bioturbation effects were examined based on a field set up in a luvic arenosol comprising of eight 50 × 50 m enclosures with greatly different numbers of common vole (Microtus arvalis L., ca. 35–150 individuals ha–1 mth–1). Eleven key soil variables were analyzed: bulk density, infiltration rate, saturated hydraulic conductivity, water holding capacity, contents of soil organic carbon (SOC) and total nitrogen (N), CO2 emission potential, C/N ratio, the stable isotopic signatures of 13C and 15N, and pH. The highest vole densities were hypothesized to cause significant changes in some variables within 21 months. Results showed that land history had still a major influence, as eight key variables displayed an additional or sole influence of topography. However, the δ15N at depths of 10–20 and 20–30 cm decreased and increased with increasing vole numbers, respectively. Also the CO2 emission potential from soil collected at a depth of 15–30 cm decreased and the C/N ratio at 5–10 cm depth narrowed with increasing vole numbers. These variables indicated the first influence of voles on the respective mineralization processes in some soil layers. Tendencies of vole activity homogenizing SOC and N contents across layers were not significant. The results of the other seven key variables did not confirm significant effects of voles. Thus overall, we found mainly a first response of variables that are indicative for changes in biogeochemical dynamics but not yet of those representing changes in pools. PMID:25954967

  6. Effects of short term bioturbation by common voles on biogeochemical soil variables.

    PubMed

    Wilske, Burkhard; Eccard, Jana A; Zistl-Schlingmann, Marcus; Hohmann, Maximilian; Methler, Annabel; Herde, Antje; Liesenjohann, Thilo; Dannenmann, Michael; Butterbach-Bahl, Klaus; Breuer, Lutz

    2015-01-01

    Bioturbation contributes to soil formation and ecosystem functioning. With respect to the active transport of matter by voles, bioturbation may be considered as a very dynamic process among those shaping soil formation and biogeochemistry. The present study aimed at characterizing and quantifying the effects of bioturbation by voles on soil water relations and carbon and nitrogen stocks. Bioturbation effects were examined based on a field set up in a luvic arenosol comprising of eight 50 × 50 m enclosures with greatly different numbers of common vole (Microtus arvalis L., ca. 35-150 individuals ha-1 mth-1). Eleven key soil variables were analyzed: bulk density, infiltration rate, saturated hydraulic conductivity, water holding capacity, contents of soil organic carbon (SOC) and total nitrogen (N), CO2 emission potential, C/N ratio, the stable isotopic signatures of 13C and 15N, and pH. The highest vole densities were hypothesized to cause significant changes in some variables within 21 months. Results showed that land history had still a major influence, as eight key variables displayed an additional or sole influence of topography. However, the δ15N at depths of 10-20 and 20-30 cm decreased and increased with increasing vole numbers, respectively. Also the CO2 emission potential from soil collected at a depth of 15-30 cm decreased and the C/N ratio at 5-10 cm depth narrowed with increasing vole numbers. These variables indicated the first influence of voles on the respective mineralization processes in some soil layers. Tendencies of vole activity homogenizing SOC and N contents across layers were not significant. The results of the other seven key variables did not confirm significant effects of voles. Thus overall, we found mainly a first response of variables that are indicative for changes in biogeochemical dynamics but not yet of those representing changes in pools.

  7. Short-term variability and mass loss in Be stars. II. Physical taxonomy of photometric variability observed by the Kepler spacecraft

    NASA Astrophysics Data System (ADS)

    Rivinius, Th.; Baade, D.; Carciofi, A. C.

    2016-09-01

    Context. Classical Be stars have been established as pulsating stars. Space-based photometric monitoring missions contributed significantly to that result. However, whether Be stars are just rapidly rotating SPB or β Cep stars, or whether they have to be understood differently, remains debated in the view of their highly complex power spectra. Aims: Kepler data of three known Be stars are re-visited to establish their pulsational nature and assess the properties of additional, non-pulsational variations. The three program stars turned out to be one inactive Be star, one active, continuously outbursting Be star, and one Be star transiting from a non-outbursting into an outbursting phase, thus forming an excellent sample to distill properties of Be stars in the various phases of their life-cycle. Methods: The Kepler data was first cleaned from any long-term variability with Lomb-Scargle based pre-whitening. Then a Lomb-Scargle analysis of the remaining short-term variations was compared to a wavelet analysis of the cleaned data. This offers a new view on the variability, as it enables us to see the temporal evolution of the variability and phase relations between supposed beating phenomena, which are typically not visualized in a Lomb-Scargle analysis. Results: The short-term photometric variability of Be stars must be disentangled into a stellar and a circumstellar part. The stellar part is on the whole not different from what is seen in non-Be stars. However, some of the observed phenomena might be to be due to resonant mode coupling, a mechanism not typically considered for B-type stars. Short-term circumstellar variability comes in the form of either a group of relatively well-defined, short-lived frequencies during outbursts, which are called Štefl frequencies, and broad bumps in the power spectra, indicating aperiodic variability on a time scale similar to typical low-order g-mode pulsation frequencies, rather than true periodicity. Conclusions: From a

  8. DETECTION OF STRONG SHORT-TERM VARIABILITY IN NGC 6946 X-1

    SciTech Connect

    Rao Fengyun; Feng Hua; Kaaret, Philip

    2010-10-10

    Using two archival XMM-Newton observations, we identify strong X-ray flux variations in NGC 6946 X-1 indicating that it is the most variable ultraluminous X-ray source (ULX) on mHz timescales known so far. The 1-10 keV light curve exhibits variability with a fractional rms amplitude of 60% integrated in the frequency range of 1-100 mHz. The power spectral density of the source shows a flat-topped spectrum that breaks at about 3 mHz with possible quasi-periodic oscillations near 8.5 mHz. Black hole binaries usually produce strong fast variability in the hard or intermediate state. The energy spectrum of NGC 6946 X-1 is dominated by two components, a 0.18 keV thermal disk and a power law with a photon index of {approx} 2.2, which is consistent with the intermediate state. The characteristic timescales of the X-ray emission suggest that the ULX may contain a black hole with a mass on the order of 10{sup 3} solar masses.

  9. A search for short-term meteorological effects of solar variability in an atmospheric circulation model

    NASA Technical Reports Server (NTRS)

    Somerville, R. C. J.; Quirk, W. J.; Hansen, J. E.; Lacis, A. A.; Stone, P. H.

    1976-01-01

    A set of numerical experiments is carried out to test the short-range sensitivity of the Goddard Institute for Space Studies global atmospheric general-circulation model to changes in solar constant and ozone amount. These experiments consist of forecasts initiated with actual atmospheric data. One set of forecasts is made with a standard version of the model; another set uses the model modified by very different values of the solar constant (two-thirds and three-halves of the standard value) and of the ozone amount (zero and twice the standard amount). Twelve-day integrations with these very large variations show such small effects that the effects of realistic variations would almost certainly be insignificant meteorologically on this time scale.

  10. Short-term Variability in the Moist Static Energy Budget Inferred from Satellite Observations

    NASA Astrophysics Data System (ADS)

    Masunaga, H.; L'Ecuyer, T. S.

    2013-12-01

    The thermodynamic variability of tropical atmosphere associated with the development of moist convection is investigated using satellite measurements from a range of platforms and instruments. Based on the analysis strategy devised by Masunaga (2013), the hourly to daily scale variability of moisture and moist static energy (MSE) convergences are derived from a coordination of TRMM, A-Train, and QuikSCAT sensors. Normalized gross moist stability (GMS; Neelin and Held 1987, Raymond et al. 2007) is then estimated as a measure of large-scale dynamics involving moist convection. GMS is found to decline toward zero before convection and gradually increase back to a positive value as the convection decays. To understand the observed behavior of GMS, large-scale vertical motion is derived from the observational constraint on moisture and thermal budget. The main results include: 1) the negative second baroclinic mode (congestus mode) enhances before convection, which is responsible for the initial reduction of GMS, 2) the rapid development of the first baroclinic mode (deep convection mode) follows and yields heavy precipitation, and 3) the second baroclinic mode switches its sign to positive (strartiform mode), resulting in the restoration of GMS, as deep convection diminishes.

  11. Beyond hydrography: daily ichthyoplankton variability and short term oceanographic events on the Sydney continental shelf

    NASA Astrophysics Data System (ADS)

    Dempster, Tim; Gibbs, Mark T.; Rissik, David; Suthers, Iain M.

    1997-10-01

    Surface ichthyoplankton concentrations along a shore-normal transect across the Sydney continental shelf and upper slope changed between three replicate nights in January and April of 1994. Over 70 families of fish were recorded, which, during January, included: Myctophidae (49% of individuals), Carangidae (14%), Gonostomatidae (11%) and Pomacentridae (8%); and during April included: Gonorhynchidae (43%), Myctophidae (10%), Berycidae (11%) and Serranidae (6%). Multidimensional scaling analysis identified inshore and offshore communities, which nightly moved between the nearshore and mid-shelf stations. During January no distinct near-surface water masses could be identified from the temperature-salinity data, although the shelf waters were under the influence of forcing by the local wind stress and the East Australian Current. Good agreement between the cross-shore transport in the near-surface layer and the temporal variability of the icthyoplankton was nevertheless found. The sampling during April was performed during a period of relatively steady oceanographic conditions, and two water masses were identified from the hydrographic data. Temporal ichthyoplankton variability at any station was correspondingly less during the April period and stable inshore and offshore communities were identified, that shifted with characteristic water masses. The results presented in this paper demonstrate that the large variance often associated with ichthyoplankton distribution within a similar water mass may be interpreted by the dynamics in cross-shelf flows, which has implications for the selection of control sites used when studying environmental impacts of coastal outfalls.

  12. Improved short-term variability in the thermosphere-ionosphere-mesosphere-electrodynamics general circulation model

    NASA Astrophysics Data System (ADS)

    Häusler, K.; Hagan, M. E.; Baumgaertner, A. J. G.; Maute, A.; Lu, G.; Doornbos, E.; Bruinsma, S.; Forbes, J. M.; Gasperini, F.

    2014-08-01

    We report on a new source of tidal variability in the National Center for Atmospheric Research thermosphere-ionosphere-mesosphere-electrodynamics general circulation model (TIME-GCM). Lower boundary forcing of the TIME-GCM for a simulation of November-December 2009 based on 3-hourly Modern-Era Retrospective Analysis for Research and Application (MERRA) reanalysis data includes day-to-day variations in both diurnal and semidiurnal tides of tropospheric origin. Comparison with TIME-GCM results from a heretofore standard simulation that includes climatological tropospheric tides from the global-scale wave model reveal evidence of the impacts of MERRA forcing throughout the model domain, including measurable tidal variability in the TIME-GCM upper thermosphere. Additional comparisons with measurements made by the Gravity field and steady-state Ocean Circulation Explorer satellite show improved TIME-GCM capability to capture day-to-day variations in thermospheric density for the November-December 2009 period with the new MERRA lower boundary forcing.

  13. Impact of short-term temperature variability on emergency hospital admissions for schizophrenia stratified by season of birth

    NASA Astrophysics Data System (ADS)

    Zhao, Desheng; Zhang, Xulai; Xu, Zhiwei; Cheng, Jian; Xie, Mingyu; Zhang, Heng; Wang, Shusi; Li, Kesheng; Yang, Huihui; Wen, Liying; Wang, Xu; Su, Hong

    2016-08-01

    Diurnal temperature range (DTR) and temperature change between neighboring days (TCN) are important meteorological indicators closely associated with global climate change. However, up to date, there have been no studies addressing the impacts of both DTR and TCN on emergency hospital admissions for schizophrenia. We conducted a time-series analysis to assess the relationship between temperature variability and daily schizophrenia onset in Hefei, an inland city in southeast China. Daily meteorological data and emergency hospital admissions for schizophrenia from 2005 to 2014 in Hefei were collected. After stratifying by season of birth, Poisson generalized linear regression combined with distributed lag nonlinear model (DLNM) was used to examine the relationship between temperature variability and schizophrenia, adjusting for long-term trend and seasonality, mean temperature, and relative humidity. Our analysis revealed that extreme temperature variability may increase the risk for schizophrenia onset among patients born in spring, while no such association was found in patients born in summer and autumn. In patients born in spring, the relative risks of extremely high DTR comparing the 95th and 99th percentiles with the reference (50th, 10 °C) at 3-day lag were 1.078 (95 % confidence interval (CI) 1.025-1.135) and 1.159 (95 % CI 1.050-1.279), respectively. For TCN effects, only comparing 99th percentile with reference (50th, 0.7 °C) was significantly associated with emergency hospital admissions for schizophrenia (relative risk (RR) 1.111, 95 % CI 1.002-1.231). This study suggested that exposure to extreme temperature variability in short-term may trigger later days of schizophrenia onset for patients born in spring, which may have important implications for developing intervention strategies to prevent large temperature variability exposure.

  14. Motor unit firing variability and synchronization during short-term light-load training in older adults.

    PubMed

    Griffin, L; Painter, P E; Wadhwa, A; Spirduso, W W

    2009-08-01

    We compared motor unit synchronization and firing rate variability within and across synergistic hand muscles during a pinching task following short-term light-load training to improve force steadiness in older adults. A total of 183 motor unit pairs before training and 158 motor unit pairs after training were recorded with intramuscular fine-wire electrodes within and across the first dorsal interosseous (FDI) and adductor pollicis (AdP) muscles during a pinch task performed by ten older adults before and after a 4-week short-term light-load training program. Nine younger adults performed the same experimental sessions 4 weeks apart with no training intervention. Two-minute sustained contractions of 2, 4, 8, and 12% maximal voluntary contraction (MVC) were performed with the non-dominant hand. The coefficient of variation (CV) of force was greater in older than in younger adults and was lower at the 2 and 4% MVC levels in both the finger (0.12 +/- 0.01 vs. 0.08 +/- 0.01, and 0.08 +/- 0.01 vs. 0.05 +/- 0.01, respectively) and thumb (0.11 +/- 0.01 vs. 0.08 +/- 0.01, and 0.09 +/- 0.01 vs. 0.05 +/- 0.01, respectively) compared to higher force levels following training in the older adults. There were no changes in CIS or k'-1 values following training. Motor unit firing rate variability significantly decreased at low force levels in the FDI muscle and also tended to decrease with training in the AdP muscle (p = 0.06). No changes occurred in the younger control group. These findings are the first to show that motor unit synchronization does not change during light-load training. Thus, it is likely that force steadiness in older adults improves by reducing motor unit firing variability rather than by changing motor unit synchronization. PMID:19578838

  15. Short-term Heart Rate Turbulence Analysis Versus Variability and Baroreceptor Sensitivity in Patients With Dilated Cardiomyopathy1

    PubMed Central

    Bauernschmitt, Robert; Meyerfeldt, Udo; Schirdewan, Alexander

    2004-01-01

    New methods for the analysis of arrhythmias and their hemodynamic consequences have been applied in risk stratification, in particular to patients after myocardial infarction. This study investigates the suitability of short-term heart rate turbulence (HRT) analysis in comparison to heart rate and blood pressure variability as well as baroreceptor sensitivity analyses to characterise the regulatory differences between patients with dilated cardiomyopathy (DCM) and healthy controls. In this study, 30 minutes data of non-invasive continuous blood pressure and ECGs of 37 DCM patients and 167 controls measured under standard resting conditions were analysed. The results show highly significant differences between DCM patients and controls in heart rate and blood pressure variability as well as in baroreceptor sensitivity parameters. Applying a combined heart rate-blood pressure trigger, ventricular premature beats were detected in 24.3% (9) of the DCM patients and 11.3% (19) of the controls. This fact demonstrates the limited applicability of short-term HRT analyses. However, the HRT parameters showed significant differences in this subgroup with ventricular premature beats (turbulence onset: DCM: 1.80±2.72, controls: - 4.34±3.10, p<0.001; turbulence slope: DCM: 6.75±5.50, controls: 21.30±17.72, p=0.021). Considering all (including HRT) parameters in the subgroup with ventricular beats, a discrimination rate between DCM patients and controls of 88.0% was obtained (max. 6 parameters). The corresponding value obtained for the total group was 86.3% (without HRT parameters). Comparable classification rates and high correlations between heart rate turbulence and variability and baroreflex parameters point to a more universal applicability of the latter methods. PMID:16943930

  16. Long and Short Term Variability of the Main Physical Parameters in the Coastal Area of the SE Baltic Proper

    NASA Astrophysics Data System (ADS)

    Mingelaite, Toma; Rukseniene, Viktorija; Dailidiene, Inga

    2015-04-01

    Keywords: SE Baltic Sea, coastal upwelling, IR Remote Sensing The memory of the ocean and seas of atmospheric forcing events contributes to the long-term climate change. Intensifying climate change processes in the North Atlantic region including Baltic Sea has drawn widespread interest, as a changing water temperature has ecological, economic and social impact in coastal areas of the Europe seas. In this work we analyse long and short term variability of the main physical parameters in the coastal area of the South Eastern Baltic Sea Proper. The analysis of long term variability is based on monitoring data measured in the South Eastern Baltic Sea for the last 50 years. The main focus of the long term variability is changes of hydro meteorological parameters relevant to the observed changes in the climate.The water salinity variations in the Baltic Sea near the Lithuanian coast and in the Curonian Lagoon, a shallow and enclosed sub-basin of the Baltic Sea, were analysed along with the time series of some related hydroclimatic factors. The short term water temperature and salinity variations were analysed with a strong focus on coastal upwelling events. Combining both remote sensing and in situ monitoring data physical parameters such as vertical salinity variations during upwelling events was analysed. The coastal upwelling in the SE Baltic Sea coast, depending on its scale and intensity, may lead to an intrusion of colder and saltier marine waters to the Curonian Lagoon resulting in hydrodynamic changes and pronounced temperature drop extending for 30-40 km further down the Lagoon. The study results show that increasing trends of water level, air and water temperature, and decreasing ice cover duration are related to the changes in meso-scale atmospheric circulation, and more specifically, to the changes in regional and local wind regime climate. That is in a good agreement with the increasing trends in local higher intensity of westerly winds, and with the winter

  17. Short-Term Blood Pressure Variability Relates to the Presence of Subclinical Brain Small Vessel Disease in Primary Hypertension.

    PubMed

    Filomena, Josefina; Riba-Llena, Iolanda; Vinyoles, Ernest; Tovar, José L; Mundet, Xavier; Castañé, Xavier; Vilar, Andrea; López-Rueda, Antonio; Jiménez-Baladó, Joan; Cartanyà, Anna; Montaner, Joan; Delgado, Pilar

    2015-09-01

    Blood pressure (BP) variability is associated with stroke risk, but less is known about subclinical cerebral small vessel disease (CSVD). We aimed to determine whether CSVD relates to short-term BP variability independently of BP levels and also, whether they improve CSVD discrimination beyond clinical variables and office BP levels. This was a cohort study on asymptomatic hypertensives who underwent brain magnetic resonance imaging and 24-hour ambulatory BP monitoring. Office and average 24-hour, daytime and nighttime BP levels, and several metrics of BP variability (SD, weighted SD, coefficient of variation, and average real variability [ARV]) were calculated. Definition of CSVD was based on the presence of lacunar infarcts and white matter hyperintensity grades. Multivariate analysis and integrated discrimination improvement were performed to assess whether BP variability and levels were independently associated with CSVD and improved its discrimination. Four hundred eighty-seven individuals participated (median age, 64; 47% women). CSVD was identified in 18.9%, related to age, male sex, diabetes mellitus, use of treatment, ambulatory BP monitoring-defined BP levels, and ARV of systolic BP at any period. The highest prevalence (33.7%) was found in subjects with both 24-hour BP levels and ARV elevated. BP levels at any period and ARV (24 hours and nocturnal) emerged as independent predictors of CSVD, and discrimination was incrementally improved although not to a clinically significant extent (integrated discrimination improvement, 5.31%, 5.17% to 5.4%). Ambulatory BP monitoring-defined BP levels and ARV of systolic BP relate to subclinical CSVD in hypertensive individuals.

  18. A Study of Short-term White Dwarf Variability Using gPhoton

    NASA Astrophysics Data System (ADS)

    Tucker, Michael; Fleming, Scott W.; Caton, Daniel B.; Million, Chase; Shiao, Bernie

    2016-01-01

    The Galaxy Evolution Explorer (GALEX) was a UV space telescope that operated from 2003 until 2013. A new project at MAST, gPhoton takes advantage of the microchannel-plate photon detector aboard GALEX, which catalogued and time-stamped every photon event by putting the one trillion photon events into a database. Utilizing associated open-source software, gPhoton can create coadd images, movies and light curves at user-defined spatial and temporal scales. As part of early science investigations with gPhoton, 364 white dwarf stars from the McCook-Sion catalog with ample GALEX coverage were photometrically inspected for inter-visit variations during an REU program at STScI. Out of the 364 white dwarfs that were studied, three previously documented pulsating white dwarf stars were confirmed in the UV and (at least) three new pulsating white dwarf stars were discovered. Follow-up observations are conducted at Appalachian State University using optical telescopes at the Dark Sky Observatory. We compare optical and UV light curves of these new white dwarf pulsators and show a selection of other variables found with gPhoton.

  19. Short term variability of aerosol optical thickness at Belsk for the period 2002-2010

    NASA Astrophysics Data System (ADS)

    Pietruczuk, Aleksander

    2013-11-01

    In this work variability of aerosol optical thickness (AOT) measured at Belsk, Poland is studied as well as modification of AOT during airmass advection towards Belsk. AOT measurements taken at Belsk and at AERONET stations located in eastern Germany, Belarus and Scandinavia are used as well as satellite measurements of AOT taken by MODIS instrument onboard Terra and Aqua satellites. Directions of airmass advection are determined by means of cluster analysis of airmass backward-trajectories. Changes of AOT at Belsk from day to day varies around zero regardless of time lag between measurements. The standard deviation of these measurements increases with increasing time lag. In case of advection from west and north direction such standard deviation is reduced. It gives good perspective for a persistent forecast of next day AOT. Analysis of AOT changes during airmass advection toward Belsk reveals two modes of AOT changes distributions. One of them with small increase of AOT and second one with larger increase of AOT, so-called loading mode. Loading mode dominates in case of advection from south direction whilst the first mode of AOT changes dominates in case of advection from other directions. Mean increase of AOT associated with the first mode is 0.034 ± 0.003. Analysis of backward-trajectories shows that aerosol loading occurs over urban/industrial regions located south and south-west of Belsk. Substantial aerosol loading is found during seasonal biomass burning episodes in Eastern Europe.

  20. Modeling short-term dynamics and variability for realistic interactive facial animation.

    PubMed

    Stoiber, Nicolas; Breton, Gaspard; Seguier, Renaud

    2010-01-01

    Modern modeling and rendering techniques have produced nearly photorealistic face models, but truly expressive digital faces also require natural-looking movements. Virtual characters in today's applications often display unrealistic facial expressions. Indeed, facial animation with traditional schemes such as keyframing and motion capture demands expertise. Moreover, the traditional schemes aren't adapted to interactive applications that require the real-time generation of context-dependent movements. A new animation system produces realistic expressive facial motion at interactive speed. The system relies on a set of motion models controlling facial-expression dynamics. The models are fitted on captured motion data and therefore retain the dynamic signature of human facial expressions. They also contain a nondeterministic component that ensures the variety of the long-term visual behavior. This system can efficiently animate any synthetic face. The video illustrates interactive use of a system that generates facial-animation sequences.

  1. Modeling short-term dynamics and variability for realistic interactive facial animation.

    PubMed

    Stoiber, Nicolas; Breton, Gaspard; Seguier, Renaud

    2010-01-01

    Modern modeling and rendering techniques have produced nearly photorealistic face models, but truly expressive digital faces also require natural-looking movements. Virtual characters in today's applications often display unrealistic facial expressions. Indeed, facial animation with traditional schemes such as keyframing and motion capture demands expertise. Moreover, the traditional schemes aren't adapted to interactive applications that require the real-time generation of context-dependent movements. A new animation system produces realistic expressive facial motion at interactive speed. The system relies on a set of motion models controlling facial-expression dynamics. The models are fitted on captured motion data and therefore retain the dynamic signature of human facial expressions. They also contain a nondeterministic component that ensures the variety of the long-term visual behavior. This system can efficiently animate any synthetic face. The video illustrates interactive use of a system that generates facial-animation sequences. PMID:20650728

  2. Modelling short-term variability in carbon and water exchange in a temperate Scots pine forest

    NASA Astrophysics Data System (ADS)

    Vermeulen, M. H.; Kruijt, B. J.; Hickler, T.; Kabat, P.

    2015-02-01

    Vegetation - atmosphere carbon and water exchange at one particular site can strongly vary from year to year, and understanding this interannual variability in carbon and water exchange (IAVcw) is a critical factor in projecting future ecosystem changes. However, the mechanisms driving this IAVcw are not well understood. We used data on carbon and water fluxes from a multi-year Eddy Covariance study (1997-2009) in a Dutch Scots pine forest and forced a process-based ecosystem model (LPJ-GUESS) with local data to, firstly, test whether the model can explain IAVcw and seasonal carbon and water exchange from direct environmental factors only. Initial model runs showed low correlations with estimated annual gross primary productivity (GPP) and annual actual evapotranspiration (AET), while monthly and daily fluxes showed high correlations. The model underestimated GPP and AET during winter and drought events. Secondly, we adapted the temperature inhibition function of photosynthesis to account for the observation that at this particular site, trees continue to assimilate at very low atmospheric temperatures (up to daily averages of -10 °C), resulting in a net carbon sink in winter. While we were able to improve daily and monthly simulations during winter by lowering the modelled minimum temperature threshold for photosynthesis, this did not increase explained IAVcw at the site. Thirdly, we implemented three alternative hypotheses concerning water uptake by plants in order to test which one best corresponds with the data. In particular, we analyse the effects during the 2003 heatwave. These simulations revealed a strong sensitivity of the modelled fluxes during dry and warm conditions, but no single formulation was consistently superior in reproducing the data for all time scales and the overall model-data match for IAVcw could not be improved. Most probably access to deep soil water leads to higher AET and GPP simulated during the heat wave of 2003. We conclude that

  3. Modelling short-term variability in carbon and water exchange in a temperate Scots pine forest

    NASA Astrophysics Data System (ADS)

    Vermeulen, M. H.; Kruijt, B. J.; Hickler, T.; Kabat, P.

    2015-07-01

    The vegetation-atmosphere carbon and water exchange at one particular site can strongly vary from year to year, and understanding this interannual variability in carbon and water exchange (IAVcw) is a critical factor in projecting future ecosystem changes. However, the mechanisms driving this IAVcw are not well understood. We used data on carbon and water fluxes from a multi-year eddy covariance study (1997-2009) in a Dutch Scots pine forest and forced a process-based ecosystem model (Lund-Potsdam-Jena General Ecosystem Simulator; LPJ-GUESS) with local data to, firstly, test whether the model can explain IAVcw and seasonal carbon and water exchange from direct environmental factors only. Initial model runs showed low correlations with estimated annual gross primary productivity (GPP) and annual actual evapotranspiration (AET), while monthly and daily fluxes showed high correlations. The model underestimated GPP and AET during winter and drought events. Secondly, we adapted the temperature inhibition function of photosynthesis to account for the observation that at this particular site, trees continue to assimilate at very low atmospheric temperatures (up to daily averages of -10 °C), resulting in a net carbon sink in winter. While we were able to improve daily and monthly simulations during winter by lowering the modelled minimum temperature threshold for photosynthesis, this did not increase explained IAVcw at the site. Thirdly, we implemented three alternative hypotheses concerning water uptake by plants in order to test which one best corresponds with the data. In particular, we analyse the effects during the 2003 heatwave. These simulations revealed a strong sensitivity of the modelled fluxes during dry and warm conditions, but no single formulation was consistently superior in reproducing the data for all timescales and the overall model-data match for IAVcw could not be improved. Most probably access to deep soil water leads to higher AET and GPP simulated

  4. Change in Measured Noncognitive Variables: A Quantitative Examination of the Influence of Short-Term Study Abroad Experiences

    ERIC Educational Resources Information Center

    Motley, Reginald James

    2013-01-01

    Students have different motivations for participating in education abroad experiences. Short-term study abroad programs offer students the opportunity to experience education abroad without spending an entire semester or year abroad. As a result of these opportunities, short-term study abroad programs have emerged to meet the demands for students…

  5. Short-term environmental variability in cold-water coral habitat at Viosca Knoll, Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Davies, Andrew J.; Duineveld, Gerard C. A.; van Weering, Tjeerd C. E.; Mienis, Furu; Quattrini, Andrea M.; Seim, Harvey E.; Bane, John M.; Ross, Steve W.

    2010-02-01

    The Lophelia pertusa community at Viosca Knoll (VK826) is the most extensive found to date in the Gulf of Mexico. As part of a multi-disciplinary study, the physical setting of this area was described using benthic landers, CTD transects and remotely operated vehicle observations. The site was broadly characterised into three main habitats: (1) dense coral cover that resembles biogenic reef complexes, (2) areas of sediment, and (3) authigenic carbonate blocks with sparse coral and chemosynthetic communities. The coral communities were dominated by L. pertusa but also contained numerous solitary coral species. Over areas that contained L. pertusa, the environmental conditions recorded were similar to those associated with communities in the north-eastern Atlantic, with temperature (8.5-10.6 °C) and salinity (˜35) falling within the known species niche for L. pertusa. However, dissolved oxygen concentrations (2.7-2.8 ml l -1) and density ( σ Θ, 27.1-27.2 kg m -3) were lower and mass fluxes from sediment trap data appeared much higher (4002-4192 mg m -2 d -1). Yet, this species still appears to thrive in this region, suggesting that L. pertusa may not be as limited by lower dissolved oxygen concentrations as previously thought. The VK826 site experienced sustained eastward water flow of 10-30 cm s -1 over the 5-day measurement period but was also subjected to significant short-term variability in current velocity and direction. In addition, two processes were observed that caused variability in salinity and temperature; the first was consistent with internal waves that caused temperature variations of 0.8 °C over 5-11 h periods. The second was high-frequency variability (20-30 min periods) in temperature recorded only at the ALBEX site. A further pattern observed over the coral habitat was the presence of a 24 h diel vertical migration of zooplankton that may form part of a food chain that eventually reaches the corals. The majority of detailed studies concerning

  6. Predicting the Effects of Short-Term Photovoltaic Variability on Power System Frequency for Systems with Integrated Energy Storage

    NASA Astrophysics Data System (ADS)

    Traube, Joshua White

    The percentage of electricity supplied by photovoltaic (PV) generators is steadily rising in power systems worldwide. This rise in PV penetration may lead to larger fluctuations in power system frequency due to variability in PV generator output at time scales that fall between the inertial damping and automatic generation control (AGC) responses of power systems. To reduce PV generator variability, active power controls can be implemented in the power electronic inverters that interface PV generators to the power system. Although various types of active power controls have been developed, no standard methodology exists for evaluating the effectiveness of these controls at improving power system frequency regulation. This dissertation presents a method for predicting the effects of short-term PV variability on power system frequency for a PV generator with active power control provided by integrated energy storage. A custom model of a PV generator with integrated energy storage is implemented in a power system dynamic simulator and validated through experiments with a grid emulator. The model is used to predict the effects of short-term PV variability on the frequency of the IEEE 9-bus test power system modified to include a PV generator with integrated energy storage. In addition, this dissertation utilizes linear analysis of power system frequency control to predict worst-case frequency deviations as a function of the amount of energy storage integrated into PV generators. Through simulation and emulation on a scaled experimental prototype, the maximum frequency deviation caused by the PV generator with a small amount of integrated energy storage is found to be approximately 33% lower than the maximum frequency deviation caused by the PV generator alone. Through linear analysis it is shown that by adding only 36.7 kWh of integrated energy storage to a 1.2 MW PV system, the worst-case frequency deviation on the IEEE 9-bus test system can be reduced 65% from 0

  7. Ozone measurements from the NOAA-9 and the Nimbus-7 satellites: Implications of short and long term variabilities

    NASA Technical Reports Server (NTRS)

    Chandra, S.; Mcpeters, Richard D.; Hudson, R. D.; Planet, Walter G.

    1990-01-01

    An overview is given of the measurements of total ozne and ozone profiles by the SBUV/2 instrument on the NOAA-9 spacecraft relative to similar measurements from the SBUV and TOMS instruments on Nimbus-7. It is shown that during the three year period from March 14, 1985, to February 28, 1988, when these data sets overlap, there have been significant changes in the calibrations of the three instruments which may be attributed to the drift of the NOSS-9 orbit to later equator crossing times (for SBUV/2). These changes in instrument characteristics have affected the absolute values of the trends derived from the three instruments, but their geophysical characteristics and response to short term variations are accurate and correlate well among the three instruments. For example, the total column ozone measured by the three instruments shows excellent agreement with respect to its day to day, seasonal, and latitudinal variabilities. At high latitudes, the day to day fluctuations in total ozone show a strong positive correlation with temperature in the lower stratosphere, as one might expect from the dynamical coupling of the two parameters at these latitudes.

  8. Ozone measurements from the NOAA-9 and the Nimbus-7 satellites - Implications of short and long term variabilities

    NASA Technical Reports Server (NTRS)

    Chandra, S.; Mcpeters, R. D.; Hudson, R. D.; Planet, W.

    1990-01-01

    An overview of the measurements of total ozone and ozone profiles by the SBUV/2 instrument on the NOAA-9 spacecraft relative to similar measurements from the solar backscatter ultraviolet (SBUV) and TOMS instruments on Nimbus-7 is presented. During the three-year period from March 14, 1985 to February 28, 1988, when these data sets overlap, it is shown that there have been significant changes in the calibrations of the three instruments that may be attributed to diffuser plate degradation (for SBUV/TOMS) and to the drift of the NOAA-9 orbit to later equator crossing times (for SBUV/2). Though these instrument characteristic changes have effected the absolute values of the trends derived from the three instruments, their geophysical characteristics and response to short-term variations are accurate and correlate well among the three instruments. It is seen that the total column ozone measured by the three instruments shows good agreement with respect to its day-to-day, seasonal, and latitudinal variabilities.

  9. MAGIC detection of short-term variability of the high-peaked BL Lac object 1ES 0806+524

    NASA Astrophysics Data System (ADS)

    Aleksić, J.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Bangale, P.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Biasuzzi, B.; Biland, A.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carmona, E.; Carosi, A.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Caneva, G.; De Lotto, B.; de Oña Wilhelmi, E.; Delgado Mendez, C.; Di Pierro, F.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher, D.; Elsaesser, D.; Fernández-Barral, A.; Fidalgo, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; Galindo, D.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Godinović, N.; González Muñoz, A.; Gozzini, S. R.; Hadasch, D.; Hanabata, Y.; Hayashida, M.; Herrera, J.; Hose, J.; Hrupec, D.; Idec, W.; Kadenius, V.; Kellermann, H.; Knoetig, M. L.; Kodani, K.; Konno, Y.; Krause, J.; Kubo, H.; Kushida, J.; La Barbera, A.; Lelas, D.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; López-Coto, R.; López-Oramas, A.; Lorenz, E.; Lozano, I.; Makariev, M.; Mallot, K.; Maneva, G.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Munar-Adrover, P.; Nakajima, D.; Neustroev, V.; Niedzwiecki, A.; Nievas Rosillo, M.; Nilsson, K.; Nishijima, K.; Noda, K.; Orito, R.; Overkemping, A.; Paiano, S.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Persic, M.; Poutanen, J.; Prada Moroni, P. G.; Prandini, E.; Puljak, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rodriguez Garcia, J.; Saito, T.; Saito, K.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schweizer, T.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Stamerra, A.; Steinbring, T.; Strzys, M.; Takalo, L.; Takami, H.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Thaele, J.; Torres, D. F.; Toyama, T.; Treves, A.; Vogler, P.; Will, M.; Zanin, R.; Berger, K.; Buson, S.; D'Ammando, F.; Gasparrini, D.; Hovatta, T.; Max-Moerbeck, W.; Readhead, A.; Richards, J.

    2015-07-01

    The high-frequency-peaked BL Lac (HBL) 1ES 0806+524 (z = 0.138) was discovered in very high energy (VHE) γ-rays in 2008. Until now, the broad-band spectrum of 1ES 0806+524 has been only poorly characterized, in particular at high energies. We analysed multiwavelength observations from γ-rays to radio performed from 2011 January to March, which were triggered by the high activity detected at optical frequencies. These observations constitute the most precise determination of the broad-band emission of 1ES 0806+524 to date. The stereoscopic Major Atmospheric Gamma-Ray Imaging Cherenkov (MAGIC) observations yielded a γ-ray signal above 250 GeV of (3.7 ± 0.7) per cent of the Crab Nebula flux with a statistical significance of 9.9σ. The multiwavelength observations showed significant variability in essentially all energy bands, including a VHE γ-ray flare that lasted less than one night, which provided unprecedented evidence for short-term variability in 1ES 0806+524. The spectrum of this flare is well described by a power law with a photon index of 2.97 ± 0.29 between ˜150 GeV and 1 TeV and an integral flux of (9.3 ± 1.9) per cent of the Crab nebula flux above 250 GeV. The spectrum during the non-flaring VHE activity is compatible with the only available VHE observation performed in 2008 with VERITAS when the source was in a low optical state. The broad-band spectral energy distribution can be described with a one-zone synchrotron self-Compton model with parameters typical for HBLs, indicating that 1ES 0806+524 is not substantially different from the HBLs previously detected.

  10. The intraspecific variability of short- and long-term carbon allocation, turnover and fluxes under different environmental conditions

    NASA Astrophysics Data System (ADS)

    Wegener, Frederik; Beyschlag, Wolfram; Werner, Christiane

    2014-05-01

    Carbon allocation strategies differ clearly between functional plant groups (e.g. grasses, shrubs and trees) and to a lesser extent between different species of the same functional group. However, little is known about the plasticity of carbon allocation within the same species. To investigate the variability of carbon (C) allocation, we induced different allocation pattern in the Mediterranean shrub Halimium halimifolium by changing growing conditions (light and nutrition) and followed the plant development for 15 months. We analyzed morphological and physiological traits, and changes in C allocation and δ13C values in seven tissue classes: 1st generation leaves, 2nd generation leaves, emerging leaves, lateral shoots, stem, main roots and fine roots. We used a soil/canopy chamber system that enables independent measurements of above and belowground δ13CO2-exchange, enabling total estimates of carbon gain during photosynthesis and the carbon loss during respiration on a whole plant level. Moreover, we followed the fate of recently assimilated carbon in all plant tissues by 13CO2 pulse labeling for 13 days. A reduction of light (Low L treatment) increased allocation to stems by 84% and the specific leaf area (SLA) by 29%, compared to control. Reduced nutrient availability (Low N treatment) enhanced carbon allocation into fine roots by 57%. We found high intraspecific variability in turnover times of C pools. The Low N treatment enhanced transport of recently assimilated C from leaves to roots in quantity (22% compared to 7% in control plants) and velocity (13C peak in main roots after 5h compared to 18h in control). The treatments differed also in fractions of 13C recovered within leaves: 48%, 28% and 41% of 13C from labeling were found after 13 days in leaves of control, Low N, and Low L, respectively. Through the combination of natural carbon isotope analysis, 13CO2 labeling and whole-plant chamber measurements we obtained information about long and short-term C

  11. Short-term X-ray spectral variability of the quasar PDS 456 observed in a low-flux state

    NASA Astrophysics Data System (ADS)

    Matzeu, G. A.; Reeves, J. N.; Nardini, E.; Braito, V.; Costa, M. T.; Tombesi, F.; Gofford, J.

    2016-05-01

    We present a detailed analysis of a recent, 2013 Suzaku campaign on the nearby (z = 0.184) luminous (Lbol ˜ 1047 erg s-1) quasar PDS 456. This consisted of three observations, covering a total duration of ˜1 Ms and a net exposure of 455 ks. During these observations, the X-ray flux was unusually low, suppressed by a factor of >10 in the soft X-ray band when compared to previous observations. We investigated the broad-band continuum by constructing a spectral energy distribution (SED), making use of the optical/UV photometry and hard X-ray spectra from the later simultaneous XMM-Newton and NuSTAR campaign in 2014. The high-energy part of this low-flux SED cannot be accounted for by physically self-consistent accretion disc and corona models without attenuation by absorbing gas, which partially covers a substantial fraction of the line of sight towards the X-ray continuum. At least two layers of absorbing gas are required, of column density log (NH,low/cm-2) = 22.3 ± 0.1 and log (NH,high/cm-2) = 23.2 ± 0.1, with average line-of-sight covering factors of ˜80 per cent (with typical ˜5 per cent variations) and 60 per cent (±10-15 per cent), respectively. During these observations PDS 456 displays significant short-term X-ray spectral variability, on time-scales of ˜100 ks, which can be accounted for by variable covering of the absorbing gas along the line of sight. The partial covering absorber prefers an outflow velocity of v_pc = 0.25^{+0.01}_{-0.05} c at the >99.9 per cent confidence level over the case where vpc = 0. This is consistent with the velocity of the highly ionized outflow responsible for the blueshifted iron K absorption profile. We therefore suggest that the partial covering clouds could be the denser, or clumpy part of an inhomogeneous accretion disc wind. Finally estimates are placed upon the size-scale of the X-ray emission region from the source variability. The radial extent of the X-ray emitter is found to be of the order ˜15-20Rg

  12. Short-term acute effects of gutkha chewing on heart rate variability among young adults: A cross-sectional study

    PubMed Central

    Itagi, Afreen Begum H; Arora, Dimple; Patil, Navin A; Bailwad, Sandeep Anant; Yunus, GY; Goel, Ankit

    2016-01-01

    Background and Objectives: An increase in the consumption of smokeless tobacco has been noticed among high school, college students, and adults. Despite the antiquity and popularity of chewing tobacco in India, its effects have not been investigated systematically in humans. The aim of this study was to investigate acute effects of gutkha chewing on heart rate variability (HRV) among healthy young adults. Materials and Methods: A total of 60 young adult males were included in the study. Each individual was asked to chew tobacco and subjected to HRV analysis. HRV analysis using short-term electrocardiogram recording was used to measure HRV parameters before gutkha chewing and at 5, 15, and 30 min after chewing tobacco. One-way analysis of variance and paired t-test was used to assess changes over time. Results: There was a significant increase in heart rate (HR) during tobacco chewing. Mean HR at baseline measured 73.0 ± 6.2 bpm. There was a rise in mean HR to 83.7 ± 9.1 bpm at 5 min during tobacco chewing and gradual reduction to baseline observed after 15 min followed by no significant change till 30 min. The normalized low-frequency power and LF/high-frequency (HF) power ratio were elevated after 5 min; however, normalized HF power was reduced after 5 min tobacco chewing. Conclusion: Gutkha is closely associated with traditional cardiovascular risk factors as detected by a transient enhancing sympathetic activity during tobacco chewing in the form of increased HRV parameters or an imbalance between sympathetic and parasympathetic neural activity among healthy young adults. PMID:26958522

  13. Spherical Harmonic Analysis of Short-Term Variability in the External and Induced Geomagnetic Field, with Supermag.

    NASA Astrophysics Data System (ADS)

    Dorrian, G.; Wild, J. A.; Freeman, M. P.; Shore, R.; Gjerloev, J. W.

    2014-12-01

    We present a methodology for developing spherical harmonic models of short-term variations in the external and induced geomagnetic field. The method uses data from the SuperMAG global magnetometer network, which is provided at 1-minute time resolution. We examine some of the technical challenges encountered in the method development and some initial results are discussed. Results are compared with those from a climatological study running in parallel, which also utilizes SuperMAG data.

  14. Numerical experiments on short-term meteorological effects of solar variability. [earth atmosphere model considering solar luminosity effects

    NASA Technical Reports Server (NTRS)

    Somerville, R. C. J.; Hansen, J. E.; Stone, P. H.; Quirk, W. J.; Lacis, A. A.

    1974-01-01

    Set of numerical experiments has been carried out to test the short range sensitivity of a large atmospheric general circulation model to changes in solar constant and ozone amount. On the basis of the results of 12-day integrations with very large variations in these parameters, it is concluded that realistic variations would produce insignificant meteorological effects. Thus any causal relationships between solar variability and weather, for time scales of two weeks or less, will have to rely upon changes in parameters other than solar constant or ozone amounts, or upon mechanisms not yet incorporated in the model.

  15. Short-Term Chromospheric Variability in alpha Tauri (K5 III): Results from IUE Time Series Observations

    NASA Technical Reports Server (NTRS)

    Cuntz, Manfred; Deeney, Bryan D.; Brown, Alexander; Stencel, Robert E.

    1996-01-01

    We evaluate time series observations of chromospheric lines (Mg II, Mg I, and C II) for the K giant alpha Tau obtained using the IUE LWP camera at high dispersion. These observations cover a time span of about 2 weeks in 1994 February-March and were designed to resolve variations occurring within hours, days, and weeks. We consider the observational results in relation to theoretical acoustic heating models, motivated by the fact that alpha Tau may exhibit a basal (i.e., minimum) level of chromospheric activity. The data reveal flux variations between the extremes of 8% in Mg II h+k and 15% in each emission component. These variations occur on timescales as short as 8 hr but not on timescales longer than approx.3 days. For the h and k components, flux variations occurring on a timescale as short as 1.5 hr are also found. These changes are often not correlated (and are sometimes even anticorrelated), leading to remarkable differences in the h/k ratios. We argue that these results are consistent with the presence of strong acoustic shocks, which can lead to variable Mg II line emission when only a small number of strong shocks are propagating through the atmosphere. We deduce the electron density in the C II lambda 2325 line formation region to be log(base e) of N. approx. equals 9.0, in agreement with previous studies. Our data provide evidence that the Mg II basal flux limit for K giants might be a factor of 4 higher than suggested by Rutten et al.

  16. Perceptual-Gestural (Mis)Mapping in Serial Short-Term Memory: The Impact of Talker Variability

    ERIC Educational Resources Information Center

    Hughes, Robert W.; Marsh, John E.; Jones, Dylan M.

    2009-01-01

    The mechanisms underlying the poorer serial recall of talker-variable lists (e.g., alternating female-male voices) as compared with single-voice lists were examined. We tested the novel hypothesis that this "talker variability effect" arises from the tendency for perceptual organization to partition the list into streams based on voice such that…

  17. Short-Term and Long-Term Variability of Antenna Position Due to Thermal Bending of Pillar Monument at Permanent GNSS Station

    NASA Astrophysics Data System (ADS)

    Gerhatova, Lubomira; Hefty, Jan; Spanik, Peter

    2016-06-01

    The variability of daily site coordinates at permanent GNSS station is a sum of many disturbing factors influencing the actual satellite observations, data processing, and bias modelling. In the paper are analysed possibilities of monitoring the instability of GNSS antenna pillar monument by the independent observations using the precise inclination sensor. Long-term series from three different types of pillars show specific features in amplitude and temporal evolution of monument bending. Correlations with daily temperature and/or solar radiation changes were proved.

  18. Short-term Variability in Outpatient Pain Intensity Scores in a National Sample of Older Veterans with Chronic Pain

    PubMed Central

    Dobscha, Steven K.; Morasco, Benjamin J.; Kovas, Anne E.; Peters, Dawn M.; Hart, Kyle; McFarland, Bentson H.

    2015-01-01

    Objective The Department of Veterans Affairs (VA) uses the 11-point pain numeric rating scale (NRS) to gather pain intensity information from veterans at outpatient appointments. Yet, little is known about how NRS scores may vary over time within individuals; NRS variability may have important ramifications for treatment planning. Our main objective was to describe variability in NRS scores within a one-month timeframe, as obtained during routine outpatient care in older patients with chronic pain treated in VA hospitals. A secondary objective was to explore for patient characteristics associated with within-month NRS score variability. Design Retrospective cohort study. Subjects National sample of veterans 65 years or older seen in VA in 2010 who had multiple elevated NRS scores indicating chronic pain. Methods VA datasets were used to identify the sample and demographic and clinical variables including NRS scores. For the main analysis, we identified subjects with 2 or more NRS scores obtained in each of 2 or more months in a 12 month period; we examined ranges in NRS scores across the first 2 qualifying months. Results Among 4,336 individuals in the main analysis cohort, the mean and median of the average NRS score range across the two months were 2.7 and 2.5, respectively. In multivariable models, main significant predictors of within-month NRS score variability were baseline pain intensity, overall medical comorbidity, and being divorced/separated. Conclusions The majority of patients in the sample had clinically meaningful variation in pain scores within a given month. This finding highlights the need for clinicians and their patients to consider multiple NRS scores when making chronic pain treatment decisions. PMID:25545398

  19. Major modes of short-term climate variability in the newly developed NUIST Earth System Model (NESM)

    NASA Astrophysics Data System (ADS)

    Cao, Jian; Wang, Bin; Xiang, Baoqiang; Li, Juan; Wu, Tianjie; Fu, Xiouhua; Wu, Liguang; Min, Jinzhong

    2015-05-01

    A coupled earth system model (ESM) has been developed at the Nanjing University of Information Science and Technology (NUIST) by using version 5.3 of the European Centre Hamburg Model (ECHAM), version 3.4 of the Nucleus for European Modelling of the Ocean (NEMO), and version 4.1 of the Los Alamos sea ice model (CICE). The model is referred to as NUIST ESM1 (NESM1). Comprehensive and quantitative metrics are used to assess the model's major modes of climate variability most relevant to subseasonal-to-interannual climate prediction. The model's assessment is placed in a multi-model framework. The model yields a realistic annual mean and annual cycle of equatorial SST, and a reasonably realistic precipitation climatology, but has difficulty in capturing the spring-fall asymmetry and monsoon precipitation domains. The ENSO mode is reproduced well with respect to its spatial structure, power spectrum, phase locking to the annual cycle, and spatial structures of the central Pacific (CP)-ENSO and eastern Pacific (EP)-ENSO; however, the equatorial SST variability, biennial component of ENSO, and the amplitude of CP-ENSO are overestimated. The model captures realistic intraseasonal variability patterns, the vertical-zonal structures of the first two leading predictable modes of Madden-Julian Oscillation (MJO), and its eastward propagation; but the simulated MJO speed is significantly slower than observed. Compared with the T42 version, the high resolution version (T159) demonstrates improved simulation with respect to the climatology, interannual variance, monsoon-ENSO lead-lag correlation, spatial structures of the leading mode of the Asian-Australian monsoon rainfall variability, and the eastward propagation of the MJO.

  20. Interannual and seasonal variability in short-term grazing impact of Euphausia superba in nearshore and offshore waters west of the Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Ross, R. M.; Quetin, L. B.; Haberman, K. L.

    1998-11-01

    Our focus in this paper is the interaction between macrozooplanktonic grazers and primary producers, and the interannual and seasonal variability in the Palmer Long-Term Ecological Research (Palmer LTER) study region from Anvers Island to Adelaide Island. Short-term grazing estimates are calculated by integrating (1) theoretical and experimental estimates of ingestion rates in response to the standing stock of phytoplankton, and (2) field measurements of phytoplankton standing stock and grazer biomass. Field data come from three austral summer cruises (January/February of 1993, 1994, and 1995) and one sequence of seasonal cruises (summer, fall and winter 1993). The relative and absolute abundance of the dominant macrozooplankton grazers, Euphausia superba and Salpa thompsoni, varied by at least an order of magnitude on the spatial and temporal scales observed. Mean grazing rates ranged from 0.4 to 9.0 μg chlorophyll m -2 h -1 for the Antarctic krill and salp populations over the three summer cruises. This leads to variability in the flow of carbon from the primary producers through the grazers on the same scales. Temporal and spatial variability in grazing impact and faecal pellet production are high.

  1. Short-term heart rate variability in a population-based sample of 10-year-old children.

    PubMed

    Jarrin, Denise C; McGrath, Jennifer J; Poirier, Paul; Séguin, Louise; Tremblay, Richard E; Montplaisir, Jacques Y; Paradis, Gilles; Séguin, Jean R

    2015-01-01

    Heart rate variability (HRV) is a non-invasive quantitative marker of cardiac autonomic function derived from continuous electrocardiogram (ECG) recordings. Normative HRV values and development factors have not been established in pediatric populations. The objective was to derive referent time- and frequency-domain HRV values for a population-based sample of children. Children aged 9-11 years (N = 1,036) participated in the Québec Longitudinal Study of Child Development cohort cardiovascular health screening. Registered nurses measured anthropometrics (height, weight) and children wore an ambulatory Holter monitor to continuously record an ECG signal. HRV variables included time (SDNN, pNN50, RMSSD, SDANN) and frequency (HF, LF, LF/HF ratio) domain variables. Normative HRV values, stratified by age, sex, and heart rate, are presented. Greater heart rate (β avg  = -0.60, R avg (2)  = 0.39), pubertal maturation (β avg = -0.11, R avg (2)  = 0.01), later ECG recording times (β avg = -0.19, R avg (2)  = 0.07), and higher diastolic blood pressure (β avg = -0.11, R avg (2)  = 0.01) were significantly associated with reduced HRV in 10-year-old children. The normative HRV values permit clinicians to monitor, describe, and establish pediatric nosologies in primary care and research settings, which may improve treatment of diseases associated with HRV in children. By better understanding existing values, the practical applicability of HRV among clinicians will be enhanced. Lastly, developmental (e.g., puberty) and procedural (e.g., recording time) factors were identified that will improve recording procedures and interpretation of results. PMID:25056158

  2. Short-term under-ice variability of prokaryotic plankton communities in coastal Antarctic waters (Cape Hallett, Ross Sea)

    NASA Astrophysics Data System (ADS)

    Celussi, Mauro; Paoli, Alessandro; Crevatin, Erica; Bergamasco, Andrea; Margiotta, Francesca; Saggiomo, Vincenzo; Umani, Serena Fonda; Del Negro, Paola

    2009-03-01

    During the 2006 Italian Antarctic expedition a diel sampling was performed close to Cape Hallett (Ross Sea) during the Austral summer. Under-ice seawater samples (˜4 m) were collected every 2 h for 28 h in order to estimate prokaryotic processes' variability and community structure dynamics. Prokaryotic and viral abundances, exoenzymatic activities (β-glucosidase, chitinase, lipase, alkaline phosphatase and leucine aminopeptidase), prokaryotic carbon production ( 3H-leucine incorporation) and community structure (Denaturing Gradient Gel Electrophoresis - DGGE fingerprints) were analysed. Results showed that the diel variability of the prokaryotic activity followed a variation in salinity, probably as a consequence of the periodical thawing of sea ice (driven by solar radiation and air temperature cycles), while negligible variation in viral and prokaryotic abundances occurred. The Bacterial and Archaeal community structures underwent an Operational Taxonomic Units (OTUs) temporal shift from the beginning to the end of the sampling, while Flavobacteria-specific primers highlighted high variations in this group possibly related to sea ice melting and substrate release.

  3. Wind forcing and short-term variability of phytoplankton and heterotrophic bacterioplankton in the coastal zone of the Concepción upwelling system (Central Chile)

    NASA Astrophysics Data System (ADS)

    Daneri, Giovanni; Lizárraga, Lorena; Montero, Paulina; González, Humberto E.; Tapia, Fabián J.

    2012-01-01

    Along South-Central Chile, upwelling-favorable winds do not blow steadily equatorward, and may remain calm or even reverse for periods of 2-8 days shifting the balance between water column stability and replenishment of inorganic nutrients to the photic zone. In this study, we focus on the short-term variability of phytoplankton and heterotrophic bacterioplankton associated with the temporal variability in upwelling at a single nearshore station at the entrance of Coliumo Bay, Central Chile. In situ sampling took place every other day between 24 January and 14 February 2007. Observed variability of wind, sea surface temperature, and surface chlorophyll concentrations during the preceding weeks and throughout our experiments indicated that nearshore productivity was tightly coupled to local upwelling conditions. Gross primary production remained relatively low (22.5 ± 6.1 μg C L -1 h -1) during the first 8 days (24 January-1 February), and increased six fold (142.4 ± 67.1 μg C L -1 h -1) during the second period (3-14 February). Average in situ chlorophyll concentrations increased from 2.0 ± 0.6 mg m -3 to 6.3 ± 3.8 mg m -3 over the same period. Bacterial Carbon Demand presented higher values (5-29.2 μg C L -1 h -1) during the first 6 days of sampling and lower values (<0.1 μg C L -1 h -1) for the rest of study period. Our results show that both biological productivity and the structure of the planktonic community can vary considerably due to short-term changes in wind conditions. Hence, previous productivity estimates for the Concepción upwelling ecosystem - based on observations gathered at lower frequencies - may not truly reflect its productivity potential.

  4. Short-term variability of the Sun-Earth system: an overview of progress made during the CAWSES-II period

    NASA Astrophysics Data System (ADS)

    Gopalswamy, Nat; Tsurutani, Bruce; Yan, Yihua

    2015-12-01

    This paper presents an overview of results obtained during the CAWSES-II period on the short-term variability of the Sun and how it affects the near-Earth space environment. CAWSES-II was planned to examine the behavior of the solar-terrestrial system as the solar activity climbed to its maximum phase in solar cycle 24. After a deep minimum following cycle 23, the Sun climbed to a very weak maximum in terms of the sunspot number in cycle 24 (MiniMax24), so many of the results presented here refer to this weak activity in comparison with cycle 23. The short-term variability that has immediate consequence to Earth and geospace manifests as solar eruptions from closed-field regions and high-speed streams from coronal holes. Both electromagnetic (flares) and mass emissions (coronal mass ejections - CMEs) are involved in solar eruptions, while coronal holes result in high-speed streams that collide with slow wind forming the so-called corotating interaction regions (CIRs). Fast CMEs affect Earth via leading shocks accelerating energetic particles and creating large geomagnetic storms. CIRs and their trailing high-speed streams (HSSs), on the other hand, are responsible for recurrent small geomagnetic storms and extended days of auroral zone activity, respectively. The latter leads to the acceleration of relativistic magnetospheric `killer' electrons. One of the major consequences of the weak solar activity is the altered physical state of the heliosphere that has serious implications for the shock-driving and storm-causing properties of CMEs. Finally, a discussion is presented on extreme space weather events prompted by the 23 July 2012 super storm event that occurred on the backside of the Sun. Many of these studies were enabled by the simultaneous availability of remote sensing and in situ observations from multiple vantage points with respect to the Sun-Earth line.

  5. Relationship Between Changes in Pulse Pressure and Frequency Domain Components of Heart Rate Variability During Short-Term Left Ventricular Pacing in Patients with Cardiac Resynchronization Therapy

    PubMed Central

    Urbanek, Bożena; Ruta, Jan; Kudryński, Krzysztof; Ptaszyński, Paweł; Klimczak, Artur; Wranicz, Jerzy Krzysztof

    2016-01-01

    Background The aim of the study was to explore the relationship between changes in pulse pressure (PP) and frequency domain heart rate variability (HRV) components caused by left ventricular pacing in patients with implanted cardiac resynchronization therapy (CRT). Material/Methods Forty patients (mean age 63±8.5 years) with chronic heart failure (CHF) and implanted CRT were enrolled in the study. The simultaneous 5-minute recording of beat-to-beat arterial systolic and diastolic blood pressure (SBP and DBP) by Finometer and standard electrocardiogram with CRT switched off (CRT/0) and left ventricular pacing (CRT/LV) was performed. PP (PP=SBP-DBP) and low- and high-frequency (LF and HF) HRV components were calculated, and the relationship between these parameters was analyzed. Results Short-term CRT/LV in comparison to CRT/0 caused a statistically significant increase in the values of PP (P<0.05), LF (P<0.05), and HF (P<0.05). A statistically significant correlation between ΔPP and ΔHF (R=0.7384, P<0.05) was observed. The ΔHF of 6 ms2 during short-term CRT/LV predicted a PP increase of ≥10% with 84.21% sensitivity and 85.71% specificity. Conclusions During short-term left ventricular pacing in patients with CRT, a significant correlation between ΔPP and ΔHF was observed. ΔHF ≥6 ms2 may serve as a tool in the selection of a suitable site for placement of a left ventricular lead. PMID:27305349

  6. Relationship Between Changes in Pulse Pressure and Frequency Domain Components of Heart Rate Variability During Short-Term Left Ventricular Pacing in Patients with Cardiac Resynchronization Therapy.

    PubMed

    Urbanek, Bożena; Ruta, Jan; Kudryński, Krzysztof; Ptaszyński, Paweł; Klimczak, Artur; Wranicz, Jerzy Krzysztof

    2016-01-01

    BACKGROUND The aim of the study was to explore the relationship between changes in pulse pressure (PP) and frequency domain heart rate variability (HRV) components caused by left ventricular pacing in patients with implanted cardiac resynchronization therapy (CRT). MATERIAL AND METHODS Forty patients (mean age 63±8.5 years) with chronic heart failure (CHF) and implanted CRT were enrolled in the study. The simultaneous 5-minute recording of beat-to-beat arterial systolic and diastolic blood pressure (SBP and DBP) by Finometer and standard electrocardiogram with CRT switched off (CRT/0) and left ventricular pacing (CRT/LV) was performed. PP (PP=SBP-DBP) and low- and high-frequency (LF and HF) HRV components were calculated, and the relationship between these parameters was analyzed. RESULTS Short-term CRT/LV in comparison to CRT/0 caused a statistically significant increase in the values of PP (P<0.05), LF (P<0.05), and HF (P<0.05). A statistically significant correlation between ΔPP and ΔHF (R=0.7384, P<0.05) was observed. The ΔHF of 6 ms2 during short-term CRT/LV predicted a PP increase of ≥10% with 84.21% sensitivity and 85.71% specificity. CONCLUSIONS During short-term left ventricular pacing in patients with CRT, a significant correlation between ΔPP and ΔHF was observed. ΔHF ≥6 ms2 may serve as a tool in the selection of a suitable site for placement of a left ventricular lead. PMID:27305349

  7. Short-term variability and mass loss in Be stars. I. BRITE satellite photometry of η and μ Centauri

    NASA Astrophysics Data System (ADS)

    Baade, D.; Rivinius, Th.; Pigulski, A.; Carciofi, A. C.; Martayan, Ch.; Moffat, A. F. J.; Wade, G. A.; Weiss, W. W.; Grunhut, J.; Handler, G.; Kuschnig, R.; Mehner, A.; Pablo, H.; Popowicz, A.; Rucinski, S.; Whittaker, G.

    2016-04-01

    Context. Empirical evidence for the involvement of nonradial pulsations (NRPs) in the mass loss from Be stars ranges from (i) a singular case (μ Cen) of repetitive mass ejections triggered by multi-mode beating to (ii) several photometric reports about enormous numbers of pulsation modes that suddenly appear during outbursts and on to (iii) effective single-mode pulsators. Aims: The purpose of this study is to develop a more detailed empirical description of the star-to-disk mass transfer and to check the hypothesis that spates of transient nonradial pulsation modes accompany and even drive mass-loss episodes. Methods: The BRITE Constellation of nanosatellites was used to obtain mmag photometry of the Be stars η and μ Cen. Results: In the low-inclination star μ Cen, light pollution by variable amounts of near-stellar matter prevented any new insights into the variability and other properties of the central star. In the equator-on star η Cen, BRITE photometry and Heros echelle spectroscopy from the 1990s reveal an intricate clockwork of star-disk interactions. The mass transfer is modulated with the frequency difference of two NRP modes and an amplitude three times as large as the amplitude sum of the two NRP modes. This process feeds a high-amplitude circumstellar activity running with the incoherent and slightly lower so-called Štefl frequency. The mass-loss-modulation cycles are tightly coupled to variations in the value of the Štefl frequency and in its amplitude, albeit with strongly drifting phase differences. Conclusions: The observations are well described by the decomposition of the mass loss into a pulsation-related engine in the star and a viscosity-dominated engine in the circumstellar disk. Arguments are developed that large-scale gas-circulation flows occur at the interface. The propagation rates of these eddies manifest themselves as Štefl frequencies. Bursts in power spectra during mass-loss events can be understood as the noise inherent to

  8. Short-term variability in euphotic zone biogeochemistry and primary productivity at Station ALOHA: A case study of summer 2012

    NASA Astrophysics Data System (ADS)

    Wilson, Samuel T.; Barone, Benedetto; Ascani, Francois; Bidigare, Robert R.; Church, Matthew J.; Valle, Daniela A.; Dyhrman, Sonya T.; Ferrón, Sara; Fitzsimmons, Jessica N.; Juranek, Laurie W.; Kolber, Zbigniew S.; Letelier, Ricardo M.; Martínez-García, Sandra; Nicholson, David P.; Richards, Kelvin J.; Rii, Yoshimi M.; Rouco, Mónica; Viviani, Donn A.; White, Angelicque E.; Zehr, Jonathan P.; Karl, David M.

    2015-08-01

    Time-series observations are critical to understand the structure, function, and dynamics of marine ecosystems. The Hawaii Ocean Time-series program has maintained near-monthly sampling at Station ALOHA (22°45'N, 158°00'W) in the oligotrophic North Pacific Subtropical Gyre (NPSG) since 1988 and has identified ecosystem variability over seasonal to interannual timescales. To further extend the temporal resolution of these near-monthly time-series observations, an extensive field campaign was conducted during July-September 2012 at Station ALOHA with near-daily sampling of upper water-column biogeochemistry, phytoplankton abundance, and activity. The resulting data set provided biogeochemical measurements at high temporal resolution and documents two important events at Station ALOHA: (1) a prolonged period of low productivity when net community production in the mixed layer shifted to a net heterotrophic state and (2) detection of a distinct sea-surface salinity minimum feature which was prominent in the upper water column (0-50 m) for a period of approximately 30 days. The shipboard observations during July-September 2012 were supplemented with in situ measurements provided by Seagliders, profiling floats, and remote satellite observations that together revealed the extent of the low productivity and the sea-surface salinity minimum feature in the NPSG.

  9. Short-term temporal and spatial variability of soil hydrophobicity in an abandoned agriculture field in Lithuania

    NASA Astrophysics Data System (ADS)

    Pereira, Paulo; Burguet, Maria; Cerdà, Artemi

    2013-04-01

    Soil water repellency (SWR) is a natural property of soils. Among other factors, SWR depends on soil moisture, mineralogy, texture, pH, organic matter, aggregate stability, fungal and microbiological activity and plant cover. It has implications on plant growth, superficial and subsurface hydrology and soil erosion. It is well known that SWR is temporarily, increasing when soils are dry and decreasing when moist. In agriculture, soil micro-topography is very heterogeneous with implications on surface water distribution and wettability. Normally, SWR studies are focused on large interval time (e.g, monthly or seasonally). The objective of this work is the study of SWR in a temporal scale and its variability in an abandoned agriculture field in Lithuania. An experimental plot with 21 m2 (07x03 m) was designed in a flat area. Inside this plot SWR was measured in the field, placing three droplets of water on the soil surface and counting the time that takes to infiltrate. A total of 105 sampling points were measured per sampling period. Soil water repellency was measured after a period of 14 days without rainfall and in the seven consequent weeks (one measurement per week between 28th May and 07th of July 2012). The results showed that in this small plot, SWR was observed in the first (May 28), third and fourth measurements (08th of June and 16th). It was observed an increasing of the percentage of hydrophobic points (Water Drop Penetration Test ≥5 seconds) between the first and the fourth measurement, decreasing thereafter. Significant differences of SWR were observed among all periods (F=78.32, p<0.0001). The coefficient of variation (CV%) changed strikingly, 361.10 % (8th of May), 151.78 % (01st of June), 83.77% (08th of June), 125.87% (16th of June), 0.45 (22nd of June), 121%(31st of June) and 67.13% (7th of July). The correlation between the mean SWR and the CV% is 0.75, p<0.05. The changes were attributed to different soil moisture conditions. The differences

  10. Serum amyloid A, haptoglobin, and ferritin in horses with colic: Association with common clinicopathological variables and short-term outcome.

    PubMed

    Dondi, Francesco; Lukacs, Robert M; Gentilini, Fabio; Rinnovati, Riccardo; Spadari, Alessandro; Romagnoli, Noemi

    2015-07-01

    Equine colic may be associated with an acute phase response (APR). Measurement of acute phase proteins (APPs) allows the detection of an APR and may help clinicians in monitoring the disease; however, the role of APPs in colic is unclear. This study aimed to evaluate the clinical usefulness of serum amyloid A (SAA), haptoglobin and ferritin in combination with an extended clinicopathological profile in equine colic. The medical records of 54 horses were retrospectively selected. Horses were grouped based on outcome (survivors vs. non-survivors), diagnosis (ischaemic/strangulating vs. non-ischaemic/non-strangulating), and treatment (medical treatment vs. surgery). Laboratory data were compared, and a logistic regression analysis was performed for outcome prediction upon admission. A high percentage of horses had abnormal SAA (29/54), haptoglobin (20/54), and ferritin (31/54) concentrations. In particular, haptoglobin was below the reference interval in 13/54 horses. Non-survivors had significantly decreased haptoglobin and increased ferritin concentrations compared with survivors. The ischaemic/strangulating group had significantly increased creatinine and ferritin and decreased haptoglobin concentrations compared with the non-ischaemic/non-strangulating group. Creatinine was the only significant predictor of mortality in the regression analysis. In conclusion, APPs including SAA, haptoglobin, and ferritin combined with clinicopathological variables may help clinicians to understand the pathogenesis of APR and underline potential complications of equine colic. The reduction in haptoglobin concentration may suggest haemolysis or muscle fibre damage; ferritin may indicate alteration in iron metabolism and tissue damage. Further prospective studies are needed to assess diagnostic and prognostic values of APPs in colic horses. PMID:25981935

  11. Short-Term Vocational Evaluation.

    ERIC Educational Resources Information Center

    Botterbusch, Karl F.

    This guide is intended to assist vocational rehabilitation counselors in planning and conducting short-term vocational evaluations of clients. The first section discusses the elements that must be included in a comprehensive vocational evaluation. Next, strategies for conducting a vocational evaluation are explained. The next section, a case study…

  12. Short-term sandbar variability based on video imagery: Comparison between Time-Average and Time-Variance techniques

    USGS Publications Warehouse

    Guedes, R.M.C.; Calliari, L.J.; Holland, K.T.; Plant, N.G.; Pereira, P.S.; Alves, F.N.A.

    2011-01-01

    Time-exposure intensity (averaged) images are commonly used to locate the nearshore sandbar position (xb), based on the cross-shore locations of maximum pixel intensity (xi) of the bright bands in the images. It is not known, however, how the breaking patterns seen in Variance images (i.e. those created through standard deviation of pixel intensity over time) are related to the sandbar locations. We investigated the suitability of both Time-exposure and Variance images for sandbar detection within a multiple bar system on the southern coast of Brazil, and verified the relation between wave breaking patterns, observed as bands of high intensity in these images and cross-shore profiles of modeled wave energy dissipation (xD). Not only is Time-exposure maximum pixel intensity location (xi-Ti) well related to xb, but also to the maximum pixel intensity location of Variance images (xi-Va), although the latter was typically located 15m offshore of the former. In addition, xi-Va was observed to be better associated with xD even though xi-Ti is commonly assumed as maximum wave energy dissipation. Significant wave height (Hs) and water level (??) were observed to affect the two types of images in a similar way, with an increase in both Hs and ?? resulting in xi shifting offshore. This ??-induced xi variability has an opposite behavior to what is described in the literature, and is likely an indirect effect of higher waves breaking farther offshore during periods of storm surges. Multiple regression models performed on xi, Hs and ?? allowed the reduction of the residual errors between xb and xi, yielding accurate estimates with most residuals less than 10m. Additionally, it was found that the sandbar position was best estimated using xi-Ti (xi-Va) when xb was located shoreward (seaward) of its mean position, for both the first and the second bar. Although it is unknown whether this is an indirect hydrodynamic effect or is indeed related to the morphology, we found that this

  13. Validity and Usefulness of `Wearable Blood Pressure Sensing' for Detection of Inappropriate Short-Term Blood Pressure Variability in the Elderly

    NASA Astrophysics Data System (ADS)

    Iijima, Katsuya; Kameyama, Yumi; Akishita, Masahiro; Ouchi, Yasuyoshi; Yanagimoto, Shintaro; Imai, Yasushi; Yahagi, Naoki; Lopez, Guillaume; Shuzo, Masaki; Yamada, Ichiro

    An increase in short-term blood pressure (BP) variability is a characteristic feature in the elderly. It makes the management of hemodynamics more difficult, because it is frequently seen disturbed baro-reflex function and increased arterial stiffness, leading to isolated systolic hypertension. Large BP variability aggravates hypertensive target organ damage and is an independent risk factor for the cardiovascular (CV) events in elderly hypertensive patients. Therefore, appropriate control in BP is indispensable to manage lifestyle-related diseases and to prevent subsequent CV events. In addition, accumulating recent reports show that excessive BP variability is also associated with a decline in cognitive function and fall in the elderly. In the clinical settings, we usually evaluate their health condition, mainly with single point BP measurement using cuff inflation. However, unfortunately we are not able to find the close changes in BP by the traditional way. Here, we can show our advantageous approach of continuous BP monitoring using newly developing device `wearable BP sensing' without a cuff stress in the elderly. The new device could reflect systolic BP and its detailed changes, in consistent with cuff-based BP measurement. Our new challenge suggests new possibility of its clinical application with high accuracy.

  14. Impacts of long- and short-term climate variability on terrestrial biogenic emissions and their influence on the remote tropical troposphere

    NASA Astrophysics Data System (ADS)

    Monks, S. A.; Arnold, S.; Guenther, A. B.; Emmons, L. K.; Carpenter, L.; Read, K.

    2013-12-01

    Terrestrial vegetation emits a wide range of biogenic volatile organic compounds (BVOC) into the atmosphere (~1150 TgC/yr), which accounts for ~90% of total VOC surface emissions. Emissions of BVOC are largely dependent on environmental factors such as sunlight and temperature, which makes them sensitive to both long-term and short-term changes in the climate system. ENSO is well-known to have global impacts on temperature and precipitation, and therefore has the potential to impact regional BVOC emissions on inter-annual time-scales. In addition to this, increased global mean temperatures and atmospheric carbon dioxide (CO2) concentrations over the past few decades may also have affected BVOC emissions. Once in the atmosphere, these compounds have the ability to influence global and regional atmospheric chemistry and climate through impacts on the hydroxyl radical, ozone, particulate matter and methane lifetime. We use the NCAR Community Land Model (CLM) coupled to the Model of Emissions of Gases and Aerosols from Nature (MEGANv2) to investigate both long-term changes and inter-annual variability of BVOC emissions over a 50-year period at regional and global spatial-scales. This is done by considering the impacts of increasing temperatures and CO2 concentrations on long-term emissions of BVOC separately, in addition to using the Multivariate ENSO Index (MEI) to investigate the regional response in emissions due to natural ENSO variability. Global composites of ENSO-positive and ENSO-negative phase emissions are then used to drive global atmospheric chemistry simulations using the NCAR Community Earth System Model (CESM). Through comparisons with 6 years of measurements from the Cape Verde observatory in the tropical Atlantic Ocean, we explore the role of inter-annual variability in terrestrial biogenic emissions in controlling the observed variability in methanol, acetone and acetaldehyde in the remote tropical atmosphere. By accounting for inter-annual changes in

  15. Short-term radio variability and parsec-scale structure in A gamma-ray narrow-line Seyfert 1 galaxy 1H 0323+342

    SciTech Connect

    Wajima, Kiyoaki; Fujisawa, Kenta; Hayashida, Masaaki; Isobe, Naoki; Ishida, Takafumi; Yonekura, Yoshinori

    2014-02-01

    We made simultaneous single-dish and very long baseline interferometer (VLBI) observations of a narrow-line Seyfert 1 galaxy 1H 323+342, showing gamma-ray activity revealed by Fermi/Large Area Telescope observations. We found significant variation of the total flux density at 8 GHz on the timescale of one month by the single-dish monitoring. The total flux density varied by 5.5% in 32 days, which is comparable to the gamma-ray variability timescale, corresponding to the variability brightness temperature of 7.0 × 10{sup 11} K. The source consists of central and southeastern components on the parsec (pc) scale. Only the flux of the central component decreased in the same way as the total flux density, indicating that the short-term radio variability, and probably the gamma-ray-emitting region, is associated with this component. From the VLBI observations, we obtained brightness temperatures of greater than (5.2 ± 0.3) × 10{sup 10} K and derived an equipartition Doppler factor of greater than 1.7, a variability Doppler factor of 2.2, and an 8 GHz radio power of 10{sup 24.6} W Hz{sup –1}. Combining them, we conclude that acceleration of radio jets and creation of high-energy particles are ongoing in the central engine and that the apparent very radio-loud feature of the source is due to the Doppler boosting effect, resulting in the intrinsic radio loudness being an order of magnitude smaller than the observed values. We also conclude that the pc-scale jet represents recurrent activity from the spectral fitting and the estimated kinematic age of pc- and kpc-scale extended components with different position angles.

  16. Short term spatio-temporal variability of soil water-extractable calcium and magnesium after a low severity grassland fire in Lithuania.

    NASA Astrophysics Data System (ADS)

    Pereira, Paulo; Martin, David

    2014-05-01

    Fire has important impacts on soil nutrient spatio-temporal distribution (Outeiro et al., 2008). This impact depends on fire severity, topography of the burned area, type of soil and vegetation affected, and the meteorological conditions post-fire. Fire produces a complex mosaic of impacts in soil that can be extremely variable at small plot scale in the space and time. In order to assess and map such a heterogeneous distribution, the test of interpolation methods is fundamental to identify the best estimator and to have a better understanding of soil nutrients spatial distribution. The objective of this work is to identify the short-term spatial variability of water-extractable calcium and magnesium after a low severity grassland fire. The studied area is located near Vilnius (Lithuania) at 54° 42' N, 25° 08 E, 158 masl. Four days after the fire, it was designed in a burned area a plot with 400 m2 (20 x 20 m with 5 m space between sampling points). Twenty five samples from top soil (0-5 cm) were collected immediately after the fire (IAF), 2, 5, 7 and 9 months after the fire (a total of 125 in all sampling dates). The original data of water-extractable calcium and magnesium did not respected the Gaussian distribution, thus a neperian logarithm (ln) was applied in order to normalize data. Significant differences of water-extractable calcium and magnesium among sampling dates were carried out with the Anova One-way test using the ln data. In order to assess the spatial variability of water-extractable calcium and magnesium, we tested several interpolation methods as Ordinary Kriging (OK), Inverse Distance to a Weight (IDW) with the power of 1, 2, 3 and 4, Radial Basis Functions (RBF) - Inverse Multiquadratic (IMT), Multilog (MTG), Multiquadratic (MTQ) Natural Cubic Spline (NCS) and Thin Plate Spline (TPS) - and Local Polynomial (LP) with the power of 1 and 2. Interpolation tests were carried out with Ln data. The best interpolation method was assessed using the

  17. Emergence of Algal Blooms: The Effects of Short-Term Variability in Water Quality on Phytoplankton Abundance, Diversity, and Community Composition in a Tidal Estuary

    PubMed Central

    Egerton, Todd A.; Morse, Ryan E.; Marshall, Harold G.; Mulholland, Margaret R.

    2014-01-01

    Algal blooms are dynamic phenomena, often attributed to environmental parameters that vary on short timescales (e.g., hours to days). Phytoplankton monitoring programs are largely designed to examine long-term trends and interannual variability. In order to better understand and evaluate the relationships between water quality variables and the genesis of algal blooms, daily samples were collected over a 34 day period in the eutrophic Lafayette River, a tidal tributary within Chesapeake Bay’s estuarine complex, during spring 2006. During this period two distinct algal blooms occurred; the first was a cryptomonad bloom and this was followed by a bloom of the mixotrophic dinoflagellate, Gymnodinium instriatum. Chlorophyll a, nutrient concentrations, and physical and chemical parameters were measured daily along with phytoplankton abundance and community composition. While 65 phytoplankton species from eight major taxonomic groups were identified in samples and total micro- and nano-phytoplankton cell densities ranged from 5.8 × 106 to 7.8 × 107 cells L−1, during blooms, cryptomonads and G. instriatum were 91.6% and 99.0%, respectively, of the total phytoplankton biomass during blooms. The cryptomonad bloom developed following a period of rainfall and concomitant increases in inorganic nitrogen concentrations. Nitrate, nitrite and ammonium concentrations 0 to 5 days prior were positively lag-correlated with cryptomonad abundance. In contrast, the G. insriatum bloom developed during periods of low dissolved nitrogen concentrations and their abundance was negatively correlated with inorganic nitrogen concentrations. PMID:27694775

  18. Emergence of Algal Blooms: The Effects of Short-Term Variability in Water Quality on Phytoplankton Abundance, Diversity, and Community Composition in a Tidal Estuary

    PubMed Central

    Egerton, Todd A.; Morse, Ryan E.; Marshall, Harold G.; Mulholland, Margaret R.

    2014-01-01

    Algal blooms are dynamic phenomena, often attributed to environmental parameters that vary on short timescales (e.g., hours to days). Phytoplankton monitoring programs are largely designed to examine long-term trends and interannual variability. In order to better understand and evaluate the relationships between water quality variables and the genesis of algal blooms, daily samples were collected over a 34 day period in the eutrophic Lafayette River, a tidal tributary within Chesapeake Bay’s estuarine complex, during spring 2006. During this period two distinct algal blooms occurred; the first was a cryptomonad bloom and this was followed by a bloom of the mixotrophic dinoflagellate, Gymnodinium instriatum. Chlorophyll a, nutrient concentrations, and physical and chemical parameters were measured daily along with phytoplankton abundance and community composition. While 65 phytoplankton species from eight major taxonomic groups were identified in samples and total micro- and nano-phytoplankton cell densities ranged from 5.8 × 106 to 7.8 × 107 cells L−1, during blooms, cryptomonads and G. instriatum were 91.6% and 99.0%, respectively, of the total phytoplankton biomass during blooms. The cryptomonad bloom developed following a period of rainfall and concomitant increases in inorganic nitrogen concentrations. Nitrate, nitrite and ammonium concentrations 0 to 5 days prior were positively lag-correlated with cryptomonad abundance. In contrast, the G. insriatum bloom developed during periods of low dissolved nitrogen concentrations and their abundance was negatively correlated with inorganic nitrogen concentrations.

  19. Tree ring isotopes of beech and spruce in response to short-term climate variability across Central European sites: Common and contrasting physiological mechanisms

    NASA Astrophysics Data System (ADS)

    Weigt, Rosemarie; Klesse, Stefan; Treydte, Kerstin; Frank, David; Saurer, Matthias; Siegwolf, Rolf T. W.

    2016-04-01

    The combined study of tree-ring width and stable C and O isotopes provides insight in the coherences between carbon allocation during stem growth and the preceding conditions of gas exchange and formation of photosynthates as all influenced by environmental variation. In this large-scale study comprising 10 sites across a range of climate gradients (temperature, precipitation) throughout Central Europe, we investigated tree-rings in European beech (Fagus sylvatica) and Norway spruce (Picea abies) trees. The sampling design included larger and smaller trees. The short-term, i.e. year-to-year, variability in the isotope time series over 100 yrs was analyzed in relation to tree-ring growth and climate variation. The generally strong correlation between the year-to-year differences in δ13C (corrected for the atmospheric shift due to 13C-depleted CO2 from fossil combustion) and δ18O across most sites emphasized the role of stomatal conductance in controlling leaf gas exchange. However, the correlation between both isotopes decreased during some periods. At several sites this reduction in correlation was particularly pronounced during recent decades. This suggests a decoupling between stomatal and photosynthetic responses to environmental conditions on the one hand, and carbon allocation to stem tissue on the other hand. Variability in the isotopic ratio largely responded to summer climate, but was weakly correlated to annual stem growth. In contrast, climate sensitivity of radial growth in both species was rather site-dependent, and was strongest at the driest (in terms of soil water capacity) site. We will also present results of isotope responses with respect to extreme climate events. Understanding the underlying physiological mechanisms controlling the short-term variation in tree-ring signals will help to assess and more precisely constrain the possible range of growth performance of these ecologically and economically important tree species under future climate

  20. The impacts of short-term exposure to noise and traffic-related air pollution on heart rate variability in young healthy adults.

    PubMed

    Huang, Jing; Deng, Furong; Wu, Shaowei; Lu, Henry; Hao, Yu; Guo, Xinbiao

    2013-01-01

    Traffic-related air pollution and noise are associated with cardiovascular diseases, and alternation of heart rate variability (HRV), which reflects cardiac autonomic function, is one of the mechanisms. However, few studies considered the impacts of noise when exploring associations between air pollution and HRV. We explored whether noise modifies associations between short-term exposure to traffic-related air pollution and HRV in young healthy adults. In this randomized, crossover study, 40 young healthy adults stayed for 2 h in a traffic center and, on a separate occasion, in a park. Personal exposure to traffic-related air pollutants and noise were measured and ambulatory electrocardiogram was performed. Effects were estimated using mixed-effects regression models. Traffic-related air pollution and noise were both associated with HRV, and effects of air pollutants were amplified at high noise level (>65.6 A-weighted decibels (dB[A])) compared with low noise level (≤ 65.6 dB[A]). High frequency (HF) decreased by -4.61% (95% confidence interval, -6.75% to-2.42%) per 10 μg/m(3) increment in fine particle (PM2.5) at 5-min moving average, but effects became insignificant at low noise level (P>0.05). Similar effects modification was observed for black carbon (BC) and carbon monoxide (CO). We conclude that noise is an important factor influencing the effects of air pollution on HRV.

  1. Systolic and diastolic short-term blood pressure variability and its determinants in patients with controlled and uncontrolled hypertension: a retrospective cohort study.

    PubMed

    Pengo, Martino F; Rossitto, Giacomo; Bisogni, Valeria; Piazza, Daniele; Frigo, Anna Chiara; Seccia, Teresa Maria; Maiolino, Giuseppe; Rossi, Gian Paolo; Pessina, Achille C; Calò, Lorenzo A

    2015-04-01

    Absolute blood pressure (BP) values are not the only causes of adverse cardiovascular consequences. BP variability (BPV) has also been demonstrated to be a predictor of mortality for cardiovascular events; however, its determinants are still unknown. This study considers 426 subjects with ambulatory BP monitoring (ABPM) measuring 24-h, diurnal and nocturnal absolute BP values and their standard deviations of the mean, along with nocturnal fall, age, sex and current treatment. Patients were divided in two subgroups, controlled and uncontrolled BP, and BPV of patients with "true" and "false" resistant hypertension was also analyzed. Nocturnal and 24-h BPV were higher in the group with uncontrolled hypertension. Multiple regression analysis showed that absolute BP, age, nocturnal fall, but not sex predicted BPV. Patients with "true" resistant hypertension had greater BPV than "false" resistant hypertension patients. Absolute BP resulted as the main determinant of 24-h and nocturnal BPV but not daytime BPV. Also nocturnal BP fall and age resulted as predictors of BPV in treated and untreated patients. Patients with "true" resistant hypertension have a higher BPV, suggesting a higher sympathetic activation. Evidence is still limited regarding the importance of short-term BPV as a prognostic factor and assessment of BPV cannot yet represent a parameter for routine use in clinical practice. Future prospective trials are necessary to define which targets of BPV can be achieved with antihypertensive drugs and whether treatment-induced reduction in BPV is accompanied by a corresponding reduction in cardiovascular events.

  2. Emotional Availability in Mother-Child Dyads: Short-Term Stability and Continuity from Variable-Centered and Person-Centered Perspectives

    ERIC Educational Resources Information Center

    Bornstein, Marc H.; Gini, Motti; Suwalsky, Joan T. D.; Putnick, Diane L.; Haynes, O. Maurice

    2006-01-01

    Emotional availability (EA) is a prominent index of socioemotional adaptation in the parent-child dyad. Can basic psychometric properties of EA be looked at from both variable (scale) and person (cluster) points of view in individuals and in dyads? Is EA stable and continuous over a short period of time? This methodological study shows significant…

  3. Developmental associations between short-term variability and long-term changes: Intraindividual correlation of positive and negative affect in daily life and cognitive aging.

    PubMed

    Hülür, Gizem; Hoppmann, Christiane A; Ram, Nilam; Gerstorf, Denis

    2015-07-01

    Conceptual notions and empirical evidence suggest that the intraindividual correlation (iCorr) of positive affect (PA) and negative affect (NA) is a meaningful characteristic of affective functioning. PA and NA are typically negatively correlated within-person. Previous research has found that the iCorr of PA and NA is relatively stable over time within individuals, that it differs across individuals, and that a less negative iCorr is associated with better resilience and less vulnerability. However, little is known about how the iCorr of PA and NA relates to cognitive aging. This project examined how the association between PA and NA in everyday life is associated with long-term cognitive aging trajectories. To do so, we linked microlongitudinal data on PA and NA obtained on up to 33 occasions over 6 consecutive days with macrolongitudinal data on fluid and crystallized cognitive abilities obtained over 15 years from a subsample of Berlin Aging Study participants (N = 81, mean age at the microlongitudinal study = 81 years, range 73-98; 41% women). Over and above age, gender, education, overall levels of PA and NA, and number of health conditions, a less negative iCorr of PA and NA was associated with lower levels of cognitive ability and steeper cognitive declines, particularly for fluency and knowledge abilities. We discuss possible mechanisms for this finding and argue that a less negative iCorr of PA and NA may be indicative of deficits in emotional integration that are tied to changes in crystallized aspects of cognitive abilities.

  4. Deglacial-Holocene short-term variability in sea-ice distribution on the Eurasian shelf (Arctic Ocean) - An IP25 biomarker reconstruction.

    NASA Astrophysics Data System (ADS)

    Hörner, Tanja; Stein, Ruediger; Fahl, Kirsten

    2016-04-01

    Four well-dated sediment cores from the Eurasian continental shelf, i.e., the Kara Sea (Cores BP99/07 and BP00/07) and Laptev Sea (Cores PS51/154 and PS51/159), were selected for high-resolution reconstruction of past Arctic environmental conditions during the deglacial-Holocene time interval. These marginal seas are strongly affected by the post-glacial sea-level rise of about 120m. The major focus of our study was the reconstruction of the paleo-sea-ice distribution as sea-ice plays a key role within the modern and past climate system. For reconstruction of paleo-sea ice, the sea-ice proxy IP25 in combination with open-water phytoplankton biomarkers was used (for approach see Belt et al., 2007; Müller et al., 2009, 2011). In addition, specific sterols were determined to reconstruct changes in river run-off and biological production. The post-glacial sea-level rise is especially reflected in prominent decrease in terrigenous biomarkers. Deglacial variations in sea-ice cover sustained for thousand of years, mostly following climatic changes like the Bølling/Allerød (14.7-12.9 ka), Younger Dryas (12.9-11.6 ka) and Holocene warm phase (10-8 ka). Superimposed on a (Late) Holocene cooling trend, short-term fluctuations in sea-ice cover (on centennial scale) are distinctly documented in the distal/off-shore Core BP00/07 from the Kara Sea, less pronounced in the proximal/near-shore Core PS99/07 and in the Laptev Sea cores. Interestingly, this short-term variability in sea-ice cover correlates quite well to changes in Siberian river run-off (e.g., Stein et al. 2004), pointing to a direct linkage between precipitation (atmospheric circulation) and sea-ice formation. References Belt, S.T., Massé, G., Rowland, S.J., Poulin, M., Michel, C., LeBlanc, B., 2007. A novel chemical fossil of palaeo sea ice: IP25. Organic Geochemistry 38, 16-27. Müller, J., Masse, G., Stein, R., Belt, S.T., 2009. Variability of sea-ice conditions in the Fram Strait over the past 30,000 years

  5. Information exchange between short term and long term operations

    NASA Astrophysics Data System (ADS)

    Weijs, Steven

    2016-04-01

    This research focuses on the interactions between optimal short term and long term operations of managed water systems. Stochastic Dynamic Programming is used as a framework to find and analyze optimal operations. When considering optimal operations under uncertainty, the short term operations are influenced by the long term optimal policy through the value function of the end-state at the short term horizon. Conversely, the optimal long-term operations are influenced by the value of future decisions, which is partly determined by the short term operations. This leads to a two-way information flow between short and long term operations. The implications of this information flow are discussed.

  6. Short-term variability of suspended sediment and phytoplankton in Tampa Bay, Florida: Observations from a coastal oceanographic tower and ocean color satellites

    NASA Astrophysics Data System (ADS)

    Chen, Zhiqiang; Hu, Chuanmin; Muller-Karger, Frank E.; Luther, Mark E.

    2010-09-01

    We examined short-term phytoplankton and sediment dynamics in Tampa Bay with data collected between 8 December 2004 and 17 January 2005 from optical, oceanographic, and meteorological sensors mounted on a coastal oceanographic tower and from satellite remote sensing. Baseline phytoplankton (chlorophyll- a, Chl) and sediment concentrations (particle backscattering coefficient at 532 nm, bbp(532)) were of the order of 3.7 mg m -3 and 0.07 m -1, respectively, during the study period. Both showed large fluctuations dominated by semidiurnal and diurnal frequencies associated with tidal forcing. Three strong wind events (hourly averaged wind speed >8.0 m s -1) generated critical bottom shear stress of >0.2 Pa and suspended bottom sediments that were clearly observed in concurrent MODIS satellite imagery. In addition, strong tidal current or swells could also suspend sediments in the lower Bay. Sediments remained suspended in the water column for 2-3 days after the wind events. Moderate Chl increases were observed after sediment resuspension with a lag time of ˜1-2 days, probably due to release of bottom nutrients and optimal light conditions associated with sediment resuspension and settling. Two large increases in Chl with one Chl > 12.0 mg m -3 over ˜2 days, were observed at neap tides. For the study site and period, because of the high temporal variability in phytoplankton and sediment concentrations, a monthly snapshot can be different by -50% to 200% from the monthly "mean" chlorophyll and sediment conditions. The combination of high-frequency observations from automated sensors and synoptic satellite imagery, when available, is an excellent complement to limited field surveys to study and monitor water quality parameters in estuarine environments.

  7. Long short-term memory.

    PubMed

    Hochreiter, S; Schmidhuber, J

    1997-11-15

    Learning to store information over extended time intervals by recurrent backpropagation takes a very long time, mostly because of insufficient, decaying error backflow. We briefly review Hochreiter's (1991) analysis of this problem, then address it by introducing a novel, efficient, gradient-based method called long short-term memory (LSTM). Truncating the gradient where this does not do harm, LSTM can learn to bridge minimal time lags in excess of 1000 discrete-time steps by enforcing constant error flow through constant error carousels within special units. Multiplicative gate units learn to open and close access to the constant error flow. LSTM is local in space and time; its computational complexity per time step and weight is O(1). Our experiments with artificial data involve local, distributed, real-valued, and noisy pattern representations. In comparisons with real-time recurrent learning, back propagation through time, recurrent cascade correlation, Elman nets, and neural sequence chunking, LSTM leads to many more successful runs, and learns much faster. LSTM also solves complex, artificial long-time-lag tasks that have never been solved by previous recurrent network algorithms.

  8. Onboard Short Term Plan Viewer

    NASA Technical Reports Server (NTRS)

    Hall, Tim; LeBlanc, Troy; Ulman, Brian; McDonald, Aaron; Gramm, Paul; Chang, Li-Min; Keerthi, Suman; Kivlovitz, Dov; Hadlock, Jason

    2011-01-01

    Onboard Short Term Plan Viewer (OSTPV) is a computer program for electronic display of mission plans and timelines, both aboard the International Space Station (ISS) and in ISS ground control stations located in several countries. OSTPV was specifically designed both (1) for use within the limited ISS computing environment and (2) to be compatible with computers used in ground control stations. OSTPV supplants a prior system in which, aboard the ISS, timelines were printed on paper and incorporated into files that also contained other paper documents. Hence, the introduction of OSTPV has both reduced the consumption of resources and saved time in updating plans and timelines. OSTPV accepts, as input, the mission timeline output of a legacy, print-oriented, UNIX-based program called "Consolidated Planning System" and converts the timeline information for display in an interactive, dynamic, Windows Web-based graphical user interface that is used by both the ISS crew and ground control teams in real time. OSTPV enables the ISS crew to electronically indicate execution of timeline steps, launch electronic procedures, and efficiently report to ground control teams on the statuses of ISS activities, all by use of laptop computers aboard the ISS.

  9. Long-term trends and short-term variability of water quality in Skive Fjord, Denmark - nutrient load and mussels are the primary pressures and drivers that influence water quality.

    PubMed

    Møhlenberg, F; Petersen, S; Petersen, A H; Gameiro, C

    2007-04-01

    Nineteen years of monitoring data from the eutrophic Skive Fjord, Denmark were examined for linkages to external pressures and drivers, including nutrient inputs, meteorology and stocks of blue mussels. Linkages were examined by: 1) time-series analysis to document effects of nutrient reduction programs, 2) Pearson Rank correlations, 3) multivariate statistical analysis (PLS) to identify water quality variables with high predictability and their linkages to pressures, and 4) regression analysis to quantify relationships between pressures and water quality. Freshwater input, nitrogen load and phosphorus load showed decreasing trends through the period 1984-2002. The load reductions were only partially translated into trends in water quality: phosphorus decreased in most seasons, while total nitrogen decreased during winter and spring only. Phosphorus concentration had the highest predictability (explained by seasonal temperature variation) followed by transparency, silicate, tot-N, chlorophyll-a, primary productivity, phytoplankton diversity and phytoplankton turnover. The variation in pressures other than nutrient input confounded the relations between loads and water quality. High biomass of mussels led to reduced chlorophyll-a and increased transparency, while short-term variability in water column mixing led to changes in chlorophyll-a due to nutrient entrainment and coupling to benthic mussels.

  10. Short-term intercultural psychotherapy: ethnographic inquiry.

    PubMed

    Seeley, Karen M

    2004-01-01

    This article examines the challenges specific to short-term intercultural treatments and recently developed approaches to intercultural treatments based on notions of cultural knowledge and cultural competence. The article introduces alternative approaches to short-term intercultural treatments based on ethnographic inquiry adapted for clinical practice. Such approaches allow clinicians conducting short-term intercultural treatments to foreground clients' indigenous conceptions of selfhood, mind, relationship, and emotional disturbance, and thus to more fully grasp their internal, interpersonal, and external worlds. This article demonstrates the uses of clinically adapted ethnographic inquiry in three short-term intercultural cases. PMID:14964524

  11. Short-term Variability of Physical and Chemical Parameters in Suboxic/Anoxic Bottom Waters of the Chesapeake Bay During Late July 2002.

    NASA Astrophysics Data System (ADS)

    Montbriand, P. J.; Lewis, B. L.; Luther, G. W.; Glazer, B. T.; Ma, S.; Reedy, S.; Nuzzio, D. B.; Spencer, T.; Theberge, S.

    2002-12-01

    concentrations of ~40-70 μM (7-12 m depth), and 0.1-0.3 μM nitrite was observed in the surface layer. In the bottom waters, nitrite increased over the sampling period from 0 to about 0.07 μM. The data imply two sources of nitrite, ammonification/nitrification in the oxygenated waters and denitrification in the deep waters. Dissolved Mn increased below 12-14 meters, coincident with oxygen concentrations < 20 μM. Concentrations in the deep waters varied widely, from ~ 0.2 to 7 μM. Dissolved Fe(II) was detected only at oxygen levels < 5 μM, with concentrations in the deep waters ranging from ~ 0.2 to 1.4 μM. Plotting the chemical data versus salinity rather than depth decreases the scatter due to tidal variation and displays a clear separation between the onset of Mn and Fe reduction. This study illustrates the dynamic, rapidly changing nature of water-column anoxia in the Chesapeake Bay. The depth of oxygen penetration, the thickness of the suboxic zone and the concentration of sulfide in the deep waters fluctuate in response to tidal oscillations and to the passage of storm events. Real-time measurements are necessary to document these short-term variations.

  12. Short-term energy outlook, January 1999

    SciTech Connect

    1999-01-01

    The Energy Information Administration (EIA) prepares the Short-Term Energy Outlook (energy supply, demand, and price projections) monthly. The forecast period for this issue of the Outlook extends from January 1999 through December 2000. Data values for the fourth quarter 1998, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in EIA`s Weekly Petroleum Status Report) or are calculated from model simulations that use the latest exogenous information available (for example, electricity sales and generation are simulated by using actual weather data). The historical energy data, compiled in the January 1999 version of the Short-Term Integrated Forecasting System (STIFS) database, are mostly EIA data regularly published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding. The STIFS model is driven principally by three sets of assumptions or inputs: estimates of key macroeconomic variables, world oil price assumptions, and assumptions about the severity of weather. Macroeconomic estimates are produced by DRI/McGraw-Hill but are adjusted by EIA to reflect EIA assumptions about the world price of crude oil, energy product prices, and other assumptions which may affect the macroeconomic outlook. By varying the assumptions, alternative cases are produced by using the STIFS model. 28 figs., 19 tabs.

  13. Short Term Exogenic Climate Change Forcing

    NASA Astrophysics Data System (ADS)

    Krahenbuhl, Daniel

    Several short term exogenic forcings affecting Earth's climate are but recently identified. Lunar nutation periodicity has implications for numerical meteorological prediction. Abrupt shifts in solar wind bulk velocity, particle density, and polarity exhibit correlation with terrestrial hemispheric vorticity changes, cyclonic strengthening and the intensification of baroclinic disturbances. Galactic Cosmic ray induced tropospheric ionization modifies cloud microphysics, and modulates the global electric circuit. This dissertation is constructed around three research questions: (1): What are the biweekly declination effects of lunar gravitation upon the troposphere? (2): How do United States severe weather reports correlate with heliospheric current sheet crossings? and (3): How does cloud cover spatially and temporally vary with galactic cosmic rays? Study 1 findings show spatial consistency concerning lunar declination extremes upon Rossby longwaves. Due to the influence of Rossby longwaves on synoptic scale circulation, our results could theoretically extend numerical meteorological forecasting. Study 2 results indicate a preference for violent tornadoes to occur prior to a HCS crossing. Violent tornadoes (EF3+) are 10% more probable to occur near, and 4% less probable immediately after a HCS crossing. The distribution of hail and damaging wind reports do not mirror this pattern. Polarity is critical for the effect. Study 3 results confirm anticorrelation between solar flux and low-level marine-layer cloud cover, but indicate substantial regional variability between cloud cover altitude and GCRs. Ultimately, this dissertation serves to extend short term meteorological forecasting, enhance climatological modeling and through analysis of severe violent weather and heliospheric events, protect property and save lives.

  14. Short-Term Intercultural Psychotherapy: Ethnographic Inquiry

    ERIC Educational Resources Information Center

    Seeley, Karen M.

    2004-01-01

    This article examines the challenges specific to short-term intercultural treatments and recently developed approaches to intercultural treatments based on notions of cultural knowledge and cultural competence. The article introduces alternative approaches to short-term intercultural treatments based on ethnographic inquiry adapted for clinical…

  15. Short-Term Effects of Climatic Variables on Hand, Foot, and Mouth Disease in Mainland China, 2008–2013: A Multilevel Spatial Poisson Regression Model Accounting for Overdispersion

    PubMed Central

    Yang, Fang; Yang, Min; Hu, Yuehua; Zhang, Juying

    2016-01-01

    Background Hand, Foot, and Mouth Disease (HFMD) is a worldwide infectious disease. In China, many provinces have reported HFMD cases, especially the south and southwest provinces. Many studies have found a strong association between the incidence of HFMD and climatic factors such as temperature, rainfall, and relative humidity. However, few studies have analyzed cluster effects between various geographical units. Methods The nonlinear relationships and lag effects between weekly HFMD cases and climatic variables were estimated for the period of 2008–2013 using a polynomial distributed lag model. The extra-Poisson multilevel spatial polynomial model was used to model the exact relationship between weekly HFMD incidence and climatic variables after considering cluster effects, provincial correlated structure of HFMD incidence and overdispersion. The smoothing spline methods were used to detect threshold effects between climatic factors and HFMD incidence. Results The HFMD incidence spatial heterogeneity distributed among provinces, and the scale measurement of overdispersion was 548.077. After controlling for long-term trends, spatial heterogeneity and overdispersion, temperature was highly associated with HFMD incidence. Weekly average temperature and weekly temperature difference approximate inverse “V” shape and “V” shape relationships associated with HFMD incidence. The lag effects for weekly average temperature and weekly temperature difference were 3 weeks and 2 weeks. High spatial correlated HFMD incidence were detected in northern, central and southern province. Temperature can be used to explain most of variation of HFMD incidence in southern and northeastern provinces. After adjustment for temperature, eastern and Northern provinces still had high variation HFMD incidence. Conclusion We found a relatively strong association between weekly HFMD incidence and weekly average temperature. The association between the HFMD incidence and climatic

  16. Analyzing Short-Term Disability Benefits.

    ERIC Educational Resources Information Center

    Houff, James N.; Wiatrowski, William J.

    1989-01-01

    The Bureau of Labour Statistics has combined data on sick leave and sickness and accident insurance. Results show that short-term disability benefits vary by length of service and between the private and public sectors. (Author)

  17. Short-term energy outlook, April 1999

    SciTech Connect

    1999-04-01

    The forecast period for this issue of the Outlook extends from April 1999 through December 2000. Data values for the first quarter 1999, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in EIA`s Weekly Petroleum Status Report) or are calculated from model simulations that use the latest exogenous information available (for example, electricity sales and generation are simulated by using actual weather data). The historical energy data, compiled in the April 1999 version of the Short-Term Integrated forecasting system (STIFS) database, are mostly EIA data regularly published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding. The STIFS model is driven principally by three sets of assumptions or inputs: estimates of key macroeconomic variables, world oil price assumptions, and assumptions about the severity of weather. Macroeconomic estimates are produced by DRI/McGraw-Hill but are adjusted by EIA to reflect EIA assumptions about the world price of crude oil, energy product prices, and other assumptions which may affect the macroeconomic outlook. By varying the assumptions, alternative cases are produced by using the STIFS model. 25 figs., 19 tabs.

  18. Short-term municipal water demand forecasting

    NASA Astrophysics Data System (ADS)

    Bougadis, John; Adamowski, Kaz; Diduch, Roman

    2005-01-01

    Water demand forecasts are needed for the design, operation and management of urban water supply systems. In this study, the relative performance of regression, time series analysis and artificial neural network (ANN) models are investigated for short-term peak water demand forecasting. The significance of climatic variables (rainfall and maximum air temperature, in addition to past water demand) on water demand management is also investigated.Numerical analysis was performed on data from the city of Ottawa, Ontario, Canada. The existing water supply infrastructure will not be able to meet the demand for projected population growth; thus, a study is needed to determine the effect of peak water demand management on the sizing and staging of facilities for developing an expansion strategy. Three different ANNs and regression models and seven time-series models have been developed and compared. The ANN models consistently outperformed the regression and time-series models developed in this study. It has been found that water demand on a weekly basis is more significantly correlated with the rainfall amount than the occurrence of rainfall. Copyright

  19. Short-term memory across eye blinks.

    PubMed

    Irwin, David E

    2014-01-01

    The effect of eye blinks on short-term memory was examined in two experiments. On each trial, participants viewed an initial display of coloured, oriented lines, then after a retention interval they viewed a test display that was either identical or different by one feature. Participants kept their eyes open throughout the retention interval on some blocks of trials, whereas on others they made a single eye blink. Accuracy was measured as a function of the number of items in the display to determine the capacity of short-term memory on blink and no-blink trials. In separate blocks of trials participants were instructed to remember colour only, orientation only, or both colour and orientation. Eye blinks reduced short-term memory capacity by approximately 0.6-0.8 items for both feature and conjunction stimuli. A third, control, experiment showed that a button press during the retention interval had no effect on short-term memory capacity, indicating that the effect of an eye blink was not due to general motoric dual-task interference. Eye blinks might instead reduce short-term memory capacity by interfering with attention-based rehearsal processes.

  20. Short-term energy outlook: Methodology

    NASA Astrophysics Data System (ADS)

    Cornett, C.; Paxson, D.; Reznek, A. P.; Chu, C.; Sitzer, S.; Gamson, N.; Childress, J. P.; Paul, S.; Weigel, H.; Sutton, S.

    1981-05-01

    Detailed discussions of forecasting methodology and analytical topics concerning short-term energy markets are presented. Major assumptions necessary to make the energy forecasts are also discussed. Supplementary analyses of topics related to short-term energy forecasting are also given. The discussions relate to the forecasts prepared using the short term integrated forecasting system. This set of computer models uses data from various sources to develop energy supply and demand balances. Econmetric models used to predict the demand for petroleum products, natural gas, coal, and electricity are discussed. Price prediction models are also discussed. The role of oil inventories in world oil markets is reviewed. Various relationship between weather patterns and energy consumption are discussed.

  1. Short and long term flux variability of the BL Lacertae object 1ES 2200+420, in the MeV - GeV range

    NASA Astrophysics Data System (ADS)

    Herath, Mahesh; Abeysekara, Anushka; Jayaratne, Chandana

    2016-03-01

    Blazars are a class of Active Galactic Nuclei (AGN) that exhibit variable flux states across the electromagnetic spectrum, from radio to TeV. Current measurements show that the MeV-GeV flux of a Blazar could have a variability time scale as small as few hours or as long as several months. In this talk I will report the MeV-GeV flux variability patterns of the BL Lacertae object (1ES 2200+420). The data has been obtained from the Fermi-LAT archival database, and analysed using the recently released Pass 8 Fermi Science Tools. The cross correlations between MeV-GeV flux and KeV flux observed by Swift-XRT will also be reported, which is an important measurement to constraint the Synchrotron models.

  2. Relationship between short- and long-term memory and short- and long-term extinction.

    PubMed

    Cammarota, Martín; Bevilaqua, Lia R M; Rossato, Janine I; Ramirez, Maria; Medina, Jorge H; Izquierdo, Iván

    2005-07-01

    Both the acquisition and the extinction of memories leave short- and long-term mnemonic traces. Here, we show that in male Wistar rats, the short-term memory for a step-down inhibitory avoidance task (IA) is resistant to extinction, and that its expression does not influence retrieval or extinction of long-term memory. It has been known for some time that short- and long-term inhibitory avoidance memory involve separate and parallel processes. Here we show that, instead, short-term extinction of IA long-term memory is the first step towards its long-term extinction, and that this link requires functional NMDA receptors and protein synthesis in the CA1 region of the dorsal hippocampus at the time of the first CS-no US presentation.

  3. Short-Term Play Therapy for Children.

    ERIC Educational Resources Information Center

    Kaduson, Heidi Gerard, Ed.; Schaefer, Charles E., Ed.

    Play therapy offers a powerful means of helping children resolve a wide range of psychological difficulties, and many play approaches are ideally suited to short-term work. This book brings together leading play therapists to share their expertise on facilitating children's healing in a shorter time frame. The book provides knowledge and skills…

  4. Metropolitan French: Familiarization & Short-Term Training.

    ERIC Educational Resources Information Center

    Iszkowski, Marie-Charlotte

    The U.S. Department of State's Foreign Service Institute French Familiarization and Short-Term (FAST) course for personnel working and living in France consists of 10 weeks of French language instruction combined with practical and cultural information. An introductory section outlines FAST course objectives and sample teaching techniques in…

  5. Short term memory for tactile stimuli.

    PubMed

    Gallace, Alberto; Tan, Hong Z; Haggard, Patrick; Spence, Charles

    2008-01-23

    Research has shown that unreported information stored in rapidly decaying visual representations may be accessed more accurately using partial report than using full report procedures (e.g., [Sperling, G., 1960. The information available in brief visual presentations. Psychological Monographs, 74, 1-29.]). In the 3 experiments reported here, we investigated whether unreported information regarding the actual number of tactile stimuli presented in parallel across the body surface can be accessed using a partial report procedure. In Experiment 1, participants had to report the total number of stimuli in a tactile display composed of up to 6 stimuli presented across their body (numerosity task), or else to detect whether or not a tactile stimulus had previously been presented in a position indicated by a visual probe given at a variable delay after offset of a tactile display (i.e., partial report). The results showed that participants correctly reported up to 3 stimuli in the numerosity judgment task, but their performance was significantly better than chance when up to 5 stimuli were presented in the partial report task. This result shows that short-lasting tactile representations can be accessed using partial report procedures similar to those used previously in visual studies. Experiment 2 showed that the duration of these representations (or the time available to consciously access them) depends on the number of stimuli presented in the display (the greater the number of stimuli that are presented, the faster their representation decays). Finally, the results of a third experiment showed that the differences in performance between the numerosity judgment and partial report tasks could not be explained solely in terms of any difference in task difficulty. PMID:18083147

  6. Quantifying decadal-scale erosion rates and their short-term variability on ecological sites in a semi-arid environment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion rates on six semi-arid loamy upland rangeland sites located in southeastern Arizona were measured using a rainfall simulator and 137Cs fallout methods. Site characteristics that have the greatest effects on soil erosion and runoff were identified. Long term (50 years) soil erosion rates...

  7. Short-term climate prediction for South-Western Siberia, based on comparison of reconstructed annual temperature variability between recent 430 yrs interval and Roman era warming

    NASA Astrophysics Data System (ADS)

    Kalugin, I.; Daryin, A.; Babich, V.; Myglan, V.; Ovchinikov, D.

    2009-04-01

    The new microstratigraphic and chronological approaches became available for research of sediment records in situ due to automated high resolution analytical technique for the last 10 years. It provides to obtain continuous series of several physical and chemical parameters along the fresh opened core and in solid preparates as well. Scanning X-ray fluorescence analysis on synchrotron radiation (SR-XRFA) as a high-efficiency method of microelement analysis is adapted to determine more than 35 elements with minimal step 0.1 mm. So it allows revealing intraannual variability of parameters as well as annual- multiannual changes after smoothing. Teletskoye Lake sediments are studied for the inference of a robust record of climatically driven solid detrital supply from the catchment, because there is no industry and agriculture in this almost non populated area. Sedimentation is rather continuous here because annual clastic supply and deposited mass are the same. The Teletskoye Lake (51°39'N, 87°40'E, 434 m a.s.l.,) is a tectonic lake in the northern part of the Altai Mountains. It has a length of 78 km, a width of 3-5 km and an average depth of 174 m and has a dimictic mixing regime. The combination of extracting sub millimeter resolution SR-XRFA data, isotope Cs-Pb-C age models, and regression based calibration methods were used to reconstruct past environmental changes for the last 3100 yrs beyond instrumental and tree ring limits. Geochemical parameters used as environmental proxies were following. Br content appeared to be broadly correlative with mean annual temperature variations because of changes of vegetation productivity in catchment. Sr/Rb ratio and Ti content reflected the proportion of the unweathered terrestrial fraction. X-ray density (XRD) appeared to reflect water yield regime and sediment flux. Multiple regression analysis was applied on normalized values in order to obtain the environmental reconstruction. Calibration was conducted with Barnaul

  8. Short-term variability of 7Be atmospheric deposition and watershed response in a Pacific coastal stream, Monterey Bay, California, USA

    USGS Publications Warehouse

    Conaway, Christopher H.; Storlazzi, Curt D.; Draut, Amy E.; Swarzenski, Peter W.

    2013-01-01

    Beryllium-7 is a powerful and commonly used tracer for environmental processes such as watershed sediment provenance, soil erosion, fluvial and nearshore sediment cycling, and atmospheric fallout. However, few studies have quantified temporal or spatial variability of 7Be accumulation from atmospheric fallout, and parameters that would better define the uses and limitations of this geochemical tracer. We investigated the abundance and variability of 7Be in atmospheric deposition in both rain events and dry periods, and in stream surface-water samples collected over a ten-month interval at sites near northern Monterey Bay (37°N, 122°W) on the central California coast, a region characterized by a rainy winters, dry summers, and small mountainous streams with flashy hydrology. The range of 7Be activity in rainwater samples from the main sampling site was 1.3–4.4 Bq L−1, with a mean (±standard deviation) of 2.2 ± 0.9 Bq L−1, and a volume-weighted average of 2.0 Bq L−1. The range of wet atmospheric deposition was 18–188 Bq m−2 per rain event, with a mean of 72 ± 53 Bq m−2. Dry deposition fluxes of 7Be ranged from less than 0.01 up to 0.45 Bq m−2 d−1, with an estimated dry season deposition of 7 Bq m−2 month−1. Annualized 7Be atmospheric deposition was approximately 1900 Bq m−2 yr−1, with most deposition via rainwater (>95%) and little via dry deposition. Overall, these activities and deposition fluxes are similar to values found in other coastal locations with comparable latitude and Mediterranean-type climate. Particulate 7Be values in the surface water of the San Lorenzo River in Santa Cruz, California, ranged from −1 to 0.6 Bq g−1, with a median activity of 0.26 Bq g−1. A large storm event in January 2010 characterized by prolonged flooding resulted in the entrainment of 7Be-depleted sediment, presumably from substantial erosion in the watershed. There were too few particulate 7Be data over the storm to accurately model a 7Be load

  9. Short-term and seasonal pH,pCO2and saturation state variability in a coral-reef ecosystem

    NASA Astrophysics Data System (ADS)

    Gray, Sarah E. C.; Degrandpre, Michael D.; Langdon, Chris; Corredor, Jorge E.

    2012-09-01

    Coral reefs are predicted to be one of the ecosystems most sensitive to ocean acidification. To improve predictions of coral reef response to acidification, we need to better characterize the natural range of variability of pH, partial pressure of carbon dioxide (pCO2) and calcium carbonate saturation states (Ω). In this study, autonomous sensors for pH and pCO2 were deployed on Media Luna reef, Puerto Rico over three seasons from 2007 to 2008. High temporal resolution CaCO3 saturation states were calculated from the in situ data, giving a much more detailed characterization of reef saturation states than previously possible. Reef pH, pCO2 and aragonite saturation (ΩAr) ranged from 7.89 to 8.17 pH units, 176-613 μatm and 2.7-4.7, respectively, in the range characteristic of most other previously studied reef ecosystems. The diel pH, pCO2 and Ω cycles were also large, encompassing about half of the seasonal range of variability. Warming explained about 50% of the seasonal supersaturation in mean pCO2, with the remaining supersaturation primarily due to net heterotrophy and net CaCO3 production. Net heterotrophy was likely driven by remineralization of mangrove derived organic carbon which continued into the fall, sustaining high pCO2 levels until early winter when the pCO2 returned to offshore values. As a consequence, the reef was a source of CO2 to the atmosphere during the summer and fall and a sink during winter, resulting in a net annual source of 0.73 ± 1.7 mol m-2 year-1. These results show that reefs are exposed to a wide range of saturation states in their natural environment. Mean ΩAr levels will drop to 3.0 when atmospheric CO2 increases to 500 μatm and ΩAr will be less than 3.0 for greater than 70% of the time in the summer. Long duration exposure to these low ΩAr levels are expected to significantly decrease calcification rates on the reef.

  10. Glycemic Variability Assessed by Continuous Glucose Monitoring and Short-Term Outcome in Diabetic Patients Undergoing Percutaneous Coronary Intervention: An Observational Pilot Study.

    PubMed

    Nusca, Annunziata; Lauria Pantano, Angelo; Melfi, Rosetta; Proscia, Claudio; Maddaloni, Ernesto; Contuzzi, Rocco; Mangiacapra, Fabio; Palermo, Andrea; Manfrini, Silvia; Pozzilli, Paolo; Di Sciascio, Germano

    2015-01-01

    Poor glycemic control is associated with unfavorable outcome in patients undergoing percutaneous coronary intervention (PCI), irrespective of diabetes mellitus. However a complete assessment of glycemic status may not be fully described by glycated hemoglobin or fasting blood glucose levels, whereas daily glycemic fluctuations may influence cardiovascular risk and have even more deleterious effects than sustained hyperglycemia. Thus, this paper investigated the effectiveness of a continuous glucose monitoring (CGM), registering the mean level of glycemic values but also the extent of glucose excursions during coronary revascularization, in detecting periprocedural outcome such as renal or myocardial damage, assessed by serum creatinine, neutrophil gelatinase-associated lipocalin (NGAL), and troponin I levels. High glycemic variability (GV) has been associated with worse postprocedural creatinine and NGAL variations. Moreover, GV, and predominantly hypoglycemic variations, has been observed to increase in patients with periprocedural myocardial infarction. Thus, our study investigated the usefulness of CGM in the setting of PCI where an optimal glycemic control should be achieved in order to prevent complications and improve outcome. PMID:26273664

  11. Status of NASA Satellite, Field Observations, and Numerical Modeling Addressing the Impact of Urbanization on Short and Long Term Precipitation Variability

    NASA Technical Reports Server (NTRS)

    Shepherd, J. Marshall; Manyin, Michael; Burian, Steve; Garza, Carlos

    2004-01-01

    Howard (1833a) made the first documented observation of a temperature difference between an urban area and its rural environment. Manley (1958) termed this contrast the "urban heat island (UHI)". The UHI has now become a widely acknowledged, observed, and researched phenomenon because of its broad implications. It is estimated that by the year 2025, 60% of the world's population will live in cities (UNFP, 1999). In the United States, the current urban growth rate is approximately 12.5%, with 80% currently living in urban areas. As cities continue to grow, urban sprawl creates unique problems related to land use, transportation, agriculture, housing, pollution, and development for policymakers. Urban expansion and its associated urban heat islands also have measurable impacts on weather and climate processes.

  12. Model documentation report: Short-Term Hydroelectric Generation Model

    SciTech Connect

    Not Available

    1993-08-01

    The purpose of this report is to define the objectives of the Short- Term Hydroelectric Generation Model (STHGM), describe its basic approach, and to provide details on the model structure. This report is intended as a reference document for model analysts, users, and the general public. Documentation of the model is in accordance with the Energy Information Administration`s (AYE) legal obligation to provide adequate documentation in support of its models (Public Law 94-385, Section 57.b.2). The STHGM performs a short-term (18 to 27- month) forecast of hydroelectric generation in the United States using an autoregressive integrated moving average (UREMIA) time series model with precipitation as an explanatory variable. The model results are used as input for the short-term Energy Outlook.

  13. Response of planktonic cladocerans (Class: Branchiopoda) to short-term changes in environmental variables in the surface waters of the Bay of Biscay

    NASA Astrophysics Data System (ADS)

    d'Elbée, Jean; Lalanne, Yann; Castège, Iker; Bru, Noelle; D'Amico, Frank

    2014-08-01

    From January 2001 to December 2008, 73 surface plankton samples and 45 vertical profiles of sea temperature, salinity, dissolved oxygen and pH were collected on a monthly basis from a single sampling station located in the Bay of Biscay (43°37N; 1°43W) (North-East Atlantic). Two types of North Atlantic Oscillation (NAO) indexes were included in the data set and submitted to a Canonical Correspondence Analysis and Spearman non-parametric test. Significant breaks and levels in time series were tested using a data segmentation method. The temperature range varies from 11 °C to 25 °C. It begins to rise from April until August and then decline. Low salinity values occur in mid-spring (<34 PSU) and high values (>36 PSU) in autumn. Dissolved oxygen mean values were around 8 mg/l. In summer, when temperature and salinity are high, surface water layer is always accompanied with a significant deoxygenation, and the process reverses in winter. pH mean values range was 7.78-8.33. Seasonal and inter-annual variations of the two NAO indexes are strongly correlated to one another, but do not correlate with any hydrological or biological variable. Five of the seven cladocerans species which are present in the Bay of Biscay were found in this study. There is a strong pattern in species succession throughout the year: Evadne nordmanni is a vernal species, while Penilia avirostris and Pseudevadne tergestina occur mainly in summer and autumn. Evadne spinifera has a maximum abundance in spring, Podon intermedius in autumn, but they both occur throughout the year. However, for some thirty years, the presence of species has tended to become significantly extended throughout the year. During the 2001-2008 period, there was a noticeable decline and even a disappearance of the categories involved in sexual reproduction as well as those involved in parthenogenesis, in favor of non-breeding individuals.

  14. Decreased aEEG continuity and baseline variability in the first 48 hours of life associated with poor short-term outcome in neonates born before 29 weeks gestation.

    PubMed

    Bowen, Jennifer R; Paradisis, Mary; Shah, Dharmesh

    2010-05-01

    Amplitude-integrated electroencephalography (aEEG) provides us with a method of assessing brain activity in critically ill neonates. In extremely premature neonates, the aEEG trace is predominantly discontinuous, making it difficult to distinguish between a "normal" and "abnormal" trace. We measured aEEG activity in the first 48 h of life in neonates born before 29-wk gestation and used both visual and quantitative analysis of the aEEG data to assess differences in neonates with poor short-term outcome [death or peri/intraventricular hemorrhage (P/IVH)] compared with those who survived without P/IVH to identify features of an abnormal aEEG. On quantitative analysis, EEG continuity <80% at 10-microV level was a sensitive and specific marker of poor short-term outcome. By using this marker, we identified 83% of neonates who died or developed grade 3 or 4 IVH and 60% of neonates who developed grades 1 or 2 IVH, with a positive predictive value for death or any IVH of 73% and a negative predictive value of 86%. Absence of sleep-wake cycling with baseline variability <2 microV was the strongest predictor of outcome using visual analysis alone. PMID:20098343

  15. The economics of short-term leasing.

    PubMed

    Flath, D

    1980-04-01

    Short-term leasing is an everyday occurrence. Tax savings cannot account for the ubiquity of leasing by temporary users. Monopoly explanations are inconsistent with concurrent leasing and selling markets for perfect substitutes. Leasing economizes upon the costs of detecting, assuring, and maintaining quality, costs of search, and costs of risk-bearing. This view is based on standard economic reasoning and has numerous specific implications.

  16. Self-Organized Short-Term Memories

    NASA Astrophysics Data System (ADS)

    Coppersmith, S. N.; Jones, T. C.; Kadanoff, L. P.; Levine, A.; McCarten, J. P.; Nagel, S. R.; Venkataramani, S. C.; Wu, Xinlei

    1997-05-01

    We report short-term memory formation in a nonlinear dynamical system with many degrees of freedom. The system ``remembers'' a sequence of impulses for a transient period, but it coarsens and eventually ``forgets'' nearly all of them. The memory duration increases as the number of degrees of freedom in the system increases. We demonstrate the existence of these transient memories in a laboratory experiment.

  17. In situ nitrate measurements capture short-term variability and seasonal transitions during a drought - flood year in the Mississippi River Basin

    NASA Astrophysics Data System (ADS)

    Pellerin, B. A.; Bergamaschi, B. A.; Saraceno, J.; Downing, B. D.; Crawford, C.; Gilliom, R.; Frederick, P.

    2013-12-01

    Nitrogen flux from the Mississippi River to the Gulf of Mexico has received considerable attention because it fuels primary production on the continental shelf and can contribute to the summer hypoxia observed in the Gulf. Accurately quantifying the load of nitrogen - particularly as nitrate - to the Gulf is critical for both predicting the size of the oxygen-depleted dead zone and establishing targets for N load reduction from the basin. Fluxes have been historically calculated with load estimation models using 5-10 years of discrete nitrate data collected approximately 12-18 times per year. These traditional monthly to biweekly sampling intervals often fail to adequately capture hydrologic pulses ranging from early snowmelt periods to short-duration rainfall events in small streams, but the ability to adequately resolve patterns in water quality in large rivers has received much less attention. The recent commercial availability of in situ optical sensors for nitrate, together with new techniques for data collection and analysis, provides an opportunity to measure nitrate concentration on time scales in which environmental conditions actually change. Data have been collected and analyzed from a USGS optical nitrate sensor deployed in the Mississippi River at Baton Rouge, Louisiana, since November 2011. Our nitrate data, collected at three hour intervals, shows a strong relationship to depth- and width-integrated discrete nitrate concentrations measured on 20 dates (r2=0.99, slope=1) after correcting for a consistent, small positive bias (0.10 mg/L). The close relationship between the in situ data measured on edge of the channel and the depth- and width-integrated sample suggests that the fixed sensor measurements provide a robust proxy for cross-sectional averaged nitrate concentrations at Baton Rouge under a range of flow conditions. Nitrate concentrations ranged from a low of 0.19 mg/L as N on September 11, 2012 to a high of 3.09 mg/L as N on July 12, 2013

  18. Is visual short-term memory depthful?

    PubMed

    Reeves, Adam; Lei, Quan

    2014-03-01

    Does visual short-term memory (VSTM) depend on depth, as it might be if information was stored in more than one depth layer? Depth is critical in natural viewing and might be expected to affect retention, but whether this is so is currently unknown. Cued partial reports of letter arrays (Sperling, 1960) were measured up to 700 ms after display termination. Adding stereoscopic depth hardly affected VSTM capacity or decay inferred from total errors. The pattern of transposition errors (letters reported from an uncued row) was almost independent of depth and cue delay. We conclude that VSTM is effectively two-dimensional. PMID:24491386

  19. Short-term electric load forecasting using neural networks

    SciTech Connect

    Daugherty, E.; Bartlett, E.

    1993-12-31

    Short-term electric load forecasting (STELF) plays an important role in electric utilities, and several techniques are used to perform these predictions and system modelings. Recently, artificial neural networks (ANN`s) have been implemented for STELF with some success. This paper will examine improved STELF by optimization of ANN techniques. The strategy for the research involves careful selection of input variables and utilization of effective generalization. Some results have been obtained which show that, with the selection of another input variable, the ANN`s use for STELF can be improved.

  20. Short-term energy outlook, July 1998

    SciTech Connect

    1998-07-01

    The Energy Information Administration (EIA) prepares The Short-Term Energy Outlook (energy supply, demand, and price projections) monthly for distribution on the internet at: www.eia.doe.gov/emeu/steo/pub/contents.html. In addition, printed versions of the report are available to subscribers in January, April, July and October. The forecast period for this issue of the Outlook extends from July 1998 through December 1999. Values for second quarter of 1998 data, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in EIA`s Weekly Petroleum Status Report) or are calculated from model simulations that use the latest exogenous information available (for example, electricity sales and generation are simulated by using actual weather data). The historical energy data, compiled in the July 1998 version of the Short-Term Integrated Forecasting System (STIFS) database, are mostly EIA data regularly published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding. 28 figs., 19 tabs.

  1. Short term energy forecasting with neural networks

    SciTech Connect

    McMenamin, J.S.; Monforte, F.A. )

    1998-01-01

    Artificial neural networks are beginning to be used by electric utilities to forecast hourly system loads on a day-ahead basis. This paper discusses the neural network specification in terms of conventional econometric language, providing parallel concepts for terms such as training, learning, and nodes in the hidden layer. It is shown that these models are flexible nonlinear equations that can be estimated using nonlinear least squares. It is argued that these models are especially well suited to hourly load forecasting, reflecting the presence of important nonlinearities and variable interactions. The paper proceeds to show how conventional statistics, such as the BIC and MAPE statistics can be used to select the number of nodes in the hidden layer. It is concluded that these models provide a powerful, robust and sensible approach to hourly load forecasting that will provide modest improvements in forecast accuracy relative to well-specified regression models.

  2. Vitreon, a short-term vitreoretinal tamponade.

    PubMed Central

    Blinder, K J; Peyman, G A; Desai, U R; Nelson, N C; Alturki, W; Paris, C L

    1992-01-01

    This investigation of the liquid perfluorocarbon, perfluorophenanthrene (Vitreon), establishes its safety and efficacy as a short-term vitreoretinal tamponade. We utilised Vitreon as an intraoperative tool and postoperative vitreoretinal tamponade in 16 patients. Proliferative vitreoretinopathy (PVR) (six), giant retinal tear (four), rhegmatogenous retinal detachment (three), retinal detachment with keratoprosthesis (two), and submacular and vitreous haemorrhage (one) were successfully repaired. Vitreon was left in the eye and removed 5 days to 4 weeks postoperatively. Complications encountered included proliferative PVR (five), limited peripheral retinal detachment (three), macular pucker (two) cataract (three), hypotony (two), excessive fibrin reaction (one), and elevated intraocular pressure (one). At the latest evaluation, all retinas are attached with a follow-up of 1.25 to 12 months (mean 6.8 months). PMID:1420054

  3. Neural network based short term load forecasting

    SciTech Connect

    Lu, C.N.; Wu, H.T. . Dept. of Electrical Engineering); Vemuri, S. . Controls and Composition Div.)

    1993-02-01

    The artificial neural network (ANN) technique for short term load forecasting (STLF) has been proposed by several authors, and gained a lot of attention recently. In order to evaluate ANN as a viable technique for STLF, one has to evaluate the performance of ANN methodology for practical considerations of STLF problems. This paper makes an attempt to address these issues. The paper presents the results of a study to investigate whether the ANN model is system dependent, and/or case dependent. Data from two utilities were used in modeling and forecasting. In addition, the effectiveness of a next 24 hour ANN model is predicting 24 hour load profile at one time was compared with the traditional next one hour ANN model.

  4. Economics of solar energy: Short term costing

    NASA Astrophysics Data System (ADS)

    Klee, H.

    The solar economics based on life cycle costs are refuted as both imaginary and irrelevant. It is argued that predicting rates of inflation and fuel escalation, expected life, maintenance costs, and legislation over the next ten to twenty years is pure guesswork. Furthermore, given the high mobility level of the U.S. population, the average consumer is skeptical of long run arguments which will pay returns only to the next owners. In the short term cost analysis, the house is sold prior to the end of the expected life of the system. The cash flow of the seller and buyer are considered. All the relevant factors, including the federal tax credit and the added value of the house because of the solar system are included.

  5. Short term dynamics of the debris-covered Miage Glacier

    NASA Astrophysics Data System (ADS)

    Fyffe, Catriona; Brock, Ben; Kirkbride, Martin; Mair, Doug; Smiraglia, Claudio; Diolaiuti, Guglielmina

    2016-04-01

    Due to the often inaccessible nature of debris-covered glaciers, studies of their dynamics tend to be restricted to those using remotely sensed data. This paper presents data on the short-term glacier dynamics of the debris-covered Miage Glacier, Western Italian Alps. The glacier velocity was calculated from repeat occupation of up to 22 points using a differential GPS system over two melt seasons. Meteorological, hydrological and water chemistry data were collected over the same time periods, and the nature of the hydrological system was studied using dye tracing, to allow the short term variations in glacier dynamics to be understood in terms of the likely glacial drainage system and its evolution. The highest glacier velocities and the greatest velocity variability was found near to where a cluster of moulins enter the glacier, close to the limit of continuous debris cover. The melt from the clean and dirty ice occasionally led to inputs overcoming the channelized system (both in spring and mid-summer), leading to increased velocities. On the debris-covered lower glacier however velocities were lower and less variable, and significant speed-up was confined to a period when subglacial water was thought to have been transferred subglacially from higher upglacier. The subdued sub-debris melt signal is thought to be the cause of the reduced velocity variability, in spite of the hydrological system beneath this part of the glacier remaining inefficient.

  6. Short-term and long-term effects of reinforcers on choice.

    PubMed

    Buckner, R L; Green, L; Myerson, J

    1993-03-01

    The relation between molar and molecular aspects of time allocation was studied in pigeons on concurrent variable-time variable-time schedules of reinforcement. Fifteen-minute reinforcer-free periods were inserted in the middle of every third session. Generalized molar matching of time ratios to reinforcer ratios was observed during concurrent reinforcement. Contrary to melioration theory, preference was unchanged during the reinforcer-free periods as well as in extinction. In addition to this long-term effect of reinforcement, short-term effects were observed: Reinforcers increased the duration of the stays during which they were delivered but had little consistent effect either on the immediately following stay in the same schedule or on the immediately following stay in the alternative schedule. Thus, an orderly effect of reinforcer delivery on molecular aspects of time allocation was observed, but because of its short-term nature, this effect cannot account for the matching observed at the molar level.

  7. Short-term and long-term effects of reinforcers on choice

    PubMed Central

    Buckner, Randy L.; Green, Leonard; Myerson, Joel

    1993-01-01

    The relation between molar and molecular aspects of time allocation was studied in pigeons on concurrent variable-time variable-time schedules of reinforcement. Fifteen-minute reinforcer-free periods were inserted in the middle of every third session. Generalized molar matching of time ratios to reinforcer ratios was observed during concurrent reinforcement. Contrary to melioration theory, preference was unchanged during the reinforcer-free periods as well as in extinction. In addition to this long-term effect of reinforcement, short-term effects were observed: Reinforcers increased the duration of the stays during which they were delivered but had little consistent effect either on the immediately following stay in the same schedule or on the immediately following stay in the alternative schedule. Thus, an orderly effect of reinforcer delivery on molecular aspects of time allocation was observed, but because of its short-term nature, this effect cannot account for the matching observed at the molar level. PMID:16812687

  8. Short-term predictions of solar flares.

    NASA Astrophysics Data System (ADS)

    Burov, V. A.

    1990-02-01

    A review of present-day theoretical investigations of the problem of the accumulation and release of energy in solar flares permits advancing the opinion that only individual flare events are described by a concrete model and that a single model alone does not describe the entire diversity of flares. Consideration of the observational data does not permit claiming the existence of a single universal mechanism known today of flare events. It appears possible to treat the problem of prediction in terms of the algebra of logic (Boolean logic) and to compare the truth table with the often-used contingency table. The introduction of a number of very general assumptions permits forming a general approach to the development of predictive schemes and selection of the individual elements of the models and informative criteria. Experimental results are given on the testing of some prediction procedures. The author's procedure of routine short-term prediction of flares on the basis of the methods of instruction on pattern recognition implemented in the form of a set of programs is outlined. The results of the application of this procedure in 1986 - 1988 are presented.

  9. Characterization of large-scale fluctuations and short-term variability of Seine river daily streamflow (France) over the period 1950-2008 by empirical mode decomposition and the Hilbert-Huang transform

    NASA Astrophysics Data System (ADS)

    Massei, N.; Fournier, M.

    2010-12-01

    Daily Seine river flow from 1950 to 2008 was analyzed using Hilbert-Huang Tranform (HHT). For the last ten years, this method which combines the so-called Empirical Mode Decomposition (EMD) multiresolution analysis and the Hilbert transform has proven its efficiency for the analysis of transient oscillatory signals, although the mathematical definition of the EMD is not totally established yet. HHT also provides an interesting alternative to other time-frequency or time-scale analysis of non-stationary signals, the most famous of which being wavelet-based approaches. In this application of HHT to the analysis of the hydrological variability of the Seine river, we seek to characterize the interannual patterns of daily flow, differenciate them from the short-term dynamics and eventually interpret them in the context of regional climate regime fluctuations. In this aim, HHT is also applied to the North-Atlantic Oscillation (NAO) through the annual winter-months NAO index time series. For both hydrological and climatic signals, dominant variability scales are extracted and their temporal variations analyzed by determination of the intantaneous frequency of each component. When compared to previous ones obtained from continuous wavelet transform (CWT) on the same data, HHT results highlighted the same scales and somewhat the same internal components for each signal. However, HHT allowed the identification and extraction of much more similar features during the 1950-2008 period (e.g., around 7-yr, between NAO and Seine flow than what was obtained from CWT, which comes to say that variability scales in flow likely to originate from climatic regime fluctuations were much properly identified in river flow. In addition, a more accurate determination of singularities in the natural processes analyzed were authorized by HHT compared to CWT, in which case the time-frequency resolution partly depends on the basic properties of the filter (i.e., the reference wavelet chosen

  10. In Search of Decay in Verbal Short-Term Memory

    ERIC Educational Resources Information Center

    Berman, Marc G.; Jonides, John; Lewis, Richard L.

    2009-01-01

    Is forgetting in the short term due to decay with the mere passage of time, interference from other memoranda, or both? Past research on short-term memory has revealed some evidence for decay and a plethora of evidence showing that short-term memory is worsened by interference. However, none of these studies has directly contrasted decay and…

  11. Short-term energy outlook quarterly projections. First quarter 1994

    SciTech Connect

    Not Available

    1994-02-07

    The Energy Information Administration (EIA) prepares quarterly, short- term energy supply, demand, and price projections for publication in February, May, August, and November in the Short-Term Energy Outlook (Outlook). An annual supplement analyzes the performance of previous forecasts, compares recent cases with those of other forecasting services, and discusses current topics related to the short-term energy markets.

  12. Continuity of Landsat observations: Short term considerations

    USGS Publications Warehouse

    Wulder, M.A.; White, Joanne C.; Masek, J.G.; Dwyer, J.; Roy, D.P.

    2011-01-01

    As of writing in mid-2010, both Landsat-5 and -7 continue to function, with sufficient fuel to enable data collection until the launch of the Landsat Data Continuity Mission (LDCM) scheduled for December of 2012. Failure of one or both of Landsat-5 or -7 may result in a lack of Landsat data for a period of time until the 2012 launch. Although the potential risk of a component failure increases the longer the sensor's design life is exceeded, the possible gap in Landsat data acquisition is reduced with each passing day and the risk of Landsat imagery being unavailable diminishes for all except a handful of applications that are particularly data demanding. Advances in Landsat data compositing and fusion are providing opportunities to address issues associated with Landsat-7 SLC-off imagery and to mitigate a potential acquisition gap through the integration of imagery from different sensors. The latter will likely also provide short-term, regional solutions to application-specific needs for the continuity of Landsat-like observations. Our goal in this communication is not to minimize the community's concerns regarding a gap in Landsat observations, but rather to clarify how the current situation has evolved and provide an up-to-date understanding of the circumstances, implications, and mitigation options related to a potential gap in the Landsat data record. ?? 2010.

  13. Short term oral minocycline treatment of meibomianitis

    PubMed Central

    Aronowicz, J D; Shine, W E; Oral, D; Vargas, J M; McCulley, J P

    2006-01-01

    Aim To evaluate the clinical impact, aqueous tear parameters, and meibomian gland morphology in patients with primary meibomianitis before, during, and 3 months after a course of oral minocycline. Methods 16 patients were prospectively enrolled, 11 male and five female (mean age 69 years old). Each patient received routine clinical evaluations before, after 3 months therapy, and at 6 month study follow up visit. The clinical appearance, tear volume, flow and turnover, evaporation, Schirmer I test, meibomian gland dropout, lissamine green staining, and bacteriology wer evaluated. Results Improvement was observed in clinical signs of meibomianitis at the second and third visits. Microbial culture findings improved. Decreased aqueous tear volume and flow, and increased evaporation rate range at 35–45% relative humidity (RH) (p<0.05) were also detected. Other related tear parameters did not change. Meibomian gland dropout showed no improvement. Conclusions 3 months of oral minocycline resulted in clinical improvements in all meibomianitis signs that persisted for at least 3 months after discontinuation despite decreased aqueous tear volume and flow with increased evaporation (35–45% RH). However, there was improvement in the turbidity of secretions. Short term minocycline therapy probably has efficacy in the management of meibomianitis that extends beyond eradication of bacteria. PMID:16613920

  14. The role of short-term memory in semantic priming.

    PubMed

    Beer, A L; Diehl, V A

    2001-07-01

    Two theories of priming were compared: spreading activation theories, in particular ACT, and compound-cue theories. Whereas ACT assumes that priming is a result of diffusing activation in long-term memory, compound-cue models suggest that priming results from a formation process of prime and target in short-term memory. Thirty-eight participants took part in a study that combined a digit span task with a double lexical decision task consisting of a prime and a target item. Digit span length (low, medium, and high) and prime type (related or unrelated word or nonword) were both within-subject variables. As expected, results showed significant priming effects. In favor of ACT, no interaction between digit span length and prime type was found. Additionally, a nonword inhibition effect (unrelated versus nonword prime) was found, which was predicted by compound-cue theories. This finding is discussed in terms of the process interference and response competition hypotheses.

  15. Short-term energy outlook: Quarterly projections, fourth quarter 1997

    SciTech Connect

    1997-10-14

    The Energy Information Administration (EIA) prepares quarterly short-term energy supply, demand, and price projections for printed publication in January, April, July, and October in the Short-Term Energy Outlook. The details of these projections, as well as monthly updates on or about the 6th of each interim month, are available on the internet at: www.eia.doe.gov/emeu/steo/pub/contents.html. The forecast period for this issue of the Outlook extends from the fourth quarter of 1997 through the fourth quarter of 1998. Values for the fourth quarter of 1997, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in EIA`s Weekly Petroleum Status Report) or are calculated from model simulations that use the latest exogenous information available (for example, electricity sales and generation are simulated by using actual weather data). The historical energy data, compiled in the fourth quarter 1997 version of the Short-Term Integrated Forecasting System (STIFS) database, are mostly EIA data regularly published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding. The STIFS model is driven principally by three sets of assumptions or inputs: estimates of key macroeconomic variables, world oil price assumptions, and assumptions about the severity of weather. 19 tabs.

  16. Short-term variability in the dates of the Indian monsoon onset and retreat on the southern and northern slopes of the central Himalayas as determined by precipitation stable isotopes

    NASA Astrophysics Data System (ADS)

    Yu, Wusheng; Yao, Tandong; Tian, Lide; Ma, Yaoming; Wen, Rong; Devkota, Lochan P.; Wang, Weicai; Qu, Dongmei; Chhetri, Tek B.

    2016-07-01

    This project launched the first study to compare the stable isotopes (δ18O and δD) in daily precipitation at Kathmandu (located on the southern slope of the central Himalayas) and Tingri (located on the northern slope). The results show that low δ18O and δD values of summer precipitation at the two stations were closely related to intense convection of the Indian monsoon. However, summer δ18O and δD values at Tingri were lower than those at Kathmandu, a result of the lift effect of the Himalayas, coupled with convection disturbances and lower temperatures at Tingri. In winter, the relatively high δ18O and δD values at the two stations appears to have resulted from the influence of the westerlies. Compared with those during the summer, the subsidence of the westerlies and northerly winds resulted in relatively high δ18O and δD values of the winter precipitation at Tingri. Winter δ18O and δD values at Kathmandu far exceeded those at Tingri, due to more intense advection of the southern branch of the westerlies, and higher temperatures and relative humidity at Kathmandu. The detailed differences in stable isotopes between the two stations follow short-term variability in the onset date of the Indian monsoon and its retreat across the central Himalayas. During the sampling period, the Indian monsoon onset at Tingri occurred approximately 1 week later than that at Kathmandu. However, the retreat at Tingri began roughly 3 days earlier. Clearly, the duration of the Indian monsoon effects last longer at Kathmandu than that at Tingri. Our findings also indicate that the India monsoon travels slowly northward across the central Himalayas due to the blocking of the Himalayas, but retreats quickly.

  17. Short- and Long-Term Outcomes for Extremely Preterm Infants.

    PubMed

    Patel, Ravi Mangal

    2016-02-01

    Prematurity is the leading cause of infant mortality worldwide. In developed countries, extremely preterm infants contribute disproportionately to both neonatal and infant mortality. Survival of this high-risk population has incrementally improved in recent years. Despite these improvements, approximately one in four extremely preterm infants dies during the birth hospitalization. Among those who survive, respiratory and other morbidities are common, although their effect on quality of life is variable. In addition, long-term neurodevelopmental impairment is a large concern for patients, clinicians, and families. However, the interplay of multiple factors contributes to neurodevelopmental impairment, with measures that change over time and outcomes that can be difficult to define and predict. Understanding outcomes of extremely preterm infants can help better counsel families regarding antenatal and postnatal care and guide strategies to improve survival without morbidity. This review summarizes recent evidence to provide an overview into the short- and long-term outcomes for extremely preterm infants.

  18. Short-Term Reciprocity in Late Parent-Child Relationships

    ERIC Educational Resources Information Center

    Leopold, Thomas; Raab, Marcel

    2011-01-01

    Long-term concepts of parent-child reciprocity assume that the amount of support given and received is only balanced in a generalized fashion over the life course. We argue that reciprocity in parent-child relationships also operates in the short term. Our analysis of short-term reciprocity focuses on concurrent exchange in its main upward and…

  19. Distinguishing short-term memory from working memory.

    PubMed

    Kail, R; Hall, L K

    2001-01-01

    The aim of the present research was to determine whether short-term memory and working memory could be distinguished. In two studies, 7- to 13-year-olds (N = 155, N = 132) were administered tasks thought to assess short-term memory as well as tasks thought to assess working memory. Both exploratory and confirmatory factor analyses distinguished short-term memory tasks from working memory tasks. In addition, performance on working memory tasks was related to word decoding skill but performance on short-term memory tasks was not. Finally, performance on both short-term memory and working memory tasks were associated with age-related increases in processing speed. Results are discussed in relation to models of short-term and working memory.

  20. Short-term energy outlook. Quarterly projections, Third quarter 1994

    SciTech Connect

    Not Available

    1994-08-02

    The Energy Information Administration (EIA) prepares quarterly, short-term energy supply, demand, and price projections for publication in February, May, August, and November in the Short-Term Energy Outlook (Outlook). An annual supplement analyzes the performance of previous forecasts, compares recent cases with those of other forecasting services, and discusses current topics related to the short-term energy markets. (See Short-Term Energy Outlook Annual Supplement, DOE/EIA-0202). The feature article for this issue is Demand, Supply and Price Outlook for Reformulated Gasoline, 1995.

  1. Short-term energy outlook. Quarterly projections, first quarter 1996

    SciTech Connect

    1996-02-01

    The Energy Information Administration (EIA) prepares quarterly, short-term energy supply, demand, and price projections for publication in February, May, August, and November in the Outlook. The forecast period for this issue of the Outlook extends from the first quarter of 1996 through the fourth quarter of 1997. Values for the fourth quarter of 1995, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in the Weekly Petroleum Status Report) or are calculated from model simulations using the latest exogenous information available (for example, electricity sales and generation are simulated using actual weather data). The historical energy data, compiled into the first quarter 1996 version of the Short-Term Integrated Forecasting System (STIFS) database, are mostly EIA data regularly published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding. The STIFS database is archived quarterly and is available from the National Technical Information Service. The cases are produced using the Short-Term Integrated Forecasting System (STIFS). The STIFS model is driven principally by three sets of assumptions or inputs: estimates of key macroeconomic variables, world oil price assumptions, and assumptions about the severity of weather. Macroeconomic estimates are produced by DRI/McGraw-Hill but are adjusted by EIA to reflect EIA assumptions about the world price of crude oil, energy product prices, and other assumptions which may affect the macroeconomic outlook.

  2. Short-term energy outlook: Quarterly projections, second quarter 1997

    SciTech Connect

    1997-04-01

    The Energy Information Administration (EIA) prepares quarterly short-term energy supply, demand, and price projections for publication in January, April, July, and October in the Outlook. The forecast period for this issue of the Outlook extends from the second quarter of 1997 through the fourth quarter of 1998. Values for the first quarter of 1997, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in EIA`s Weekly Petroleum Status Report) or are calculated from model simulations that use the latest exogenous information available (for example, electricity sales and generation are simulated by using actual weather data). The historical energy data, compiled in the second quarter 1997 version of the Short-Term Integrated Forecasting System (STIFS) database, are mostly EIA data regularly published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding. The STIFS database is archived quarterly and is available from the National Technical Information Service. The STIFS model is driven principally by three sets of assumptions or inputs: estimates of key macroeconomic variables, world oil price assumptions, and assumptions about the severity of weather. Macroeconomic estimates are produced by DRI/McGraw-Hill but are adjusted by EIA to reflect EIA assumptions about the world price of crude oil, energy product prices, and other assumptions which may affect the macroeconomic outlook. By varying the assumptions, alternative cases are produced by using the Short-Term Integrated Forecasting System (STIFS). 34 figs., 19 tabs.

  3. Short-term predictions in forex trading

    NASA Astrophysics Data System (ADS)

    Muriel, A.

    2004-12-01

    Using a kinetic equation that is used to model turbulence (Physica A, 1985-1988, Physica D, 2001-2003), we redefine variables to model the time evolution of the foreign exchange rates of three major currencies. We display live and predicted data for one period of trading in October, 2003.

  4. Short-term algal toxicity test based on phosphate uptake.

    PubMed

    Kaneko, H Hidehiro; Shimada, Akiko; Hirayama, Kimiaki

    2004-04-01

    In order to develop a short-term algal toxicity test, the growth of and the phosphate uptake by the green alga Selenastrum capricornutum during batch culture were observed. In the control medium, S. capricornutum took up phosphate earlier than it grew. It was also observed that the phosphate uptake was inhibited by the presence of a toxicant. From these results, phosphate uptake was considered as one of the useful effect parameters for a short-term algal toxicity test. As the removal rate of phosphate from the medium is a function of the amount of algal cell initially inoculated, the test period is variable. The relationship between the amount of inoculation and phosphate uptake was examined and the test conditions suitable for a 3-h toxicity test were established as one example. According to this test procedure, the inhibitory effect of some toxicants on the phosphate uptake was determined. For comparison, a conventional algal assay based on algal growth was also performed. The EC50s for both tests were close. This indicated that the algal toxicity test method proposed in this paper would be useful for the uses where rapidity is required. PMID:15087199

  5. Gaze direction affects visuo-spatial short-term memory.

    PubMed

    Carlei, Christophe; Kerzel, Dirk

    2014-10-01

    Hemispheric asymmetries were investigated by changing the horizontal position of stimuli that had to be remembered in a visuo-spatial short-term memory task. Observers looked at matrices containing a variable number of filled squares on the left or right side of the screen center. At stimulus offset, participants reproduced the positions of the filled squares in an empty response matrix. Stimulus and response matrices were presented in the same quadrant. We observed that memory performance was better when the matrices were shown on the left side of the screen. We distinguished between recall strategies that relied on visual or non-visual (verbal) cues and found that the effect of gaze position occurred more reliably in participants using visual recall strategies. Overall, the results show that there is a solid enhancement of visuo-spatial short-term memory when observers look to the left. In contrast, vertical position had no influence on performance. We suggest that unilateral gaze to the left activates centers in the right hemisphere contributing to visuo-spatial memory. PMID:24998909

  6. 22 CFR 62.21 - Short-term scholars.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Short-term scholars. 62.21 Section 62.21 Foreign Relations DEPARTMENT OF STATE PUBLIC DIPLOMACY AND EXCHANGES EXCHANGE VISITOR PROGRAM Specific Program Provisions § 62.21 Short-term scholars. (a) Introduction. These regulations govern scholars...

  7. Short-term energy outlook annual supplement, 1993

    SciTech Connect

    1993-08-06

    The Short-Term Energy Outlook Annual Supplement (supplement) is published once a year as a complement to the Short-Term Energy Outlook (Outlook), Quarterly Projections. The purpose of the Supplement is to review the accuracy of the forecasts published in the Outlook, make comparisons with other independent energy forecasts, and examine current energy topics that affect the forecasts.

  8. Double Dissociations in Visual and Spatial Short-Term Memory

    ERIC Educational Resources Information Center

    Klauer, Karl Christoph; Zhao, Zengmei

    2004-01-01

    A visual short-term memory task was more strongly disrupted by visual than spatial interference, and a spatial memory task was simultaneously more strongly disrupted by spatial than visual interference. This double dissociation supports a fractionation of visuospatial short-term memory into separate visual and spatial components. In 6 experiments,…

  9. Short-Term Training--Where the Action Is!

    ERIC Educational Resources Information Center

    Moore, George R.

    In order to address major permanent changes in the economic structure and workforce of its community, Chemeketa Community College (CCC) in Oregon has made a commitment to initiate as many short-term training programs as its resources permit. Short-term training, which takes less time than regular one-year certificate or two-year associate degree…

  10. Short-Term Memory; An Annotated Bibliography. Supplement 1.

    ERIC Educational Resources Information Center

    Fisher, Dennis F.

    A compilation of 165 references dealing with short term memory, this bibliography supplements "Short-Term Memory: An Annotated Bibliography" (August 1968). The time period covered is predominantly June 1968 to June 1969. Such aspects and topics as psychometrics, motivation, human engineering, vision, auditory perception, verbal and nonverbal…

  11. Short-Term Memory: An Annotated Bibliography. Supplement II.

    ERIC Educational Resources Information Center

    Fisher, Dennis F.

    This bibliography is an annotated compilation of 198 references dealing with short-term memory. It is added as a second supplement to Short-Term Memory: An Annotated Bibliography, August, 1968. The time period covered is predominantly June, 1969 to December, 1970. References included are arranged alphabetically by author. An alphabetical index of…

  12. Short-Term Group Treatment for Adult Children of Alcoholics.

    ERIC Educational Resources Information Center

    Cooper, Alvin; McCormack, WIlliam A.

    1992-01-01

    Adult children of alcoholics (n=24) were tested on measures of loneliness, anxiety, hostility, depression, and interpersonal dependency before and after participation in short-term group therapy. Highly significant test score changes supported effectiveness of individual therapy in short-term groups. (Author/NB)

  13. Short-term energy outlook, annual supplement 1994

    SciTech Connect

    Not Available

    1994-08-01

    The Short-Term Energy Outlook Annual Supplement (Supplement) is published once a year as a complement to the Short-Term Energy Outlook (Outlook), Quarterly Projections. The purpose of the Supplement is to review the accuracy of the forecasts published in the Outlook, make comparisons with other independent energy forecasts, and examine current energy topics that affect the forecasts.

  14. Long vs. short-term energy storage:sensitivity analysis.

    SciTech Connect

    Schoenung, Susan M. (Longitude 122 West, Inc., Menlo Park, CA); Hassenzahl, William V. (,Advanced Energy Analysis, Piedmont, CA)

    2007-07-01

    This report extends earlier work to characterize long-duration and short-duration energy storage technologies, primarily on the basis of life-cycle cost, and to investigate sensitivities to various input assumptions. Another technology--asymmetric lead-carbon capacitors--has also been added. Energy storage technologies are examined for three application categories--bulk energy storage, distributed generation, and power quality--with significant variations in discharge time and storage capacity. Sensitivity analyses include cost of electricity and natural gas, and system life, which impacts replacement costs and capital carrying charges. Results are presented in terms of annual cost, $/kW-yr. A major variable affecting system cost is hours of storage available for discharge.

  15. Risk Quantification for ANN Based Short-Term Load Forecasting

    NASA Astrophysics Data System (ADS)

    Iwashita, Daisuke; Mori, Hiroyuki

    A new risk assessment method for short-term load forecasting is proposed. The proposed method makes use of an Artificial Neural Network (ANN) to forecast one-step ahead daily maximum loads and evaluate uncertainty of in load forecasting. As ANN the model, the Radial Basis Function (RBF) network is employed to forecast loads due to the good performance. Sufficient realistic pseudo-scenarios are required to carry out quantitative risk analysis. The multivariate normal distribution with the correlation between input variables is used to give more realistic results to ANN. In addition, the method of Moment Matching is used to improve the accuracy of the multivariate normal distribution. The Peak Over Threshold (POT) approach is used to evaluate risk that exceeds the upper bounds of generation capacity. The proposed method is successfully applied to real data of daily maximum load forecasting.

  16. Artificial neural networks for short term electrical load forecasting

    SciTech Connect

    Reinschmidt, K.F.

    1995-10-01

    The accurate prediction of hourly electrical demand one or more days ahead is of great economic importance to electric utilities for generation unit dispatch and unit commitment. Artificial neural networks for pattern recognition are developed to identify days in the historical record that are most similar to the days being forecasted, to use for load prediction. Artificial neural networks are also used to generate linear and nonlinear multivariate time series models, to project demands forward in time. The genetic algorithm is used to select the optimal set of independent variables for forecasting. Techniques are developed to combine forecasts derived from independent methods, to achieve better accuracy than any single forecast. In this way, artificial neural networks can be used to generate practical, accurate short-term electrical load forecasts.

  17. Small mammals as indicators of short-term and long-term disturbance in mixed prairie.

    PubMed

    Leis, Sherry A; Leslie, David M; Engle, David M; Fehmi, Jeffrey S

    2008-02-01

    Disturbance by military maneuvers over short and long time scales may have differential effects on grassland communities. We assessed small mammals as indicators of disturbance by military maneuvers in a mixed prairie in southern Oklahoma USA. We examined sites on two soil series, Foard and Lawton, across a gradient of disturbance intensity. A MANOVA showed that abundance of small mammals was associated (p = 0.03) with short-term (cover of vehicle tracks) disturbance but was not associated (p = 0.12) with long-term (loss of soil organic carbon, SOC) disturbance intensity. At the individual species level, Sigmodon hispidus (cotton rat) and Peromyscus maniculatus (deer mouse) occurred across all levels of disturbance and in both soil types. Only P. maniculatus abundance changed (p < 0.01) with short-term disturbance and increased by about one individual per 5% of additional track-cover. Abundance of P. maniculatus also increased (p = 0.04) by about three individuals per 1% increase in soil carbon. Chaetodipus hispidus (hispid pocket mouse) and Reithrodontomys fulvescens (fulvous harvest mouse) only occurred in single soil types limiting their potential as more general indicators. Abundance of P. maniculatus was positively related to shifts in plant species composition and likely reflected changes in vegetation structure (i.e. litter depth) and forage availability resulting from disturbance. Peromyscus maniculatus may be a useful biological indicator of ecosystem change because it responded predictably to both long-term and short-term disturbance and, when coupled with soil, plant, and disturbance history variables, can reveal land condition trends. PMID:17458511

  18. Small mammals as indicators of short-term and long-term disturbance in mixed prairie

    USGS Publications Warehouse

    Leis, S.A.; Leslie, David M.; Engle, David M.; Fehmi, J.S.

    2008-01-01

    Disturbance by military maneuvers over short and long time scales may have differential effects on grassland communities. We assessed small mammals as indicators of disturbance by military maneuvers in a mixed prairie in southern Oklahoma USA. We examined sites on two soil series, Foard and Lawton, across a gradient of disturbance intensity. A MANOVA showed that abundance of small mammals was associated (p = 0.03) with short-term (cover of vehicle tracks) disturbance but was not associated (p = 0.12) with long-term (loss of soil organic carbon, SOC) disturbance intensity. At the individual species level, Sigmodon hispidus (cotton rat) and Peromyscus maniculatus (deer mouse) occurred across all levels of disturbance and in both soil types. Only P. maniculatus abundance changed (p < 0.01) with short-term disturbance and increased by about one individual per 5% of additional track-cover. Abundance of P. maniculatus also increased (p = 0.04) by about three individuals per 1% increase in soil carbon. Chaetodipus hispidus (hispid pocket mouse) and Reithrodontomys fulvescens (fulvous harvest mouse) only occurred in single soil types limiting their potential as more general indicators. Abundance of P. maniculatus was positively related to shifts in plant species composition and likely reflected changes in vegetation structure (i.e. litter depth) and forage availability resulting from disturbance. Peromyscus maniculatus may be a useful biological indicator of ecosystem change because it responded predictably to both long-term and short-term disturbance and, when coupled with soil, plant, and disturbance history variables, can reveal land condition trends. ?? Springer Science+Business Media B.V. 2007.

  19. Short-Term Energy Outlook Model Documentation: Macro Bridge Procedure to Update Regional Macroeconomic Forecasts with National Macroeconomic Forecasts

    EIA Publications

    2010-01-01

    The Regional Short-Term Energy Model (RSTEM) uses macroeconomic variables such as income, employment, industrial production and consumer prices at both the national and regional1 levels as explanatory variables in the generation of the Short-Term Energy Outlook (STEO). This documentation explains how national macroeconomic forecasts are used to update regional macroeconomic forecasts through the RSTEM Macro Bridge procedure.

  20. The mind and brain of short-term memory.

    PubMed

    Jonides, John; Lewis, Richard L; Nee, Derek Evan; Lustig, Cindy A; Berman, Marc G; Moore, Katherine Sledge

    2008-01-01

    The past 10 years have brought near-revolutionary changes in psychological theories about short-term memory, with similarly great advances in the neurosciences. Here, we critically examine the major psychological theories (the "mind") of short-term memory and how they relate to evidence about underlying brain mechanisms. We focus on three features that must be addressed by any satisfactory theory of short-term memory. First, we examine the evidence for the architecture of short-term memory, with special attention to questions of capacity and how--or whether--short-term memory can be separated from long-term memory. Second, we ask how the components of that architecture enact processes of encoding, maintenance, and retrieval. Third, we describe the debate over the reason about forgetting from short-term memory, whether interference or decay is the cause. We close with a conceptual model tracing the representation of a single item through a short-term memory task, describing the biological mechanisms that might support psychological processes on a moment-by-moment basis as an item is encoded, maintained over a delay with some forgetting, and ultimately retrieved.

  1. Efficacy of Short-Term Dynamic Psychotherapy

    PubMed Central

    BARBER, JACQUES P.

    1994-01-01

    The author outlines the history of brief dynamic psychotherapy, describes some of its characteristics, and addresses methodological requirements for assessing the efficacy of psychotherapy. Review of two major meta-analyses suggests that manual-based brief dynamic psychotherapy by trained therapists is likely to be as effective as other forms of psychotherapy and more effective than no treatment. More studies are needed that 1) compare brief dynamic psychotherapy with other forms of treatment for specific psychiatric disorders; 2) use theory-specific measures of outcome in addition to measures of symptoms; and 3) compare brief dynamic psychotherapy with long-term psychotherapy. PMID:22700185

  2. Short-term forgetting without interference.

    PubMed

    McKeown, Denis; Mercer, Tom

    2012-07-01

    In the 1st reported experiment, we demonstrate that auditory memory is robust over extended retention intervals (RIs) when listeners compare the timbre of complex tones, even when active or verbal rehearsal is difficult or impossible. Thus, our tones have an abstract timbre that resists verbal labeling, they differ across trials so that no "standard" comparison stimulus is built up, and the spectral change to be discriminated is very slight and therefore does not shift stimuli across verbal categories. Nonetheless, performance in this nonverbal immediate memory task was better at short (1-, 2-, or 4-s) than long (8-, 16-, or 32-s) RIs, an outcome predicted by temporal distinctiveness theory whereby at long RIs, tones are closer in time to tones on previous trials. We reject this account in the 2nd experiment, where we demonstrate that the ratio of RI to intertrial interval makes absolutely no difference to performance. We suggest that steady forgetting is consistent with a psychoacoustically derived conception of an auditory memory (the timbre memory model) that embodies time-based forgetting in the absence of feature-specific interference. PMID:22449135

  3. Encephalopathy and vestibulopathy following short-term hydrocarbon exposure.

    PubMed

    Hodgson, M J; Furman, J; Ryan, C; Durrant, J; Kern, E

    1989-01-01

    Dizziness, headaches, and weakness occurred among three men after short-term hydrocarbon exposure during improper welding procedures in a closed container. Symptoms were related to objective evidence of vestibular and cognitive dysfunction. Symptoms and abnormal test results persisted for 6 to 18 months. Simulation of the accident failed to demonstrate likely exposures except aliphatic hydrocarbons, well within the permissible exposure levels. Short-term exposures to neurotoxins may lead to long-term central nervous system abnormalities.

  4. Encephalopathy and vestibulopathy following short-term hydrocarbon exposure

    SciTech Connect

    Hodgson, M.J.; Furman, J.; Ryan, C.; Durrant, J.; Kern, E.

    1989-01-01

    Dizziness, headaches, and weakness occurred among three men after short-term hydrocarbon exposure during improper welding procedures in a closed container. Symptoms were related to objective evidence of vestibular and cognitive dysfunction. Symptoms and abnormal test results persisted for 6 to 18 months. Simulation of the accident failed to demonstrate likely exposures except aliphatic hydrocarbons, well within the permissible exposure levels. Short-term exposures to neurotoxins may lead to long-term central nervous system abnormalities.

  5. Working memory training improves visual short-term memory capacity.

    PubMed

    Schwarb, Hillary; Nail, Jayde; Schumacher, Eric H

    2016-01-01

    Since antiquity, philosophers, theologians, and scientists have been interested in human memory. However, researchers today are still working to understand the capabilities, boundaries, and architecture. While the storage capabilities of long-term memory are seemingly unlimited (Bahrick, J Exp Psychol 113:1-2, 1984), working memory, or the ability to maintain and manipulate information held in memory, seems to have stringent capacity limits (e.g., Cowan, Behav Brain Sci 24:87-185, 2001). Individual differences, however, do exist and these differences can often predict performance on a wide variety of tasks (cf. Engle What is working-memory capacity? 297-314, 2001). Recently, researchers have promoted the enticing possibility that simple behavioral training can expand the limits of working memory which indeed may also lead to improvements on other cognitive processes as well (cf. Morrison and Chein, Psychol Bull Rev 18:46-60 2011). However, initial investigations across a wide variety of cognitive functions have produced mixed results regarding the transferability of training-related improvements. Across two experiments, the present research focuses on the benefit of working memory training on visual short-term memory capacity-a cognitive process that has received little attention in the training literature. Data reveal training-related improvement of global measures of visual short-term memory as well as of measures of the independent sub-processes that contribute to capacity (Awh et al., Psychol Sci 18(7):622-628, 2007). These results suggest that the ability to inhibit irrelevant information within and between trials is enhanced via n-back training allowing for selective improvement on untrained tasks. Additionally, we highlight a potential limitation of the standard adaptive training procedure and propose a modified design to ensure variability in the training environment.

  6. Focusing on Short-Term Achievement Gains Fails to Produce Long-Term Gains

    ERIC Educational Resources Information Center

    Grissmer, David W.; Ober, David R.; Beekman, John A.

    2014-01-01

    The short-term emphasis engendered by No Child Left Behind (NCLB) has focused research predominantly on unraveling the complexities and uncertainties in assessing short-term results, rather than developing methods and assessing results over the longer term. In this paper we focus on estimating long-term gains and address questions important to…

  7. Long-Term Wind Power Variability

    SciTech Connect

    Wan, Y. H.

    2012-01-01

    The National Renewable Energy Laboratory started collecting wind power data from large commercial wind power plants (WPPs) in southwest Minnesota with dedicated dataloggers and communication links in the spring of 2000. Over the years, additional WPPs in other areas were added to and removed from the data collection effort. The longest data stream of actual wind plant output is more than 10 years. The resulting data have been used to analyze wind power fluctuations, frequency distribution of changes, the effects of spatial diversity, and wind power ancillary services. This report uses the multi-year wind power data to examine long-term wind power variability.

  8. Short-term energy outlook. Quarterly projections, Third quarter 1995

    SciTech Connect

    1995-08-02

    The Energy Information Administration (EIA) prepares quarterly, short-term energy supply, demand, and price projections for publication in February, May, August, and November in the Short-Term Energy Outlook (Outlook). An annual supplement analyzes the performance of previous forecasts, compares recent projections with those of other forecasting services, and discusses current topics related to the short-term energy markets. The forecast period for this issue of the Outlook extends from the third quarter of 1995 through the fourth quarter of 1996. Values for the second quarter of 1995, however, are preliminary EIA estimates.

  9. The long-term variability of Vega

    NASA Astrophysics Data System (ADS)

    Butkovskaya, V.; Plachinda, S.; Valyavin, G.; Baklanova, D.; Lee, B.-C.

    2011-12-01

    Over the time of 60 years Vega (α Lyrae = HD 172167, A0V) has been generally accepted as a standard star in the near-infrared, optical, and ultraviolet regions. But is the spectrophotometric standard Vega really non-variable star? Researchers give very different answers to this question. We aim to search a periodicity in our results of spectropolarimetric study of Vega, namely periodic variations in equivalent width of the spectral lines and longitudinal magnetic field measurements. High-accuracy spectropolarimetric observations of Vega have been performed during 26 nights from 1997 to 2010 using the Coudé spectrograph of the 2.6-m Shain reflector at the Crimean Astrophysical Observatory (CrAO, Ukraine) and during 4 nights in 2007 and 2008 using the echelle spectrograph BOES at the Bohyunsan Optical Astronomy Observatory (BOAO, South Korea). The long-term (year-to-year) variability of Vega was confirmed. It was concluded that this variability does not have magnetic nature. The paper is dedicated to the memory of V.P. Merezhin.

  10. An integrated approach based on uniform quantization for the evaluation of complexity of short-term heart period variability: Application to 24 h Holter recordings in healthy and heart failure humans

    NASA Astrophysics Data System (ADS)

    Porta, A.; Faes, L.; Masé, M.; D'Addio, G.; Pinna, G. D.; Maestri, R.; Montano, N.; Furlan, R.; Guzzetti, S.; Nollo, G.; Malliani, A.

    2007-03-01

    We propose an integrated approach based on uniform quantization over a small number of levels for the evaluation and characterization of complexity of a process. This approach integrates information-domain analysis based on entropy rate, local nonlinear prediction, and pattern classification based on symbolic analysis. Normalized and non-normalized indexes quantifying complexity over short data sequences (˜300 samples) are derived. This approach provides a rule for deciding the optimal length of the patterns that may be worth considering and some suggestions about possible strategies to group patterns into a smaller number of families. The approach is applied to 24h Holter recordings of heart period variability derived from 12 normal (NO) subjects and 13 heart failure (HF) patients. We found that: (i) in NO subjects the normalized indexes suggest a larger complexity during the nighttime than during the daytime; (ii) this difference may be lost if non-normalized indexes are utilized; (iii) the circadian pattern in the normalized indexes is lost in HF patients; (iv) in HF patients the loss of the day-night variation in the normalized indexes is related to a tendency of complexity to increase during the daytime and to decrease during the nighttime; (v) the most likely length L =3 indicates that stable patterns (i.e., those with no variations) are more present during the daytime, while highly variable patterns (i.e., those with two unlike variations) are more frequent during the nighttime; (vii) during the daytime in HF patients, the percentage of highly variable patterns increases with respect to NO subjects, while during the nighttime, the percentage of patterns with one or two like variations decreases.

  11. Auditory short-term memory behaves like visual short-term memory.

    PubMed

    Visscher, Kristina M; Kaplan, Elina; Kahana, Michael J; Sekuler, Robert

    2007-03-01

    Are the information processing steps that support short-term sensory memory common to all the senses? Systematic, psychophysical comparison requires identical experimental paradigms and comparable stimuli, which can be challenging to obtain across modalities. Participants performed a recognition memory task with auditory and visual stimuli that were comparable in complexity and in their neural representations at early stages of cortical processing. The visual stimuli were static and moving Gaussian-windowed, oriented, sinusoidal gratings (Gabor patches); the auditory stimuli were broadband sounds whose frequency content varied sinusoidally over time (moving ripples). Parallel effects on recognition memory were seen for number of items to be remembered, retention interval, and serial position. Further, regardless of modality, predicting an item's recognizability requires taking account of (1) the probe's similarity to the remembered list items (summed similarity), and (2) the similarity between the items in memory (inter-item homogeneity). A model incorporating both these factors gives a good fit to recognition memory data for auditory as well as visual stimuli. In addition, we present the first demonstration of the orthogonality of summed similarity and inter-item homogeneity effects. These data imply that auditory and visual representations undergo very similar transformations while they are encoded and retrieved from memory.

  12. Sequential dynamics in visual short-term memory.

    PubMed

    Kool, Wouter; Conway, Andrew R A; Turk-Browne, Nicholas B

    2014-10-01

    Visual short-term memory (VSTM) is thought to help bridge across changes in visual input, and yet many studies of VSTM employ static displays. Here we investigate how VSTM copes with sequential input. In particular, we characterize the temporal dynamics of several different components of VSTM performance, including: storage probability, precision, variability in precision, guessing, and swapping. We used a variant of the continuous-report VSTM task developed for static displays, quantifying the contribution of each component with statistical likelihood estimation, as a function of serial position and set size. In Experiments 1 and 2, storage probability did not vary by serial position for small set sizes, but showed a small primacy effect and a robust recency effect for larger set sizes; precision did not vary by serial position or set size. In Experiment 3, the recency effect was shown to reflect an increased likelihood of swapping out items from earlier serial positions and swapping in later items, rather than an increased rate of guessing for earlier items. Indeed, a model that incorporated responding to non-targets provided a better fit to these data than alternative models that did not allow for swapping or that tried to account for variable precision. These findings suggest that VSTM is updated in a first-in-first-out manner, and they bring VSTM research into closer alignment with classical working memory research that focuses on sequential behavior and interference effects.

  13. Diverse thalamocortical short-term plasticity elicited by ongoing stimulation.

    PubMed

    Díaz-Quesada, Marta; Martini, Francisco J; Ferrati, Giovanni; Bureau, Ingrid; Maravall, Miguel

    2014-01-01

    To produce sensation, neuronal pathways must transmit and process stimulus patterns that unfold over time. This behavior is determined by short-term synaptic plasticity (STP), which shapes the temporal filtering properties of synapses in a pathway. We explored STP variability across thalamocortical (TC) synapses, measuring whole-cell responses to stimulation of TC fibers in layer 4 neurons of mouse barrel cortex in vitro. As expected, STP during stimulation from rest was dominated by depression. However, STP during ongoing stimulation was strikingly diverse across TC connections. Diversity took the form of variable tuning to the latest interstimulus interval: some connections responded weakly to shorter intervals, while other connections were facilitated. These behaviors did not cluster into categories but formed a continuum. Diverse tuning did not require disynaptic inhibition. Hence, monosynaptic excitatory lemniscal TC connections onto layer 4 do not behave uniformly during ongoing stimulation. Each connection responds differentially to particular stimulation intervals, enriching the ability of the pathway to convey complex, temporally fluctuating information.

  14. Short Term Weather Forecasting and Long Term Climate Predictions in Mesoamerica

    NASA Astrophysics Data System (ADS)

    Hardin, D. M.; Daniel, I.; Mecikalski, J.; Graves, S.

    2008-05-01

    The SERVIR project utilizes several predictive models to support regional monitoring and decision support in Mesoamerica. Short term forecasts ranging from a few hours to several days produce more than 30 data products that are used daily by decision makers, as well as news organizations in the region. The forecast products can be visualized in both two and three dimensional viewers such as Google Maps and Google Earth. Other viewers developed specifically for the Mesoamerican region by the University of Alabama in Huntsville and the Institute for the Application of Geospatial Technologies in Auburn New York can also be employed. In collaboration with the NASA Short Term Prediction Research and Transition (SpoRT) Center SERVIR utilizes the Weather Research and Forecast (WRF) model to produce short-term (24 hr) regional weather forecasts twice a day. Temperature, precipitation, wind, and other variables are forecast in 10km and 30km grids over the Mesoamerica region. Using the PSU/NCAR Mesoscale Model, known as MM5, SERVIR produces 48 hour- forecasts of soil temperature, two meter surface temperature, three hour accumulated precipitation, winds at different heights, and other variables. These are forecast hourly in 9km grids. Working in collaboration with the Atmospheric Science Department of the University of Alabama in Huntsville produces a suite of short-term (0-6 hour) weather prediction products are generated. These "convective initiation" products predict the onset of thunderstorm rainfall and lightning within a 1-hour timeframe. Models are also employed for long term predictions. The SERVIR project, under USAID funding, has developed comprehensive regional climate change scenarios of Mesoamerica for future years: 2010, 2015, 2025, 2050, and 2099. These scenarios were created using the Pennsylvania State University/National Center for Atmospheric Research (MM5) model and processed on the Oak Ridge National Laboratory Cheetah supercomputer. The goal of these

  15. Heterogeneous artificial neural network for short term electrical load forecasting

    SciTech Connect

    Piras, A.; Germond, A.; Buchenel, B.; Imhof, K.; Jaccard, Y.

    1995-12-31

    Short term electrical load forecasting is a topic of major interest for the planning of energy production and distribution. The use of artificial neural networks has been demonstrated as a valid alternative to classical statistical methods in terms of accuracy of results. However, a common architecture able to forecast the load in different geographical regions, showing different load shape and climate characteristics, is still missing. In this paper the authors discuss a heterogeneous neural network architecture composed of an unsupervised part, namely a neural gas, which is used to analyze the process in submodels finding local features in the data and suggesting regression variables, and a supervised one, a multilayer perceptron, which performs the approximation of the underlying function. The results outputs are then summed by a weighted fuzzy average, allowing a smooth transition between sub models. The effectiveness of the proposed architecture is demonstrated by two days ahead load forecasting of EOS power system sub areas, corresponding to five different geographical regions, and of its total electrical load.

  16. Heterogeneous artificial neural network for short term electrical load forecasting

    SciTech Connect

    Piras, A.; Germond, A.; Buchenel, B.; Imhof, K.; Jaccard, Y.

    1996-02-01

    Short term electrical load forecasting is a topic of major interest for the planning of energy production and distribution. The use of artificial neural networks has been demonstrated as a valid alternative to classical statistical methods in terms of accuracy of results. However a common architecture able to forecast the load in different geographical regions, showing different load shape and climate characteristics, is still missing. In this paper the authors discuss a heterogeneous neural network architecture composed of an unsupervised part, namely a neural gas, which is used to analyze the process in sub models finding local features in the data and suggesting regression variables, and a supervised one, a multilayer perceptron, which performs the approximation of the underlying function. The resulting outputs are then summed by a weighted fuzzy average, allowing a smooth transition between sub models. The effectiveness of the proposed architecture is demonstrated by two days ahead load forecasting of EOS power system sub areas, corresponding to five different geographical regions, and of its total electrical load.

  17. Retrieval-Induced Inhibition in Short-Term Memory.

    PubMed

    Kang, Min-Suk; Choi, Joongrul

    2015-07-01

    We used a visual illusion called motion repulsion as a model system for investigating competition between two mental representations. Subjects were asked to remember two random-dot-motion displays presented in sequence and then to report the motion directions for each. Remembered motion directions were shifted away from the actual motion directions, an effect similar to the motion repulsion observed during perception. More important, the item retrieved second showed greater repulsion than the item retrieved first. This suggests that earlier retrieval exerted greater inhibition on the other item being held in short-term memory. This retrieval-induced motion repulsion could be explained neither by reduced cognitive resources for maintaining short-term memory nor by continued inhibition between short-term memory representations. These results indicate that retrieval of memory representations inhibits other representations in short-term memory. We discuss mechanisms of retrieval-induced inhibition and their implications for the structure of memory. PMID:26001735

  18. Regional Short-Term Energy Model (RSTEM) Overview

    EIA Publications

    2009-01-01

    The Regional Short-Term Energy Model (RSTEM) utilizes estimated econometric relationships for demand, inventories and prices to forecast energy market outcomes across key sectors and selected regions throughout the United States.

  19. Optimal fuzzy inference for short-term load forecasting

    SciTech Connect

    Mori, Hiroyuki; Kobayashi, Hidenori

    1996-02-01

    This paper proposes an optimal fuzzy inference method for short-term load forecasting. The proposed method constructs an optimal structure of the simplified fuzzy inference that minimizes model errors and the number of the membership functions to grasp nonlinear behavior of power system short-term loads. The model is identified by simulated annealing and the steepest descent method. The proposed method is demonstrated in examples.

  20. Optimal fuzzy inference for short-term load forecasting

    SciTech Connect

    Mori, Hiroyuki; Kobayashi, Hidenori

    1995-12-31

    This paper proposes an optimal fuzzy inference method for short-term load forecasting. The proposed method constructs an optimal structure of the simplified fuzzy inference that minimizes model errors and the number of the membership functions to grasp nonlinear behavior of power system short-term loads. The model is identified by simulated annealing and the steepest descent method. The proposed method is demonstrated in examples.

  1. Comparison of very short-term load forecasting techniques

    SciTech Connect

    Liu, K.; Kwan, C.; Lewis, F.L.; Subbarayan, S.; Shoults, R.R.; Manry, M.T.; Naccarino, J.

    1996-05-01

    Three practical techniques--Fuzzy Logic (FL), Neural Networks (NN), and Auto-regressive model (AR)--for very short-term load forecasting have been proposed and discussed in this paper. Their performances are evaluated through a simulation study. The preliminary study shows that it is feasible to design a simple, satisfactory dynamic forecaster to predict the very short-term load trends on-line. FL and NN can be good candidates for this application.

  2. The Effects of Storytelling and Pretend Play on Cognitive Processes, Short-Term and Long-Term Narrative Recall.

    ERIC Educational Resources Information Center

    Kim, Sook-Yi

    1999-01-01

    Examined effects of storytelling and pretend play on short- and long-term narrative recall in preschoolers. Found that: (1) storytelling and pretend play affected cognitive variables; (2) differences between storytelling and pretend play in facilitating narrative recall were significant; (3) encoding ability exceeded ability to make inferences;…

  3. Short-term landfill methane emissions dependency on wind.

    PubMed

    Delkash, Madjid; Zhou, Bowen; Han, Byunghyun; Chow, Fotini K; Rella, Chris W; Imhoff, Paul T

    2016-09-01

    Short-term (2-10h) variations of whole-landfill methane emissions have been observed in recent field studies using the tracer dilution method for emissions measurement. To investigate the cause of these variations, the tracer dilution method is applied using 1-min emissions measurements at Sandtown Landfill (Delaware, USA) for a 2-h measurement period. An atmospheric dispersion model is developed for this field test site, which is the first application of such modeling to evaluate atmospheric effects on gas plume transport from landfills. The model is used to examine three possible causes of observed temporal emissions variability: temporal variability of surface wind speed affecting whole landfill emissions, spatial variability of emissions due to local wind speed variations, and misaligned tracer gas release and methane emissions locations. At this site, atmospheric modeling indicates that variation in tracer dilution method emissions measurements may be caused by whole-landfill emissions variation with wind speed. Field data collected over the time period of the atmospheric model simulations corroborate this result: methane emissions are correlated with wind speed on the landfill surface with R(2)=0.51 for data 2.5m above ground, or R(2)=0.55 using data 85m above ground, with emissions increasing by up to a factor of 2 for an approximately 30% increase in wind speed. Although the atmospheric modeling and field test are conducted at a single landfill, the results suggest that wind-induced emissions may affect tracer dilution method emissions measurements at other landfills. PMID:26896003

  4. Short-term memory and dual task performance

    NASA Technical Reports Server (NTRS)

    Regan, J. E.

    1982-01-01

    Two hypotheses concerning the way in which short-term memory interacts with another task in a dual task situation are considered. It is noted that when two tasks are combined, the activity of controlling and organizing performance on both tasks simultaneously may compete with either task for a resource; this resource may be space in a central mechanism or general processing capacity or it may be some task-specific resource. If a special relationship exists between short-term memory and control, especially if there is an identity relationship between short-term and a central controlling mechanism, then short-term memory performance should show a decrement in a dual task situation. Even if short-term memory does not have any particular identity with a controlling mechanism, but both tasks draw on some common resource or resources, then a tradeoff between the two tasks in allocating resources is possible and could be reflected in performance. The persistent concurrence cost in memory performance in these experiments suggests that short-term memory may have a unique status in the information processing system.

  5. Role of Satellite Rainfall Information in Improving Understanding of the Dynamical Link Between the Tropics and Extratropics Prospects of Improved Forecasts of Weather and Short-Term Climate Variability on Sub-Seasonal Time Scales

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.

    2002-01-01

    The tropics and extratropics are two dynamically distinct regimes. The coupling between these two regimes often defies simple analytical treatment. Progress in understanding of the dynamical interaction between the tropics and extratropics relies on better observational descriptions to guide theoretical development. However, global analyses currently contain significant errors in primary hydrological variables such as precipitation, evaporation, moisture, and clouds, especially in the tropics. Tropical analyses have been shown to be sensitive to parameterized precipitation processes, which are less than perfect, leading to order-one discrepancies between estimates produced by different data assimilation systems. One strategy for improvement is to assimilate rainfall observations to constrain the analysis and reduce uncertainties in variables physically linked to precipitation. At the Data Assimilation Office at the NASA Goddard Space Flight Center, we have been exploring the use of tropical rain rates derived from the TRMM Microwave Imager (TMI) and the Special Sensor Microwave/ Imager (SSM/I) instruments in global data assimilation. Results show that assimilating these data improves not only rainfall and moisture fields but also related climate parameters such as clouds and radiation, as well as the large-scale circulation and short-range forecasts. These studies suggest that assimilation of microwave rainfall observations from space has the potential to significantly improve the quality of 4-D assimilated datasets for climate investigations (Hou et al. 2001). In the next few years, there will be a gradual increase in microwave rain products available from operational and research satellites, culminating to a target constellation of 9 satellites to provide global rain measurements every 3 hours with the proposed Global Precipitation Measurement (GPM) mission in 2007. Continued improvements in assimilation methodology, rainfall error estimates, and model

  6. Long term variability of B supergiant winds

    NASA Technical Reports Server (NTRS)

    Massa, Derck L.

    1995-01-01

    The object of this observing proposal was to sample wind variability in B supergiants on a daily basis over a period of several days in order to determine the time scale with which density variability occurs in their winds. Three stars were selected for this project: 69 Cyg (B0 Ib), HD 164402 (B0 Ib), and HD 47240 (B1 Ib). Three grey scale representations of the Si IV lambda lambda 1400 doublet in each star are attached. In these figures, time (in days) increases upward, and the wavelength (in terms of velocity relative to the rest wavelength of the violet component of the doublet) is the abscissa. The spectra are normalized by a minimum absorption (maximum flux) template, so that all changes appear as absorptions. As a result of these observations, we can now state with some certainty that typical B supergiants develop significant wind inhomogeneities with recurrence times of a few days, and that some of these events show signs of strong temporal coherence.

  7. Risk factors and prediction of very short term versus short/intermediate term post-stroke mortality: a data mining approach.

    PubMed

    Easton, Jonathan F; Stephens, Christopher R; Angelova, Maia

    2014-11-01

    Data mining and knowledge discovery as an approach to examining medical data can limit some of the inherent bias in the hypothesis assumptions that can be found in traditional clinical data analysis. In this paper we illustrate the benefits of a data mining inspired approach to statistically analysing a bespoke data set, the academic multicentre randomised control trial, U.K Glucose Insulin in Stroke Trial (GIST-UK), with a view to discovering new insights distinct from the original hypotheses of the trial. We consider post-stroke mortality prediction as a function of days since stroke onset, showing that the time scales that best characterise changes in mortality risk are most naturally defined by examination of the mortality curve. We show that certain risk factors differentiate between very short term and intermediate term mortality. In particular, we show that age is highly relevant for intermediate term risk but not for very short or short term mortality. We suggest that this is due to the concept of frailty. Other risk factors are highlighted across a range of variable types including socio-demographics, past medical histories and admission medication. Using the most statistically significant risk factors we build predictive classification models for very short term and short/intermediate term mortality.

  8. Chromospheric Variability in Sloan Digital Sky Survey M Dwarfs. II. Short-timescale Hα Variability

    NASA Astrophysics Data System (ADS)

    Kruse, E. A.; Berger, E.; Knapp, G. R.; Laskar, T.; Gunn, J. E.; Loomis, C. P.; Lupton, R. H.; Schlegel, D. J.

    2010-10-01

    We present the first comprehensive study of short-timescale chromospheric Hα variability in M dwarfs using the individual 15 minute spectroscopic exposures for 52, 392 objects from the Sloan Digital Sky Survey. Our sample contains about 103-104 objects per spectral type bin in the range M0-M9, with a typical number of three exposures per object (ranging up to a maximum of 30 exposures). Using this extensive data set, we find that about 16% of the sources exhibit Hα emission in at least one exposure, and of those about 45% exhibit Hα emission in all of the available exposures. As in previous studies of Hα activity (L Hα/L bol), we find a rapid increase in the fraction of active objects from M0-M6. However, we find a subsequent decline in later spectral types that we attribute to our use of the individual spectra. Similarly, we find saturated activity at a level of L Hα/L bol ≈ 10-3.6 for spectral types M0-M5 followed by a decline to about 10-4.3 in the range M7-M9. Within the sample of objects with Hα emission, only 26% are consistent with non-variable emission, independent of spectral type. The Hα variability, quantified in terms of the ratio of maximum to minimum Hα equivalent width (R EW), exhibits a rapid rise from M0 to M5, followed by a plateau and a possible decline in M9 objects. In particular, variability with R EW >~ 10 is only observed in objects later than M5, and survival analysis indicates a probability of lsim0.1% that the R EW values for M0-M4 and M5-M9 are drawn from the same distribution. We further find that for an exponential distribution, the R EW values follow N(R EW) vprop exp[ - (R EW - 1)/2.3] for M0-M4 and vpropexp[ - (R EW - 1)/2.9] for M5-M9. Finally, comparing objects with persistent and intermittent Hα emission, we find that the latter exhibit greater variability. Based on these results, we conclude that Hα variability in M dwarfs on timescales of 15 minutes to 1 hr increases with later spectral type, and that the

  9. What are the differences between long-term, short-term, and working memory?

    PubMed Central

    Cowan, Nelson

    2008-01-01

    In the recent literature there has been considerable confusion about the three types of memory: long-term, short-term, and working memory. This chapter strives to reduce that confusion and makes up-to-date assessments of these types of memory. Long- and short-term memory could differ in two fundamental ways, with only short-term memory demonstrating (1) temporal decay and (2) chunk capacity limits. Both properties of short-term memory are still controversial but the current literature is rather encouraging regarding the existence of both decay and capacity limits. Working memory has been conceived and defined in three different, slightly discrepant ways: as short-term memory applied to cognitive tasks, as a multi-component system that holds and manipulates information in short-term memory, and as the use of attention to manage short-term memory. Regardless of the definition, there are some measures of memory in the short term that seem routine and do not correlate well with cognitive aptitudes and other measures (those usually identified with the term “working memory”) that seem more attention demanding and do correlate well with these aptitudes. The evidence is evaluated and placed within a theoretical framework depicted in Fig. 1. PMID:18394484

  10. Transfer of Information from Short- to Long-Term Memory

    ERIC Educational Resources Information Center

    Modigliani, Vito; Seamon, John G.

    1974-01-01

    The present study examined current hypotheses concerning information transfer from short-term memory (STM) to long-term memory (LTM) using a Peterson STM task with word triplets presented over retention intervals of 0, 3, 6, 9, and 18 sec. (Editor)

  11. The role of semantic knowledge in short-term memory.

    PubMed

    Forde, Emer M E; Humphreys, Glyn W

    2002-01-01

    In this paper we examine the role of stored semantic knowledge in recall from short-term memory. We assessed the performance of a patient (FK), who showed a consistent lack of semantic knowledge for some words ('unknown') but not others ('known') on a range of serial recall tasks using both spoken and written words. Overall, FK was significantly better at recalling lists of known compared with unknown words. His recall of unknown words was characterized by numerous phonological errors, such as repeating 'bear skunk' as 'bunk scare'. FK showed a relatively normal primacy effect in immediate recall, but a striking lack of a recency effect. This pattern of performance is useful for constraining theoretical accounts of language production and verbal short-term memory and for understanding the role that long-term semantic knowledge may play in maintaining information in short-term memory.

  12. Verbal short-term memory and vocabulary learning in polyglots.

    PubMed

    Papagno, C; Vallar, G

    1995-02-01

    Polyglot and non-polyglot Italian subjects were given tests assessing verbal (phonological) and visuo-spatial short-term and long-term memory, general intelligence, and vocabulary knowledge in their native language. Polyglots had a superior level of performance in verbal short-term memory tasks (auditory digit span and nonword repetition) and in a paired-associate learning test, which assessed the subjects' ability to acquire new (Russian) words. By contrast, the two groups had comparable performance levels in tasks assessing general intelligence, visuo-spatial short-term memory and learning, and paired-associate learning of Italian words. These findings, which are in line with neuropsychological and developmental evidence, as well as with data from normal subjects, suggest a close relationship between the capacity of phonological memory and the acquisition of foreign languages. PMID:7754088

  13. Short-term energy outlook, quarterly projections, first quarter 1998

    SciTech Connect

    1998-01-01

    The forecast period for this issue of the Outlook extends from the first quarter of 1998 through the fourth quarter of 1999. Values for the fourth quarter of 1997, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in EIA`s Weekly Petroleum Status Report) or are calculated from model simulations that use the latest exogenous information available (for example, electricity sales and generation are simulated by using actual weather data). The historical energy data, compiled in the first quarter 1998 version of the Short-Term Integrated Forecasting System (STIFS) database, are mostly EIA data regularly published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding. The STIFS model is driven principally by three sets of assumptions or inputs: estimates of key macroeconomic variables, world oil price assumptions, and assumptions about the severity of weather. Macroeconomic estimates are adjusted by EIA to reflect EIA assumptions which may affect the macroeconomic outlook. By varying the assumptions, alternative cases are produced by using the STIFS model. 24 figs., 19 tabs.

  14. Short term fluctuations of wind and solar power systems

    NASA Astrophysics Data System (ADS)

    Anvari, M.; Lohmann, G.; Wächter, M.; Milan, P.; Lorenz, E.; Heinemann, D.; Rahimi Tabar, M. Reza; Peinke, Joachim

    2016-06-01

    Wind and solar power are known to be highly influenced by weather events and may ramp up or down abruptly. Such events in the power production influence not only the availability of energy, but also the stability of the entire power grid. By analysing significant amounts of data from several regions around the world with resolutions of seconds to minutes, we provide strong evidence that renewable wind and solar sources exhibit multiple types of variability and nonlinearity in the time scale of seconds and characterise their stochastic properties. In contrast to previous findings, we show that only the jumpy characteristic of renewable sources decreases when increasing the spatial size over which the renewable energies are harvested. Otherwise, the strong non-Gaussian, intermittent behaviour in the cumulative power of the total field survives even for a country-wide distribution of the systems. The strong fluctuating behaviour of renewable wind and solar sources can be well characterised by Kolmogorov-like power spectra and q-exponential probability density functions. Using the estimated potential shape of power time series, we quantify the jumpy or diffusive dynamic of the power. Finally we propose a time delayed feedback technique as a control algorithm to suppress the observed short term non-Gaussian statistics in spatially strong correlated and intermittent renewable sources.

  15. Leukocyte subsets and neutrophil function after short-term spaceflight

    NASA Technical Reports Server (NTRS)

    Stowe, R. P.; Sams, C. F.; Mehta, S. K.; Kaur, I.; Jones, M. L.; Feeback, D. L.; Pierson, D. L.

    1999-01-01

    Changes in leukocyte subpopulations and function after spaceflight have been observed but the mechanisms underlying these changes are not well defined. This study investigated the effects of short-term spaceflight (8-15 days) on circulating leukocyte subsets, stress hormones, immunoglobulin levels, and neutrophil function. At landing, a 1.5-fold increase in neutrophils was observed compared with preflight values; lymphocytes were slightly decreased, whereas the results were variable for monocytes. No significant changes were observed in plasma levels of immunoglobulins, cortisol, or adrenocorticotropic hormone. In contrast, urinary epinephrine, norepinephrine, and cortisol were significantly elevated at landing. Band neutrophils were observed in 9 of 16 astronauts. Neutrophil chemotactic assays showed a 10-fold decrease in the optimal dose response after landing. Neutrophil adhesion to endothelial cells was increased both before and after spaceflight. At landing, the expression of MAC-1 was significantly decreased while L-selectin was significantly increased. These functional alterations may be of clinical significance on long-duration space missions.

  16. Short term effects of airborne pollen concentrations on asthma epidemic

    PubMed Central

    Tobias, A; Galan, I; Banegas, J; Aranguez, E

    2003-01-01

    Methods: This study, based on time series analysis adjusting for meteorological factors and air pollution variables, assessed the short term effects of different types of allergenic pollen on asthma hospital emergencies in the metropolitan area of Madrid (Spain) for the period 1995–8. Results: Statistically significant associations were found for Poaceae pollen (lag of 3 days) and Plantago pollen (lag of 2 days), representing an increase in the range between the 99th and 95th percentiles of 17.1% (95% confidence interval (CI) 3.2 to 32.8) and 15.9% (95% CI 6.5 to 26.2) for Poaceae and Plantago, respectively. A positive association was also observed for Urticaceae (lag of 1 day) with an 8.4% increase (95% CI 2.8 to 14.4). Conclusions: There is an association between pollen levels and asthma related emergencies, independent of the effect of air pollutants. The marked relationship observed for Poaceae and Plantago pollens suggests their implication in the epidemic distribution of asthma during the period coinciding with their abrupt release into the environment. PMID:12885991

  17. Short-term energy outlook: Quarterly projections. Second quarter 1995

    SciTech Connect

    1995-05-02

    The Energy Information Administration (EIA) prepares quarterly, short-term energy supply, demand, and price projections for publication in February, May, August, and November in the Short-Term Energy Outlook (Outlook). An annual supplement analyzes the performance of previous forecasts, compares recent projections with those of other forecasting services, and discusses current topics related to the short-term energy markets. (See Short-Term Energy Outlook Annual Supplement, DOE/EIA-0202.) The forecast period for this issue of the Outlook extends from the second quarter of 1995 through the fourth quarter of 1996. Values for the first quarter of 1995, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in the Weekly Petroleum Status Report) or are calculated from model simulations using the latest exogenous information available (for example, electricity sales and generation are simulated using actual weather data). The historical energy data, compiled into the second quarter 1995 version of the Short-Term Integrated Forecasting System (STIFS) database, are mostly EIA data regularly published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding. The STIFS database is archived quarterly and is available from the National Technical Information Service.

  18. SHORT-TERM MEMORY IS INDEPENDENT OF BRAIN PROTEIN SYNTHESIS

    SciTech Connect

    Davis, Hasker P.; Rosenzweig, Mark R.; Jones, Oliver W.

    1980-09-01

    Male Swiss albino CD-1 mice given a single injection of a cerebral protein synthesis inhibitor, anisomycin (ANI) (1 mg/animal), 20 min prior to single trial passive avoidance training demonstrated impaired retention at tests given 3 hr, 6 hr, 1 day, and 7 days after training. Retention was not significantly different from saline controls when tests were given 0.5 or 1.5 hr after training. Prolonging inhibition of brain protein synthesis by giving either 1 or 2 additional injections of ANI 2 or 2 and 4 hr after training did not prolong short-term retention performance. The temporal development of impaired retention in ANI treated mice could not be accounted for by drug dosage, duration of protein synthesis inhibition, or nonspecific sickness at test. In contrast to the suggestion that protein synthesis inhibition prolongs short-term memory (Quinton, 1978), the results of this experiment indicate that short-term memory is not prolonged by antibiotic drugs that inhibit cerebral protein synthesis. All evidence seems consistent with the hypothesis that short-term memory is protein synthesis independent and that the establishment of long-term memory depends upon protein synthesis during or shortly after training. Evidence for a role of protein synthesis in memory maintenance is discussed.

  19. Language repetition and short-term memory: an integrative framework

    PubMed Central

    Majerus, Steve

    2013-01-01

    Short-term maintenance of verbal information is a core factor of language repetition, especially when reproducing multiple or unfamiliar stimuli. Many models of language processing locate the verbal short-term maintenance function in the left posterior superior temporo-parietal area and its connections with the inferior frontal gyrus. However, research in the field of short-term memory has implicated bilateral fronto-parietal networks, involved in attention and serial order processing, as being critical for the maintenance and reproduction of verbal sequences. We present here an integrative framework aimed at bridging research in the language processing and short-term memory fields. This framework considers verbal short-term maintenance as an emergent function resulting from synchronized and integrated activation in dorsal and ventral language processing networks as well as fronto-parietal attention and serial order processing networks. To-be-maintained item representations are temporarily activated in the dorsal and ventral language processing networks, novel phoneme and word serial order information is proposed to be maintained via a right fronto-parietal serial order processing network, and activation in these different networks is proposed to be coordinated and maintained via a left fronto-parietal attention processing network. This framework provides new perspectives for our understanding of information maintenance at the non-word-, word- and sentence-level as well as of verbal maintenance deficits in case of brain injury. PMID:23874280

  20. Short-term cardiac memory and mother rotor fibrillation.

    PubMed

    Baher, Ali; Qu, Zhilin; Hayatdavoudi, Ashkan; Lamp, Scott T; Yang, Ming-Jim; Xie, Fagen; Turner, Stephen; Garfinkel, Alan; Weiss, James N

    2007-01-01

    Short-term cardiac memory refers to the effects of pacing history on action potential duration (APD). Although the ionic mechanisms for short-term memory occurring over many heartbeats (also called APD accommodation) are poorly understood, they may have important effects on reentry and fibrillation. To explore this issue, we incorporated a generic memory current into the Phase I Luo and Rudy action potential model, which lacks short-term memory. The properties of this current were matched to simulate quantitatively human ventricular monophasic action potential accommodation. We show that, theoretically, short-term memory can resolve the paradox of how mother rotor fibrillation is initiated in heterogeneous tissue by physiological pacing. In simulated heterogeneous two-dimensional tissue and three-dimensional ventricles containing an inward rectifier K(+) current gradient, short-term memory could spontaneously convert multiple wavelet fibrillation to mother rotor fibrillation or to a mixture of both fibrillation types. This was due to progressive acceleration and stabilization of rotors as accumulation of memory shortened APD and flattened APD restitution slope nonuniformly throughout the tissue. PMID:16891403

  1. A Revised Model of Short-Term Memory and Long-Term Learning of Verbal Sequences

    ERIC Educational Resources Information Center

    Burgess, Neil; Hitch, Graham J.

    2006-01-01

    The interaction between short- and long-term memory is studied within a model in which phonemic and (temporal) contextual information have separate influences on immediate verbal serial recall via connections with short- and long-term plasticity [Burgess, N., & Hitch, G.J. (1999). Memory for serial order: a network model of the phonological loop…

  2. Correlation between short-term and long-term intraocular pressure fluctuation in glaucoma patients

    PubMed Central

    Tojo, Naoki; Abe, Shinya; Miyakoshi, Mari; Hayashi, Atsushi

    2016-01-01

    Purpose We investigated correlations between short-term and long-term intraocular pressure (IOP) fluctuations. Methods We examined 50 eyes of glaucoma patients who were followed for >2 years. We measured short-term IOP fluctuation using a Triggerfish® contact lens sensor (CLS). The short-term IOP fluctuation (mVeq) was defined as the difference between the maximum value and the minimum value measured during the 24-hour course with CLS. The long-term IOP fluctuation was defined by four parameters: 1) the mean IOP (mmHg) determined during follow-up; 2) the IOP difference, which was defined as the difference between the maximum IOP and the minimum IOP; 3) the standard deviation of IOP; and 4) the peak IOP, which was defined as the maximum IOP. Correlations between these parameters and the short-term IOP fluctuation were examined. Results The mean follow-up period was 5.4 years. The average IOP was 15.0±4.0 mmHg. The range of short-term IOP fluctuation identified with CLS was significantly correlated with all the four long-term IOP fluctuation parameters. Conclusion Short-term IOP fluctuations were found to be associated with long-term IOP fluctuations. Examination of 24-hour IOP fluctuations with the CLS might be useful for predicting the long-term IOP fluctuation. PMID:27621590

  3. Correlation between short-term and long-term intraocular pressure fluctuation in glaucoma patients

    PubMed Central

    Tojo, Naoki; Abe, Shinya; Miyakoshi, Mari; Hayashi, Atsushi

    2016-01-01

    Purpose We investigated correlations between short-term and long-term intraocular pressure (IOP) fluctuations. Methods We examined 50 eyes of glaucoma patients who were followed for >2 years. We measured short-term IOP fluctuation using a Triggerfish® contact lens sensor (CLS). The short-term IOP fluctuation (mVeq) was defined as the difference between the maximum value and the minimum value measured during the 24-hour course with CLS. The long-term IOP fluctuation was defined by four parameters: 1) the mean IOP (mmHg) determined during follow-up; 2) the IOP difference, which was defined as the difference between the maximum IOP and the minimum IOP; 3) the standard deviation of IOP; and 4) the peak IOP, which was defined as the maximum IOP. Correlations between these parameters and the short-term IOP fluctuation were examined. Results The mean follow-up period was 5.4 years. The average IOP was 15.0±4.0 mmHg. The range of short-term IOP fluctuation identified with CLS was significantly correlated with all the four long-term IOP fluctuation parameters. Conclusion Short-term IOP fluctuations were found to be associated with long-term IOP fluctuations. Examination of 24-hour IOP fluctuations with the CLS might be useful for predicting the long-term IOP fluctuation.

  4. Reconstructing Clusters for Preconditioned Short-term Load Forecasting

    NASA Astrophysics Data System (ADS)

    Itagaki, Tadahiro; Mori, Hiroyuki

    This paper presents a new preconditioned method for short-term load forecasting that focuses on more accurate predicted value. In recent years, the deregulated and competitive power market increases the degree of uncertainty. As a result, more sophisticated short-term load forecasting techniques are required to deal with more complicated load behavior. To alleviate the complexity of load behavior, this paper presents a new preconditioned model. In this paper, clustering results are reconstructed to equalize the number of learning data after clustering with the Kohonen-based neural network. That enhances a short-term load forecasting model at each reconstructed cluster. The proposed method is successfully applied to real data of one-step ahead daily maximum load forecasting.

  5. Short-Termed Integrated Forecasting System: 1993 Model documentation report

    SciTech Connect

    Not Available

    1993-05-01

    The purpose of this report is to define the Short-Term Integrated Forecasting System (STIFS) and describe its basic properties. The Energy Information Administration (EIA) of the US Energy Department (DOE) developed the STIFS model to generate short-term (up to 8 quarters), monthly forecasts of US supplies, demands, imports exports, stocks, and prices of various forms of energy. The models that constitute STIFS generate forecasts for a wide range of possible scenarios, including the following ones done routinely on a quarterly basis: A base (mid) world oil price and medium economic growth. A low world oil price and high economic growth. A high world oil price and low economic growth. This report is written for persons who want to know how short-term energy markets forecasts are produced by EIA. The report is intended as a reference document for model analysts, users, and the public.

  6. Differential effects of reciprocity and attitude similarity across long- versus short-term mating contexts.

    PubMed

    Lehr, Andrew T; Geher, Glenn

    2006-08-01

    Participants were 24 male and 32 female undergraduate and graduate students whom the authors recruited for an examination of the effects of attitude similarity and reciprocity on the degree of attraction toward potential mates. The authors examined the effects of these 2 variables on degree of liking in long-term and short-term contexts. The authors administered a vignette about a bogus stranger to each participant, varying the stranger's attitude similarity with and liking of the participant. The authors enclosed the vignette in a folder that described the stranger as having either very similar or very different attitudes from the participant and that included a passage that notified the participant that the stranger either likes or does not like him or her. The dependent variables included 4 indexes of the extent to which participants reported liking the bogus stranger: a scale that measured short-term mating items, a scale that measured long-term mating items, a degree-of-liking scale, and a behavioral-intention item. Across these 4 attraction-relevant dependent variables, the authors found significant main effects of the reciprocity variable. Also, the authors found a significant main effect of attitude similarity on the likability measure. The authors found significant main effects of reciprocity in a long-term mating context and a short-term mating context. PMID:16894702

  7. Differential effects of reciprocity and attitude similarity across long- versus short-term mating contexts.

    PubMed

    Lehr, Andrew T; Geher, Glenn

    2006-08-01

    Participants were 24 male and 32 female undergraduate and graduate students whom the authors recruited for an examination of the effects of attitude similarity and reciprocity on the degree of attraction toward potential mates. The authors examined the effects of these 2 variables on degree of liking in long-term and short-term contexts. The authors administered a vignette about a bogus stranger to each participant, varying the stranger's attitude similarity with and liking of the participant. The authors enclosed the vignette in a folder that described the stranger as having either very similar or very different attitudes from the participant and that included a passage that notified the participant that the stranger either likes or does not like him or her. The dependent variables included 4 indexes of the extent to which participants reported liking the bogus stranger: a scale that measured short-term mating items, a scale that measured long-term mating items, a degree-of-liking scale, and a behavioral-intention item. Across these 4 attraction-relevant dependent variables, the authors found significant main effects of the reciprocity variable. Also, the authors found a significant main effect of attitude similarity on the likability measure. The authors found significant main effects of reciprocity in a long-term mating context and a short-term mating context.

  8. Short-term treatment of a Central American torture survivor.

    PubMed

    Munczek, D S

    1998-01-01

    The short-term treatment of a Honduran torture survivor is recounted. Torture--the "counter-therapy of the State" (Ritterman 1987, p. 43)--involves intentional physical and psychological destruction of human beings. The socio-political context in which the traumatic events occurred is described, as are the theoretical and ethical assumptions underlying the work. Treatment of victims of organized violence is a formidable challenge. Obstacles and advantages of short-term psychotherapy and use of the therapist's emotional reactions to understand survivors' experiences are emphasized.

  9. Short-Term Teacher Workshops: Examining the Assumption of Teacher-to-Student Transfer.

    ERIC Educational Resources Information Center

    Storti, Janet

    This study explored the feasibility of evaluating the effectiveness of learning transfer from National Aeronautics and Space Administration (NASA) short-term (1 day or less) workshops to the teacher and through the teacher to the student, focusing on attitude toward science, science-related behavior, and knowledge variables. Participants were 33…

  10. Climax spent fuel dosimetry. Short term exposure, 8 March 1983

    SciTech Connect

    Quam, W.; DeVore, T.

    1984-06-01

    The second short-term exposure (performed 8 March 1983) in Hole CFH3 at the Climax Spent Fuel Test site is described. These short-term (1 hour long) exposures are intended to provide an independent measurement of the exposure rate at the wall and the 0.51-m and 0.66-m locations. Only CaF{sub 2} TLD`s were used in the second short-term exposure. Harshaw chips were cut to 0.32 x 0.18 x 0.09 cm size and aged by several exposure/readout/bakeout cycles until all odd chips were weeded out and the remaining chips exhibited stable sensitivities. Exposure at Climax was done by removing the existing long-term dosimetry strings and inserting identical strings using the CaF{sub 2} TLD`s in the stainless steel holders. The first short-term exposure produced absorbed doses as high as {similar_to}000 rads-LiF. The linearity corrections determined for the CaF{sub 2} TLD`s at these exposure levels were {similar_to}2%. The present post-exposure calibration method used calibration doses very close to those encountered in the field.

  11. Short term UV line profile variation in 59 Cyg

    NASA Technical Reports Server (NTRS)

    Grady, C. A.; Doazan, V.; Peters, G. J.; Willis, A.; Snow, T. P.; Aitken, D.; Barker, P. K.; Bolton, C. T.; Henrichs, H.; Kitchen, C. R.

    1982-01-01

    The International ultraviolet Explorer high dispersion spectra of 59 Cyg obtained as part of the long term monitoring program have shown that noticeable variation can occur in C 5 and N 5 on timescales 3 hours t24 to 28 hours. In order to begin to resolve whether these changes occur continuously or sporadically, 48 hours were devoted to monitoring this star in January 1982. The January spectra show no short term variation, which may be consistent with sporadic rather than continuous variation.

  12. 22 CFR 62.21 - Short-term scholars.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... shall satisfy the definition of a short-term scholar as set forth in § 62.4. (e) Cross-cultural... shall be exempted from the requirements of providing cross-cultural activities and orientation as set... listed on the Form DS-2019 if his or her Responsible Officer issues a written authorization of...

  13. End Anchoring in Short-Term Order Memory

    ERIC Educational Resources Information Center

    Farrell, Simon; Lelievre, Anna

    2009-01-01

    Temporally grouping lists has systematic effects on immediate serial recall accuracy, order errors, and recall latencies, and is generally taken to reflect the use of multiple dimensions of ordering in short-term memory. It has been argued that these representations are fully relative, in that all sequence positions are anchored to both the start…

  14. A Short Term Real Time Study in Syntactic Change.

    ERIC Educational Resources Information Center

    Duarte, Maria Eugenia Lamoglia

    Recent research has shown that Brazilian Portuguese is undergoing a change regarding the null subject parameter, evolving from a null subject to a non-null subject language. This paper presents the results of a short term, real time study of speakers of Brazilian Portuguese with low and mid levels of formal education. The study was based on…

  15. The Challenge of Short-Term Service-Learning

    ERIC Educational Resources Information Center

    Tryon, Elizabeth; Stoecker, Randy; Martin, Amy; Seblonka, Kristy; Hilgendorf, Amy; Nellis, Margaret

    2008-01-01

    This paper presents the results of interviews with staff from 64 community organizations regarding their experiences with service-learners. One of the themes that emerged from the interviews focused on concerns related to short-term service-learning commitments that last a semester or less. We explore the challenges presented to community groups…

  16. CONTROLLED, SHORT-TERM DERMAL AND INHALATION EXPOSURE TO CHLOROFORM

    EPA Science Inventory

    Studies were conducted to determine the uptake by humans of chloroform as a result of controlled short-term dermal and inhalation exposures. The approach used continuous real-time breath analysis to determine exhaled-breath profiles and evaluate chloroform kinetics in the huma...

  17. A DAPHNIA MAGNA SHORT-TERM SURVIVAL AND GROWTH TEST

    EPA Science Inventory

    With the change in acceptable test temperatures for invertebrate toxicity tests from <20oC to 25oC, it is now possible to use Daphnia magna for short-term chronic testing. When cultured at 25oC the dry weight of <24 hr old D. magna ranges from 7 to 15 g depending upon nutrition,...

  18. Exogenous Attention Influences Visual Short-Term Memory in Infants

    ERIC Educational Resources Information Center

    Ross-Sheehy, Shannon; Oakes, Lisa M.; Luck, Steven J.

    2011-01-01

    Two experiments examined the hypothesis that developing visual attentional mechanisms influence infants' Visual Short-Term Memory (VSTM) in the context of multiple items. Five- and 10-month-old infants (N = 76) received a change detection task in which arrays of three differently colored squares appeared and disappeared. On each trial one square…

  19. Interference-Based Forgetting in Verbal Short-Term Memory

    ERIC Educational Resources Information Center

    Lewandowsky, Stephan; Geiger, Sonja M.; Oberauer, Klaus

    2008-01-01

    This article presents four experiments that tested predictions of SOB (Serial Order in a Box), an interference-based theory of short-term memory. Central to SOB is the concept of novelty-sensitive encoding, which holds that items are encoded to the extent that they differ from already-encoded information. On the additional assumption that…

  20. Decay uncovered in nonverbal short-term memory.

    PubMed

    Mercer, Tom; McKeown, Denis

    2014-02-01

    Decay theory posits that memory traces gradually fade away over the passage of time unless they are actively rehearsed. Much recent work exploring verbal short-term memory has challenged this theory, but there does appear to be evidence for trace decay in nonverbal auditory short-term memory. Numerous discrimination studies have reported a performance decline as the interval separating two tones is increased, consistent with a decay process. However, most of this tone comparison research can be explained in other ways, without reference to decay, and these alternative accounts were tested in the present study. In Experiment 1, signals were employed toward the end of extended retention intervals to ensure that listeners were alert to the presence and frequency content of the memoranda. In Experiment 2, a mask stimulus was employed in an attempt to distinguish between a highly detailed sensory trace and a longer-lasting short-term memory, and the distinctiveness of the stimuli was varied. Despite these precautions, slow-acting trace decay was observed. It therefore appears that the mere passage of time can lead to forgetting in some forms of short-term memory. PMID:23801385

  1. Validation of a Fish Short-term Reproduction Assay

    EPA Science Inventory

    The Fish Short-term Reproduction Assay is an in vivo assay conducted with fathead minnows and is designed to detect changes in spawning, gross morphology, histopathology, and specific biochemical endpoints that reflect disturbances in the hypothalamic-pituitary-gonadal (HPG) axis...

  2. 47 CFR 74.24 - Short-term operation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... the transmission of the call sign of the associated part 73 broadcast station or broadcast auxiliary... base station, a remote pickup automatic relay station, an aural broadcast STL station, an aural... to commencing short-term operation of a remote pickup broadcast station, a remote pickup...

  3. Short-Term Memory, Executive Control, and Children's Route Learning

    ERIC Educational Resources Information Center

    Purser, Harry R. M.; Farran, Emily K.; Courbois, Yannick; Lemahieu, Axelle; Mellier, Daniel; Sockeel, Pascal; Blades, Mark

    2012-01-01

    The aim of this study was to investigate route-learning ability in 67 children aged 5 to 11 years and to relate route-learning performance to the components of Baddeley's model of working memory. Children carried out tasks that included measures of verbal and visuospatial short-term memory and executive control and also measures of verbal and…

  4. Short Term Skill Training. Alternative Approaches. Information Series No. 222.

    ERIC Educational Resources Information Center

    Paulsen, Russell

    Short term skill training programs are those programs, usually one year or less, designed to train, retrain, or upgrade the skills of workers. Such programs provide an opportunity for postsecondary vocational institutions to respond to the human resource needs of their communities. A number of important policy issues are involved in the provision…

  5. Short-Term Memory Effects in Four Learning Modes.

    ERIC Educational Resources Information Center

    Furukawa, James M.; And Others

    The effect of three levels of short-term memory (STM) and four learning modes (control, chunking organizational strategy, programmed instruction, and adjunct questions) on prose learning and recall was studied. The participants in this study were educational psychology students at Towson State College in Maryland. Significant STM and learning mode…

  6. Valuing Short-Term Study Abroad in Business

    ERIC Educational Resources Information Center

    Loh, Chung-Ping A.; Steagall, Jeffrey W.; Gallo, Andres; Michelman, Jeffrey E.

    2011-01-01

    Short-term study abroad courses often claim to provide a unique experience for students, but it is not clear how the value translates into a dollar amount. The paper uses the contingent valuation method to assess participating students' pre- and post-trip perceived dollar value of their study abroad courses at an AACSB accredited business school.…

  7. Visual Short-Term Memory During Smooth Pursuit Eye Movements

    ERIC Educational Resources Information Center

    Kerzel, Dirk; Ziegler, Nathalie E.

    2005-01-01

    Visual short-term memory (VSTM) was probed while observers performed smooth pursuit eye movements. Smooth pursuit keeps a moving object stabilized in the fovea. VSTM capacity for position was reduced during smooth pursuit compared with a condition with eye fixation. There was no difference between a condition in which the items were approximately…

  8. Retention interval affects visual short-term memory encoding.

    PubMed

    Bankó, Eva M; Vidnyánszky, Zoltán

    2010-03-01

    Humans can efficiently store fine-detailed facial emotional information in visual short-term memory for several seconds. However, an unresolved question is whether the same neural mechanisms underlie high-fidelity short-term memory for emotional expressions at different retention intervals. Here we show that retention interval affects the neural processes of short-term memory encoding using a delayed facial emotion discrimination task. The early sensory P100 component of the event-related potentials (ERP) was larger in the 1-s interstimulus interval (ISI) condition than in the 6-s ISI condition, whereas the face-specific N170 component was larger in the longer ISI condition. Furthermore, the memory-related late P3b component of the ERP responses was also modulated by retention interval: it was reduced in the 1-s ISI as compared with the 6-s condition. The present findings cannot be explained based on differences in sensory processing demands or overall task difficulty because there was no difference in the stimulus information and subjects' performance between the two different ISI conditions. These results reveal that encoding processes underlying high-precision short-term memory for facial emotional expressions are modulated depending on whether information has to be stored for one or for several seconds.

  9. Short-term energy outlook, Quarterly projections. Third quarter 1993

    SciTech Connect

    1993-08-04

    The Energy Information Administration (EIA) prepares quarterly, short-term energy supply, demand, and price projections for publication in February, May, August, and November in the Short-Term Energy Outlook (Outlook). An annual supplement analyzes the performance of previous forecasts, compares recent cases with those of other forecasting services, and discusses current topics related to the short-term energy markets. (See Short-Term Energy Outlook Annual Supplement, DOE/EIA-0202.) The forecast period for this issue of the Outlook extends from the third quarter of 1993 through the fourth quarter of 1994. Values for the second quarter of 1993, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in the Weekly Petroleum Status Report) or are calculated from model simulations using the latest exogenous information available (for example, electricity sales and generation are simulated using actual weather data). The historical energy data are EIA data published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding.

  10. Short-Term Effects of Playing Computer Games on Attention

    ERIC Educational Resources Information Center

    Tahiroglu, Aysegul Yolga; Celik, Gonca Gul; Avci, Ayse; Seydaoglu, Gulsah; Uzel, Mehtap; Altunbas, Handan

    2010-01-01

    Objective: The main aim of the present study is to investigate the short-term cognitive effects of computer games in children with different psychiatric disorders and normal controls. Method: One hundred one children are recruited for the study (aged between 9 and 12 years). All participants played a motor-racing game on the computer for 1 hour.…

  11. A Test of Tactile Concentration and Short-Term Memory.

    ERIC Educational Resources Information Center

    Kainthola, S. D.; Singh, T. B.

    1992-01-01

    Twenty students and 45 adults with visual impairments or blindness were administered a test of tactile concentration and short-term memory involving the reproduction of the order of finger stimulation using the Finger Knocking Box. Reliability and validity scores indicated encouraging results with use of the instrument. (JDD)

  12. Relation between Intelligence and Short-Term Memory

    ERIC Educational Resources Information Center

    Cohen, Ronald L.; Sandberg, Tor

    1977-01-01

    Intelligence and short-term memory correlations in children were measured using probed serial recall of supraspan digit lists. Results showed the predictive power of intelligence to range from a maximum in the case of recall for recency items to practically zero in the case of primacy items. (Author/MV)

  13. Short-Term Energy Outlook: Quarterly projections. Fourth quarter 1993

    SciTech Connect

    Not Available

    1993-11-05

    The Energy Information Administration (EIA) prepares quarterly, short-term energy supply, demand, and price projections for publication in February, May, August, and November in the Short-Term Energy Outlook (Outlook). An annual supplement analyzes the performance of previous forecasts, compares recent cases with those of other forecasting services, and discusses current topics related to the short-term energy markets. (See Short-Term Energy Outlook Annual Supplement, DOE/EIA-0202.) The forecast period for this issue of the Outlook extends from the fourth quarter of 1993 through the fourth quarter of 1994. Values for the third quarter of 1993, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in the Weekly Petroleum Status Report) or are calculated from model simulations using the latest exogenous information available (for example, electricity sales and generation are simulated using actual weather data). The historical energy data are EIA data published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications.

  14. Assurance of Learning in Short-Term, Study Abroad Programs

    ERIC Educational Resources Information Center

    Tucker, Mary L.; Gullekson, Nicole L.; McCambridge, Jim

    2011-01-01

    Business students are increasingly seeking international experience in short-term, study abroad programs to enhance their intercultural knowledge, intercultural communication skills, and global perspectives to be more competitive in the global arena. Intuitively, universities initiating these programs and the students sojourning abroad believe in…

  15. Short-term energy outlook. Quarterly projections, second quarter 1996

    SciTech Connect

    1996-04-01

    The Energy Information Administration prepares quarterly, short-term energy supply, demand, and price projections. The forecasts in this issue cover the second quarter of 1996 through the fourth quarter of 1997. Changes to macroeconomic measures by the Bureau of Economic Analysis have been incorporated into the STIFS model used.

  16. Short-term storage of Atlantic sturgeon spermatozoa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is significant interest to restore the Atlantic sturgeon, a species of concern. Biologists are interested in both the short-term storage and cryopreservation of semen to maximize availability of viable spermatozoa whenever a rare ripe female is found and available for spawning. We conducted sh...

  17. Short-Term Therapy: A Shift in Thinking.

    ERIC Educational Resources Information Center

    Fuhriman, Addie

    1992-01-01

    Responds to previous article by Steenbarger on science-practice integration in brief counseling and therapy. Considers three dimensions that emerge from the integrated analysis presented in Steenbarger's article: catalysis, involvement, and time. Discusses each of these three characteristics as they are related specifically to a short-term format.…

  18. Short-term load forecasting using neural network for future smart grid application

    NASA Astrophysics Data System (ADS)

    Zennamo, Joseph Anthony, III

    Short-term load forecasting of power system has been a classic problem for a long time. Not merely it has been researched extensively and intensively, but also a variety of forecasting methods has been raised. This thesis outlines some aspects and functions of smart meter. It also presents different policies and current statuses as well as future projects and objectives of SG development in several countries. Then the thesis compares main aspects about latest products of smart meter from different companies. Lastly, three types of prediction models are established in MATLAB to emulate the functions of smart grid in the short-term load forecasting, and then their results are compared and analyzed in terms of accuracy. For this thesis, more variables such as dew point temperature are used in the Neural Network model to achieve more accuracy for better short-term load forecasting results.

  19. Semantic and phonological contributions to short-term repetition and long-term cued sentence recall.

    PubMed

    Meltzer, Jed A; Rose, Nathan S; Deschamps, Tiffany; Leigh, Rosie C; Panamsky, Lilia; Silberberg, Alexandra; Madani, Noushin; Links, Kira A

    2016-02-01

    The function of verbal short-term memory is supported not only by the phonological loop, but also by semantic resources that may operate on both short and long time scales. Elucidation of the neural underpinnings of these mechanisms requires effective behavioral manipulations that can selectively engage them. We developed a novel cued sentence recall paradigm to assess the effects of two factors on sentence recall accuracy at short-term and long-term stages. Participants initially repeated auditory sentences immediately following a 14-s retention period. After this task was complete, long-term memory for each sentence was probed by a two-word recall cue. The sentences were either concrete (high imageability) or abstract (low imageability), and the initial 14-s retention period was filled with either an undemanding finger-tapping task or a more engaging articulatory suppression task (Exp. 1, counting backward by threes; Exp. 2, repeating a four-syllable nonword). Recall was always better for the concrete sentences. Articulatory suppression reduced accuracy in short-term recall, especially for abstract sentences, but the sentences initially recalled following articulatory suppression were retained better at the subsequent cued-recall test, suggesting that the engagement of semantic mechanisms for short-term retention promoted encoding of the sentence meaning into long-term memory. These results provide a basis for using sentence imageability and subsequent memory performance as probes of semantic engagement in short-term memory for sentences.

  20. Business Students' Choice of Short-Term or Long-Term Study Abroad Opportunities

    ERIC Educational Resources Information Center

    Fitzsimmons, Stacey R.; Flanagan, David J.; Wang, Xiaodan

    2013-01-01

    Recent years have seen a proliferation of short-term study abroad opportunities. Although they are both supplementing and replacing semester-long study abroad programs, research has focused primarily on semester (long-term) programs. We draw on the theory of planned behavior (TPB) to explore factors that predict why students choose long-term and…

  1. VALIDATION OF A METHOD FOR ESTIMATING LONG-TERM EXPOSURES BASED ON SHORT-TERM MEASUREMENTS

    EPA Science Inventory

    A method for estimating long-term exposures from short-term measurements is validated using data from a recent EPA study of exposure to fine particles. The method was developed a decade ago but long-term exposure data to validate it did not exist until recently. In this paper, ...

  2. Long-term X-ray Variability of NGC 4945

    SciTech Connect

    Miller, Amara; /UC, Davis /SLAC

    2007-08-29

    Though short-term X-ray variability has been studied for the active galaxy NGC 4945, long-term studies promise to contribute to our understanding of the processes involved in accretion onto supermassive black holes. In order to understand the relationship between black hole mass and breaks in the power spectral density (PSD), the long-term X-ray variability of NGC 4945 was studied over the energy range 8-30 keV. Observations occurred over the year 2006 using the Rossi X-ray Timing Explorer. The data was reduced using the package FTOOLS, most notably the scripts Rex and faxbary. Light curves were produced and a PSD was obtained using a Fast Fourier Transform algorithm. Preliminary studies of the light curve show greater X-ray variability at higher frequencies. This result complements previous studies of NGC 4945 by Martin Mueller. However, the PSD produced must go through further study before accurate results can be obtained. A way to account for the window function of the PSD must be found before the behavior at lower frequencies can be studied with accuracy and the relationship between black hole mass and the break in NGC 4945's PSD can be better understood. Further work includes exploration into ways to subtract the window function from the PSD, as well as a closer analysis of the PSD produced by averaging the data into logarithmic bins. The possibility of a better way to bin the data should be considered so that the window function would be minimized.

  3. Short-term load forecasting using an artificial neural network

    SciTech Connect

    Lee, K.Y.; Cha, Y.T. ); Park, J.H. )

    1992-02-01

    Artificial Neural Network (ANN) Method is applied to forecast the short-term load for a large power system. The load has two distinct patterns: weekday and weekend-day patterns. The weekend-day pattern include Saturday, Sunday, and Monday loads. In this paper a nonlinear load model is proposed and several structures of ANN for short-term load forecasting are tested. Inputs to the ANN are past loads and the output of the ANN is the load forecast for a given day. The network with one or two hidden layers are tested with various combination of neurons, and results are compared in terms of forecasting error. The neural network, when grouped into different load patterns, gives good load forecast.

  4. Short-term synaptic plasticity and heterogeneity in neural systems

    NASA Astrophysics Data System (ADS)

    Mejias, J. F.; Kappen, H. J.; Longtin, A.; Torres, J. J.

    2013-01-01

    We review some recent results on neural dynamics and information processing which arise when considering several biophysical factors of interest, in particular, short-term synaptic plasticity and neural heterogeneity. The inclusion of short-term synaptic plasticity leads to enhanced long-term memory capacities, a higher robustness of memory to noise, and irregularity in the duration of the so-called up cortical states. On the other hand, considering some level of neural heterogeneity in neuron models allows neural systems to optimize information transmission in rate coding and temporal coding, two strategies commonly used by neurons to codify information in many brain areas. In all these studies, analytical approximations can be made to explain the underlying dynamics of these neural systems.

  5. Assessment of highly active dune mobility in the medium, short and very short term

    NASA Astrophysics Data System (ADS)

    Navarro, Marina; Muñoz-Pérez, Juan J.; Román-Sierra, Jorge; Tsoar, Haim; Rodríguez, Inmaculada; Gómez-Pina, Gregorio

    2011-06-01

    Dune activity or stability has usually been studied over long time periods; however, this may not reflect changes that occur in the short term, especially for highly active dunefields. Extreme wind conditions that are generated near the Strait of Gibraltar (SW Spain) have given rise to the transgressive Valdevaqueros dunefield. The current work focuses on analyzing the sand drift potential and the evolution of the dune profile in the medium term (months), the short term (days) and the very short term (hours). Topographic data, which were collected with a differential GPS, were interpreted from reconstructed empirical orthogonal functions (EOF). The results showed that generally the dune profile presented shifting morphologies, especially around the crest and brink, and a trend towards migration to a gentler steady state. As a result, the leeward side adopted continuous slope variations during the different survey periods, whereas the windward slope did not undergo any significant change. Lateral and vertical displacements were analyzed during a severe easterly sandstorm, when the dune brink experienced an advance migration rate of 1.75 m in 24 h. Sand transport rates of 25.5-36.5 m 3 m - 1 month - 1 , 22.52 m 3 m - 1 day - 1 and 0.93 m 3 m - 1 h - 1 were measured for the medium term, short term and very short term, respectively. These values were compared to the theoretical sand transport rate for Valdevaqueros dune, based on the classic Bagnold equation as well other more recent formulae, to obtain a ratio between the real and the theoretical rates for each study period. These results together with the sand drift potential (up to 10,000 vector units) demonstrate that Valdevaqueros (Tarifa) is a dunefield with one of the highest sand transport capacities in Europe.

  6. 2-arachidonoylglycerol signaling impairs short-term fear extinction.

    PubMed

    Hartley, N D; Gunduz-Cinar, O; Halladay, L; Bukalo, O; Holmes, A; Patel, S

    2016-03-01

    Impairments in fear extinction are thought to be central to the psychopathology of posttraumatic stress disorder, and endocannabinoid (eCB) signaling has been strongly implicated in extinction learning. Here we utilized the monoacylglycerol lipase inhibitor JZL184 to selectively augment brain 2-AG levels combined with an auditory cue fear-conditioning paradigm to test the hypothesis that 2-AG-mediated eCB signaling modulates short-term fear extinction learning in mice. We show that systemic JZL184 impairs short-term extinction learning in a CB1 receptor-dependent manner without affecting non-specific freezing behavior or the acquisition of conditioned fear. This effect was also observed in over-conditioned mice environmentally manipulated to re-acquire fear extinction. Cumulatively, the effects of JZL184 appear to be partly due to augmentation of 2-AG signaling in the basolateral nucleus of the amygdala (BLA), as direct microinfusion of JZL184 into the BLA produced similar results. Moreover, we elucidate a short ~3-day temporal window during which 2-AG augmentation impairs extinction behavior, suggesting a preferential role for 2-AG-mediated eCB signaling in the modulation of short-term behavioral sequelae to acute traumatic stress exposure.

  7. 2-arachidonoylglycerol signaling impairs short-term fear extinction

    PubMed Central

    Hartley, N D; Gunduz-Cinar, O; Halladay, L; Bukalo, O; Holmes, A; Patel, S

    2016-01-01

    Impairments in fear extinction are thought to be central to the psychopathology of posttraumatic stress disorder, and endocannabinoid (eCB) signaling has been strongly implicated in extinction learning. Here we utilized the monoacylglycerol lipase inhibitor JZL184 to selectively augment brain 2-AG levels combined with an auditory cue fear-conditioning paradigm to test the hypothesis that 2-AG-mediated eCB signaling modulates short-term fear extinction learning in mice. We show that systemic JZL184 impairs short-term extinction learning in a CB1 receptor-dependent manner without affecting non-specific freezing behavior or the acquisition of conditioned fear. This effect was also observed in over-conditioned mice environmentally manipulated to re-acquire fear extinction. Cumulatively, the effects of JZL184 appear to be partly due to augmentation of 2-AG signaling in the basolateral nucleus of the amygdala (BLA), as direct microinfusion of JZL184 into the BLA produced similar results. Moreover, we elucidate a short ~3-day temporal window during which 2-AG augmentation impairs extinction behavior, suggesting a preferential role for 2-AG-mediated eCB signaling in the modulation of short-term behavioral sequelae to acute traumatic stress exposure. PMID:26926885

  8. Ordered Short-Term Memory Differs in Signers and Speakers: Implications for Models of Short-Term Memory

    ERIC Educational Resources Information Center

    Bavelier, Daphne; Newport, Elissa L.; Hall, Matt; Supalla, Ted; Boutla, Mrim

    2008-01-01

    Capacity limits in linguistic short-term memory (STM) are typically measured with forward span tasks in which participants are asked to recall lists of words in the order presented. Using such tasks, native signers of American Sign Language (ASL) exhibit smaller spans than native speakers ([Boutla, M., Supalla, T., Newport, E. L., & Bavelier, D.…

  9. Short-term memory load and pronunciation rate

    NASA Technical Reports Server (NTRS)

    Schweickert, Richard; Hayt, Cathrin

    1988-01-01

    In a test of short-term memory recall, two subjects attempted to recall various lists. For unpracticed subjects, the time it took to read the list is a better predictor of immediate recall than the number of items on the list. For practiced subjects, the two predictors do about equally well. If the items that must be recalled are unfamiliar, it is advantageous to keep the items short to pronounce. On the other hand, if the same items will be encountered over and over again, it is advantageous to make them distinctive, even at the cost of adding to the number of syllables.

  10. Speed selectivity in visual short term memory for motion.

    PubMed

    McKeefry, D J; Burton, M P; Vakrou, C

    2007-08-01

    In this study we employed a 'memory masking' paradigm to determine which stimulus attributes are important in the storage of information about the speed of moving grating stimuli in visual short term memory (VSTM). Delayed speed discrimination thresholds were measured in the presence of masking stimuli which varied in terms of their spatial and temporal frequency content. Memory masking results demonstrate that it is genuinely the speed of the stimulus, as opposed to temporal or spatial frequency content, that is crucial in the retention of information about motion in visual short term memory. The property of speed selectivity exhibited by VSTM mirrors that reported for neurons in area V5/MT, a brain area crucial for the processing of visual motion in primate brain. This link between area V5/MT and VSTM for motion is consistent with current views which suggest that there is a close association between the neural mechanisms involved in the analysis of sensory information and those involved in its retention in short term memory.

  11. Auditory short-term memory activation during score reading.

    PubMed

    Simoens, Veerle L; Tervaniemi, Mari

    2013-01-01

    Performing music on the basis of reading a score requires reading ahead of what is being played in order to anticipate the necessary actions to produce the notes. Score reading thus not only involves the decoding of a visual score and the comparison to the auditory feedback, but also short-term storage of the musical information due to the delay of the auditory feedback during reading ahead. This study investigates the mechanisms of encoding of musical information in short-term memory during such a complicated procedure. There were three parts in this study. First, professional musicians participated in an electroencephalographic (EEG) experiment to study the slow wave potentials during a time interval of short-term memory storage in a situation that requires cross-modal translation and short-term storage of visual material to be compared with delayed auditory material, as it is the case in music score reading. This delayed visual-to-auditory matching task was compared with delayed visual-visual and auditory-auditory matching tasks in terms of EEG topography and voltage amplitudes. Second, an additional behavioural experiment was performed to determine which type of distractor would be the most interfering with the score reading-like task. Third, the self-reported strategies of the participants were also analyzed. All three parts of this study point towards the same conclusion according to which during music score reading, the musician most likely first translates the visual score into an auditory cue, probably starting around 700 or 1300 ms, ready for storage and delayed comparison with the auditory feedback.

  12. Verbal Short-Term Memory Reflects the Organization of Long-Term Memory: Further Evidence from Short-Term Memory for Emotional Words

    ERIC Educational Resources Information Center

    Majerus, Steve; D'Argembeau, Arnaud

    2011-01-01

    Many studies suggest that long-term lexical-semantic knowledge is an important determinant of verbal short-term memory (STM) performance. This study explored the impact of emotional valence on word immediate serial recall as a further lexico-semantic long-term memory (LTM) effect on STM. This effect is particularly interesting for the study of…

  13. Terrestrial short-term ecotoxicity of a green formicide.

    PubMed

    Tiepo, Erasmo N; Corrêa, Albertina X R; Resgalla, Charrid; Cotelle, Sylvie; Férard, Jean-François; Radetski, Claudemir M

    2010-07-01

    When ants become annoying, large quantities of formicide are applied to terrestrial ecosystems in tropical regions, but awareness of the health and environmental impacts related to the use of synthetic pesticides has been increasing. The use of green pesticides to combat target organisms could reduce these impacts. In this regard, terrestrial ecotoxicity tests with higher plants (Brassica olaracea, Lactuca sativa and Mucuna aterrima), annelids (Eisenia foetida), Collembola (Folsomia candida) and soil enzyme activity analysis (diacetate fluorescein hydrolysis) were used to evaluate short-term terrestrial ecotoxicity of a green pesticide prepared from naturally-occurring organic compounds. At the highest formicide concentration tested in these experiments (i.e., 50 g kg(-1) soil) no toxicity toward terrestrial organisms was observed. The lack of short-term terrestrial ecotoxicity suggest that this green formicide can be classed as an environmentally friendly product as compared to the ecotoxicity of the most commonly used commercialized formicides.

  14. SHORT-TERM N215-INCORPORATION BY AZOTOBACTER1

    PubMed Central

    Bulen, W. A.; LeComte, J. R.; Bales, H. E.

    1963-01-01

    Bulen, W. A. (Charles F. Kettering Research Laboratory, Yellow Springs, Ohio), J. R. LeComte, and H. E. Bales. Short-term N215-incorporation by Azotobacter. J. Bacteriol. 85:666–670. 1963.—Short-term N215-incorporation measurements were used to determine which of the growth requirements were necessary for nitrogen fixation by Azotobacter agilis (A. vinelandii). Normal cells required neither added iron nor molybdenum, but a marked stimulation by Na+ and a minor stimulation by Mg2+ were observed. The Na+ stimulation was not accompanied by an increase in O2 uptake. A lag period preceded the response of molybdenum-deficient cells to added Mo. In systems employing 10 and 20% O2 with 10% N215 in the gas phase, O2 appeared to be both required and inhibitory. These observations may be helpful in attempts to fractionate cell-free nitrogen-fixing systems from this aerobe. PMID:14042947

  15. Vasopressin analogues and spatial short-term memory in rats.

    PubMed

    Buresová, O; Skopková, J

    1980-01-01

    The effect of vasopressin analogues on short-term memory was tested in the 12-arm radical maze. After the first 6 choices rat (n = 16) were removed from the apparatus and allowed to complete the remaining 6 choices 20 min later. Whereas desgly-NH2-VP, AVP, dAVP and dDAVP (3.0 mu/kg) administered 40 min before or immediately after the first 6 choices did not change the incidence of errors in the second series of choices (2.0 errors under control conditions), similarly applied dDAVP deteriorated the rat's performance almost to the chance level of 3 errors. The significance of short-term memory tests for assessing the mnestic role of peptide hormones is stressed.

  16. Short-term case mix management with linear programming.

    PubMed

    Hughes, W L; Soliman, S Y

    1985-01-01

    One short-term economic incentive created by a prospective payment system based on diagnosis-related groups (DRGs) is for hospital managers to optimally and efficiently use the hospital's current mix of services to maximize net contribution. DRGs provide a managerial definition of the hospital's product by determining the number of patients discharged within each of the 467 groupings. Thus, the DRG case mix can be thought of as the hospital's product mix. As in major industry, linear programming models may prove useful in determining the hospital's financially optimal case mix. This article provides a framework for applying the linear programming concept to case mix planning in the hospital setting. It also presents an illustration and interpretation of a linear programming model that provides information about the short-term optimal case mix.

  17. Short-term hydroelectric generation model. Model documentation report

    SciTech Connect

    1996-12-01

    The purpose of this report is to define the objectives of the Energy Information Administration`s (EIA) Short-Term Hydroelectric Generation Model (STHGM), describe its basic approach, and to provide details on the model structure. This report is intended as a reference document for model analysts, users, and the general public. Documentation of the model is in accordance with the EIA`s legal obligation to provide adequate documentation in support of its models.

  18. An ethics curriculum for short-term global health trainees

    PubMed Central

    2013-01-01

    Background Interest in short-term global health training and service programs continues to grow, yet they can be associated with a variety of ethical issues for which trainees or others with limited global health experience may not be prepared to address. Therefore, there is a clear need for educational interventions concerning these ethical issues. Methods We developed and evaluated an introductory curriculum, “Ethical Challenges in Short-term Global Health Training.” The curriculum was developed through solicitation of actual ethical issues experienced by trainees and program leaders; content drafting; and external content review. It was then evaluated from November 1, 2011, through July 1, 2012, by analyzing web usage data and by conducting user surveys. The survey included basic demographic data; prior experience in global health and global health ethics; and assessment of cases within the curriculum. Results The ten case curriculum is freely available at http://ethicsandglobalhealth.org. An average of 238 unique visitors accessed the site each month (standard deviation, 19). Of users who had been abroad before for global health training or service, only 31% reported prior ethics training related to short-term work. Most users (62%) reported accessing the site via personal referral or their training program; however, a significant number (28%) reported finding the site via web search, and 8% discovered it via web links. Users represented different fields: medicine (46%), public health (15%), and nursing (11%) were most common. All cases in the curriculum were evaluated favorably. Conclusions The curriculum is meeting a critical need for an introduction to the ethical issues in short-term global health training. Future work will integrate this curriculum within more comprehensive curricula for global health and evaluate specific knowledge and behavioral effects, including at training sites abroad. PMID:23410089

  19. Electricity price short-term forecasting using artificial neural networks

    SciTech Connect

    Szkuta, B.R.; Sanabria, L.A.; Dillon, T.S.

    1999-08-01

    This paper presents the System Marginal Price (SMP) short-term forecasting implementation using the Artificial Neural Networks (ANN) computing technique. The described approach uses the three-layered ANN paradigm with back-propagation. The retrospective SMP real-world data, acquired from the deregulated Victorian power system, was used for training and testing the ANN. The results presented in this paper confirm considerable value of the ANN based approach in forecasting the SMP.

  20. "Short and long-term therapies in psychosomatic disorders".

    PubMed

    Philippopoulos, G S

    Narcoanalysis (narcosynthesis) as well as psychoanalytically oriented psychotherapy (psychoanalytic psychotherapy) are both, in my opinion, practical and useful short-term methods of therapy in psychosomatic disorders. Psychoanalytic psychoterapy may also be used as an alternative to narcoanalysis when the latter method decisively fails the therapist. In selecting candidates for psychotherapy in psychosomatic practice, 3 essential factors should be taken into consideration, viz. the time of onset of the illness, the patient's personality structure and his intellectual capacities. PMID:1052268

  1. Cardioprotective Signature of Short-Term Caloric Restriction

    PubMed Central

    Isserlin, Ruth; Arab, Sara; Momen, Abdul; Cheng, Henry S.; Wu, Jun; Afroze, Talat; Li, Ren-Ke; Fish, Jason E.; Bader, Gary D.; Husain, Mansoor

    2015-01-01

    Objective To understand the molecular pathways underlying the cardiac preconditioning effect of short-term caloric restriction (CR). Background Lifelong CR has been suggested to reduce the incidence of cardiovascular disease through a variety of mechanisms. However, prolonged adherence to a CR life-style is difficult. Here we reveal the pathways that are modulated by short-term CR, which are associated with protection of the mouse heart from ischemia. Methods Male 10-12 wk old C57bl/6 mice were randomly assigned to an ad libitum (AL) diet with free access to regular chow, or CR, receiving 30% less food for 7 days (d), prior to myocardial infarction (MI) via permanent coronary ligation. At d8, the left ventricles (LV) of AL and CR mice were collected for Western blot, mRNA and microRNA (miR) analyses to identify cardioprotective gene expression signatures. In separate groups, infarct size, cardiac hemodynamics and protein abundance of caspase 3 was measured at d2 post-MI. Results This short-term model of CR was associated with cardio-protection, as evidenced by decreased infarct size (18.5±2.4% vs. 26.6±1.7%, N=10/group; P=0.01). mRNA and miR profiles pre-MI (N=5/group) identified genes modulated by short-term CR to be associated with circadian clock, oxidative stress, immune function, apoptosis, metabolism, angiogenesis, cytoskeleton and extracellular matrix (ECM). Western blots pre-MI revealed CR-associated increases in phosphorylated Akt and GSK3ß, reduced levels of phosphorylated AMPK and mitochondrial related proteins PGC-1α, cytochrome C and cyclooxygenase (COX) IV, with no differences in the levels of phosphorylated eNOS or MAPK (ERK1/2; p38). CR regimen was also associated with reduced protein abundance of cleaved caspase 3 in the infarcted heart and improved cardiac function. PMID:26098549

  2. Short-term energy outlook. Volume 2. Methodology

    NASA Astrophysics Data System (ADS)

    1983-05-01

    Recent changes in forecasting methodology for nonutility distillate fuel oil demand and for the near-term petroleum forecasts are discussed. The accuracy of previous short-term forecasts of most of the major energy sources published in the last 13 issues of the Outlook is evaluated. Macroeconomic and weather assumptions are included in this evaluation. Energy forecasts for 1983 are compared. Structural change in US petroleum consumption, the use of appropriate weather data in energy demand modeling, and petroleum inventories, imports, and refinery runs are discussed.

  3. Variable cosmological term \\varLambda(t)

    NASA Astrophysics Data System (ADS)

    Socorro, J.; D'oleire, M.; Pimentel, Luis O.

    2015-11-01

    We present the case of time-varying cosmological term \\varLambda(t). The main idea arises by proposing that as in the cosmological constant case, the scalar potential is identified as V(φ)=2\\varLambda, with \\varLambda a constant, this identification should be kept even when the cosmological term has a temporal dependence, i.e., V(φ(t))=2\\varLambda(t). We use the Lagrangian formalism for a scalar field φ with standard kinetic energy and arbitrary potential V(φ) and apply this model to the Friedmann-Robertson-Walker (FRW) cosmology. Exact solutions of the field equations are obtained by a special ansatz to solve the Einstein-Klein-Gordon equation and a particular potential for the scalar field and barotropic perfect fluid. We present the evolution on this cosmological term with different scenarios.

  4. Short-term memory deficit after focal parietal damage.

    PubMed

    Markowitsch, H J; Kalbe, E; Kessler, J; von Stockhausen, H M; Ghaemi, M; Heiss, W D

    1999-12-01

    The neuropsychological symptomatology is reported for a 44-year-old patient of normal intelligence, EE, after removal of a circumscribed left hemispheric tumor the major part of which was located in the angular gyrus and in the subcortical white matter. EE had a distinct and persistent short-term memory impairment together with an equally severe impairment in transcoding numbers. On the other hand, his performance was flawless in calculation tasks and in all other tests involving number processing. Impairments in language tests could be attributed to his short-term memory deficit, which furthermore was characterized by a strong primacy effect in the absence of a recency effect. His graphomotoric output was temporarily inhibited. The patient, with a strong left-sided dominance, manifested a bi-hemispherical activation of the Broca and Wernicke regions in a positron-emission-tomographic investigation when required to produce verbs which he was to derive from nouns. The findings in EE suggest that unilateral and restricted lateral parietal damage can result in a profound short-term memory deficit together with a transcoding deficit for stimuli extending over only a few digits or syllables in the absence of any symptoms of the Gerstmann syndrome.

  5. Does tonality boost short-term memory in congenital amusia?

    PubMed

    Albouy, Philippe; Schulze, Katrin; Caclin, Anne; Tillmann, Barbara

    2013-11-01

    Congenital amusia is a neuro-developmental disorder of music perception and production. Recent findings have demonstrated that this deficit is linked to an impaired short-term memory for tone sequences. As it has been shown before that non-musicians' implicit knowledge of musical regularities can improve short-term memory for tone information, the present study investigated if this type of implicit knowledge could also influence amusics' short-term memory performance. Congenital amusics and their matched controls, who were non-musicians, had to indicate whether sequences of five tones, presented in pairs, were the same or different; half of the pairs respected musical regularities (tonal sequences) and the other half did not (atonal sequences). As previously reported for non-musician participants, the control participants showed better performance (as measured with d') for tonal sequences than for atonal ones. While this improvement was not observed in amusics, both control and amusic participants showed faster response times for tonal sequences than for atonal sequences. These findings suggest that some implicit processing of tonal structures is potentially preserved in congenital amusia. This observation is encouraging as it strengthens the perspective to exploit implicit knowledge to help reducing pitch perception and memory deficits in amusia. PMID:24041778

  6. Robust short-term memory without synaptic learning.

    PubMed

    Johnson, Samuel; Marro, J; Torres, Joaquín J

    2013-01-01

    Short-term memory in the brain cannot in general be explained the way long-term memory can--as a gradual modification of synaptic weights--since it takes place too quickly. Theories based on some form of cellular bistability, however, do not seem able to account for the fact that noisy neurons can collectively store information in a robust manner. We show how a sufficiently clustered network of simple model neurons can be instantly induced into metastable states capable of retaining information for a short time (a few seconds). The mechanism is robust to different network topologies and kinds of neural model. This could constitute a viable means available to the brain for sensory and/or short-term memory with no need of synaptic learning. Relevant phenomena described by neurobiology and psychology, such as local synchronization of synaptic inputs and power-law statistics of forgetting avalanches, emerge naturally from this mechanism, and we suggest possible experiments to test its viability in more biological settings. PMID:23349664

  7. An approach to distribution short-term load forecasting

    SciTech Connect

    Stratton, R.C.; Gaustad, K.L.

    1995-03-01

    This paper reports on the developments and findings of the Distribution Short-Term Load Forecaster (DSTLF) research activity. The objective of this research is to develop a distribution short-term load forecasting technology consisting of a forecasting method, development methodology, theories necessary to support required technical components, and the hardware and software tools required to perform the forecast The DSTLF consists of four major components: monitored endpoint load forecaster (MELF), nonmonitored endpoint load forecaster (NELF), topological integration forecaster (TIF), and a dynamic tuner. These components interact to provide short-term forecasts at various points in the, distribution system, eg., feeder, line section, and endpoint. This paper discusses the DSTLF methodology and MELF component MELF, based on artificial neural network technology, predicts distribution endpoint loads for an hour, a day, and a week in advance. Predictions are developed using time, calendar, historical load, and weather data. The overall DSTLF architecture and a prototype MELF module for retail endpoints have been developed. Future work will be focused on refining and extending MELF and developing NELF and TIF capabilities.

  8. Short-term memory in zebrafish (Danio rerio).

    PubMed

    Jia, Jason; Fernandes, Yohaan; Gerlai, Robert

    2014-08-15

    Learning and memory represent perhaps the most complex behavioral phenomena. Although their underlying mechanisms have been extensively analyzed, only a fraction of the potential molecular components have been identified. The zebrafish has been proposed as a screening tool with which mechanisms of complex brain functions may be systematically uncovered. However, as a relative newcomer in behavioral neuroscience, the zebrafish has not been well characterized for its cognitive and mnemonic features, thus learning and/or memory screens with adults have not been feasible. Here we study short-term memory of adult zebrafish. We show animated images of conspecifics (the stimulus) to the experimental subject during 1 min intervals on ten occasions separated by different (2, 4, 8 or 16 min long) inter-stimulus intervals (ISI), a between subject experimental design. We quantify the distance of the subject from the image presentation screen during each stimulus presentation interval, during each of the 1-min post-stimulus intervals immediately following the stimulus presentations and during each of the 1-min intervals furthest away from the last stimulus presentation interval and just before the next interval (pre-stimulus interval), respectively. Our results demonstrate significant retention of short-term memory even in the longest ISI group but suggest no acquisition of reference memory. Because in the employed paradigm both stimulus presentation and behavioral response quantification is computer automated, we argue that high-throughput screening for drugs or mutations that alter short-term memory performance of adult zebrafish is now becoming feasible.

  9. Robust Short-Term Memory without Synaptic Learning

    PubMed Central

    Johnson, Samuel; Marro, J.; Torres, Joaquín J.

    2013-01-01

    Short-term memory in the brain cannot in general be explained the way long-term memory can – as a gradual modification of synaptic weights – since it takes place too quickly. Theories based on some form of cellular bistability, however, do not seem able to account for the fact that noisy neurons can collectively store information in a robust manner. We show how a sufficiently clustered network of simple model neurons can be instantly induced into metastable states capable of retaining information for a short time (a few seconds). The mechanism is robust to different network topologies and kinds of neural model. This could constitute a viable means available to the brain for sensory and/or short-term memory with no need of synaptic learning. Relevant phenomena described by neurobiology and psychology, such as local synchronization of synaptic inputs and power-law statistics of forgetting avalanches, emerge naturally from this mechanism, and we suggest possible experiments to test its viability in more biological settings. PMID:23349664

  10. VLT Spectroscopy of Four Short Period Cataclysmic Variables

    NASA Astrophysics Data System (ADS)

    Skinner, Julie N.; Howell, S. B.; Mason, E.

    2006-12-01

    VLT UVES spectroscopy of four short period, non-magnetic cataclysmic variable stars is presented. The stars observed were GW Lib, BW Scl, VY Aqr, and Z Cha. The 0.1A resolution spectra were uses to measure line strengths and velocity information. Using these measured values, physical parameters, such as the stellar masses, the binary inclination, and the nature of the accretion disk were determined. Mass constraints in the stars BW Scl and GW Lib strongly suggest that the mass donors are likely to be degenerate stars with masses less than 0.06 M-sun. Skinner's research was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation through Scientific Program Order No. 3 (AST-0243875) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.

  11. Methodology for predicting long-term fuel-cell performance from short-term testing. Final technical report

    SciTech Connect

    Patel, D.; Farooque, M.; Maru, H.; Ware, C.

    1981-08-01

    The objective of this program was to develop a methodology for predicting long-term fuel cell performance from short-term testing, utilizing a perturbation testing technique. The technique applies small changes of predetermined levels in a predetermined sequence to the operating variables such that the decay mechanisms are not altered. This technique was tested on the phosphoric acid fuel cell (PAFC), because this technology is approaching a mature stage. The initial series of perturbation tests appear to be reasonably successful and a methodology is now available for further refinements. The progress made during the study is detailed.

  12. 24 CFR 576.106 - Short-term and medium-term rental assistance.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... under 24 CFR part 888, and complies with HUD's standard of rent reasonableness, as established under 24 CFR 982.507. (2) For purposes of calculating rent under this section, the rent shall equal the sum of... 24 Housing and Urban Development 3 2013-04-01 2013-04-01 false Short-term and medium-term...

  13. 24 CFR 576.106 - Short-term and medium-term rental assistance.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... under 24 CFR part 888, and complies with HUD's standard of rent reasonableness, as established under 24 CFR 982.507. (2) For purposes of calculating rent under this section, the rent shall equal the sum of... 24 Housing and Urban Development 3 2014-04-01 2013-04-01 true Short-term and medium-term...

  14. 24 CFR 576.106 - Short-term and medium-term rental assistance.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... under 24 CFR part 888, and complies with HUD's standard of rent reasonableness, as established under 24 CFR 982.507. (2) For purposes of calculating rent under this section, the rent shall equal the sum of... 24 Housing and Urban Development 3 2012-04-01 2012-04-01 false Short-term and medium-term...

  15. VALIDATION OF A METHOD FOR ESTIMATING LONG-TERM EXPOSURES BASED ON SHORT-TERM MEASUREMENTS

    EPA Science Inventory

    A method for estimating long-term exposures from short-term measurements is validated using data from a recent EPA study of exposure to fine particles. The method was developed a decade ago but data to validate it did not exist until recently. In this paper, data from repeated ...

  16. The interaction of short-term and long-term memory in phonetic category formation

    NASA Astrophysics Data System (ADS)

    Harnsberger, James D.

    2002-05-01

    This study examined the role that short-term memory capacity plays in the relationship between novel stimuli (e.g., non-native speech sounds, native nonsense words) and phonetic categories in long-term memory. Thirty native speakers of American English were administered five tests: categorial AXB discrimination using nasal consonants from Malayalam; categorial identification, also using Malayalam nasals, which measured the influence of phonetic categories in long-term memory; digit span; nonword span, a short-term memory measure mediated by phonetic categories in long-term memory; and paired-associate word learning (word-word and word-nonword pairs). The results showed that almost all measures were significantly correlated with one another. The strongest predictor for the discrimination and word-nonword learning results was nonword (r=+0.62) and digit span (r=+0.51), respectively. When the identification test results were partialed out, only nonword span significantly correlated with discrimination. The results show a strong influence of short-term memory capacity on the encoding of phonetic detail within phonetic categories and suggest that long-term memory representations regulate the capacity of short-term memory to preserve information for subsequent encoding. The results of this study will also be discussed with regards to resolving the tension between episodic and abstract models of phonetic category structure.

  17. Short-term Action Intentions Overrule Long-Term Semantic Knowledge

    ERIC Educational Resources Information Center

    van Elk, M.; van Schie, H.T.; Bekkering, H.

    2009-01-01

    In the present study, we investigated whether the preparation of an unusual action with an object (e.g. bringing a cup towards the eye) could selectively overrule long-term semantic representations. In the first experiment it was found that unusual action intentions activated short-term semantic goal representations, rather than long-term…

  18. Comparison of jobs, exposures, and mortality risks for short-term and long-term workers

    SciTech Connect

    Stewart, P.A.; Schairer, C.; Blair, A. )

    1990-08-01

    We compared the jobs, estimates of exposures, and mortality experience of short-term (less than or equal to 1 year) and long-term (greater than 1 year) workers from nine plants producing formaldehyde or formaldehyde products. There were few jobs that were filled solely or primarily by newly hired workers. The estimated median level of formaldehyde exposure experienced by short-term workers on their first job was nearly identical to that for long-term workers, although short-term workers were more likely to be in jobs exposed to particulates than were long-term workers. As duration of employment increased, there was little change in the average estimated exposure level of formaldehyde, but the likelihood of being exposed to particulates decreased. Short-term workers had greater risks than long-term workers of dying from diseases of the circulatory system, arteriosclerotic heart disease, emphysema, diseases of the digestive system, cirrhosis of the liver, motor vehicle accidents, suicide and malignant neoplasms, particularly cancers of the stomach, colon, lung, prostate, and brain.

  19. A mathematical approach for predicting long-term indoor radon concentrations from short-term measurements

    SciTech Connect

    Al-Ahmady, K.K.; Hintenlang, D.E.

    1995-12-31

    Assessment of long-term radon concentrations from short-term testing results are of significant importance when radon risk assessment and liability issues are considered. These issues are based on the figure of annual exposure to indoor radon while radon measurement practices are mainly followed the EPA short-term testing protocols. A mathematical framework has been developed that facilities non-statistical approach to construct the relationship between the short-term indoor radon measurements and the long term annual indoor radon levels. This approach was based on the application of the time-dependent indoor radon concentrations calculated from the corresponding contributions of indoor radon driving forces for different time periods having a reference starting time. The approach utilizes an analytical procedure that is based on the solutions of the mass balance equation for the radon gas in the indoor environment. The solutions are applied through semi-analytical modeling of time-dependent indoor radon concentrations. This treatment provides a powerful tool and procedure to assess long-term indoor radon concentrations from short-term testing results.

  20. Short-term action intentions overrule long-term semantic knowledge.

    PubMed

    van Elk, M; van Schie, H T; Bekkering, H

    2009-04-01

    In the present study, we investigated whether the preparation of an unusual action with an object (e.g. bringing a cup towards the eye) could selectively overrule long-term semantic representations. In the first experiment it was found that unusual action intentions activated short-term semantic goal representations, rather than long-term conceptual associations. In a second experiment the reversal of long-term priming effects was replicated, while reducing the need for internal verbalization as a possible strategy to accomplish the task. Priming effects in the first two experiments were found to involve the selection of object knowledge at a semantic level, rather than reflecting a general effect of action preparation on word processing (Experiment 3). Finally, in a fourth experiment short-term priming effects were shown to extend beyond a lexical level by showing faster responses to pictures representing the short-term action goal. Together, the present findings extend the 'selection-for-action' principle previously used in visual attention to a semantic level, by showing that semantic information is selectively activated in line with the short-term goal of the actor.

  1. Musical and Verbal Memory in Alzheimer's Disease: A Study of Long-Term and Short-Term Memory

    ERIC Educational Resources Information Center

    Menard, Marie-Claude; Belleville, Sylvie

    2009-01-01

    Musical memory was tested in Alzheimer patients and in healthy older adults using long-term and short-term memory tasks. Long-term memory (LTM) was tested with a recognition procedure using unfamiliar melodies. Short-term memory (STM) was evaluated with same/different judgment tasks on short series of notes. Musical memory was compared to verbal…

  2. Short-Term Energy Outlook Supplement: Key drivers for EIA's short-term U.S. crude oil production outlook

    EIA Publications

    2013-01-01

    Crude oil production increased by 790,000 barrels per day (bbl/d) between 2011 and 2012, the largest increase in annual output since the beginning of U.S. commercial crude oil production in 1859. The U.S. Energy Information Administration (EIA) expects U.S. crude oil production to continue rising over the next two years represented in the Short-Term Energy Outlook (STEO).

  3. Short-term energy outlook, Annual supplement 1995

    SciTech Connect

    1995-07-25

    This supplement is published once a year as a complement to the Short- Term Energy Outlook, Quarterly Projections. The purpose of the Supplement is to review the accuracy of the forecasts published in the Outlook, make comparisons with other independent energy forecasts, and examine current energy topics that affect the forecasts. Chap. 2 analyzes the response of the US petroleum industry to the recent four Federal environmental rules on motor gasoline. Chap. 3 compares the EIA base or mid case energy projections for 1995 and 1996 (as published in the first quarter 1995 Outlook) with recent projections made by four other major forecasting groups. Chap. 4 evaluates the overall accuracy. Chap. 5 presents the methology used in the Short- Term Integrated Forecasting Model for oxygenate supply/demand balances. Chap. 6 reports theoretical and empirical results from a study of non-transportation energy demand by sector. The empirical analysis involves the short-run energy demand in the residential, commercial, industrial, and electrical utility sectors in US.

  4. Similarity as an organising principle in short-term memory.

    PubMed

    LeCompte, D C; Watkins, M J

    1993-03-01

    The role of stimulus similarity as an organising principle in short-term memory was explored in a series of seven experiments. Each experiment involved the presentation of a short sequence of items that were drawn from two distinct physical classes and arranged such that item class changed after every second item. Following presentation, one item was re-presented as a probe for the 'target' item that had directly followed it in the sequence. Memory for the sequence was considered organised by class if probability of recall was higher when the probe and target were from the same class than when they were from different classes. Such organisation was found when one class was auditory and the other was visual (spoken vs. written words, and sounds vs. pictures). It was also found when both classes were auditory (words spoken in a male voice vs. words spoken in a female voice) and when both classes were visual (digits shown in one location vs. digits shown in another). It is concluded that short-term memory can be organised on the basis of sensory modality and on the basis of certain features within both the auditory and visual modalities.

  5. Inter-daily variability of a strong thermally-driven wind system over the Atacama Desert of South America: synoptic forcing and short-term predictability using the GFS global model

    NASA Astrophysics Data System (ADS)

    Jacques-Coper, Martín; Falvey, Mark; Muñoz, Ricardo C.

    2015-07-01

    Crucial aspects of a strong thermally-driven wind system in the Atacama Desert in northern Chile during the extended austral winter season (May-September) are studied using 2 years of measurement data from the Sierra Gorda 80-m meteorological mast (SGO, 22° 56' 24″ S; 69° 7' 58″ W, 2,069 m above sea level (a.s.l.)). Daily cycles of atmospheric variables reveal a diurnal (nocturnal) regime, with northwesterly (easterly) flow and maximum mean wind speed of 8 m/s (13 m/s) on average. These distinct regimes are caused by pronounced topographic conditions and the diurnal cycle of the local radiative balance. Wind speed extreme events of each regime are negatively correlated at the inter-daily time scale: High diurnal wind speed values are usually observed together with low nocturnal wind speed values and vice versa. The associated synoptic conditions indicate that upper-level troughs at the coastline of southwestern South America reinforce the diurnal northwesterly wind, whereas mean undisturbed upper-level conditions favor the development of the nocturnal easterly flow. We analyze the skill of the numerical weather model Global Forecast System (GFS) in predicting wind speed at SGO. Although forecasted wind speeds at 800 hPa do show the diurnal and nocturnal phases, observations at 80 m are strongly underestimated by the model. This causes a pronounced daily cycle of root-mean-squared error (RMSE) and bias in the forecasts. After applying a simple Model Output Statistics (MOS) post-processing, we achieve a good representation of the wind speed intra-daily and inter-daily variability, a first step toward reducing the uncertainties related to potential wind energy projects in the region.

  6. The Short-term Clinical Outcome of Total Hip Arthroplasty Using Short Metaphyseal Loading Femoral Stem

    PubMed Central

    Choi, Yoo Wang

    2016-01-01

    Purpose The purpose of this study was to retrospectively evaluate the short-term clinical and radiological outcomes of total hip arthroplasty (THA) with short metaphyseal loading femoral stem. Materials and Methods We retrospectively reviewed the records of 56 cases in 47 patients who had undergone THA with short metaphyseal loading femoral stem from April 2010 to December 2011. There were 20 males and 27 females. The mean age was 54 years (range, 26-77 years). The average follow up period was 4.6 years. Clinical results were evaluated by Harris hip scores (HHS) before the operation and at the last follow-up. Radiographic analysis was done by evaluating osteolysis, loosening, stress shielding, and alignement. Results The mean HHS significantly improved from 45 (range, 15-58) preoperatively to 98 (range, 85-100) at the last follow-up. In radiographic analyses, there was no evidence of osteolysis or loosening around the stems and the acetabuluar components. All cases showed rounding off of the calcar, grade 1 bone resorption of the proximal femur. With regard to implant alignment, 51 femoral component (91.1%) were in neutral position, and 5 (8.9%) were in varus position. There was 1 intraoperative fracture treated by cerclage wiring and no case was revised during follow-up period. Conclusion Although longer follow-up is needed to confirm the durability of the short metaphyseal loading femoral stem, this short stem might provide stable fixation without diaphyseal fixation and demonstrated good clinical result at mean 4.6 year short term follow-up. PMID:27536649

  7. Interactions between short-term and long-term cardiovascular control mechanisms

    NASA Astrophysics Data System (ADS)

    Hoyer, Dirk; Frank, Birgit; Götze, Christine; Stein, Phyllis K.; Żebrowski, Jan J.; Baranowski, Rafal; Palacios, Manuel; Vallverdú, Montserrat; Caminal, Pere; Bayés de Luna, Anthony; Schmidt, Georg; Schmidt, Hendrik

    2007-03-01

    The cardiovascular system incorporates several controlling mechanisms acting as feedback loops over different time horizons. Because of their complex interrelationships, information-based methods such as autonomic information flow (AIF) functions promise to be useful in identifying normal and pathological behavior. Optimal adjustment between those controllers is necessary for healthy global behavior of the organism. We investigated the question as to whether there are typical relationships between short-term and long-term AIF by means of a meta-analysis of several of our own clinical studies of the mortality of patients with multiple organ dysfunction syndrome, heart failure, idiopathic dilated cardiomyopathy, and the length of stay in hospital after abdominal aorta surgery. We found a fundamental association of increased short-term randomness (decreased AIF) and decreased long-term randomness (increased AIF) due to pathology. A systems theoretic validation of this fundamental type of association was done by an appropriate mathematical model using a dissipative system with two feedback loops over different time horizons. The systematic simulation of an increasing collapse of the short feedback loop confirmed the inverse association between short-term and long-term information flow as a fundamental, system inherent type of readjustment that occurs under pathological conditions.

  8. Short Term Electricity Storage For CPV Power Plants

    NASA Astrophysics Data System (ADS)

    Desrumaux, C.; Auberton, A.; Gombert, A.; Heile, I.; Röttger, M.

    2011-12-01

    An initial analysis of short term electricity storage for CPV power plants is performed with respect to its functions "power output smoothing" and "end of day energy production". First, the different storage technologies are shortly discussed. Then charge and discharge of the storage device of a model CPV plant is studied by using measured DNI data for selected days at a good CPV location. The selection of days is done according to their average DNI per day classification. The power to energy ratio of the storage, the allowed minimum state of charge (SOC) and the requested power from the storage are the varying parameters of the study. With increasing capacity of the storage, the requirements can be best fulfilled with the used initial storage strategies but the power output is shifted significantly.

  9. Perceptions of short-term medical volunteer work: a qualitative study in Guatemala

    PubMed Central

    Green, Tyler; Green, Heidi; Scandlyn, Jean; Kestler, Andrew

    2009-01-01

    Background Each year medical providers from wealthy countries participate in short-term medical volunteer work in resource-poor countries. Various authors have raised concern that such work has the potential to be harmful to recipient communities; however, the social science and medical literature contains little research into the perceptions of short-term medical volunteer work from the perspective of members of recipient communities. This exploratory study examines the perception of short-term medical volunteer work in Guatemala among groups of actors affected by or participating in these programs. Methods The researchers conducted in-depth, semi-structured interviews with 72 individuals, including Guatemalan healthcare providers and health authorities, foreign medical providers, non-medical personnel working on health projects, and Guatemalan parents of children treated by a short-term volunteer group. Detailed notes and summaries of these interviews were uploaded, coded and annotated using Atlas.ti (Scientific Software Development GmbH, Berlin) to identify recurrent themes from the interviews. Results Informants commonly identified a need for increased access to medical services in Guatemala, and many believed that short-term medical volunteers are in a position to offer improved access to medical care in the communities where they serve. Informants most frequently cited appropriate patient selection and attention to payment systems as the best means to avoid creating dependence on foreign aid. The most frequent suggestion to improve short-term medical volunteer work was coordination with and respect for local Guatemalan healthcare providers and their communities, as insufficient understanding of the country's existing healthcare resources and needs may result in perceived harm to the recipient community. Conclusion The perceived impact of short-term medical volunteer projects in Guatemala is highly variable and dependent upon the individual project. In this

  10. Attention Problems, Phonological Short-Term Memory, and Visuospatial Short-Term Memory: Differential Effects on Near- and Long-Term Scholastic Achievement

    ERIC Educational Resources Information Center

    Sarver, Dustin E.; Rapport, Mark D.; Kofler, Michael J.; Scanlan, Sean W.; Raiker, Joseph S.; Altro, Thomas A.; Bolden, Jennifer

    2012-01-01

    The current study examined individual differences in children's phonological and visuospatial short-term memory as potential mediators of the relationship among attention problems and near- and long-term scholastic achievement. Nested structural equation models revealed that teacher-reported attention problems were associated negatively with…

  11. Power system very short-term load prediction

    SciTech Connect

    Trudnowski, D.J.; Johnson, J.M.; Whitney, P.

    1997-02-01

    A fundamental objective of a power-system operating and control scheme is to maintain a match between the system`s overall real-power load and generation. To accurately maintain this match, modern energy management systems require estimates of the future total system load. Several strategies and tools are available for estimating system load. Nearly all of these estimate the future load in 1-hour steps over several hours (or time frames very close to this). While hourly load estimates are very useful for many operation and control decisions, more accurate estimates at closer intervals would also be valuable. This is especially true for emerging Area Generation Control (AGC) strategies such as look-ahead AGC. For these short-term estimation applications, future load estimates out to several minutes at intervals of 1 to 5 minutes are required. The currently emerging operation and control strategies being developed by the BPA are dependent on accurate very short-term load estimates. To meet this need, the BPA commissioned the Pacific Northwest National Laboratory (PNNL) and Montana Tech (an affiliate of the University of Montana) to develop an accurate load prediction algorithm and computer codes that automatically update and can reliably perform in a closed-loop controller for the BPA system. The requirements include accurate load estimation in 5-minute steps out to 2 hours. This report presents the results of this effort and includes: a methodology and algorithms for short-term load prediction that incorporates information from a general hourly forecaster; specific algorithm parameters for implementing the predictor in the BPA system; performance and sensitivity studies of the algorithms on BPA-supplied data; an algorithm for filtering power system load samples as a precursor to inputting into the predictor; and FORTRAN 77 subroutines for implementing the algorithms.

  12. Short-term energy outlook, quarterly projections, second quarter 1998

    SciTech Connect

    1998-04-01

    The Energy Information Administration (EIA) prepares quarterly short-term energy supply, demand, and price projections. The details of these projections, as well as monthly updates, are available on the Internet at: www.eia.doe.gov/emeu/steo/pub/contents.html. The paper discusses outlook assumptions; US energy prices; world oil supply and the oil production cutback agreement of March 1998; international oil demand and supply; world oil stocks, capacity, and net trade; US oil demand and supply; US natural gas demand and supply; US coal demand and supply; US electricity demand and supply; US renewable energy demand; and US energy demand and supply sensitivities. 29 figs., 19 tabs.

  13. Auditory short-term memory in the Japanese monkey.

    PubMed

    Kojima, S

    1985-01-01

    Auditory short-term memory in Japanese monkeys (Macaca fuscata) was studied using a GO/NO GO auditory delayed matching to sample task. Three temporal parameters: delay interval, intertrial interval and sample stimulus duration were manipulated. Delayed matching performance deteriorated as the delay interval was lengthened, and reached a near chance level at 16 sec. Longer intertrial intervals and sample duration ameliorated performance. When the number of the sample stimulus was increased to 3 tones to examine a serial position effect, a primary effect was not observed, although a recency effect was obtained. The fragility of auditory delayed matching performance was discussed.

  14. Improving digit span assessment of short-term verbal memory.

    PubMed

    Woods, David L; Kishiyamaa, Mark M; Lund, E William; Herron, Timothy J; Edwards, Ben; Poliva, Oren; Hink, Robert F; Reed, Bruce

    2011-01-01

    We measured digit span (DS) in two experiments that used computerized presentation of randomized auditory digits with performance-adapted list length adjustment. A new mean span (MS) metric of DS was developed that showed reduced variance, improved test-retest reliability, and higher correlations with the results of other neuropsychological test results when compared to traditional DS measures. The MS metric also enhanced the sensitivity of forward versus backward span comparisons, enabled the development of normative performance criteria with subdigit precision, and elucidated changes in DS performance with age and education level. Computerized stimulus delivery and improved scoring metrics significantly enhance the precision of DS assessments of short-term verbal memory.

  15. Short-term prospective spirometric study of new coal miners

    SciTech Connect

    Hankinson, J.L.; Hodous, T.K.

    1982-09-01

    This study examined prospectively a small cohort (N=116) of new coal miners with questionnaires and spirometry. Data collection began just prior to underground employment and extended over a two year period at 6 month intervals to address the question or short-term adverse occupational pulmonary effects and their relationship to outward migration from the industry. A comparison of the initial (unexposed) and six month (exposed) changes in lung function over the work shift was also conducted to detect an acute effect due to dust, which might be related to chronic decline in lung function.

  16. Short-term bioconcentration studies of Np in freshwater biota

    SciTech Connect

    Poston, T.M.; Klopfer, D.C.; Simmons, M.A. )

    1990-12-01

    Short-term laboratory exposures were conducted to determine the potential accumulation of Np in aquatic organisms. Concentration factors were highest in green algae. Daphnia magna, a filter-feeding crustacean, accumulated Np at levels one order of magnitude greater than the amphipod Gammarus sp., an omnivorous substrate feeder. Accumulation of Np in juvenile rainbow trout (Oncorhynchus mykiss) was highest in carcass (generally greater than 78% of the total body burden) and lowest in fillets. Recommended concentration factors for Np, based on fresh weight, were 300 for green algae, 100 for filter-feeding invertebrates, for nonfilter-feeding invertebrates, 10 for whole fish, and one for fish flesh.

  17. Conversion of short-term to long-term memory in the novel object recognition paradigm.

    PubMed

    Moore, Shannon J; Deshpande, Kaivalya; Stinnett, Gwen S; Seasholtz, Audrey F; Murphy, Geoffrey G

    2013-10-01

    It is well-known that stress can significantly impact learning; however, whether this effect facilitates or impairs the resultant memory depends on the characteristics of the stressor. Investigation of these dynamics can be confounded by the role of the stressor in motivating performance in a task. Positing a cohesive model of the effect of stress on learning and memory necessitates elucidating the consequences of stressful stimuli independently from task-specific functions. Therefore, the goal of this study was to examine the effect of manipulating a task-independent stressor (elevated light level) on short-term and long-term memory in the novel object recognition paradigm. Short-term memory was elicited in both low light and high light conditions, but long-term memory specifically required high light conditions during the acquisition phase (familiarization trial) and was independent of the light level during retrieval (test trial). Additionally, long-term memory appeared to be independent of stress-mediated glucocorticoid release, as both low and high light produced similar levels of plasma corticosterone, which further did not correlate with subsequent memory performance. Finally, both short-term and long-term memory showed no savings between repeated experiments suggesting that this novel object recognition paradigm may be useful for longitudinal studies, particularly when investigating treatments to stabilize or enhance weak memories in neurodegenerative diseases or during age-related cognitive decline.

  18. Complex network structure influences processing in long-term and short-term memory

    PubMed Central

    Vitevitch, Michael S.; Chan, Kit Ying; Roodenrys, Steven

    2012-01-01

    Complex networks describe how entities in systems interact; the structure of such networks is argued to influence processing. One measure of network structure, clustering coefficient, C, measures the extent to which neighbors of a node are also neighbors of each other. Previous psycholinguistic experiments found that the C of phonological word-forms influenced retrieval from the mental lexicon (that portion of long-term memory dedicated to language) during the on-line recognition and production of spoken words. In the present study we examined how network structure influences other retrieval processes in long- and short-term memory. In a false-memory task—examining long-term memory—participants falsely recognized more words with low- than high-C. In a recognition memory task—examining veridical memories in long-term memory—participants correctly recognized more words with low- than high-C. However, participants in a serial recall task—examining redintegration in short-term memory—recalled lists comprised of high-C words more accurately than lists comprised of low-C words. These results demonstrate that network structure influences cognitive processes associated with several forms of memory including lexical, long-term, and short-term. PMID:22745522

  19. No temporal decay in verbal short-term memory.

    PubMed

    Lewandowsky, Stephan; Oberauer, Klaus; Brown, Gordon D A

    2009-03-01

    Many models of short-term memory (STM) ascribe an important role to temporal decay and forgetting because of the passage of time alone. We argue against decay as the primary form of forgetting from STM, and suggest that new experimental methodologies and recent models provide new perspectives on the old issue of the causes of forgetting. We show that several classic sources of evidence for time-based forgetting can be re-interpreted in terms of an interference-based view, and that new experiments provide compelling evidence against decay. We conclude that progress requires moving beyond demonstrations of qualitative effects and focusing instead on testing quantitative predictions of models. PMID:19223224

  20. Cash benefits for short-term sickness, 1948--76.

    PubMed

    Price, D N

    1978-10-01

    National income-maintenance programs provide cash benefits when workers become unemployed, retire, are injured on the job, have a long-term disability, or die. For short-term sickness, however, only five States, one other jurisdiction, and a single industry require wage-replacement protection. Voluntary plans cover a substantial number of additional workers, including many whose protection was established through labor-management negotiations. In this annual update of estimates on the extent of protection provided, many of the historical statistics have been revised back to 1967 as a result of new information on the amount of sick-leave benefits paid to employees of the Federal Government. The effects of the new data on the benefit series are examined, as are trends in the provision of sickness benefits for maternity--an issue subject to considerable recent controversy. PMID:715639

  1. Short and long-term strength of shale rocks

    NASA Astrophysics Data System (ADS)

    Rybacki, Erik; Dresen, Georg

    2016-04-01

    Stimulation of oil and gas bearing shales commonly utilizes advanced hydraulic fracturing techniques to enhance the production rate. Successful hydrofrac campaigns depend on the geomechanical properties of the reservoir. For example, the short term strength and brittleness may control the hydraulic breakdown pressure and borehole stability. The long term creep properties may determine the closure rate of hydraulically induced fractures, for example by proppant embedment. We performed a series of mechanical tests on shales with different mineral content, porosity and maturity. Cylindrical samples of 1-5 cm in diameter and 2-10 cm in length were deformed at confining pressures of 0.1 - 400 MPa and temperatures of 25°-400°C in constant strain rate and constant stress mode in order to evaluate the influence of loading conditions and composition on their strength and ductility. Short-term constant strain rate tests show that, at fixed loading direction with respect to bedding orientation, the peak strength and Young's modulus vary with mineral content, humidity and porosity, but depend also on applied pressure, temperature and strain rate. The (porosity-corrected) variation of peak strength and Young's modulus with composition can be roughly estimated from the mechanical behavior of all components at given pressure-temperature conditions and their volumetric proportion. Samples deforming in the brittle-semibrittle regime may be characterized by empirical brittleness indices based on their deformation behavior, Young's modulus, or bulk composition. These indices are correlated at low pressure-temperature conditions (corresponding to < about 4 km depth). First long-term deformation experiments at constant load show transient viscoplastic creep behavior. The associated strain rates increase with increasing differential stress, increasing temperature and decreasing pressure, accompanied by slight porosity reduction. Therefore, estimates of fracture healing rates by

  2. Probing short-term face memory in developmental prosopagnosia.

    PubMed

    Shah, Punit; Gaule, Anne; Gaigg, Sebastian B; Bird, Geoffrey; Cook, Richard

    2015-03-01

    It has recently been proposed that the face recognition deficits seen in neurodevelopmental disorders may reflect impaired short-term face memory (STFM). For example, introducing a brief delay between the presentation of target and test faces seems to disproportionately impair matching or recognition performance in individuals with Autism Spectrum Disorders. The present study sought to determine whether deficits of STFM contribute to impaired face recognition seen in Developmental Prosopagnosia. To determine whether developmental prosopagnosics exhibit impaired STFM, the present study used a six-alternative-forced-choice match-to-sample procedure. Memory demand was manipulated by employing a short or long delay between the presentation of the target face, and the six test faces. Crucially, the perceptual demands were identical in both conditions, thereby allowing the independent contribution of STFM to be assessed. Prosopagnosics showed clear evidence of a category-specific impairment for face-matching in both conditions; they were both slower and less accurate than matched controls. Crucially, however, the prosopagnosics showed no evidence of disproportionate face recognition impairment in the long-interval condition. While individuals with DP may have problems with the perceptual encoding of faces, it appears that their representations are stable over short durations. These results suggest that the face recognition difficulties seen in DP and autism may be qualitatively different, attributable to deficits of perceptual encoding and perceptual maintenance, respectively.

  3. Predicting Time Series from Short-Term High-Dimensional Data

    NASA Astrophysics Data System (ADS)

    Ma, Huanfei; Zhou, Tianshou; Aihara, Kazuyuki; Chen, Luonan

    The prediction of future values of time series is a challenging task in many fields. In particular, making prediction based on short-term data is believed to be difficult. Here, we propose a method to predict systems' low-dimensional dynamics from high-dimensional but short-term data. Intuitively, it can be considered as a transformation from the inter-variable information of the observed high-dimensional data into the corresponding low-dimensional but long-term data, thereby equivalent to prediction of time series data. Technically, this method can be viewed as an inverse implementation of delayed embedding reconstruction. Both methods and algorithms are developed. To demonstrate the effectiveness of the theoretical result, benchmark examples and real-world problems from various fields are studied.

  4. Short-term energy outlook. Quarterly projections, third quarter 1996

    SciTech Connect

    1996-07-01

    The Energy Information Administration (EIA) prepares quarterly, short-term energy supply, demand, and price projections for publication in January, April, July, and October in the Outlook. The forecast period for this issue of the Outlook extends from the third quarter of 1996 through the fourth quarter of 1997. Values for the second quarter of 1996, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in the Weekly Petroleum Status Report) or are calculated from model simulations using the latest exogenous information available (for example, electricity sales and generation are simulated using actual weather data). The historical energy data, compiled in the third quarter 1996 version of the Short-Term Integrated Forecasting System (STIFS) database, are mostly EIA data regularly published in the Monthly energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding. The STIFS database is archived quarterly and is available from the National Technical Information Service.

  5. Plant community controls on short-term ecosystem nitrogen retention.

    PubMed

    de Vries, Franciska T; Bardgett, Richard D

    2016-05-01

    Retention of nitrogen (N) is a critical ecosystem function, especially in the face of widespread anthropogenic N enrichment; however, our understanding of the mechanisms involved is limited. Here, we tested under glasshouse conditions how plant community attributes, including variations in the dominance, diversity and range of plant functional traits, influence N uptake and retention in temperate grassland. We added a pulse of (15) N to grassland plant communities assembled to represent a range of community-weighted mean plant traits, trait functional diversity and divergence, and species richness, and measured plant and microbial uptake of (15) N, and leaching losses of (15) N, as a short-term test of N retention in the plant-soil system. Root biomass, herb abundance and dominant plant traits were the main determinants of N retention in the plant-soil system: greater root biomass and herb abundance, and lower root tissue density, increased plant (15) N uptake, while higher specific leaf area and root tissue density increased microbial (15) N uptake. Our results provide novel, mechanistic insight into the short-term fate of N in the plant-soil system, and show that dominant plant traits, rather than trait functional diversity, control the fate of added N in the plant-soil system.

  6. Short-Term Effects of Hydrokinesiotherapy in Hospitalized Preterm Newborns

    PubMed Central

    de Oliveira Tobinaga, Welcy Cassiano; Abelenda, Vera Lucia Barros; de Sá, Paula Morisco

    2016-01-01

    Background. In the neonatal intensive care unit (NICU) environment, preterm newborns are subject to environmental stress and numerous painful interventions. It is known that hydrokinesiotherapy promotes comfort and reduces stress because of the physiological properties of water. Objective. To evaluate the short-term effects of hydrokinesiotherapy on reducing stress in preterm newborns admitted to the NICU. Materials and Methods. Fifteen preterm newborns underwent salivary cortisol measurement, pain evaluation using the Neonatal Infant Pain Scale (NIPS), and heart rate, respiratory rate, and peripheral oxygen saturation measurements before and after the application of hydrokinesiotherapy. Results. The mean gestational age of the newborns was 34.2 ± 1.66 weeks, and the mean weight was 1823.3 ± 437.4 g. Immediately after application of hydrokinesiotherapy, a significant reduction was observed in salivary cortisol (p = 0.004), heart rate (p = 0.003), and respiratory rate (p = 0.004) and a significant increase was observed in peripheral oxygen saturation (p = 0.002). However, no significant difference was observed in the NIPS score (p > 0.05). Conclusion. In the present study, neonatal hydrotherapy promoted short-term relief from feelings of stress. Neonatal hydrokinesiotherapy may be a therapeutic alternative. However, this therapy needs to be studied in randomized, crossover, and blinded trials. This trial is registered with NCT02707731.

  7. Biochemical and hematologic changes after short-term space flight

    NASA Technical Reports Server (NTRS)

    Leach, C. S.

    1992-01-01

    Clinical laboratory data from blood samples obtained from astronauts before and after 28 flights (average duration = 6 days) of the Space Shuttle were analyzed by the paired t-test and the Wilcoxon signed-rank test and compared with data from the Skylab flights (duration approximately 28, 59, and 84 days). Angiotensin I and aldosterone were elevated immediately after short-term space flights, but the response of angiotensin I was delayed after Skylab flights. Serum calcium was not elevated after Shuttle flights, but magnesium and uric acid decreased after both Shuttle and Skylab. Creatine phosphokinase in serum was reduced after Shuttle but not Skylab flights, probably because exercises to prevent deconditioning were not performed on the Shuttle. Total cholesterol was unchanged after Shuttle flights, but low density lipoprotein cholesterol increased and high density lipoprotein cholesterol decreased. The concentration of red blood cells was elevated after Shuttle flights and reduced after Skylab flights. Reticulocyte count was decreased after both short- and long-term flights, indicating that a reduction in red blood cell mass is probably more closely related to suppression of red cell production than to an increase in destruction of erythrocytes. Serum ferritin and number of platelets were also elevated after Shuttle flights. In determining the reasons for postflight differences between the shorter and longer flights, it is important to consider not only duration but also countermeasures, differences between spacecraft, and procedures for landing and egress.

  8. Short-Term Effects of Hydrokinesiotherapy in Hospitalized Preterm Newborns.

    PubMed

    de Oliveira Tobinaga, Welcy Cassiano; de Lima Marinho, Cirlene; Abelenda, Vera Lucia Barros; de Sá, Paula Morisco; Lopes, Agnaldo José

    2016-01-01

    Background. In the neonatal intensive care unit (NICU) environment, preterm newborns are subject to environmental stress and numerous painful interventions. It is known that hydrokinesiotherapy promotes comfort and reduces stress because of the physiological properties of water. Objective. To evaluate the short-term effects of hydrokinesiotherapy on reducing stress in preterm newborns admitted to the NICU. Materials and Methods. Fifteen preterm newborns underwent salivary cortisol measurement, pain evaluation using the Neonatal Infant Pain Scale (NIPS), and heart rate, respiratory rate, and peripheral oxygen saturation measurements before and after the application of hydrokinesiotherapy. Results. The mean gestational age of the newborns was 34.2 ± 1.66 weeks, and the mean weight was 1823.3 ± 437.4 g. Immediately after application of hydrokinesiotherapy, a significant reduction was observed in salivary cortisol (p = 0.004), heart rate (p = 0.003), and respiratory rate (p = 0.004) and a significant increase was observed in peripheral oxygen saturation (p = 0.002). However, no significant difference was observed in the NIPS score (p > 0.05). Conclusion. In the present study, neonatal hydrotherapy promoted short-term relief from feelings of stress. Neonatal hydrokinesiotherapy may be a therapeutic alternative. However, this therapy needs to be studied in randomized, crossover, and blinded trials. This trial is registered with NCT02707731. PMID:27672453

  9. Short-Term Effects of Hydrokinesiotherapy in Hospitalized Preterm Newborns

    PubMed Central

    de Oliveira Tobinaga, Welcy Cassiano; Abelenda, Vera Lucia Barros; de Sá, Paula Morisco

    2016-01-01

    Background. In the neonatal intensive care unit (NICU) environment, preterm newborns are subject to environmental stress and numerous painful interventions. It is known that hydrokinesiotherapy promotes comfort and reduces stress because of the physiological properties of water. Objective. To evaluate the short-term effects of hydrokinesiotherapy on reducing stress in preterm newborns admitted to the NICU. Materials and Methods. Fifteen preterm newborns underwent salivary cortisol measurement, pain evaluation using the Neonatal Infant Pain Scale (NIPS), and heart rate, respiratory rate, and peripheral oxygen saturation measurements before and after the application of hydrokinesiotherapy. Results. The mean gestational age of the newborns was 34.2 ± 1.66 weeks, and the mean weight was 1823.3 ± 437.4 g. Immediately after application of hydrokinesiotherapy, a significant reduction was observed in salivary cortisol (p = 0.004), heart rate (p = 0.003), and respiratory rate (p = 0.004) and a significant increase was observed in peripheral oxygen saturation (p = 0.002). However, no significant difference was observed in the NIPS score (p > 0.05). Conclusion. In the present study, neonatal hydrotherapy promoted short-term relief from feelings of stress. Neonatal hydrokinesiotherapy may be a therapeutic alternative. However, this therapy needs to be studied in randomized, crossover, and blinded trials. This trial is registered with NCT02707731. PMID:27672453

  10. Early neural signatures of visual short-term memory.

    PubMed

    Agam, Yigal; Hyun, Joo-Seok; Danker, Jared F; Zhou, Feng; Kahana, Michael J; Sekuler, Robert

    2009-01-15

    Visual short-term memory (VSTM) relies on a distributed network including sensory-related, posterior regions of the brain and frontal areas associated with attention and cognitive control. To characterize the fine temporal details of processing within this network, we recorded event-related potentials (ERPs) while human subjects performed a recognition-memory task. The task's difficulty was graded by varying the perceptual similarity between the items held in memory and the probe used to access memory. The evaluation of VSTM's contents against a test stimulus produced clear similarity-dependent differences in ERPs as early as 156 ms after probe onset. Posterior recording sites were the first to reflect the difficulty of the analysis, preceding their frontal counterparts by about 50 ms. Our results suggest an initial feed-forward interaction underlying stimulus-memory comparisons, consistent with the idea that visual areas contribute to temporary storage of visual information for use in ongoing tasks. This study provides a first look into early neural activity underlying the processing of visual information in short-term memory.

  11. Statistical approaches to short-term electricity forecasting

    NASA Astrophysics Data System (ADS)

    Kellova, Andrea

    The study of the short-term forecasting of electricity demand has played a key role in the economic optimization of the electric energy industry and is essential for power systems planning and operation. In electric energy markets, accurate short-term forecasting of electricity demand is necessary mainly for economic operations. Our focus is directed to the question of electricity demand forecasting in the Czech Republic. Firstly, we describe the current structure and organization of the Czech, as well as the European, electricity market. Secondly, we provide a complex description of the most powerful external factors influencing electricity consumption. The choice of the most appropriate model is conditioned by these electricity demand determining factors. Thirdly, we build up several types of multivariate forecasting models, both linear and nonlinear. These models are, respectively, linear regression models and artificial neural networks. Finally, we compare the forecasting power of both kinds of models using several statistical accuracy measures. Our results suggest that although the electricity demand forecasting in the Czech Republic is for the considered years rather a nonlinear than a linear problem, for practical purposes simple linear models with nonlinear inputs can be adequate. This is confirmed by the values of the empirical loss function applied to the forecasting results.

  12. Short-term memory for emotional faces in dysphoria.

    PubMed

    Noreen, Saima; Ridout, Nathan

    2010-07-01

    The study aimed to determine if the memory bias for negative faces previously demonstrated in depression and dysphoria generalises from long- to short-term memory. A total of 29 dysphoric (DP) and 22 non-dysphoric (ND) participants were presented with a series of faces and asked to identify the emotion portrayed (happiness, sadness, anger, or neutral affect). Following a delay, four faces were presented (the original plus three distractors) and participants were asked to identify the target face. Half of the trials assessed memory for facial emotion, and the remaining trials examined memory for facial identity. At encoding, no group differences were apparent. At memory testing, relative to ND participants, DP participants exhibited impaired memory for all types of facial emotion and for facial identity when the faces featured happiness, anger, or neutral affect, but not sadness. DP participants exhibited impaired identity memory for happy faces relative to angry, sad, and neutral, whereas ND participants exhibited enhanced facial identity memory when faces were angry. In general, memory for faces was not related to performance at encoding. However, in DP participants only, memory for sad faces was related to sadness recognition at encoding. The results suggest that the negative memory bias for faces in dysphoria does not generalise from long- to short-term memory. PMID:20544496

  13. Short-Term Test Results: Multifamily Home Energy Efficiency Retrofit

    SciTech Connect

    Lyons, J.

    2013-01-01

    Multifamily deep energy retrofits (DERs) represent great potential for energy savings, while also providing valuable insights on research-generated efficiency measures, cost-effectiveness metrics, and risk factor strategies for the multifamily housing industry. The Bay Ridge project is comprised of a base scope retrofit with a goal of achieving 30% savings (relative to pre-retrofit), and a DER scope with a goal of 50% savings (relative to pre-retrofit). The base scope has been applied to the entire complex, except for one 12-unit building which underwent the DER scope. Findings from the implementation, commissioning, and short-term testing at Bay Ridge include air infiltration reductions of greater than 60% in the DER building; a hybrid heat pump system with a Savings to Investment Ratio (SIR) > 1 (relative to a high efficiency furnace) which also provides the resident with added incentive for energy savings; and duct leakage reductions of > 60% using an aerosolized duct sealing approach. Despite being a moderate rehab instead of a gut rehab, the Bay Ridge DER is currently projected to achieve energy savings ≥ 50% compared to pre-retrofit, and the short-term testing supports this estimate.

  14. Bilateral femur fractures associated with short-term bisphosphonate use.

    PubMed

    Rifai, Aiman; Pourtaheri, Sina; Carbone, Andrew; Callaghan, John J; Stadler, Chris M; Record, Nicole; Issa, Kimona

    2015-02-01

    Bisphosphonates are the most commonly prescribed drugs to treat osteoporosis because they have been proposed to prevent bone loss. Nevertheless, in up to 0.1% of patients, long-term use may cause atypical stress or insufficiency femoral fractures. Bilateral femoral shaft fractures have been reported after long-term use of bisphosphonates; however, there is limited evidence of the effect of short-term use. The current study reports a case of bilateral femoral fractures after a low-energy fall in a 56-year-old woman and provides a review of the literature on bilateral femoral shaft fractures after long-term use of bisphosphonates. Patients should be educated about the potential for stress fractures with the use of this treatment. In patients with thigh pain, a thorough history and physical examination, including the contralateral thigh, may be beneficial to detect bilateral traumatic or atypical stress fracture patterns. More studies with larger sample sizes are necessary to better identify patients who may be at risk for fracture, including histomorphometric evidence of low bone turnover in patients with unfortunate bilateral cases.

  15. Two Distinct Origins of Long-Term Learning Effects in Verbal Short-Term Memory

    ERIC Educational Resources Information Center

    Majerus, Steve; Perez, Trecy Martinez; Oberauer, Klaus

    2012-01-01

    Verbal short-term memory (STM) is highly sensitive to learning effects: digit sequences or nonword sequences which have been rendered more familiar via repeated exposure are recalled more accurately. In this study we show that sublist-level, incidental learning of item co-occurrence regularities affects immediate serial recall of words and…

  16. Short term precursors of Strombolian explosions at Yasur volcano (Vanuatu)

    NASA Astrophysics Data System (ADS)

    Battaglia, Jean; Métaxian, Jean-Philippe; Garaebiti, Esline

    2016-03-01

    The seismic wavefield associated with Strombolian activity is usually dominated by explosion quakes (EQs), tremor, and various signals generated by surface phenomena. Looking at the seismicity recorded at Yasur volcano in 2008, we found that beside the transient events which occur simultaneously with surface explosions, the seismicity includes events related to a deeper process. These long period (LP) events form a family of similar events located below the southeastern part of the crater rim at a depth of about 700-1200 m below the summit. They are commonly followed by EQs with a variable delay. The examination of about 20,000 LP-EQ sequences at several stations near the summit shows that interevent delays follow distributions peaked around 11-12 s. This short delay compared to the relatively great source depth of the LPs favors a causal relationship linked to pressure transfer rather than gas slug propagation after nucleation at the LP source.

  17. Auditory short-term memory in the primate auditory cortex.

    PubMed

    Scott, Brian H; Mishkin, Mortimer

    2016-06-01

    Sounds are fleeting, and assembling the sequence of inputs at the ear into a coherent percept requires auditory memory across various time scales. Auditory short-term memory comprises at least two components: an active ׳working memory' bolstered by rehearsal, and a sensory trace that may be passively retained. Working memory relies on representations recalled from long-term memory, and their rehearsal may require phonological mechanisms unique to humans. The sensory component, passive short-term memory (pSTM), is tractable to study in nonhuman primates, whose brain architecture and behavioral repertoire are comparable to our own. This review discusses recent advances in the behavioral and neurophysiological study of auditory memory with a focus on single-unit recordings from macaque monkeys performing delayed-match-to-sample (DMS) tasks. Monkeys appear to employ pSTM to solve these tasks, as evidenced by the impact of interfering stimuli on memory performance. In several regards, pSTM in monkeys resembles pitch memory in humans, and may engage similar neural mechanisms. Neural correlates of DMS performance have been observed throughout the auditory and prefrontal cortex, defining a network of areas supporting auditory STM with parallels to that supporting visual STM. These correlates include persistent neural firing, or a suppression of firing, during the delay period of the memory task, as well as suppression or (less commonly) enhancement of sensory responses when a sound is repeated as a ׳match' stimulus. Auditory STM is supported by a distributed temporo-frontal network in which sensitivity to stimulus history is an intrinsic feature of auditory processing. This article is part of a Special Issue entitled SI: Auditory working memory.

  18. Integrating short-term and long-term forecasting with reservoir optimisation; Mantaro Basin, Peru.

    NASA Astrophysics Data System (ADS)

    Jensen, R. A.; Lasarte, A.; Butts, M. B.

    2009-04-01

    Operational water management often requires a trade-off between short-term and long-term water demands, where short-term demands are driven for example by hydropower generation and flood protection requirements and the long-term demands by water and irrigation supply, sustainable reservoir management and the seasonal impacts of snow melt or climate. This paper presents an operational decision support system designed to forecast and optimise reservoir operations in both the short-term and long-term. The system has been established for the 20,000 km2 Mantaro river basin located in the high Andes with altitudes ranging from 3500 to nearly 6000 m.a.s.l.. The two main power stations at Tablachaca have a combined capacity of more than 1000 MW that supplies 30% of Peru's electrical energy. In addition, the basin's water resources supply extensive agricultural areas, an urban population and mining activities and sustain important ecological habitats. In this paper, the methodologies used for the integrating short-term and long-term forecasting are presented together with their application to the optimal operation of reservoirs. A key element in the system is the MIKE BASIN modelling tool. The system uses several modelling capabilities of MIKE BASIN: rainfall-runoff, reservoir operation, hydropower production, and river flow routing. The system also takes advantage of long-term forecasts (based on statistical information) and short-term forecasts (based on telemetry data). The continually updated runoff and flow forecasts enter the optimization, which applies the Model Predictive Control principle for MIKE BASIN as the core simulation model. For each optimization, a non-linear program algorithm is used to find the best release strategy. On the basis of the forecasted inflows and the real time data the system suggests to the user from which reservoirs to release water for alleviation of possible forecasted deficits. In addition to the Tablachaca scheme the model accounts for

  19. Elliptic Anomaly in Constructing Long-Term and Short-Term Dynamical Theories

    NASA Astrophysics Data System (ADS)

    Brumberg, V. A.; Brumberg, E. V.

    2001-07-01

    The techniques of Brumberg and Brumberg (1999) based on the use of elliptic anomaly are specified in this paper in two aspects. The iteration technique (Broucke, 1969) to construct short-term semi-analytical theories of motion in rectangular coordinates in lines of Encke and Hill is reelaborated in terms of elliptic anomaly resulting in extending this technique for high-eccentricity orbits. In constructing long-term semi-analytical theories the key point is to integrate trigonometric functions of several angular arguments related to time by different differential expressions. This problem is reduced in the paper to linear algebraic recurrence relations admitting efficient solution by iterations.

  20. An analysis of long-term trends, seasonality and short-term dynamics in water quality data from Plynlimon, Wales.

    PubMed

    Halliday, Sarah J; Wade, Andrew J; Skeffington, Richard A; Neal, Colin; Reynolds, Brian; Rowland, Philip; Neal, Margaret; Norris, Dave

    2012-09-15

    This paper examines two hydrochemical time-series derived from stream samples taken in the Upper Hafren catchment, Plynlimon, Wales. One time-series comprises data collected at 7-hour intervals over 22 months (Neal et al., 2012-this issue), while the other is based on weekly sampling over 20 years. A subset of determinands: aluminium, calcium, chloride, conductivity, dissolved organic carbon, iron, nitrate, pH, silicon and sulphate are examined within a framework of non-stationary time-series analysis to identify determinand trends, seasonality and short-term dynamics. The results demonstrate that both long-term and high-frequency monitoring provide valuable and unique insights into the hydrochemistry of a catchment. The long-term data allowed analysis of long-term trends, demonstrating continued increases in DOC concentrations accompanied by declining SO(4) concentrations within the stream, and provided new insights into the changing amplitude and phase of the seasonality of the determinands such as DOC and Al. Additionally, these data proved invaluable for placing the short-term variability demonstrated within the high-frequency data within context. The 7-hour data highlighted complex diurnal cycles for NO(3), Ca and Fe with cycles displaying changes in phase and amplitude on a seasonal basis. The high-frequency data also demonstrated the need to consider the impact that the time of sample collection can have on the summary statistics of the data and also that sampling during the hours of darkness provides additional hydrochemical information for determinands which exhibit pronounced diurnal variability. Moving forward, this research demonstrates the need for both long-term and high-frequency monitoring to facilitate a full and accurate understanding of catchment hydrochemical dynamics.

  1. Short- and Long-Term Propagation of Spacecraft Orbits

    NASA Technical Reports Server (NTRS)

    Smith, John C., Jr.; Sweetser, Theodore; Chung, Min-Kun; Yen, Chen-Wan L.; Roncoli, Ralph B.; Kwok, Johnny H.; Vincent, Mark A.

    2008-01-01

    The Planetary Observer Planning Software (POPS) comprises four computer programs for use in designing orbits of spacecraft about planets. These programs are the Planetary Observer High Precision Orbit Propagator (POHOP), the Planetary Observer Long-Term Orbit Predictor (POLOP), the Planetary Observer Post Processor (POPP), and the Planetary Observer Plotting (POPLOT) program. POHOP and POLOP integrate the equations of motion to propagate an initial set of classical orbit elements to a future epoch. POHOP models shortterm (one revolution) orbital motion; POLOP averages out the short-term behavior but requires far less processing time than do older programs that perform long-term orbit propagations. POPP postprocesses the spacecraft ephemeris created by POHOP or POLOP (or optionally can use a less accurate internal ephemeris) to search for trajectory-related geometric events including, for example, rising or setting of a spacecraft as observed from a ground site. For each such event, POPP puts out such user-specified data as the time, elevation, and azimuth. POPLOT is a graphics program that plots data generated by POPP. POPLOT can plot orbit ground tracks on a world map and can produce a variety of summaries and generic ordinate-vs.-abscissa plots of any POPP data.

  2. A Single Brief Burst Induces GluR1-Dependent Associative Short-Term Potentiation: A Potential Mechanism for Short-Term Memory

    ERIC Educational Resources Information Center

    Erickson, Martha A.; Maramara, Lauren A.; Lisman, John

    2010-01-01

    Recent work showed that short-term memory (STM) is selectively reduced in GluR1 knockout mice. This raises the possibility that a form of synaptic modification dependent on GluR1 might underlie STM. Studies of synaptic plasticity have shown that stimuli too weak to induce long-term potentiation induce short-term potentiation (STP), a phenomenon…

  3. Short-Term Plasticity and Long-Term Potentiation in Magnetic Tunnel Junctions: Towards Volatile Synapses

    NASA Astrophysics Data System (ADS)

    Sengupta, Abhronil; Roy, Kaushik

    2016-02-01

    Synaptic memory is considered to be the main element responsible for learning and cognition in humans. Although traditionally nonvolatile long-term plasticity changes are implemented in nanoelectronic synapses for neuromorphic applications, recent studies in neuroscience reveal that biological synapses undergo metastable volatile strengthening followed by a long-term strengthening provided that the frequency of the input stimulus is sufficiently high. Such "memory strengthening" and "memory decay" functionalities can potentially lead to adaptive neuromorphic architectures. In this paper, we demonstrate the close resemblance of the magnetization dynamics of a magnetic tunnel junction (MTJ) to short-term plasticity and long-term potentiation observed in biological synapses. We illustrate that, in addition to the magnitude and duration of the input stimulus, the frequency of the stimulus plays a critical role in determining long-term potentiation of the MTJ. Such MTJ synaptic memory arrays can be utilized to create compact, ultrafast, and low-power intelligent neural systems.

  4. Short-term contracts: Descending the career ladder

    NASA Astrophysics Data System (ADS)

    Griffin, Elizabeth

    2002-12-01

    Elizabeth Griffin brings a personal insight to the hurdles that women seeking a scientific career face, arguing that the only gender differences are those of attitude, tradition and style. The policy of employing some but not all academic researchers through short-term contracts is highly divisive, in that it creates a two-tier system not only of opportunities and expectations but also of personal worth and value. Far more women than men are trapped in these career cul-de-sacs, and a seriously large fraction is unable to stay in research until retirement. It is the employment policy that is at fault, not the potential of the researchers or the quality of their research.

  5. Short-Term Test Results. Multifamily Home Energy Efficiency Retrofit

    SciTech Connect

    Lyons, James

    2013-01-01

    Multifamily deep energy retrofits (DERs) represent great potential for energy savings, while also providing valuable insights on research-generated efficiency measures, cost-effectiveness metrics, and risk factor strategies for the multifamily housing industry. This report describes the Bay Ridge project, a base scope retrofit with a goal of achieving 30% savings (relative to pre-retrofit), and a DER scope with a goal of 50% savings (relative to pre-retrofit). Findings from the short-term testing at Bay Ridge include air infiltration reductions of greater than 60% in the DER building; a hybrid heat pump system with a Savings to Investment Ratio (SIR) > 1 (relative to a high efficiency furnace) which also provides the resident with added incentive for energy savings; and duct leakage reductions of > 60% using an aerosolized duct sealing approach.

  6. The effects of short-term hypergravity on Caenorhabditis elegans.

    PubMed

    Saldanha, Jenifer N; Pandey, Santosh; Powell-Coffman, Jo Anne

    2016-08-01

    As we seek to recognize the opportunities of advanced aerospace technologies and spaceflight, it is increasingly important to understand the impacts of hypergravity, defined as gravitational forces greater than those present on the earth's surface. The nematode Caenorhabditis elegans has been established as a powerful model to study the effects of altered gravity regimens and has displayed remarkable resilience to space travel. In this study, we investigate the effects of short-term and defined hypergravity exposure on C. elegans motility, brood size, pharyngeal pumping rates, and lifespan. The results from this study advance our understanding of the effects of shorter durations of exposure to increased gravitational forces on C. elegans, and also contribute to the growing body of literature on the impacts of altered gravity regimens on earth's life forms. PMID:27662786

  7. Biochemical and hematologic changes after short-term space flight

    NASA Technical Reports Server (NTRS)

    Leach, Carolyn S.

    1991-01-01

    Clinical laboratory data from blood samples obtained from astronauts before and after 28 flights (average duration = 6 days) of the Space Shuttle were analyzed by the paired t-test and the Wilcoxon signed-rank test and compared with data from the Skylab flights (duration = 28, 56, and 84 days). Angiotensin I and aldosterone were elevated immediately after short-term space flights, but the response of angiotensin I was delayed after Skylab flights. Serum calcium was not elevated after Shuttle flights, but magnesium and uric acid decreased after both Shuttle and Skylab. Creatine phosphokinase in serum was reduced after Shuttle but not Skylab flights, probably because exercises to prevent deconditioning were not performed on the Shuttle. Total cholesterol was unchanged after Shuttle flights, but low density lipoprotein cholesterol increased and high density lipoprotein cholesterol decreased. The concentration of red blood cells was elevated after Shuttle flights and reduced after Skylab flights.

  8. The effects of short-term hypergravity on Caenorhabditis elegans.

    PubMed

    Saldanha, Jenifer N; Pandey, Santosh; Powell-Coffman, Jo Anne

    2016-08-01

    As we seek to recognize the opportunities of advanced aerospace technologies and spaceflight, it is increasingly important to understand the impacts of hypergravity, defined as gravitational forces greater than those present on the earth's surface. The nematode Caenorhabditis elegans has been established as a powerful model to study the effects of altered gravity regimens and has displayed remarkable resilience to space travel. In this study, we investigate the effects of short-term and defined hypergravity exposure on C. elegans motility, brood size, pharyngeal pumping rates, and lifespan. The results from this study advance our understanding of the effects of shorter durations of exposure to increased gravitational forces on C. elegans, and also contribute to the growing body of literature on the impacts of altered gravity regimens on earth's life forms.

  9. Short-Term Outlook for Hydrocarbon Gas Liquids

    EIA Publications

    2016-01-01

    U.S. liquid fuels production increased from 7.43 million barrels per day (b/d) in 2008 to 13.75 million b/d in 2015. However, the Short-Term Energy Outlook (STEO) expects liquid fuels production to decline to 12.99 million b/d in 2017, mainly as a result of prolonged low oil prices. The liquid fuels production forecast reflects a 1.24 million b/d decline in crude oil production by 2017 that is partially offset by a 450,000 b/d increase in the production of hydrocarbon gas liquids (HGL)—a group of products including ethane, propane, butane (normal and isobutane), natural gasoline, and refinery olefins. This analysis will discuss the outlook for each of these four HGL streams and related infrastructure projects through 2017.

  10. Short-term load forecasting with local ANN predictors

    SciTech Connect

    Drezga, I.; Rahman, S.

    1999-08-01

    A new technique for artificial neural network (ANN) based short-term load forecasting (STLF) is present in this paper. The technique implemented active selection of training data, employing the k-nearest neighbors concept. A novel concept of pilot simulation was used to determine the number of hidden units for the ANNs. The ensemble of local ANN predictors was used to produce the final forecast, whereby the iterative forecasting procedure used a simple average of ensemble ANNs. Results obtained using data from two US utilities showed forecasting accuracy comparable to those using similar techniques. Excellent forecasts for one-hour-ahead and five-days-ahead forecasting, robust behavior for sudden and large weather changes, low maximum errors and accurate peak-load predictions are some of the findings discussed in the paper.

  11. Short term load forecasting using fuzzy neural networks

    SciTech Connect

    Bakirtzis, A.G.; Theocharis, J.B.; Kiartzis, S.J.; Satsios, K.J.

    1995-08-01

    This paper presents the development of a fuzzy system for short term load forecasting. The fuzzy system has the network structure and the training procedure of a neural network and is called Fuzzy Neural Network (FNN). A FNN initially creates a rule base from existing historical load data. The parameters of the rule base are then tuned through a training process, so that the output of the FNN adequately matches the available historical load data. Once trained, the FNN can be used to forecast future loads. Test results show that the FNN can forecast future loads with an accuracy comparable to that of neural networks, while its training is much faster than that of neural networks.

  12. Short-term memory impairment and arithmetical ability.

    PubMed

    Butterworth, B; Cipolotti, L; Warrington, E K

    1996-02-01

    We document the dissociation of preserved calculation skills in a patient with impaired auditory short-term memory. The patient (MRF) had a memory span of three digits. Furthermore, he showed rapid decrement in performance of single digits and letters with both auditory and visual presentation in the Brown-Peterson forgetting task. Analysis of his calculation skills revealed a normal ability to solve auditorily presented multidigit addition and subtraction problems such as 173 + 68 and to execute the Paced Auditory Serial Addition Task (Sampson, 1956, 1958; Gronwall, 1977). In addition, his performance on other tests, including arithmetic manipulation of natural numbers, decimals and fractions, approximation, magnitude, ratio, and percentage, appeared to be normal (Hitch, 1978b). It is argued that these findings require a revision of Baddeley and Hitch's (1974) concept of the function of working memory. PMID:8920104

  13. Astronomical observation tasks short-term scheduling using PDDS algorithm

    NASA Astrophysics Data System (ADS)

    Kornilov, M. V.

    2016-07-01

    A concept of the ground-based optical astronomical observation efficiency is considered in this paper. We believe that a telescope efficiency can be increased by properly allocating observation tasks with respect to the current environment state and probability to obtain the data with required properties under the current conditions. An online observations scheduling is assumed to be an essential part for raising the efficiency. The short-term online scheduling is treated as the discrete optimisation problems which are stated using several abstraction levels. The optimisation problems are solved using the parallel depth-bounded discrepancy search (PDDS) algorithm by Moisan et al. (2014). Some aspects of the algorithm performance are discussed. The presented algorithm is a core of open-source chelyabinsk C++ library which is planned to be used at 2.5 m telescope of Sternberg Astronomical Institute of Lomonosov Moscow State University.

  14. Emulating short-term synaptic dynamics with memristive devices

    PubMed Central

    Berdan, Radu; Vasilaki, Eleni; Khiat, Ali; Indiveri, Giacomo; Serb, Alexandru; Prodromakis, Themistoklis

    2016-01-01

    Neuromorphic architectures offer great promise for achieving computation capacities beyond conventional Von Neumann machines. The essential elements for achieving this vision are highly scalable synaptic mimics that do not undermine biological fidelity. Here we demonstrate that single solid-state TiO2 memristors can exhibit non-associative plasticity phenomena observed in biological synapses, supported by their metastable memory state transition properties. We show that, contrary to conventional uses of solid-state memory, the existence of rate-limiting volatility is a key feature for capturing short-term synaptic dynamics. We also show how the temporal dynamics of our prototypes can be exploited to implement spatio-temporal computation, demonstrating the memristors full potential for building biophysically realistic neural processing systems. PMID:26725838

  15. Short and long term variations in the solar constant

    NASA Technical Reports Server (NTRS)

    Schatten, K. H.

    1981-01-01

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

  16. Short-Term Planning of Hybrid Power System

    NASA Astrophysics Data System (ADS)

    Knežević, Goran; Baus, Zoran; Nikolovski, Srete

    2016-07-01

    In this paper short-term planning algorithm for hybrid power system consist of different types of cascade hydropower plants (run-of-the river, pumped storage, conventional), thermal power plants (coal-fired power plants, combined cycle gas-fired power plants) and wind farms is presented. The optimization process provides a joint bid of the hybrid system, and thus making the operation schedule of hydro and thermal power plants, the operation condition of pumped-storage hydropower plants with the aim of maximizing profits on day ahead market, according to expected hourly electricity prices, the expected local water inflow in certain hydropower plants, and the expected production of electrical energy from the wind farm, taking into account previously contracted bilateral agreement for electricity generation. Optimization process is formulated as hourly-discretized mixed integer linear optimization problem. Optimization model is applied on the case study in order to show general features of the developed model.

  17. The effects of short-term hypergravity on Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Saldanha, Jenifer N.; Pandey, Santosh; Powell-Coffman, Jo Anne

    2016-08-01

    As we seek to recognize the opportunities of advanced aerospace technologies and spaceflight, it is increasingly important to understand the impacts of hypergravity, defined as gravitational forces greater than those present on the earth's surface. The nematode Caenorhabditis elegans has been established as a powerful model to study the effects of altered gravity regimens and has displayed remarkable resilience to space travel. In this study, we investigate the effects of short-term and defined hypergravity exposure on C. elegans motility, brood size, pharyngeal pumping rates, and lifespan. The results from this study advance our understanding of the effects of shorter durations of exposure to increased gravitational forces on C. elegans, and also contribute to the growing body of literature on the impacts of altered gravity regimens on earth's life forms.

  18. [Activity of Ginkgo biloba extract on short-term memory].

    PubMed

    Hindmarch, I

    1986-09-25

    Eight healthy female volunteers were included in a double-blind, cross-over trial comparing Ginkgo biloba extract in acute and ascending doses (120, 240, 600 mg) with a placebo. One hour after treatment they were subjected to a battery of tests, including: critical flicker fusion, choice reaction time, subjective rating scale and Sternberg memory scanning test. No statistically significant differences with the placebo were observed in the first three tests. In contrast, short term memory, as assessed by the Sternberg technique, was very significantly improved following 600 mg of Ginkgo biloba extract, as compared with the placebo. These results differentiate Ginkgo biloba extract from sedative and stimulant drugs and suggest a specific effect on memory processes.

  19. Short-term scheduling of reactive power controllers

    SciTech Connect

    Hong Yingyi; Liao Csongming

    1995-05-01

    A two-level approach is presented to solve the problem of optimal short-term (one day) scheduling of reactive power controllers in this paper. The entire problem is decomposed into two levels: the master and the slave levels. The master level deals with minimization of the depreciation cost of compensators and EHV transformer taps in order to reduce the control action for compensators and EHV transformer taps while satisfying operating constraints. The slave level treats minimization of capitalized MW losses while satisfying system security constraints. The slave level also treats OLTCs and determines scheduling of the generator voltages. These two levels interact through linear constraints in the iteration process. A practical 265-bus system, namely Taiwan Power System, are used to serve as a sample to show the applicability of the presented approach.

  20. Short-term memory stores organized by information domain.

    PubMed

    Noyce, Abigail L; Cestero, Nishmar; Shinn-Cunningham, Barbara G; Somers, David C

    2016-04-01

    Vision and audition have complementary affinities, with vision excelling in spatial resolution and audition excelling in temporal resolution. Here, we investigated the relationships among the visual and auditory modalities and spatial and temporal short-term memory (STM) using change detection tasks. We created short sequences of visual or auditory items, such that each item within a sequence arose at a unique spatial location at a unique time. On each trial, two successive sequences were presented; subjects attended to either space (the sequence of locations) or time (the sequence of inter item intervals) and reported whether the patterns of locations or intervals were identical. Each subject completed blocks of unimodal trials (both sequences presented in the same modality) and crossmodal trials (Sequence 1 visual, Sequence 2 auditory, or vice versa) for both spatial and temporal tasks. We found a strong interaction between modality and task: Spatial performance was best on unimodal visual trials, whereas temporal performance was best on unimodal auditory trials. The order of modalities on crossmodal trials also mattered, suggesting that perceptual fidelity at encoding is critical to STM. Critically, no cost was attributable to crossmodal comparison: In both tasks, performance on crossmodal trials was as good as or better than on the weaker unimodal trials. STM representations of space and time can guide change detection in either the visual or the auditory modality, suggesting that the temporal or spatial organization of STM may supersede sensory-specific organization.

  1. The serial-position effect in short-term motor retention.

    PubMed

    Wrisberg, C A

    1975-12-01

    The existence of inter-item interference was demonstrated in an experiment investigating proactive inhibition in motor short-term memory. Blindfolded subjects moved a slide to a stop and then attempted to replace the slide in the correct (criterion) location with the stop removed. Independent variables were positions recalled in addition to the criterion (zero or four) and retention interval length (5 or 50 sec). While retention loss on the criterion position was found only for the group with four additional positions and a 50-sec retention interval, analysis of recall error at each position for subjects given a five-item sequence and a 5-sec retention interval indicated a serial-position effect. Implications of the findings for the role of cognitive processes in motor short-term memory were discussed.

  2. Limitless capacity: a dynamic object-oriented approach to short-term memory

    PubMed Central

    Macken, Bill; Taylor, John; Jones, Dylan

    2015-01-01

    The notion of capacity-limited processing systems is a core element of cognitive accounts of limited and variable performance, enshrined within the short-term memory construct. We begin with a detailed critical analysis of the conceptual bases of this view and argue that there are fundamental problems – ones that go to the heart of cognitivism more generally – that render it untenable. In place of limited capacity systems, we propose a framework for explaining performance that focuses on the dynamic interplay of three aspects of any given setting: the particular task that must be accomplished, the nature and form of the material upon which the task must be performed, and the repertoire of skills and perceptual-motor functions possessed by the participant. We provide empirical examples of the applications of this framework in areas of performance typically accounted for by reference to capacity-limited short-term memory processes. PMID:25852610

  3. Short-Term Load Forecasting using Dynamic Neural Networks

    NASA Astrophysics Data System (ADS)

    Chogumaira, Evans N.; Hiyama, Takashi

    This paper presents short-term electricity load forecasting using dynamic neural networks, DNN. The proposed approach includes an assessment of the DNN's stability to ascertain continued reliability. A comparative study between three different neural network architectures, which include feedforward, Elman and the radial basis neural networks, is performed. The performance and stability of each DNN is evaluated using actual hourly load data. Stability for each of the three different networks is determined through Eigen values analysis. The neural networks weights are dynamically adapted to meet the performance and stability requirements. A new approach for adapting radial basis function (RBF) neural network weights is also proposed. Evaluation of the networks is done in terms of forecasting error, stability and the effort required in training a particular network. The results show that DNN based on the radial basis neural network architecture performs much better than the rest. Eigen value analysis also shows that the radial basis based DNN is more stable making it very reliable as the input varies.

  4. Severe neurotrauma in Switzerland: have short-term outcomes improved?

    PubMed

    Haller, Chiara Simone; Walder, Bernhard

    2015-01-01

    Neurotrauma has a high incidence in high-income countries (790 per 100,000 population per year) and can be considered a silent epidemic. Severe traumatic brain injury (TBI) is a major burden for societies and is associated with high costs for both immediate and long-term care. Population-based studies including patients with severe TBI are rare. A recent cohort study in Switzerland observed an incidence of 11 / 100,000 population / year. Mortality rate at 14 days post-injury was 30% in Switzerland and was associated with the severity of the injury and the age of the injured person. Thirty-five percent of patients were >65 years; in this subpopulation the incidence (22/100,000/year) and death rate (41%) were higher; this high proportion of elderly patients in this setting is new. A decrease in disability in the first year after TBI was observed in large multicentre cohort studies including the Swiss cohort study. There is some evidence that the speed of decrease of disability over time is associated with intensive neurorehabilitation. In conclusion, short-term outcome may have improved for younger patients over recent years, but this improvement may be masked by the higher proportion of elderly patients with less favourable outcomes. Additionally, we propose that clinical pathways from the prehospital period to rehabilitation could be improved, and in turn allow a higher level of positive outcomes not only in young but also in elderly patients.

  5. Molecular pharmacological dissection of short- and long-term memory.

    PubMed

    Izquierdo, Luciana A; Barros, Daniela M; Vianna, Monica R M; Coitinho, Adriana; deDavid e Silva, Tiago; Choi, Humberto; Moletta, Beatriz; Medina, Jorge H; Izquierdo, Ivan

    2002-06-01

    1. It has been discussed for over 100 years whether short-term memory (STM) is separate from, or just an early phase of, long-term memory (LTM). The only way to solve this dilemma is to find out at least one treatment that blocks STM while keeping LTM intact for the same task in the same animal. 2. The effect of a large number of treatments infused into the hippocampus, amygdala, and entorhinal, posterior parietal or prefrontal cortex on STM and LTM of a one-trial step-down inhibitory avoidance task was studied. The animals were tested at 1.5 h for STM, and again at 24 h for LTM. The treatments were given after training. 3. Eleven different treatments blocked STM without affecting LTM. Eighteen treatments affected the two memory types differentially, either blocking or enhancing LTM alone. Thus, STM is separate from, and parallel to the first hours of processing of, LTM of that task. 4. The mechanisms of STM are different from those of LTM. The former do not include gene expression or protein synthesis; the latter include a double peak of cAMP-dependent protein kinase activity, accompanied by the phosphorylation of CREB, and both gene expression and protein synthesis. 5. Possible cellular and molecular events that do not require mRNA or protein synthesis should account for STM. These might include a hyperactivation of glutamate AMPA receptors, ribosome changes, or the exocytosis of glycoproteins that participate in cell addition.

  6. Short-Term International Internship Experiences for Future Teachers and Other Child Development Professionals

    ERIC Educational Resources Information Center

    Miller, Kari Knutson; Gonzalez, Amber M.

    2016-01-01

    This paper examines outcomes associated with participation in short-term, international internship experiences. Results suggest short-term international internship experiences contribute to rich personal and professional development outcomes. Findings highlight participant challenges associated with initial internship experiences, professional…

  7. Short-term Gains with Long-term Consequences: The Evolving Story of Sepsis Survivorship.

    PubMed

    Maley, Jason H; Mikkelsen, Mark E

    2016-06-01

    Sepsis is an acute, life-threatening condition that afflicts millions of patients annually. Advances in care and heightened awareness have led to substantial declines in short-term mortality. An expanding body of literature describes the long-term impact of sepsis, revealing long-term cognitive and functional impairments, sustained inflammation and immune dysfunction, increased healthcare resource use, reduced health-related quality of life, and increased mortality. The evidence challenges the notion that sepsis is an acute, transient illness, revealing rather that sepsis is an acute illness with lingering consequences. This article provides a state-of-the-art review of the emerging literature of the long-term consequences of sepsis. PMID:27229651

  8. Estimation of desmosponge (Porifera, Demospongiae) larval settlement rates from short-term recruitment rates: Preliminary experiments

    NASA Astrophysics Data System (ADS)

    Zea, Sven

    1992-09-01

    During a study of the spatial and temporal patterns of desmosponge (Porifera, Demospongiae) recruitment on rocky and coral reef habitats of Santa Marta, Colombian Caribbean Sea, preliminary attempts were made to estimate actual settlement rates from short-term (1 to a few days) recruitment censuses. Short-term recruitment rates on black, acrylic plastic plates attached to open, non-cryptic substratum by anchor screws were low and variable (0 5 recruits/plate in 1 2 days, sets of n=5 10 plates), but reflected the depth and seasonal trends found using mid-term (1 to a few months) censusing intervals. Moreover, mortality of recruits during 1 2 day intervals was low (0 12%). Thus, short-term censusing intervals can be used to estimate actual settlement rates. To be able to make statistical comparisons, however, it is necessary to increase the number of recruits per census by pooling data of n plates per set, and to have more than one set per site or treatment.

  9. Short Term Gains, Long Term Pains: How Cues About State Aid Learning in Dynamic Environments

    PubMed Central

    Gureckis, Todd M.; Love, Bradley C.

    2009-01-01

    Successful investors seeking returns, animals foraging for food, and pilots controlling aircraft all must take into account how their current decisions will impact their future standing. One challenge facing decision makers is that options that appear attractive in the short-term may not turn out best in the long run. In this paper, we explore human learning in a dynamic decision-making task which places short- and long-term rewards in conflict. Our goal in these studies was to evaluate how people’s mental representation of a task affects their ability to discover an optimal decision strategy. We find that perceptual cues that readily align with the underlying state of the task environment help people overcome the impulsive appeal of short-term rewards. Our experimental manipulations, predictions, and analyses are motivated by current work in reinforcement learning which details how learners value delayed outcomes in sequential tasks and the importance that “state” identification plays in effective learning. PMID:19427635

  10. Short-term dynamics of indoor and outdoor endotoxin exposure: Case of Santiago, Chile, 2012.

    PubMed

    Barraza, Francisco; Jorquera, Héctor; Heyer, Johanna; Palma, Wilfredo; Edwards, Ana María; Muñoz, Marcelo; Valdivia, Gonzalo; Montoya, Lupita D

    2016-01-01

    Indoor and outdoor endotoxin in PM2.5 was measured for the very first time in Santiago, Chile, in spring 2012. Average endotoxin concentrations were 0.099 and 0.094 [EU/m(3)] for indoor (N=44) and outdoor (N=41) samples, respectively; the indoor-outdoor correlation (log-transformed concentrations) was low: R=-0.06, 95% CI: (-0.35 to 0.24), likely owing to outdoor spatial variability. A linear regression model explained 68% of variability in outdoor endotoxins, using as predictors elemental carbon (a proxy of traffic emissions), chlorine (a tracer of marine air masses reaching the city) and relative humidity (a modulator of surface emissions of dust, vegetation and garbage debris). In this study, for the first time a potential source contribution function (PSCF) was applied to outdoor endotoxin measurements. Wind trajectory analysis identified upwind agricultural sources as contributors to the short-term, outdoor endotoxin variability. Our results confirm an association between combustion particles from traffic and outdoor endotoxin concentrations. For indoor endotoxins, a predictive model was developed but it only explained 44% of endotoxin variability; the significant predictors were tracers of indoor PM2.5 dust (Si, Ca), number of external windows and number of hours with internal doors open. Results suggest that short-term indoor endotoxin variability may be driven by household dust/garbage production and handling. This would explain the modest predictive performance of published models that use answers to household surveys as predictors. One feasible alternative is to increase the sampling period so that household features would arise as significant predictors of long-term airborne endotoxin levels. PMID:27065310

  11. Short-term dynamics of indoor and outdoor endotoxin exposure: Case of Santiago, Chile, 2012.

    PubMed

    Barraza, Francisco; Jorquera, Héctor; Heyer, Johanna; Palma, Wilfredo; Edwards, Ana María; Muñoz, Marcelo; Valdivia, Gonzalo; Montoya, Lupita D

    2016-01-01

    Indoor and outdoor endotoxin in PM2.5 was measured for the very first time in Santiago, Chile, in spring 2012. Average endotoxin concentrations were 0.099 and 0.094 [EU/m(3)] for indoor (N=44) and outdoor (N=41) samples, respectively; the indoor-outdoor correlation (log-transformed concentrations) was low: R=-0.06, 95% CI: (-0.35 to 0.24), likely owing to outdoor spatial variability. A linear regression model explained 68% of variability in outdoor endotoxins, using as predictors elemental carbon (a proxy of traffic emissions), chlorine (a tracer of marine air masses reaching the city) and relative humidity (a modulator of surface emissions of dust, vegetation and garbage debris). In this study, for the first time a potential source contribution function (PSCF) was applied to outdoor endotoxin measurements. Wind trajectory analysis identified upwind agricultural sources as contributors to the short-term, outdoor endotoxin variability. Our results confirm an association between combustion particles from traffic and outdoor endotoxin concentrations. For indoor endotoxins, a predictive model was developed but it only explained 44% of endotoxin variability; the significant predictors were tracers of indoor PM2.5 dust (Si, Ca), number of external windows and number of hours with internal doors open. Results suggest that short-term indoor endotoxin variability may be driven by household dust/garbage production and handling. This would explain the modest predictive performance of published models that use answers to household surveys as predictors. One feasible alternative is to increase the sampling period so that household features would arise as significant predictors of long-term airborne endotoxin levels.

  12. SULFURIC ACID REMOVAL PROCESS EVALUATION: SHORT-TERM RESULTS

    SciTech Connect

    Gary M. Blythe; Richard McMillan

    2002-03-04

    results of the short-term tests; the long-term test results will be reported in a later document. The short-term test results showed that three of the four reagents tested, dolomite powder, commercial magnesium hydroxide slurry, and byproduct magnesium hydroxide slurry, were able to achieve 90% or greater removal of sulfuric acid compared to baseline levels. The molar ratio of alkali to flue gas sulfuric acid content (under baseline conditions) required to achieve 90% sulfuric acid removal was lowest for the byproduct magnesium hydroxide slurry. However, this result may be confounded because this was the only one of the three slurries tested with injection near the top of the furnace across from the pendant superheater platens. Injection at the higher level was demonstrated to be advantageous for this reagent over injection lower in the furnace, where the other slurries were tested.

  13. SULFURIC ACID REMOVAL PROCESS EVALUATION: SHORT-TERM RESULTS

    SciTech Connect

    Gary M. Blythe; Richard McMillan

    2002-02-04

    the results of the short-term tests; the long-term test results will be reported in a later document. The short-term test results showed that three of the four reagents tested, dolomite powder, commercial magnesium hydroxide slurry, and byproduct magnesium hydroxide slurry, were able to achieve 90% or greater removal of sulfuric acid compared to baseline levels. The molar ratio of alkali to flue gas sulfuric acid content (under baseline conditions) required to achieve 90% sulfuric acid removal was lowest for the byproduct magnesium hydroxide slurry. However, this result may be confounded because this was the only one of the three slurries tested with injection near the top of the furnace across from the pendant superheater platens. Injection at the higher level was demonstrated to be advantageous for this reagent over injection lower in the furnace, where the other slurries were tested.

  14. Tritanium acetabular wedge augments: short-term results

    PubMed Central

    Restrepo, Camilo; Heller, Snir

    2016-01-01

    Background Reconstruction of acetabular defects in total hip arthroplasty (THA) presents a great challenge to orthopaedic surgeons. Previous studies have reported on the use and outcomes of trabecular metal acetabular augments for the reconstruction of acetabular defects. However, no study has been conducted evaluating the short-term results of tritanium acetabular wedge augments for the reconstruction of acetabular defects in THA. Methods A retrospective study was conducted using a prospective database at a single institution including primary and revision THA patients from January 2013 to December 2014. Patients were included if they received a tritanium acetabular wedge augment system and had a minimum of 2-year follow-up (average 2.2 years ±0.3, range, 2–2.6 years). Demographic data and outcomes data [Harris Hip Score—HHS and Short Form (SF)-36] was collected. Radiographic data was also collected on THA revision cases (Paprosky classification), developmental dysplasia of the hip (DDH) cases (Crowe classification), and radiographic follow-up using DeLee and Charnley’s classification system. Results There were 4 revision THA patients, 3 DDH patients, and 1 patient with posttraumatic arthritis. At the latest radiographic follow-up, there were no lucent lines in DeLee and Charnley Zones I, II or III. During the follow-up period, there was no open revision surgery. The SF-36 physical score significantly improved from preoperative measurement (29.6±2.2) to postoperative measurement (52.2±8.7, P=0.003), and the SF-36 mental score also significantly improved from preoperative assessment (34.5±4.5) to postoperative assessment (52.2±7.5, P=0.003). Total HHS scores also significantly improved postoperatively (P=0.02), with significant improvements in both the pain score (P=0.01) and function score (P=0.02). Conclusions Tritanium acetabular wedge augments in this short follow-up case series exhibit high clinical outcome scores, no radiographic lucency, and no

  15. Short-Term Effects of Midseason Coach Turnover on Team Performance in Soccer

    ERIC Educational Resources Information Center

    Balduck, Anne-Line; Buelens, Marc; Philippaerts, Renaat

    2010-01-01

    The present study addressed the issue of short-term performance effects of midseason coach turnover in soccer. The goal of this study was to examine this effect on subsequent short-term team performance. The purposes of this study were to (a) examine whether midseason coach turnover improved results in the short term, and (b) examine how team…

  16. 47 CFR 1.9035 - Short-term de facto transfer leasing arrangements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Short-term de facto transfer leasing... PROCEDURE Spectrum Leasing General Policies and Procedures § 1.9035 Short-term de facto transfer leasing...) and a spectrum lessee may enter into a short-term de facto transfer leasing arrangement in which...

  17. 22 CFR 71.11 - Short-term full diet program.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Short-term full diet program. 71.11 Section 71.... Nationals Incarcerated Abroad § 71.11 Short-term full diet program. (a) Eligibility criteria. A prisoner is considered eligible for the short-term full diet program under the following general criteria: (1)...

  18. 22 CFR 71.11 - Short-term full diet program.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Short-term full diet program. 71.11 Section 71.... Nationals Incarcerated Abroad § 71.11 Short-term full diet program. (a) Eligibility criteria. A prisoner is considered eligible for the short-term full diet program under the following general criteria: (1)...

  19. 22 CFR 71.11 - Short-term full diet program.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Short-term full diet program. 71.11 Section 71.... Nationals Incarcerated Abroad § 71.11 Short-term full diet program. (a) Eligibility criteria. A prisoner is considered eligible for the short-term full diet program under the following general criteria: (1)...

  20. 22 CFR 71.11 - Short-term full diet program.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Short-term full diet program. 71.11 Section 71.... Nationals Incarcerated Abroad § 71.11 Short-term full diet program. (a) Eligibility criteria. A prisoner is considered eligible for the short-term full diet program under the following general criteria: (1)...

  1. 22 CFR 71.11 - Short-term full diet program.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Short-term full diet program. 71.11 Section 71.... Nationals Incarcerated Abroad § 71.11 Short-term full diet program. (a) Eligibility criteria. A prisoner is considered eligible for the short-term full diet program under the following general criteria: (1)...

  2. 34 CFR 664.11 - What is a short-term seminar project?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 3 2011-07-01 2011-07-01 false What is a short-term seminar project? 664.11 Section... Projects Does the Secretary Assist Under This Program? § 664.11 What is a short-term seminar project? A short-term seminar project is— (a) Designed to help integrate international studies into an...

  3. 34 CFR 664.11 - What is a short-term seminar project?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 3 2012-07-01 2012-07-01 false What is a short-term seminar project? 664.11 Section... Projects Does the Secretary Assist Under This Program? § 664.11 What is a short-term seminar project? A short-term seminar project is— (a) Designed to help integrate international studies into an...

  4. 24 CFR 574.330 - Additional standards for short-term supported housing.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Uses of Grant Funds § 574.330 Additional standards for short-term supported housing. Short-term... 24 Housing and Urban Development 3 2013-04-01 2013-04-01 false Additional standards for short-term supported housing. 574.330 Section 574.330 Housing and Urban Development Regulations Relating to Housing...

  5. 24 CFR 574.330 - Additional standards for short-term supported housing.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Uses of Grant Funds § 574.330 Additional standards for short-term supported housing. Short-term... 24 Housing and Urban Development 3 2014-04-01 2013-04-01 true Additional standards for short-term supported housing. 574.330 Section 574.330 Housing and Urban Development Regulations Relating to Housing...

  6. Musical and verbal memory in Alzheimer's disease: a study of long-term and short-term memory.

    PubMed

    Ménard, Marie-Claude; Belleville, Sylvie

    2009-10-01

    Musical memory was tested in Alzheimer patients and in healthy older adults using long-term and short-term memory tasks. Long-term memory (LTM) was tested with a recognition procedure using unfamiliar melodies. Short-term memory (STM) was evaluated with same/different judgment tasks on short series of notes. Musical memory was compared to verbal memory using a task that used pseudowords (LTM) or syllables (STM). Results indicated impaired musical memory in AD patients relative to healthy controls. The deficit was found for both long-term and short-term memory. Furthermore, it was of the same magnitude for both musical and verbal domains whether tested with short-term or long-term memory tasks. No correlation was found between musical and verbal LTM. However, there was a significant correlation between verbal and musical STM in AD participants and healthy older adults, which suggests that the two domains may share common mechanisms. PMID:19398148

  7. Language Identification in Short Utterances Using Long Short-Term Memory (LSTM) Recurrent Neural Networks.

    PubMed

    Zazo, Ruben; Lozano-Diez, Alicia; Gonzalez-Dominguez, Javier; Toledano, Doroteo T; Gonzalez-Rodriguez, Joaquin

    2016-01-01

    Long Short Term Memory (LSTM) Recurrent Neural Networks (RNNs) have recently outperformed other state-of-the-art approaches, such as i-vector and Deep Neural Networks (DNNs), in automatic Language Identification (LID), particularly when dealing with very short utterances (∼3s). In this contribution we present an open-source, end-to-end, LSTM RNN system running on limited computational resources (a single GPU) that outperforms a reference i-vector system on a subset of the NIST Language Recognition Evaluation (8 target languages, 3s task) by up to a 26%. This result is in line with previously published research using proprietary LSTM implementations and huge computational resources, which made these former results hardly reproducible. Further, we extend those previous experiments modeling unseen languages (out of set, OOS, modeling), which is crucial in real applications. Results show that a LSTM RNN with OOS modeling is able to detect these languages and generalizes robustly to unseen OOS languages. Finally, we also analyze the effect of even more limited test data (from 2.25s to 0.1s) proving that with as little as 0.5s an accuracy of over 50% can be achieved.

  8. Language Identification in Short Utterances Using Long Short-Term Memory (LSTM) Recurrent Neural Networks

    PubMed Central

    Zazo, Ruben; Lozano-Diez, Alicia; Gonzalez-Dominguez, Javier; T. Toledano, Doroteo; Gonzalez-Rodriguez, Joaquin

    2016-01-01

    Long Short Term Memory (LSTM) Recurrent Neural Networks (RNNs) have recently outperformed other state-of-the-art approaches, such as i-vector and Deep Neural Networks (DNNs), in automatic Language Identification (LID), particularly when dealing with very short utterances (∼3s). In this contribution we present an open-source, end-to-end, LSTM RNN system running on limited computational resources (a single GPU) that outperforms a reference i-vector system on a subset of the NIST Language Recognition Evaluation (8 target languages, 3s task) by up to a 26%. This result is in line with previously published research using proprietary LSTM implementations and huge computational resources, which made these former results hardly reproducible. Further, we extend those previous experiments modeling unseen languages (out of set, OOS, modeling), which is crucial in real applications. Results show that a LSTM RNN with OOS modeling is able to detect these languages and generalizes robustly to unseen OOS languages. Finally, we also analyze the effect of even more limited test data (from 2.25s to 0.1s) proving that with as little as 0.5s an accuracy of over 50% can be achieved. PMID:26824467

  9. Language Identification in Short Utterances Using Long Short-Term Memory (LSTM) Recurrent Neural Networks.

    PubMed

    Zazo, Ruben; Lozano-Diez, Alicia; Gonzalez-Dominguez, Javier; Toledano, Doroteo T; Gonzalez-Rodriguez, Joaquin

    2016-01-01

    Long Short Term Memory (LSTM) Recurrent Neural Networks (RNNs) have recently outperformed other state-of-the-art approaches, such as i-vector and Deep Neural Networks (DNNs), in automatic Language Identification (LID), particularly when dealing with very short utterances (∼3s). In this contribution we present an open-source, end-to-end, LSTM RNN system running on limited computational resources (a single GPU) that outperforms a reference i-vector system on a subset of the NIST Language Recognition Evaluation (8 target languages, 3s task) by up to a 26%. This result is in line with previously published research using proprietary LSTM implementations and huge computational resources, which made these former results hardly reproducible. Further, we extend those previous experiments modeling unseen languages (out of set, OOS, modeling), which is crucial in real applications. Results show that a LSTM RNN with OOS modeling is able to detect these languages and generalizes robustly to unseen OOS languages. Finally, we also analyze the effect of even more limited test data (from 2.25s to 0.1s) proving that with as little as 0.5s an accuracy of over 50% can be achieved. PMID:26824467

  10. Acute kidney injury: short-term and long-term effects.

    PubMed

    Doyle, James F; Forni, Lui G

    2016-01-01

    Acute kidney injury (AKI) is the most common cause of organ dysfunction in critically ill adults, with a single episode of AKI, regardless of stage, carrying a significant morbidity and mortality risk. Since the consensus on AKI nomenclature has been reached, data reflecting outcomes have become more apparent allowing investigation of both short- and long-term outcomes.Classically the short-term effects of AKI can be thought of as those reflecting an acute deterioration in renal function per se. However, the effects of AKI, especially with regard to distant organ function ("organ cross-talk"), are being elucidated as is the increased susceptibility to other conditions. With regards to the long-term effects, the consideration that outcome is a simple binary endpoint of dialysis or not, or survival or not, is overly simplistic, with the reality being much more complex.Also discussed are currently available treatment strategies to mitigate these adverse effects, as they have the potential to improve patient outcome and provide considerable economic health savings. Moving forward, an agreement for defining renal recovery is warranted if we are to assess and extrapolate the efficacy of novel therapies. Future research should focus on targeted therapies assessed by measure of long-term outcomes. PMID:27373891

  11. Short-term outcome of patients with preeclampsia

    PubMed Central

    Koual, Meriem; Abbou, Hind; Carbonnel, Marie; Picone, Olivier; Ayoubi, Jean-Marc

    2013-01-01

    Introduction Preeclampsia constitutes a cause of increased mortality in mothers and fetuses. Screening for promoting factors is essential for adequate prevention in the event of any subsequent pregnancy, and for the adequate follow-up of concerned patients. The aim of the present study was to evaluate the short-term outcome of patients with preeclampsia and to identify possible new factors predisposing them to the disease. Methods One hundred fifty-five patients having experienced preeclampsia between 2005 and 2010 from the Gynecology and Obstetrics Department of the Foch Hospital (Suresnes, France) were included in the study. All patients had undergone close clinical and standard biological follow-up immediately postpartum and then 3 months later with a reference practitioner. In severe cases, further investigation was carried out by full etiological examination with an assessment of both autoimmune and thrombophilic status. Results Obesity and gestational diabetes were observed to be major risk factors for preeclampsia, which were found in 46% and 15% of the cases, respectively. The etiological assessment showed abnormalities in 11% of the patients. Impaired thrombophilia was found in 3% of the patients, impaired autoimmune status in 4%, a combination of both abnormalities in only 1% of the patients, and detection of renal abnormalities in 3% of the patients were observed. In the immediate postpartum period, 66% of patients had maintained elevated blood pressure levels, and 66% had proteinuria > 0.3 g/24 hours. At the 3-month postpartum assessment, persisting arterial hypertension was found in 16% of the patients, requiring continuation of antihypertensive therapy, and 22% of the patients had proteinuria over the accepted threshold (0.15 g/24 hours). Conclusion Patients with preeclampsia have increased cardiovascular risk, necessitating lifestyle measures and long-term follow-up. Etiological assessment must be carried out, systematically aiming at the detection

  12. Conceptual short term memory in perception and thought.

    PubMed

    Potter, Mary C

    2012-01-01

    Conceptual short term memory (CSTM) is a theoretical construct that provides one answer to the question of how perceptual and conceptual processes are related. CSTM is a mental buffer and processor in which current perceptual stimuli and their associated concepts from long term memory (LTM) are represented briefly, allowing meaningful patterns or structures to be identified (Potter, 1993, 1999, 2009). CSTM is different from and complementary to other proposed forms of working memory: it is engaged extremely rapidly, has a large but ill-defined capacity, is largely unconscious, and is the basis for the unreflective understanding that is characteristic of everyday experience. The key idea behind CSTM is that most cognitive processing occurs without review or rehearsal of material in standard working memory and with little or no conscious reasoning. When one perceives a meaningful stimulus such as a word, picture, or object, it is rapidly identified at a conceptual level and in turn activates associated information from LTM. New links among concurrently active concepts are formed in CSTM, shaped by parsing mechanisms of language or grouping principles in scene perception and by higher-level knowledge and current goals. The resulting structure represents the gist of a picture or the meaning of a sentence, and it is this structure that we are conscious of and that can be maintained in standard working memory and consolidated into LTM. Momentarily activated information that is not incorporated into such structures either never becomes conscious or is rapidly forgotten. This whole cycle - identification of perceptual stimuli, memory recruitment, structuring, consolidation in LTM, and forgetting of non-structured material - may occur in less than 1 s when viewing a pictured scene or reading a sentence. The evidence for such a process is reviewed and its implications for the relation of perception and cognition are discussed. PMID:22557984

  13. Short-term Physical Inactivity Impairs Vascular Function

    PubMed Central

    Nosova, Emily V.; Yen, Priscilla; Chong, Karen C.; Alley, Hugh F.; Stock, Eveline O.; Quinn, Alex; Hellmann, Jason; Conte, Michael S.; Owens, Christopher D.; Spite, Matthew; Grenon, S. Marlene

    2014-01-01

    Introduction Sedentarism, also termed physical inactivity, is an independent risk factor for cardiovascular diseases. Mechanisms thought to be involved include insulin resistance, dyslipidemia, hypertension, and increased inflammation. It is unknown whether changes in vascular and endothelial function also contribute to this excess risk. We hypothesized that short-term exposure to inactivity would lead to endothelial dysfunction, arterial stiffening and increased vascular inflammation. Methods Five healthy subjects (4 males and 1 female) underwent 5 days of bed rest (BR) to simulate inactivity. Measurements of vascular function [flow-mediated vasodilation (FMD) to evaluate endothelial function; applanation tonometry to assess arterial resistance], inflammation and metabolism were made before BR, daily during BR and after 2 recovery days. Subjects maintained an isocaloric diet throughout. Results Bed rest led to significant decreases in brachial artery and femoral artery FMD [Brachial: 11 ± 3% pre-BR vs. 9 ± 2% end-BR, P=0.04; Femoral: 4 ± 1% vs. 2 ± 1%, P=0.04]. The central augmentation index increased with BR [−4 ± 9% vs. 5 ± 11%, P=0.03]. Diastolic blood pressure (DBP) increased [58 ± 7 mmHg vs. 62 ± 7 mmHg, P=0.02], while neither systolic blood pressure nor heart rate changed. 15-HETE, an arachidonic acid metabolite, increased but the other inflammatory and metabolic biomarkers were unchanged. Conclusions Our findings show that acute exposure to sedentarism results in decreased endothelial function, arterial stiffening, increased DBP, and an increase in 15-HETE. We speculate that inactivity promotes a vascular “deconditioning” state characterized by impaired endothelial function, leading to arterial stiffness and increased arterial tone. Although physiologically significant, the underlying mechanisms and clinical relevance of these findings need to be further explored. PMID:24630521

  14. Short term hypothyroidism affects ovarian function in the cycling rat

    PubMed Central

    2010-01-01

    Background Rats made hypothyroid with propilthyouracil start showing abnormal cycling on the second cycle after the start of the treatment, with a high proportion of spontaneous pseudopregnancies and reduced fertility. Methods To investigate some of the mechanisms involved in these reproductive abnormalities, hypothyroidism was induced in virgin rats by propilthyouracil (0.1 g/L in the drinking water) and we determined circulating hormones by radioimmunoassay and whole ovary expression of ovarian hormone receptors, growth factors and steroidogenic enzymes using semi-quantitative RT-PCR. The study was performed on days 6 to 9 of treatment, corresponding to diestrus I (at 20.00-22.00 h), diestrus II (at 20.00-22.00 h), proestrus and estrus (both at 8.00-10.00 h and 20.00-22.00 h) of the second estrous cycle after beginning propilthyouracil treatment. Another group of rats was mated on day 8 and the treatment continued through the entire pregnancy to evaluate reproductive performance. Results Hypothyroidism increased circulating prolactin and estradiol on estrus 5 to 7-fold and 1.2 to 1.4-fold respectively. Growth hormone and insulin-like growth factor 1 diminished 60 and 20% respectively on proestrus morning. Hypothyroidism doubled the ovarian mRNA contents of estrogen receptor-beta on proestrus and estrus evenings, cyp19A1 aromatase mRNA on estrus evening and of growth hormone receptor on proestrus evening. Hypothyroidism did not influence ovulation rate or the number of corpora lutea at term, but a diminished number of implantation sites and pups per litter were observed (Hypothyroid: 11.7 +/- 0.8 vs. Control: 13.9 +/- 0.7). Conclusions Short term hypothyroidism alters normal hormone profile in the cycling rat increasing the expression of estrogen receptor-beta and cyp19A1 aromatase on estrus, which in turn may stimulate estradiol and prolactin secretion, favouring corpus luteum survival and the subsequent instauration of pseudopregnancy. PMID:20149258

  15. Long-term variability of a complete sample of quasars

    SciTech Connect

    Cristiani, S.; Vio, R.; Andreani, P. )

    1990-07-01

    The long-term variability of a complete sample of quasars selected in the field of the SA 94 has been investigated. Using Schmidt plates covering a time baseline of seven years, about one-third of the quasars are found to be variable. It is suggested that all the quasi-stellar objects are variable with amplitudes of a few tenths of a magnitude on timescales of the order of some years in their restframes. The application of the variability technique to the selection of complete samples of quasars is discussed. The timescales estimated can be easily accounted for in the accreting black hole with thermal and viscous timescales. The variability is found to be correlated with the absolute magnitude and/or the redshift. 21 refs.

  16. Short-Term Dynamical Interactions Among Extrasolar Planets

    NASA Technical Reports Server (NTRS)

    Laughlin, Gregory; Chambers, John E.; DiVincenzi, Donald (Technical Monitor)

    2001-01-01

    We show that short-term perturbations among massive planets in multiple planet systems can result in radial velocity variations of the central star which differ substantially from velocity variations derived assuming the planets are executing independent Keplerian motions. We discuss two alternate fitting methods which can lead to an improved dynamical description of multiple planet systems. In the first method, the osculating orbital elements are determined via a Levenberg-Marquardt minimization scheme driving an N-body integrator. The second method is an improved analytic model in which orbital elements such as the periods and longitudes of periastron are allowed to vary according to a simple model for resonant interactions between the planets. Both of these methods can potentially determine the true masses for the planets by eliminating the sin(i) degeneracy inherent in fits that assume independent Keplerian motions. As more radial velocity data is accumulated from stars such as GJ876, these methods should allow for unambiguous determination of the planetary masses and relative inclinations.

  17. Vaccination: short- to long-term benefits from investment.

    PubMed

    Carroll, Stuart; Rojas, Amós José García; Glenngård, Anna H; Marin, Carmen

    2015-01-01

    In the context of current economic difficulties across Europe, accurate budgeting and resource allocation have become increasingly important. Vaccination programmes can respond to the needs of governments to budget with confidence. It may be more reliable and accurate to forecast budget and resource allocation for a vaccination programme than for unpredictable seasonal disease peaks of infections such as rotavirus gastroenteritis, influenza, and pneumonia. In addition, prevention through vaccination involves low levels of investment relative to the substantial benefits that may be obtained. In France, total lifelong vaccination costs, per fully compliant individual, ranged from €865 to €3,313, covering 12 to 16 diseases, which is comparable to, or lower than, costs of other preventive measures. In addition, effectively implemented vaccination programmes have the potential to generate substantial savings both in the short and in the long term. For example, vaccination programmes for rotavirus, meningitis C, human papillomavirus, influenza, and pneumonia have all been shown to significantly reduce the disease burden, and thus the associated costs, in the first years following vaccination implementation. These programmes demonstrate the potential for health authorities to obtain early, and often substantial, return on investment.

  18. Genotoxicity Assessment of Erythritol by Using Short-term Assay

    PubMed Central

    Chung, Young-Shin

    2013-01-01

    Erythritol is a sugar alcohol that is widely used as a natural sugar substitute. Thus, the safety of its usage is very important. In the present study, short-term genotoxicity assays were conducted to evaluate the potential genotoxic effects of erythritol. According to the OECD test guidelines, the maximum test dose was 5,000 μg/plate in bacterial reverse mutation tests, 5,000 μg/ml in cell-based assays, and 5,000 mg/kg for in vivo testing. An Ames test did not reveal any positive results. No clastogenicity was observed in a chromosomal aberration test with CHL cells or an in vitro micronucleus test with L5178Y tk+/− cells. Erythritol induced a marginal increase of DNA damage at two high doses by 24 hr of exposure in a comet assay using L5178Y tk+/− cells. Additionally, in vivo micronucleus tests clearly demonstrated that oral administration of erythritol did not induce micronuclei formation of the bone marrow cells of male ICR mice. Taken together, our results indicate that erythritol is not mutagenic to bacterial cells and does not cause chromosomal damage in mammalian cells either in vitro or in vivo. PMID:24578795

  19. Short-term Aerosol Trends: Reality or Myth?

    NASA Technical Reports Server (NTRS)

    Leptoukh, Gregory; Zubko, Viktor

    2009-01-01

    The main questions addressed in this slide presentation involve short-term trends of MODIS aerosol optical thickness (AOT) over 6 years: (1) Why are the trends different in different regions? (2) How are these trends so high? (3) Why are they "coherent" in many areas? (4) Are these changes in aerosol concentrations real, i.e., are they monotonic changes in emissions? Several views of the Spatial Distribution of AOT from Terra are shown. In conclusion there are several trends: (1) There is a broad spatial inhomogenueity in AOT trends over 6 years of MODIS Terra and Aqua (2) Some of the areas demonstrate clear positive trends related to increase of emission (e.g., Eastern China) (3) Strong trends in some other areas are superficial and might be attributed, in part, to: (3a) Least squares linear trend sensitivity to outliers (need to use more robust linear fitting method) (3b) Spatial and temporal shifts or trends in meteorological conditions, especially in wind patterns responsible for aerosol transport (6) Aerosol trends should be studied together with changes in meteorology patterns as they might closely linked together

  20. Audiovisual integration facilitates monkeys' short-term memory.

    PubMed

    Bigelow, James; Poremba, Amy

    2016-07-01

    Many human behaviors are known to benefit from audiovisual integration, including language and communication, recognizing individuals, social decision making, and memory. Exceptionally little is known about the contributions of audiovisual integration to behavior in other primates. The current experiment investigated whether short-term memory in nonhuman primates is facilitated by the audiovisual presentation format. Three macaque monkeys that had previously learned an auditory delayed matching-to-sample (DMS) task were trained to perform a similar visual task, after which they were tested with a concurrent audiovisual DMS task with equal proportions of auditory, visual, and audiovisual trials. Parallel to outcomes in human studies, accuracy was higher and response times were faster on audiovisual trials than either unisensory trial type. Unexpectedly, two subjects exhibited superior unimodal performance on auditory trials, a finding that contrasts with previous studies, but likely reflects their training history. Our results provide the first demonstration of a bimodal memory advantage in nonhuman primates, lending further validation to their use as a model for understanding audiovisual integration and memory processing in humans.

  1. Short-term stabilization of grape marc through earthworms.

    PubMed

    Gómez-Brandón, María; Lazcano, Cristina; Lores, Marta; Domínguez, Jorge

    2011-03-15

    The winery industry generates vast amounts of organic waste during the various stages of wine production. Among the possible methodological alternatives available for its treatment, vermicomposting is one of the best-known processes for the biological stabilization of solid organic wastes by transforming them into safer and more stabilized materials suitable for application to soil. In this study we carried out a mesocosm experiment to evaluate the effectiveness of the active phase of vermicomposting for the stabilization of grape marc, an enriched lignocellulosic by-product obtained after the grape crushing and pressing stages in wine production. For this we analysed the chemical, biochemical and microbiological properties of the product resulting from this phase, in comparison with those in a control treatment. Earthworm activity reduced the abundance of both bacterial and fungal PLFA biomarkers. Decreases in microbial activity and in protease and cellulase activities were also attributed to the presence of earthworms. The differences in microbial communities were accompanied by a reduction in the labile C pool and the cellulose content. These results indicate that earthworms played a key role in the stabilization of the grape marc in the short-term, via its effects on organic matter decomposition and microbial biomass and activity.

  2. Short-term toxicity of nine industrial chemicals

    SciTech Connect

    Komsta, E.; Secours, V.E.; Chu, I.; Morris, R.; Harrison, J.; Baranowski, E.; Villeneuve, D.C. ); Valli, V.E. )

    1989-07-01

    There are a number of industrial chemicals currently used in Canada in sufficiently large quantities that warrant a careful environmental and human health hazard assessment by the regulatory agencies. A review of the existing toxicity data for these chemicals indicated that most of the studies were inadequate due to study design, small group size, inadequate procedures or insufficient parameters being monitored. In order to determine if further studies were warranted it was decided to screen 9 of these chemicals in a short-term study using male and female rats. The chemicals were chosen based on considerations such as quantity, availability of toxicological data, chemical and structural properties and commercial availability. The chemicals selected were: tri(butoxyethyl) phosphate, dimethylol urea, 2-butyne-1,4-diol, triallyl-s-triazine-trione, cyclohexanone oxime, p-toluene sulphonhydrazide, 2-nitroaniline, propargyl alcohol and 5-methyl-1H-benzotriazole. The assay consisted of a 14-day oral dosing regime followed by a comprehensive evaluation of biochemical, hematological and histophathological changes.

  3. Airway response to ultra short-term exposure to ozone

    SciTech Connect

    Fouke, J.M.; Delemos, R.A.; McFadden, E.R. Jr.

    1988-02-01

    To determine whether acute short-term exposure to oxidant pollutants can cause changes in respiratory mechanics, we gave 0.5 ppm ozone for 5 min to 7 baboons. We measured pulmonary resistance (RL) and obtained dose response curves to methacholine before and after the exposures. This brief insult increased resistance (control RL = 1.53 +/- 0.21 cm H/sub 2/O.L-1 s; post-ozone RL = 3.53 +/- 0.54 cm H/sub 2/O.L-1 s). On a second occasion, 6 of these animals were restudied before and after the administration of cromolyn sodium. Although this drug had no effect on the measurements of mechanics made in the control period, it significantly reduced the ozone-induced changes in mechanics. The increase in RL was 52% of that produced in the first study. The results demonstrated that the ozone injury with its acute and subacute airway sequelae occurs quite rapidly and after very brief exposure. The time course of the change in mechanics and the effects of cromolyn suggest the hypothesis that surface epithelial cells are disrupted, causing subsequent release of bronchoconstricting agents.

  4. Visual short-term memory load strengthens selective attention.

    PubMed

    Roper, Zachary J J; Vecera, Shaun P

    2014-04-01

    Perceptual load theory accounts for many attentional phenomena; however, its mechanism remains elusive because it invokes underspecified attentional resources. Recent dual-task evidence has revealed that a concurrent visual short-term memory (VSTM) load slows visual search and reduces contrast sensitivity, but it is unknown whether a VSTM load also constricts attention in a canonical perceptual load task. If attentional selection draws upon VSTM resources, then distraction effects-which measure attentional "spill-over"-will be reduced as competition for resources increases. Observers performed a low perceptual load flanker task during the delay period of a VSTM change detection task. We observed a reduction of the flanker effect in the perceptual load task as a function of increasing concurrent VSTM load. These findings were not due to perceptual-level interactions between the physical displays of the two tasks. Our findings suggest that perceptual representations of distractor stimuli compete with the maintenance of visual representations held in memory. We conclude that access to VSTM determines the degree of attentional selectivity; when VSTM is not completely taxed, it is more likely for task-irrelevant items to be consolidated and, consequently, affect responses. The "resources" hypothesized by load theory are at least partly mnemonic in nature, due to the strong correspondence they share with VSTM capacity.

  5. Short Term Memory, Working Memory, and Syntactic Comprehension in Aphasia

    PubMed Central

    Caplan, David; Michaud, Jennifer; Hufford, Rebecca

    2013-01-01

    Sixty one people with aphasia were tested on ten tests of short term memory (STM) and for the ability to use syntactic structure to determine the meanings of eleven types of sentences in three tasks – object manipulation, picture matching and picture matching with self-paced listening. Multilevel models showed relationships between measures of the ability to retain and manipulate item and order information in STM and accuracy and RT, and a greater relationship between these STM measures and accuracy and RT for several more complex sentence types in individual tasks. There were no effects of measures of STM that reflect the use of phonological codes or rehearsal on comprehension. There was only one effect of STM measures on self-paced listening times. There were double dissociations between performance on STM and individual comprehension tasks, indicating that normal STM is not necessary to perform normally on these tasks. The results are most easily related to the view that STM plays a facilitatory role in supporting the use of the products of the comprehension process to accomplish operations related to tasks. PMID:23865692

  6. Audiovisual integration facilitates monkeys' short-term memory.

    PubMed

    Bigelow, James; Poremba, Amy

    2016-07-01

    Many human behaviors are known to benefit from audiovisual integration, including language and communication, recognizing individuals, social decision making, and memory. Exceptionally little is known about the contributions of audiovisual integration to behavior in other primates. The current experiment investigated whether short-term memory in nonhuman primates is facilitated by the audiovisual presentation format. Three macaque monkeys that had previously learned an auditory delayed matching-to-sample (DMS) task were trained to perform a similar visual task, after which they were tested with a concurrent audiovisual DMS task with equal proportions of auditory, visual, and audiovisual trials. Parallel to outcomes in human studies, accuracy was higher and response times were faster on audiovisual trials than either unisensory trial type. Unexpectedly, two subjects exhibited superior unimodal performance on auditory trials, a finding that contrasts with previous studies, but likely reflects their training history. Our results provide the first demonstration of a bimodal memory advantage in nonhuman primates, lending further validation to their use as a model for understanding audiovisual integration and memory processing in humans. PMID:27010716

  7. Perceptual asymmetries are preserved in short-term memory tasks.

    PubMed

    Montaser-Kouhsari, Leila; Carrasco, Marisa

    2009-11-01

    Visual performance is heterogeneous at isoeccentric locations; it is better on the horizontal than on the vertical meridian and worse at the upper than at the lower region of the vertical meridian (Carrasco, Talgar, & Cameron, 2001; Talgar & Carrasco, 2002). It is unknown whether these performance inhomogeneities are also present in spatial frequency tasks and whether asymmetries present during encoding of visual information also emerge in visual short-term memory (VSTM) tasks. Here, we investigated the similarity of the perceptual and VSTM tasks in spatial frequency discrimination (Experiments 1 and 2) and perceived spatial frequency (Experiments 3 and 4). We found that (1) performance in both simultaneous (perceptual) and delayed (VSTM) spatial frequency discrimination tasks varies as a function of location; it is better along the horizontal than along the vertical meridian; and (2) perceived spatial frequency in both tasks is higher along the horizontal than along the vertical meridian. These results suggest that perceived spatial frequency may mediate performance differences in VSTM tasks across the visual field, implying that the quality with which we encode information affects VSTM.

  8. An information capacity limitation of visual short-term memory.

    PubMed

    Sewell, David K; Lilburn, Simon D; Smith, Philip L

    2014-12-01

    Research suggests that visual short-term memory (VSTM) has both an item capacity, of around 4 items, and an information capacity. We characterize the information capacity limits of VSTM using a task in which observers discriminated the orientation of a single probed item in displays consisting of 1, 2, 3, or 4 orthogonally oriented Gabor patch stimuli that were presented in noise for 50 ms, 100 ms, 150 ms, or 200 ms. The observed capacity limitations are well described by a sample-size model, which predicts invariance of ∑(i)(d'(i))² for displays of different sizes and linearity of (d'(i))² for displays of different durations. Performance was the same for simultaneous and sequentially presented displays, which implicates VSTM as the locus of the observed invariance and rules out explanations that ascribe it to divided attention or stimulus encoding. The invariance of ∑(i)(d'(i))² is predicted by the competitive interaction theory of Smith and Sewell (2013), which attributes it to the normalization of VSTM traces strengths arising from competition among stimuli entering VSTM.

  9. Dimension-based attention in visual short-term memory.

    PubMed

    Pilling, Michael; Barrett, Doug J K

    2016-07-01

    We investigated how dimension-based attention influences visual short-term memory (VSTM). This was done through examining the effects of cueing a feature dimension in two perceptual comparison tasks (change detection and sameness detection). In both tasks, a memory array and a test array consisting of a number of colored shapes were presented successively, interleaved by a blank interstimulus interval (ISI). In Experiment 1 (change detection), the critical event was a feature change in one item across the memory and test arrays. In Experiment 2 (sameness detection), the critical event was the absence of a feature change in one item across the two arrays. Auditory cues indicated the feature dimension (color or shape) of the critical event with 80 % validity; the cues were presented either prior to the memory array, during the ISI, or simultaneously with the test array. In Experiment 1, the cue validity influenced sensitivity only when the cue was given at the earliest position; in Experiment 2, the cue validity influenced sensitivity at all three cue positions. We attributed the greater effectiveness of top-down guidance by cues in the sameness detection task to the more active nature of the comparison process required to detect sameness events (Hyun, Woodman, Vogel, Hollingworth, & Luck, Journal of Experimental Psychology: Human Perception and Performance, 35; 1140-1160, 2009). PMID:26920437

  10. Perceptual asymmetries are preserved in short-term memory tasks

    PubMed Central

    Montaser-Kouhsari, Leila; Carrasco, Marisa

    2013-01-01

    Visual performance is heterogeneous at isoeccentric locations; it is better on the horizontal than on the vertical meridian and worse at the upper than at the lower region of the vertical meridian (Carrasco, Talgar, & Cameron, 2001; Talgar & Carrasco, 2002). It is unknown whether these performance inhomogeneities are also present in spatial frequency tasks and whether asymmetries present during encoding of visual information also emerge in visual short-term memory (VSTM) tasks. Here, we investigated the similarity of the perceptual and VSTM tasks in spatial frequency discrimination (Experiments 1 and 2) and perceived spatial frequency (Experiments 3 and 4). We found that (1) performance in both simultaneous (perceptual) and delayed (VSTM) spatial frequency discrimination tasks varies as a function of location; it is better along the horizontal than along the vertical meridian; and (2) perceived spatial frequency in both tasks is higher along the horizontal than along the vertical meridian. These results suggest that perceived spatial frequency may mediate performance differences in VSTM tasks across the visual field, implying that the quality with which we encode information affects VSTM. PMID:19933562

  11. Exogenous attention influences visual short-term memory in infants

    PubMed Central

    Ross-Sheehy, Shannon; Oakes, Lisa M.; Luck, Steven J.

    2011-01-01

    Two experiments examined the hypothesis that developing visual attentional mechanisms influence infants' Visual Short-Term Memory (VSTM) in the context of multiple items. Five-and 10-month-old infants (N = 76) received a change detection task in which arrays of 3 differently colored squares appeared and disappeared. On each trial one square changed color and one square was cued; sometimes the cued item was the changing item, and sometimes the changing item was not the cued item. Ten-month-old infants exhibited enhanced memory for the cued item when the cue was a spatial pre-cue (Experiment 1) and 5-month-old infants exhibited enhanced memory for the cued item when the cue was relative motion (Experiment 2). These results demonstrate for the first time that infants younger than 6 months can encode information in VSTM about individual items in multiple-object arrays, and that attention-directing cues influence both perceptual and VSTM encoding of stimuli in infants as in adults. PMID:21477189

  12. Positive illusions about the self: short-term benefits and long-term costs.

    PubMed

    Robins, R W; Beer, J S

    2001-02-01

    Two studies addressed parallel questions about the correlates and consequences of self-enhancement bias. Study 1 was conducted in a laboratory context and examined self-enhancing evaluations of performance in a group-interaction task. Study 2 assessed students' illusory beliefs about their academic ability when they first entered college and then followed them longitudinally to test claims about the long-term benefits of positive illusions. Both studies showed that self-enhancement bias was related to narcissism, ego involvement, self-serving attributions, and positive affect. Study 2 found that self-enhancement was associated with decreasing levels of self-esteem and well-being as well as with increasing disengagement from the academic context. Self-enhancement did not predict higher academic performance or higher graduate rates. Thus, the findings suggest that self-enhancing beliefs may be adaptive in the short term but not in the long term.

  13. A phenomenological memristor model for short-term/long-term memory

    NASA Astrophysics Data System (ADS)

    Chen, Ling; Li, Chuandong; Huang, Tingwen; Ahmad, Hafiz Gulfam; Chen, Yiran

    2014-08-01

    Memristor is considered to be a natural electrical synapse because of its distinct memory property and nanoscale. In recent years, more and more similar behaviors are observed between memristors and biological synapse, e.g., short-term memory (STM) and long-term memory (LTM). The traditional mathematical models are unable to capture the new emerging behaviors. In this article, an updated phenomenological model based on the model of the Hewlett-Packard (HP) Labs has been proposed to capture such new behaviors. The new dynamical memristor model with an improved ion diffusion term can emulate the synapse behavior with forgetting effect, and exhibit the transformation between the STM and the LTM. Further, this model can be used in building new type of neural networks with forgetting ability like biological systems, and it is verified by our experiment with Hopfield neural network.

  14. A novel approach for short-term load forecasting using support vector machines.

    PubMed

    Tian, Liang; Noore, Afzel

    2004-10-01

    A support vector machine (SVM) modeling approach for short-term load forecasting is proposed. The SVM learning scheme is applied to the power load data, forcing the network to learn the inherent internal temporal property of power load sequence. We also study the performance when other related input variables such as temperature and humidity are considered. The performance of our proposed SVM modeling approach has been tested and compared with feed-forward neural network and cosine radial basis function neural network approaches. Numerical results show that the SVM approach yields better generalization capability and lower prediction error compared to those neural network approaches.

  15. A neural network short term load forecasting model for the Greek power system

    SciTech Connect

    Bakirtzis, A.G.; Petridis, V.; Kiartzis, S.J.; Alexiadis, M.C.; Maissis, A.H.

    1996-05-01

    This paper presents the development of an Artificial Neural Network (ANN) based short-term load forecasting model for the Energy Control Center of the Greek Public Power Corporation (PPC). The model can forecast daily load profiles with a lead time of one to seven days. Attention was paid for the accurate modeling of holidays. Experiences gained during the development of the model regarding the selection of the input variables, the ANN structure, and the training data set are described in the paper. The results indicate that the load forecasting model developed provides accurate forecasts.

  16. Unveiling long-term variability in XMM-Newton surveys: the EXTraS project

    NASA Astrophysics Data System (ADS)

    Rosen, S.; Read, A.; De Luca, A.; EXTraS Collaboration

    2014-07-01

    The 3XMM-DR4 catalogue, the XMM-Newton Slew Survey (XSS) and the associated XMM-Newton EPIC data, are extensive resources for exploring high energy, time-domain astrophysics. Amongst these data are potential, hitherto unidentified variable sources, ranging from short duration (~seconds) transients through to objects varying on timescales of years. Variability signatures can be key to understanding the energetics and physical processes in a diverse range of astrophysical settings. The EU/FP7-Cooperation Space framework project, `Exploring the X-ray transient and variable sky' (EXTraS), aims to exploit these XMM-Newton resources to explore, as fully as possible, the range of X-ray variability present and provide the results to the community through a public database. Here we outline one of the project's core aims, i.e. identifying and characterising long-term (days to years) variability. The 3XMM-DR4 catalogue contains ˜67000 sources with multiple detections. 3XMM, in conjunction with the XSS, which has now covered almost 70% of the sky, often with multiple slews, offers excellent scope for identifying new variable objects by tracking their flux between XMM-Newton observations. We discuss the plans for the EXTraS long-term variability catalogue and highlight some examples of the detection of long-term variability in 3XMM-DR4/XSS data.

  17. Linking genetic counseling content to short-term outcomes in individuals at elevated breast cancer risk.

    PubMed

    Kelly, Kimberly M; Ellington, Lee; Schoenberg, Nancy; Agarwal, Parul; Jackson, Thomas; Dickinson, Stephanie; Abraham, Jame; Paskett, Electra D; Leventhal, Howard; Andrykowski, Michael

    2014-10-01

    Few studies have linked actual genetic counseling content to short-term outcomes. Using the Self-regulation Model, the impact of cognitive and affective content in genetic counseling on short-term outcomes was studied in individuals at elevated risk of familial breast-ovarian cancer. Surveys assessed dependent variables: distress, perceived risk, and 6 knowledge measures (Meaning of Positive Test; Meaning of Negative Test; Personal Behavior; Practitioner Knowledge; Mechanisms of Cancer Inheritance; Frequency of Inherited Cancer) measured at pre- and post-counseling. Proportion of participant cognitive and affective and counselor cognitive and affective content during sessions (using LIWC software) were predictors in regressions. Knowledge increased for 5 measures and decreased for Personal Behavior, Distress and Perceived Risk. Controlling for age and education, results were significant/marginally significant for three measures. More counselor content was associated with decreases in knowledge of Personal Behavior. More participant and less counselor affective content was associated with gains in Practitioner Knowledge. More counselor cognitive, and interaction of counselor cognitive and affective content, were associated with higher perceived risk. Genetic counselors dominate the content of counseling sessions. Therefore, their content is tied more closely to short term outcomes than participant content. A lack of patient communication in sessions may pose problems for understanding of complex concepts.

  18. Ramp Forecasting Performance from Improved Short-Term Wind Power Forecasting: Preprint

    SciTech Connect

    Zhang, J.; Florita, A.; Hodge, B. M.; Freedman, J.

    2014-05-01

    The variable and uncertain nature of wind generation presents a new concern to power system operators. One of the biggest concerns associated with integrating a large amount of wind power into the grid is the ability to handle large ramps in wind power output. Large ramps can significantly influence system economics and reliability, on which power system operators place primary emphasis. The Wind Forecasting Improvement Project (WFIP) was performed to improve wind power forecasts and determine the value of these improvements to grid operators. This paper evaluates the performance of improved short-term wind power ramp forecasting. The study is performed for the Electric Reliability Council of Texas (ERCOT) by comparing the experimental WFIP forecast to the current short-term wind power forecast (STWPF). Four types of significant wind power ramps are employed in the study; these are based on the power change magnitude, direction, and duration. The swinging door algorithm is adopted to extract ramp events from actual and forecasted wind power time series. The results show that the experimental short-term wind power forecasts improve the accuracy of the wind power ramp forecasting, especially during the summer.

  19. Linking Genetic Counseling Content to Short-Term Outcomes in Individuals at Elevated Breast Cancer Risk

    PubMed Central

    Ellington, Lee; Schoenberg, Nancy; Agarwal, Parul; Jackson, Thomas; Dickinson, Stephanie; Abraham, Jame; Paskett, Electra D.; Leventhal, Howard; Andrykowski, Michael

    2014-01-01

    Few studies have linked actual genetic counseling content to short-term outcomes. Using the Self-regulation Model, the impact of cognitive and affective content in genetic counseling on short-term outcomes was studied in individuals at elevated risk of familial breast-ovarian cancer. Surveys assessed dependent variables: distress, perceived risk, and 6 knowledge measures (Meaning of Positive Test; Meaning of Negative Test; Personal Behavior; Practitioner Knowledge; Mechanisms of Cancer Inheritance; Frequency of Inherited Cancer) measured at pre- and post-counseling. Proportion of participant cognitive and affective and counselor cognitive and affective content during sessions (using LIWC software) were predictors in regressions. Knowledge increased for 5 measures and decreased for Personal Behavior, Distress and Perceived Risk. Controlling for age and education, results were significant/marginally significant for three measures. More counselor content was associated with decreases in knowledge of Personal Behavior. More participant and less counselor affective content was associated with gains in Practitioner Knowledge. More counselor cognitive, and interaction of counselor cognitive and affective content, were associated with higher perceived risk. Genetic counselors dominate the content of counseling sessions. Therefore, their content is tied more closely to short term outcomes than participant content. A lack of patient communication in sessions may pose problems for understanding of complex concepts. PMID:24671341

  20. Robust Speech Recognition by Combining Short-Term and Long-Term Spectrum Based Position-Dependent CMN with Conventional CMN

    NASA Astrophysics Data System (ADS)

    Wang, Longbiao; Nakagawa, Seiichi; Kitaoka, Norihide

    In a distant-talking environment, the length of channel impulse response is longer than the short-term spectral analysis window. Conventional short-term spectrum based Cepstral Mean Normalization (CMN) is therefore, not effective under these conditions. In this paper, we propose a robust speech recognition method by combining a short-term spectrum based CMN with a long-term one. We assume that a static speech segment (such as a vowel, for example) affected by reverberation, can be modeled by a long-term cepstral analysis. Thus, the effect of long reverberation on a static speech segment may be compensated by the long-term spectrum based CMN. The cepstral distance of neighboring frames is used to discriminate the static speech segment (long-term spectrum) and the non-static speech segment (short-term spectrum). The cepstra of the static and non-static speech segments are normalized by the corresponding cepstral means. In a previous study, we proposed an environmentally robust speech recognition method based on Position-Dependent CMN (PDCMN) to compensate for channel distortion depending on speaker position, and which is more efficient than conventional CMN. In this paper, the concept of combining short-term and long-term spectrum based CMN is extended to PDCMN. We call this Variable Term spectrum based PDCMN (VTPDCMN). Since PDCMN/VT-PDCMN cannot normalize speaker variations because a position-dependent cepstral mean contains the average speaker characteristics over all speakers, we also combine PDCMN/VT-PDCMN with conventional CMN in this study. We conducted the experiments based on our proposed method using limited vocabulary (100 words) distant-talking isolated word recognition in a real environment. The proposed method achieved a relative error reduction rate of 60.9% over the conventional short-term spectrum based CMN and 30.6% over the shortterm spectrum based PDCMN.

  1. Computational classifiers for predicting the short-term course of Multiple sclerosis

    PubMed Central

    2011-01-01

    Background The aim of this study was to assess the diagnostic accuracy (sensitivity and specificity) of clinical, imaging and motor evoked potentials (MEP) for predicting the short-term prognosis of multiple sclerosis (MS). Methods We obtained clinical data, MRI and MEP from a prospective cohort of 51 patients and 20 matched controls followed for two years. Clinical end-points recorded were: 1) expanded disability status scale (EDSS), 2) disability progression, and 3) new relapses. We constructed computational classifiers (Bayesian, random decision-trees, simple logistic-linear regression-and neural networks) and calculated their accuracy by means of a 10-fold cross-validation method. We also validated our findings with a second cohort of 96 MS patients from a second center. Results We found that disability at baseline, grey matter volume and MEP were the variables that better correlated with clinical end-points, although their diagnostic accuracy was low. However, classifiers combining the most informative variables, namely baseline disability (EDSS), MRI lesion load and central motor conduction time (CMCT), were much more accurate in predicting future disability. Using the most informative variables (especially EDSS and CMCT) we developed a neural network (NNet) that attained a good performance for predicting the EDSS change. The predictive ability of the neural network was validated in an independent cohort obtaining similar accuracy (80%) for predicting the change in the EDSS two years later. Conclusions The usefulness of clinical variables for predicting the course of MS on an individual basis is limited, despite being associated with the disease course. By training a NNet with the most informative variables we achieved a good accuracy for predicting short-term disability. PMID:21649880

  2. The paleoclimate record of long-term climate variability

    SciTech Connect

    Webb, R.S.; Bartlein, P.J.; Overpeck, J.T. Univ. of Oregon, Eugene )

    1993-06-01

    Climate variability occurs on time scales ranging from decades or shorter to millions of years. An important step in determining the effects of trace-gas-induced warming on climate variability and ecosystems is characterizing past natural variability and change. Throughout the Quaternary long-term climate variability has been dominated by Milankovitch forcing of glacial/interglacial cycles. Superimposed on this millennia-scale orbitally forced variability have been more rapid climate events (e.g. Younger Dryas, Little Ice Age, Medieval Warm Period, Sahelian droughts). Although highly relevant to understanding possible responses of ecosystems to future climate change, most decade to century scale climate variability remains poorly understood. Insights into mechanisms and responses can be obtained from tree rings, ice cores, corals, marine, lake and fluvial sediments, pollen, and macrofossils. These paleoclimate records reveal that the range of natural climate variability is much larger than indicated by the instrumental record of the past 150 years. Global networks of well-dated, high-resolution paleocrunate records for key intervals of the past are currently being assembled. These networks should provide the baseline of natural variability required to understand climate-ecosystem dynamics and to identify anthropogenic-induced change.

  3. Comparison of Short-term and Long-term Earthquake Forecast Models for Southern California

    NASA Astrophysics Data System (ADS)

    Helmstetter, A.; Kagan, Y. Y.; Jackson, D. D.

    2004-12-01

    Many earthquakes are triggered in part by preceding events. Aftershocks are the most obvious examples, but many large earthquakes are preceded by smaller ones. The large fluctuations of seismicity rate due to earthquake interactions thus provide a way to improve earthquake forecasting significantly. We have developed a model to estimate daily earthquake probabilities in Southern California, using the Epidemic Type Earthquake Sequence model [Kagan and Knopoff, 1987; Ogata, 1988]. The forecasted seismicity rate is the sum of a constant external loading and of the aftershocks of all past earthquakes. The background rate is estimated by smoothing past seismicity. Each earthquake triggers aftershocks with a rate that increases exponentially with its magnitude and which decreases with time following Omori's law. We use an isotropic kernel to model the spatial distribution of aftershocks for small (M≤5.5) mainshocks, and a smoothing of the location of early aftershocks for larger mainshocks. The model also assumes that all earthquake magnitudes follow the Gutenberg-Richter law with a unifom b-value. We use a maximum likelihood method to estimate the model parameters and tests the short-term and long-term forecasts. A retrospective test using a daily update of the forecasts between 1985/1/1 and 2004/3/10 shows that the short-term model decreases the uncertainty of an earthquake occurrence by a factor of about 10.

  4. Short-Term and Long-Term Effects of Orthopedic Biodegradable Implants

    PubMed Central

    Amini, Ami R.; Wallace, James S.; Nukavarapu, Syam P.

    2012-01-01

    Presently, orthopedic and oral/maxillofacial implants represent a combined $2.8 billion market, a figure expected to experience significant and continued growth. Although traditional permanent implants have been proved clinically efficacious, they are also associated with several drawbacks, including secondary revision and removal surgeries. Non-permanent, biodegradable implants offer a promising alternative for patients, as they provide temporary support and degrade at a rate matching tissue formation, and thus, eliminate the need for secondary surgeries. These implants have been in clinical use for nearly 25 years, competing directly with, or maybe even exceeding, the performance of permanent implants. The initial implantation of biodegradable materials, as with permanent materials, mounts an acute host inflammatory response. Over time, the implant degradation profile and possible degradation product toxicity mediate long-term biodegradable implant-induced inflammation. However, unlike permanent implants, this inflammation is likely to cease once the material disappears. Implant-mediated inflammation is a critical determinant for implant success. Thus, for the development of a proactive biodegradable implant that has the ability to promote optimal bone regeneration and minimal detrimental inflammation, a thorough understanding of short- and long-term inflammatory events is required. Here, we discuss an array of biodegradable orthopedic implants, their associated short- and long- term inflammatory effects, and methods to mediate these inflammatory events. PMID:22043969

  5. Romantic preferences in Brazilian undergraduate students: from the short term to the long term.

    PubMed

    Castro, Felipe Nalon; de Araújo Lopes, Fívia

    2011-09-01

    A number of studies have described different preference patterns typically found for men and women when choosing romantic mates. These vary according to the involvement level expected in the relationship. Despite the number of investigations on the topic, one must be careful not to generalize because most studies use samples composed of North American university undergraduates. This study sought to determine if the preference patterns typically found in other countries also occur among Brazilian undergraduates. The importance of characteristics and modifications in preference patterns under gradually restrictive conditions was also investigated. In general, the results obtained suggest that the preferences found in a number of countries also occur in Brazil. In short-term relationships, men prioritize physical attributes, whereas personal traits gain importance when involvement increases. Women in short-term relationships value physical and personal traits, whereas in the long term, they emphasize personal characteristics and their mate's desire to acquire resources. Resource-related traits were less important than the other traits, and were more important for women than for men. PMID:20830643

  6. Short- and Long-Term Outcomes in Very Low Birth Weight Infants with Admission Hypothermia

    PubMed Central

    Wang, Shwu-Meei; Lung, Hou-Ling; Chang, Jui-Hsing; Hsu, Chyong-Hsin; Jim, Wai-Tim; Lee, Ching-Hsiao; Hung, Hsiao-Fang

    2015-01-01

    Background Neonatal hypothermia remains a common problem and is related to elevated morbidities and mortality. However, the long-term neurodevelopmental effects of admission hypothermia are still unknown. This study attempted to determine the short-term and long-term consequences of admission hypothermia in VLBW preterm infants. Study Design This retrospective study measured the incidence and compared the outcomes of admission hypothermia in very low birth weight (VLBW) preterm infants in a tertiary-level neonatal intensive care unit. Infants were divided into the following groups: normothermia (36.5–37.5°C), mild hypothermia (36.0–36.4°C), moderate hypothermia (32.0–35.9°C), and severe hypothermia (< 32°C). We compared the distribution, demographic variables, short-term outcomes, and neurodevelopmental outcomes at 24 months of corrected age among groups. Results We studied 341 infants: 79 with normothermia, 100 with mild hypothermia, 162 with moderate hypothermia, and 0 with severe hypothermia. Patients in the moderate hypothermia group had significantly lower gestational ages (28.1 wk vs. 29.7 wk, P < .02) and smaller birth weight (1004 g vs. 1187 g, P < .001) compared to patients in the normothermia group. Compared to normothermic infants, moderately hypothermic infants had significantly higher incidences of 1-min Apgar score < 7 (63.6% vs. 31.6%, P < .001), respiratory distress syndrome (RDS) (58.0% vs. 39.2%, P = .006), and mortality (18.5% vs. 5.1%, P = .005). Moderate hypothermia did not affect neurodevelopmental outcomes at 2 years’ corrected age. Mild hypothermia had no effect on short-term or long-term outcomes. Conclusions Admission hypothermia was common in VLBW infants and correlated inversely with birth weight and gestational age. Although moderate hypothermia was associated with higher RDS and mortality rates, it may play a limited role among multifactorial causes of neurodevelopmental impairment. PMID:26193370

  7. Second-Language Learners' Identification of Target-Language Phonemes: A Short-Term Phonetic Training Study

    ERIC Educational Resources Information Center

    Cebrian, Juli; Carlet, Angelica

    2014-01-01

    This study examined the effect of short-term high-variability phonetic training on the perception of English /b/, /v/, /d/, /ð/, /ae/, /? /, /i/, and /i/ by Catalan/Spanish bilinguals learning English as a foreign language. Sixteen English-major undergraduates were tested before and after undergoing a four-session perceptual training program…

  8. Teachers' Burnout Levels in Terms of Some Variables

    ERIC Educational Resources Information Center

    Koruklu, Nermin; Feyzioglu, Burak; Ozenoglu-kiremit, Hatice; Aladag, Elif

    2012-01-01

    The aim of this study is to examine burnout levels of secondary education teachers in terms of some variables. The study was conducted with descriptive survey model and 532 secondary education teachers working in Aydin in 2009-2010 academic year participated in the study. At the end of the study it was found that there was a significant difference…

  9. Canonical orbital elements in terms of an arbitrary independent variable

    NASA Technical Reports Server (NTRS)

    Bond, V. R.; Janin, G.

    1981-01-01

    Within the framework of the Hamiltonian mechanics in the extended phase space, a set of canonical elements of the Delaunay type is developed in terms of an arbitary independent angular variable. Application to the four classical anomalies - eccentric, true, elliptic, and mean - is presented. Particular attention is given to the generalized time equation and its conjugate energy equation.

  10. A multiobjective short-term optimal operation model for a cascade system of reservoirs considering the impact on long-term energy production

    NASA Astrophysics Data System (ADS)

    Xu, Bin; Zhong, Ping-An; Stanko, Zachary; Zhao, Yunfa; Yeh, William W.-G.

    2015-05-01

    This paper examines the impact of short-term operation on long-term energy production. We propose a multiobjective optimization model for the short-term, daily operation of a system of cascade reservoirs. The two objectives considered in the daily model are: (1) minimizing the total amount of water released and (2) maximizing the stored energy in the system. Optimizing short-term operation without considering its impact on long-term energy production does not guarantee maximum energy production in the system. Therefore, a major goal of this paper is to identify desirable short-term operation strategies that, at the same time, optimize long-term energy production. First, we solve the daily model for 1 month (30 days) using a nondominated genetic algorithm (NSGAII). We then use the nondominated solutions obtained by NSGAII to assess the impact on long-term energy production using a monthly model. We use historical monthly inflows to characterize the inflow variability. We apply the proposed methodology to the Qingjiang cascade system of reservoirs in China. The results show: (1) in average hydrology scenarios, the solution maximizing stored energy produces the most overall long-term energy production; (2) in moderately wet hydrology scenarios, the solution minimizing water released outperforms the maximizing stored energy solution; and (3) when extremely wet hydrology scenarios are expected, a compromise solution is the best strategy.

  11. Short-term energy outlook. Quarterly projections, 2nd quarter 1994

    SciTech Connect

    Not Available

    1994-05-01

    The Energy Information Administration (EIA) prepares quarterly, short-term energy supply, demand, and price projections for publication in February, May, August, and November in the Short-Term Energy Outlook (Outlook). An annual supplement analyzes the performance of previous forecasts, compares recent cases with those of other forecasting services, and discusses current topics related to the short-term energy markets. The forecast period for this issue of the Outlook extends from the second quarter of 1994 through the fourth quarter of 1995. Values for the first quarter of 1994, however, are preliminary EIA estimates (for example, some monthly values for petroleum supply and disposition are derived in part from weekly data reported in the Weekly Petroleum Status Report) or are calculated from model simulations using the latest exogenous information available. The historical energy data, compiled into the second quarter 1994 version of the Short-Term Integrated Forecasting System (STIFS) database, are mostly EIA data regularly published in the Monthly Energy Review, Petroleum Supply Monthly, and other EIA publications. Minor discrepancies between the data in these publications and the historical data in this Outlook are due to independent rounding. The STIFS database is archived quarterly and is available from the National Technical Information Service. The cases are produced using the STIFS. The STIFS model is driven principally by three sets of assumptions or inputs: estimates of key macroeconomic variables, world oil price assumptions, and assumptions about the severity of weather. Macroeconomic estimates are produced by DRI/McGraw-Hill but are adjusted by EIA to reflect EIA assumptions about the world price of crude oil, energy product prices, and other assumptions which may affect the macroeconomic outlook. The EIA model is available on computer tape from the National Technical Information Service.

  12. Remote Measurement of Short-term Post-fire Vegetation Regrowth in Sierra Nevadan Forests

    NASA Astrophysics Data System (ADS)

    Meng, R.; Dennison, P. E.; Huang, C.

    2014-12-01

    Forest ecosystems in the Sierra Nevada are greatly influenced by wildfire disturbance. A study of vegetation regrowth following fire is essential for us to better understand and evaluate the effects of disturbances on ecological processes, such as carbon and nitrogen storage, soil erosion, water quality and forest dynamics. The rate of short-term vegetation recovery, as measured by Normalized Difference Vegetation Index (NDVI), was explored following fire over multiple years (1999-2006) in Sierra Nevadan forests. The role of both temporal (e.g. variations in multiple years' precipitation) and landscape factors (e.g. altitude, slope, aspect, pre-fire and immediate post-fire vegetation status, and burn severity) were investigated in explaining the short-term vegetation regrowth following fire using remote sensing on the landscape scale. Our results indicate that spatial-temporal variability existed in the short-term post-fire vegetation regrowth. Pre-fire vegetation status, burn severity, immediate post-fire wet season precipitation and elevation were found to play important roles in short-term post-fire vegetation recovery trends. Consistent with a local forest gap model, our results also corroborate that water availability may be the limiting factor for the post-fire vegetation regrowth in the lower elevation of Sierra Nevadan forests. In the future, post-disturbance vegetation regrowth trends and related controlling environmental factors following various forest disturbances (e.g. insect outbreak and forest harvest) other than wildfire can also be studied and compared using the methodology proposed in this study.

  13. Post larval, short-term, colonization patterns: The effect of substratum complexity across subtidal, adjacent, habitats

    NASA Astrophysics Data System (ADS)

    García-Sanz, Sara; Tuya, Fernando; Navarro, Pablo G.; Angulo-Preckler, Carlos; Haroun, Ricardo J.

    2012-10-01

    Benthic habitats are colonized by organisms from the water column and adjacent habitats. There are, however, variations in the 'acceptability' of any habitat to potential colonists. We assessed whether the structural complexity of artificial substrata affected patterns of short-term colonization of post larval faunal assemblages across subtidal habitats within a coastal landscape. Specifically, we tested whether short-term colonization patterns on 3 types of artificial substrata encompassing a range of complexities, including a leaf-like unit, a cushion-shaped leaf-like unit and a cushion-shaped unit, were consistent across 4 adjacent habitats: macroalgal-dominated bottoms, urchin-grazed barrens, seagrass meadows and sandy patches, at Gran Canaria (eastern Atlantic). A total of 16,174 organisms were collected after 4 weeks and 4 taxonomic groups (Crustacea, Chordata, Echinodermata and Mollusca) dominated the assemblage. Despite considerable among-taxa variability being observed in response to habitat effects, the total abundance of colonizers, as well as the abundance of Arthropoda, Chordata and Echinodermata, was affected by the habitat where collectors were deployed, but did not differ among types of collectors. Similarly, the assemblage structure of colonizers was mainly affected by the habitat, but not by the type of collector; habitat contributed to explain most variation in the assemblage structure of the four dominant taxonomic groups (from ca. 5.44-19.23%), and obscured, in all cases, variation explained by the type of collector. As a result, the variation in short-term colonization patterns of faunal assemblages into artificial collectors was mostly affected by variation associated with habitats rather than by differences in the structural complexity of collectors. The largest abundances of colonizers, particularly Echinodermata, were found on sandy patches relative to other habitats, suggesting that the 'availability', rather than any particular attribute

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

    PubMed Central

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

    2015-01-01

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

  15. Short-term cholinergic desensitization of rat pancreatic secretory response

    SciTech Connect

    Asselin, J.; Larose, L.; Morisset, J.

    1987-03-01

    Dispersed pancreatic acini were first exposed to carbamylcholine (10/sup -7/-10/sup -4/ M) for 60 min, washed, and reexposed to this same agonist (10/sup -8/-10/sup -3/ M) for 15 min. During this second incubation, the functional secretory capacity of these acini was evaluated by measuring amylase release. Acini preexposed to concentrations of carbamylcholine of 10/sup -6/ M or greater showed shifts to the right in the subsequent carbamylcholine dose-response curves of amylase release. A 3-h recovery period (without carbamylcholine) did not restore the altered carbamylcholine dose-response curve. Ca/sup 2 +/ concentrations of 10/sup -7/ M or 2.5 x 10/sup -3/ M instead of 0.5 x 10/sup -3/ M during the 60-min preincubation did not affect the desensitization process. With use of N-(/sup 3/H)methylscopolamine to evaluate muscarinic receptors, the only changes observed after desensitization were a significant decrease in the high-affinity and an equivalent increase in that of the low-affinity receptors. After cholinergic exposure amylase release stimulated by caerulein was only slightly modified, whereas amylase release in response to a phorbol ester 12-O-tetradecanoylphorbol-13-acetate and to the ionophore A23187 was not altered. These data indicate that short-term desensitization with a cholinergic agent is relatively specific to muscarinic agonists, causes changes in the muscarinic receptor high-and low-affinity concentration but does not alter intracellular steps after calcium mobilization or protein kinase C activation known to be involved in the secretion process.

  16. Short-term wind speed predictions with machine learning techniques

    NASA Astrophysics Data System (ADS)

    Ghorbani, M. A.; Khatibi, R.; FazeliFard, M. H.; Naghipour, L.; Makarynskyy, O.

    2016-02-01

    Hourly wind speed forecasting is presented by a modeling study with possible applications to practical problems including farming wind energy, aircraft safety and airport operations. Modeling techniques employed in this paper for such short-term predictions are based on the machine learning techniques of artificial neural networks (ANNs) and genetic expression programming (GEP). Recorded values of wind speed were used, which comprised 8 years of collected data at the Kersey site, Colorado, USA. The January data over the first 7 years (2005-2011) were used for model training; and the January data for 2012 were used for model testing. A number of model structures were investigated for the validation of the robustness of these two techniques. The prediction results were compared with those of a multiple linear regression (MLR) method and with the Persistence method developed for the data. The model performances were evaluated using the correlation coefficient, root mean square error, Nash-Sutcliffe efficiency coefficient and Akaike information criterion. The results indicate that forecasting wind speed is feasible using past records of wind speed alone, but the maximum lead time for the data was found to be 14 h. The results show that different techniques would lead to different results, where the choice between them is not easy. Thus, decision making has to be informed of these modeling results and decisions should be arrived at on the basis of an understanding of inherent uncertainties. The results show that both GEP and ANN are equally credible selections and even MLR should not be dismissed, as it has its uses.

  17. Short-term potentiation of breathing in humans.

    PubMed

    Fregosi, R F

    1991-09-01

    The purpose of this study was to determine if the increase in ventilation induced by hypoxic stimulation of the carotid bodies (CB) persists after cessation of the stimulus in humans. I reasoned that a short-term potentiation (STP) of breathing, sometimes called an "afterdischarge," could be unmasked by combining hypoxia with exercise, because ventilation increases synergistically under these conditions. Seven young healthy men performed mild bicycle exercise (30% peak power) while breathing O2 for 1.5 min ("control" state), and their CB were then stimulated by 1.5 min of hypoxic exercise (10% O2--balance N2). CB stimulation was then terminated by changing the inspirate back to O2 as exercise continued. Inspiratory and expiratory duration (TI and TE) and inspiratory flow and its time integral [tidal volume (VT)] were measured with a pneumotachometer. Inspired minute ventilation (VI) and mean inspiratory flow (VT/TI) declined exponentially after the cessation of CB stimulation, with first-order time constants of 28.6 +/- 6.7 and 24.6 +/- 1.6 (SD) s, respectively. The slow decay of VI was due primarily to potentiation of both TI and TE, although the effect on the latter predominated. Additional experiments in six subjects showed that brief intense CB stimulation with four to five breaths of N2 during mild exercise induced STP of similar magnitude to that observed in the hypoxic exercise experiments. Finally, the imposition of hyperoxia during air breathing exercise at a level of respiratory drive similar to that induced by the hypoxic exercise did not change VI significantly.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1757326

  18. Short Term Effects of Cocoa Consumption on Blood Pressure

    PubMed Central

    Alleyne, T; Alleyne, A; Arrindell, D; Balleram, N; Cozier, D; Haywood, R; Humphrey, C; Pran, L; Rampersad, K; Reyes, D; Bahall, S; Holder, R; Ignacio, D

    2014-01-01

    Hypertension, defined as diastolic pressure ≥ 90 mmHg and systolic pressure ≥ 140 mmHg, is a major cause of morbidity and mortality among black populations globally. Several studies have shown that prolonged consumption of cocoa or cocoa containing products leads to decreased blood pressure (BP) in hypertensives. In this study, we investigated the flavonoid content of the top selling cocoa/cocoa based products in Trinidad and Tobago and attempted to determine if consumption of cocoa had any immediate impact on blood pressure levels. The flavonoid content of three 100% cocoa powder products and four cocoa-based formulas was measured using a modified Folin-Ciocalteu procedure. The brand with the highest flavonoid content, 372 gallic acid equivalents, was selected to evaluate the short-term impact of cocoa consumption on blood pressure. Thirty-six participants comprising nineteen hypertensives and seventeen persons with normal blood pressure had their blood pressure recorded on three separate days using ambulatory blood pressure monitors; the blood pressure was recorded every half hour for eight hours. On the first day, the participants received no intervention but on the second and third days, they received either the intervention (5 g cocoa in 125 ml water) or a placebo, in any order. Statistical analysis conducted using t-test statistic and a 95% confidence interval revealed that whether participants regularly took antihypertensive medication or not, a single intervention of cocoa induced decreases in both the diastolic and systolic BPs that were significant (p = 0.0001). Mean decreases of between 8 mmHg and 18 mmHg were observed. PMID:25429467

  19. Short term outcome of laparoscopic ventral rectopexy for rectal prolapse

    PubMed Central

    Naeem, Muhammad; Anwer, Mariyah; Qureshi, Muhammad Shamim

    2016-01-01

    Objective: To find out the short term outcomes of effectiveness and safety of laparoscopic ventral rectopexy for rectal prolapse. Methods: It was a descriptive case series study of 31 consecutive patients of rectal prolapse in Colorectal division of Ward 2, Department of General surgery, Jinnah Post Graduate Medical Center, Karachi, from November 2009 to November 2015. These patients were admitted through outpatient department with complains of something coming out of anus, constipation and per rectal bleeding. All patients were clinically examined and baseline investigations were done. All patients underwent laparoscopic repair with ventral mesh placement on rectum. Results: Among 31 patients, mean age was 45 years range (20 - 72). While females were 14(45%) and males 17(55%). We observed variety of presentations, including solitary rectal ulcers (n=4) and rectocele (n=3) but full thickness rectal prolapse was predominant(n=24). All patients had laparoscopic repair with mesh placement. Average hospital stay was three days. Out of 31 patients, there was one (3.2%) recurrence. Port site minor infection in 3(9.7%) patients, while conversion to open approach was done in two (6.4%), postoperative ileus observed in two (6.4%) patients. one(3.2%) patient developed intractable back pain and mesh was removed six weeks after the operation. one(4.8%) patient complained of abdominal pain off and on postoperatively. No patient developed denovo or worsening constipation while constipation was improved in 21 patients (67%). Sexual dysfunction such as dysperunia in females and impotence in males was not detected in follow up. Conclusions: This study provides the limited evidence that nerve sparing laparoscopic ventral rectopexy is safe and effective treatment of external and symptomatic internal rectal prolapse. It has better cosmetic and functional outcome as advantages of minimal access and comparable recurrence rate.

  20. Short-term effect of antibiotics on human gut microbiota.

    PubMed

    Panda, Suchita; El khader, Ismail; Casellas, Francesc; López Vivancos, Josefa; García Cors, Montserrat; Santiago, Alba; Cuenca, Silvia; Guarner, Francisco; Manichanh, Chaysavanh

    2014-01-01

    From birth onwards, the human gut microbiota rapidly increases in diversity and reaches an adult-like stage at three years of age. After this age, the composition may fluctuate in response to external factors such as antibiotics. Previous studies have shown that resilience is not complete months after cessation of the antibiotic intake. However, little is known about the short-term effects of antibiotic intake on the gut microbial community. Here we examined the load and composition of the fecal microbiota immediately after treatment in 21 patients, who received broad-spectrum antibiotics such as fluoroquinolones and β-lactams. A fecal sample was collected from all participants before treatment and one week after for microbial load and community composition analyses by quantitative PCR and pyrosequencing of the 16S rRNA gene, respectively. Fluoroquinolones and β-lactams significantly decreased microbial diversity by 25% and reduced the core phylogenetic microbiota from 29 to 12 taxa. However, at the phylum level, these antibiotics increased the Bacteroidetes/Firmicutes ratio (p = 0.0007, FDR = 0.002). At the species level, our findings unexpectedly revealed that both antibiotic types increased the proportion of several unknown taxa belonging to the Bacteroides genus, a Gram-negative group of bacteria (p = 0.0003, FDR<0.016). Furthermore, the average microbial load was affected by the treatment. Indeed, the β-lactams increased it significantly by two-fold (p = 0.04). The maintenance of or possible increase detected in microbial load and the selection of Gram-negative over Gram-positive bacteria breaks the idea generally held about the effect of broad-spectrum antibiotics on gut microbiota.

  1. Neural circuit mechanisms of short-term memory

    NASA Astrophysics Data System (ADS)

    Goldman, Mark

    Memory over time scales of seconds to tens of seconds is thought to be maintained by neural activity that is triggered by a memorized stimulus and persists long after the stimulus is turned off. This presents a challenge to current models of memory-storing mechanisms, because the typical time scales associated with cellular and synaptic dynamics are two orders of magnitude smaller than this. While such long time scales can easily be achieved by bistable processes that toggle like a flip-flop between a baseline and elevated-activity state, many neuronal systems have been observed experimentally to be capable of maintaining a continuum of stable states. For example, in neural integrator networks involved in the accumulation of evidence for decision making and in motor control, individual neurons have been recorded whose activity reflects the mathematical integral of their inputs; in the absence of input, these neurons sustain activity at a level proportional to the running total of their inputs. This represents an analog form of memory whose dynamics can be conceptualized through an energy landscape with a continuum of lowest-energy states. Such continuous attractor landscapes are structurally non-robust, in seeming violation of the relative robustness of biological memory systems. In this talk, I will present and compare different biologically motivated circuit motifs for the accumulation and storage of signals in short-term memory. Challenges to generating robust memory maintenance will be highlighted and potential mechanisms for ameliorating the sensitivity of memory networks to perturbations will be discussed. Funding for this work was provided by NIH R01 MH065034, NSF IIS-1208218, Simons Foundation 324260, and a UC Davis Ophthalmology Research to Prevent Blindness Grant.

  2. Short term outcome of laparoscopic ventral rectopexy for rectal prolapse

    PubMed Central

    Naeem, Muhammad; Anwer, Mariyah; Qureshi, Muhammad Shamim

    2016-01-01

    Objective: To find out the short term outcomes of effectiveness and safety of laparoscopic ventral rectopexy for rectal prolapse. Methods: It was a descriptive case series study of 31 consecutive patients of rectal prolapse in Colorectal division of Ward 2, Department of General surgery, Jinnah Post Graduate Medical Center, Karachi, from November 2009 to November 2015. These patients were admitted through outpatient department with complains of something coming out of anus, constipation and per rectal bleeding. All patients were clinically examined and baseline investigations were done. All patients underwent laparoscopic repair with ventral mesh placement on rectum. Results: Among 31 patients, mean age was 45 years range (20 - 72). While females were 14(45%) and males 17(55%). We observed variety of presentations, including solitary rectal ulcers (n=4) and rectocele (n=3) but full thickness rectal prolapse was predominant(n=24). All patients had laparoscopic repair with mesh placement. Average hospital stay was three days. Out of 31 patients, there was one (3.2%) recurrence. Port site minor infection in 3(9.7%) patients, while conversion to open approach was done in two (6.4%), postoperative ileus observed in two (6.4%) patients. one(3.2%) patient developed intractable back pain and mesh was removed six weeks after the operation. one(4.8%) patient complained of abdominal pain off and on postoperatively. No patient developed denovo or worsening constipation while constipation was improved in 21 patients (67%). Sexual dysfunction such as dysperunia in females and impotence in males was not detected in follow up. Conclusions: This study provides the limited evidence that nerve sparing laparoscopic ventral rectopexy is safe and effective treatment of external and symptomatic internal rectal prolapse. It has better cosmetic and functional outcome as advantages of minimal access and comparable recurrence rate. PMID:27648031

  3. Frailty as a predictor of short-term adverse outcomes

    PubMed Central

    Coelho, Tiago; Paúl, Constança; Gobbens, Robbert J.J.

    2015-01-01

    The objectives of this study were to compare how different frailty measures (Frailty Phenotype/FP, Groningen Frailty Indicator/GFI and Tilburg Frailty Indicator/TFI) predict short-term adverse outcomes. Secondarily, adopting a multidimensional approach to frailty (integral conceptual model–TFI), this study aims to compare how physical, psychological and social frailty predict the outcomes. A longitudinal study was carried out with 95 community-dwelling elderly. Participants were assessed at baseline for frailty, determinants of frailty, and adverse outcomes (healthcare utilization, quality of life, disability in basic and instrumental activities of daily living/ADL and IADL). Ten months later the outcomes were assessed again. Frailty was associated with specific healthcare utilization indicators: the FP with a greater utilization of informal care; GFI with an increased contact with healthcare professionals; and TFI with a higher amount of contacts with a general practitioner. After controlling for the effect of life-course determinants, comorbidity and adverse outcome at baseline, GFI predicted IADL disability and TFI predicted quality of life. The effect of the FP on the outcomes was not significant, when compared with the other measures. However, when comparing TFI’s domains, the physical domain was the most significant predictor of the outcomes, even explaining part of the variance of ADL disability. Frailty at baseline was associated with adverse outcomes at follow-up. However, the relationship of each frailty measure (FP, GFI and TFI) with the outcomes was different. In spite of the role of psychological frailty, TFI’s physical domain was the determinant factor for predicting disability and most of the quality of life. PMID:26246968

  4. Is Earthquake Prediction Possible from Short-Term Foreshocks?

    NASA Astrophysics Data System (ADS)

    Papadopoulos, Gerassimos; Avlonitis, Markos; Di Fiore, Boris; Minadakis, George

    2015-04-01

    Foreshocks preceding mainshocks in the short-term, ranging from minutes to a few months prior the mainshock, have been known from several decades ago. Understanding the generation mechanisms of foreshocks was supported by seismicity observations and statistics, laboratory experiments, theoretical considerations and simulation results. However, important issues remain open. For example, (1) How foreshocks are defined? (2) Why only some mainshocks are preceded by foreshocks but others do not? (2) Is the mainshock size dependent on some attributes of the foreshock sequence? (3) Is that possible to discriminate foreshocks from other seismicity styles (e.g. swarms, aftershocks)? To approach possible replies to these issues we reviewed about 400 papers, reports, books and other documents referring to foreshocks as well as to relevant laboratory experiments. We found that different foreshock definitions are used by different authors. We found also that the ratio of mainshocks preceded by foreshocks increases with the increase of monitoring capabilities and that foreshock activity is dependent on source mechanical properties and favoured by material heterogeneity. Also, the mainshock size does not depend on the largest foreshock size but rather by the foreshock area. Seismicity statistics may account for an effective discrimination of foreshocks from other seismicity styles since during foreshock activities the seismicity rate increases with the inverse of time and, at the same, the b-value of the G-R relationship as a rule drops significantly. Our literature survey showed that only the last years the seismicity catalogs organized in some well monitored areas are adequately complete to search for foreshock activities. Therefore, we investigated for a set of "good foreshock examples" covering a wide range of mainshock magnitudes from 4.5 to 9 in Japan (Tohoku 2011), S. California, Italy (including L' Aquila 2009) and Greece. The good examples used indicate that foreshocks

  5. Short-term change detection for UAV video

    NASA Astrophysics Data System (ADS)

    Saur, Günter; Krüger, Wolfgang

    2012-11-01

    In the last years, there has been an increased use of unmanned aerial vehicles (UAV) for video reconnaissance and surveillance. An important application in this context is change detection in UAV video data. Here we address short-term change detection, in which the time between observations ranges from several minutes to a few hours. We distinguish this task from video motion detection (shorter time scale) and from long-term change detection, based on time series of still images taken between several days, weeks, or even years. Examples for relevant changes we are looking for are recently parked or moved vehicles. As a pre-requisite, a precise image-to-image registration is needed. Images are selected on the basis of the geo-coordinates of the sensor's footprint and with respect to a certain minimal overlap. The automatic imagebased fine-registration adjusts the image pair to a common geometry by using a robust matching approach to handle outliers. The change detection algorithm has to distinguish between relevant and non-relevant changes. Examples for non-relevant changes are stereo disparity at 3D structures of the scene, changed length of shadows, and compression or transmission artifacts. To detect changes in image pairs we analyzed image differencing, local image correlation, and a transformation-based approach (multivariate alteration detection). As input we used color and gradient magnitude images. To cope with local misalignment of image structures we extended the approaches by a local neighborhood search. The algorithms are applied to several examples covering both urban and rural scenes. The local neighborhood search in combination with intensity and gradient magnitude differencing clearly improved the results. Extended image differencing performed better than both the correlation based approach and the multivariate alternation detection. The algorithms are adapted to be used in semi-automatic workflows for the ABUL video exploitation system of Fraunhofer

  6. Short-Term Temporal Stability in Observed Retail Food Characteristics

    ERIC Educational Resources Information Center

    Zenk, Shannon N.; Grigsby-Toussaint, Diana S.; Curry, Susan J.; Berbaum, Michael; Schneider, Linda

    2010-01-01

    Objective: Use of direct observation to characterize neighborhood retail food environments is increasing, but to date most studies have relied on a single observation. If food availability, prices, and quality vary over short time periods, repeated measures may be needed to portray these food characteristics. This study evaluated short-term…

  7. An Opportunistic Routing Mechanism Combined with Long-Term and Short-Term Metrics for WMN

    PubMed Central

    Piao, Xianglan; Qiu, Tie

    2014-01-01

    WMN (wireless mesh network) is a useful wireless multihop network with tremendous research value. The routing strategy decides the performance of network and the quality of transmission. A good routing algorithm will use the whole bandwidth of network and assure the quality of service of traffic. Since the routing metric ETX (expected transmission count) does not assure good quality of wireless links, to improve the routing performance, an opportunistic routing mechanism combined with long-term and short-term metrics for WMN based on OLSR (optimized link state routing) and ETX is proposed in this paper. This mechanism always chooses the highest throughput links to improve the performance of routing over WMN and then reduces the energy consumption of mesh routers. The simulations and analyses show that the opportunistic routing mechanism is better than the mechanism with the metric of ETX. PMID:25250379

  8. Plastic mulching in agriculture. Trading short-term agronomic benefits for long-term soil degradation?

    PubMed

    Steinmetz, Zacharias; Wollmann, Claudia; Schaefer, Miriam; Buchmann, Christian; David, Jan; Tröger, Josephine; Muñoz, Katherine; Frör, Oliver; Schaumann, Gabriele Ellen

    2016-04-15

    Plastic mulching has become a globally applied agricultural practice for its instant economic benefits such as higher yields, earlier harvests, improved fruit quality and increased water-use efficiency. However, knowledge of the sustainability of plastic mulching remains vague in terms of both an environmental and agronomic perspective. This review critically discusses the current understanding of the environmental impact of plastic mulch use by linking knowledge of agricultural benefits and research on the life cycle of plastic mulches with direct and indirect implications for long-term soil quality and ecosystem services. Adverse effects may arise from plastic additives, enhanced pesticide runoff and plastic residues likely to fragment into microplastics but remaining chemically intact and accumulating in soil where they can successively sorb agrochemicals. The quantification of microplastics in soil remains challenging due to the lack of appropriate analytical techniques. The cost and effort of recovering and recycling used mulching films may offset the aforementioned benefits in the long term. However, comparative and long-term agronomic assessments have not yet been conducted. Furthermore, plastic mulches have the potential to alter soil quality by shifting the edaphic biocoenosis (e.g. towards mycotoxigenic fungi), accelerate C/N metabolism eventually depleting soil organic matter stocks, increase soil water repellency and favour the release of greenhouse gases. A substantial process understanding of the interactions between the soil microclimate, water supply and biological activity under plastic mulches is still lacking but required to estimate potential risks for long-term soil quality. Currently, farmers mostly base their decision to apply plastic mulches rather on expected short-term benefits than on the consideration of long-term consequences. Future interdisciplinary research should therefore gain a deeper understanding of the incentives for farmers

  9. Plastic mulching in agriculture. Trading short-term agronomic benefits for long-term soil degradation?

    PubMed

    Steinmetz, Zacharias; Wollmann, Claudia; Schaefer, Miriam; Buchmann, Christian; David, Jan; Tröger, Josephine; Muñoz, Katherine; Frör, Oliver; Schaumann, Gabriele Ellen

    2016-04-15

    Plastic mulching has become a globally applied agricultural practice for its instant economic benefits such as higher yields, earlier harvests, improved fruit quality and increased water-use efficiency. However, knowledge of the sustainability of plastic mulching remains vague in terms of both an environmental and agronomic perspective. This review critically discusses the current understanding of the environmental impact of plastic mulch use by linking knowledge of agricultural benefits and research on the life cycle of plastic mulches with direct and indirect implications for long-term soil quality and ecosystem services. Adverse effects may arise from plastic additives, enhanced pesticide runoff and plastic residues likely to fragment into microplastics but remaining chemically intact and accumulating in soil where they can successively sorb agrochemicals. The quantification of microplastics in soil remains challenging due to the lack of appropriate analytical techniques. The cost and effort of recovering and recycling used mulching films may offset the aforementioned benefits in the long term. However, comparative and long-term agronomic assessments have not yet been conducted. Furthermore, plastic mulches have the potential to alter soil quality by shifting the edaphic biocoenosis (e.g. towards mycotoxigenic fungi), accelerate C/N metabolism eventually depleting soil organic matter stocks, increase soil water repellency and favour the release of greenhouse gases. A substantial process understanding of the interactions between the soil microclimate, water supply and biological activity under plastic mulches is still lacking but required to estimate potential risks for long-term soil quality. Currently, farmers mostly base their decision to apply plastic mulches rather on expected short-term benefits than on the consideration of long-term consequences. Future interdisciplinary research should therefore gain a deeper understanding of the incentives for farmers

  10. Renovating? Take a look at the new short-term paths to financing.

    PubMed

    Kluger, M

    1984-02-01

    A hospital's renovation project can be financed through a diversity of financing techniques. Although the traditional vehicle for hospital capital financing is long-term, fixed-rate debt, there are a growing number of short-term financing alternatives that can provide greater flexibility and generate debt service savings. The author describes some of the new short-term financing techniques, as well as the advantages and disadvantages of short- versus long-term financing.

  11. Short-Term Memory for Temporal Intervals: Contrasting Explanations of the Choose-Short Effect in Pigeons

    ERIC Educational Resources Information Center

    Pinto, Carlos; Machado, Armando

    2011-01-01

    To better understand short-term memory for temporal intervals, we re-examined the choose-short effect. In Experiment 1, to contrast the predictions of two models of this effect, the subjective shortening and the coding models, pigeons were exposed to a delayed matching-to-sample task with three sample durations (2, 6 and 18 s) and retention…

  12. Responses of Emergent Behaviour in Headwater Catchments to Long-term and Short-term Environmental Change

    NASA Astrophysics Data System (ADS)

    Tetzlaff, D.; Soulsby, C.; Malcolm, I. A.; Brewer, M. J.

    2007-12-01

    Emergent behaviour of hydrological processes at the catchment scale often results in relatively simple and predictable functional characteristics which are underpinned by heterogeneous, complex processes at the small scale. It is unclear how such small-scale processes are affected by long- and short-term perturbations in forcing factors affected by various environmental changes. This leads to uncertainty in how emergent behaviour will change and how hydrology and hydrochemistry will respond at the catchment scale. A powerful resource in improving predictions of such responses is applying advanced statistical analysis to long-term data sets of conservative tracers, particularly in gauged catchments that are subject to marked environmental change. Changes in tracer behaviour can provide an integrated insight into the emergent response of system functioning and its non-linear characteristics. In this paper, we present the analysis of long-term tracer data collected since 1982 in 2 small (ca. 1km2) experimental catchments in the Scottish highlands. These have been affected by marked change and variability in driving variables of climate, land cover and rainfall chemistry: Annual rainfall ranged between 1490 and 2500mm and an average 1°C increase in air temperatures was observed over the monitoring period. In addition, forestry operations resulted in 70% of each catchment being clear felled. Finally, air pollution legislation targeting acid emissions has improved the quality of precipitation, resulting in a marked reduction in acid deposition. Long-term (20 year, weekly) time-series analyses of two tracers are used to assess changes in emergent catchment behaviour. Chloride input-output time series are analysed using a range of residence time models which highlighted non-stationarity in the catchment mean residence times (which ranged between 2-11 months for individual years) and corresponding residence time distributions. At the catchments scale these were driven

  13. Exercise during Short-Term and Long-Term Continuous Exposure to Hypoxia Exacerbates Sleep-Related Periodic Breathing

    PubMed Central

    Tellez, Helio Fernandez; Morrison, Shawnda A.; Neyt, Xavier; Mairesse, Olivier; Piacentini, Maria Francesca; Macdonald-Nethercott, Eoin; Pangerc, Andrej; Dolenc-Groselj, Leja; Eiken, Ola; Pattyn, Nathalie; Mekjavic, Igor B.; Meeusen, Romain

    2016-01-01

    Study Objectives: Exposure to hypoxia elevates chemosensitivity, which can lead to periodic breathing. Exercise impacts gas exchange, altering chemosensitivity; however, interactions between sleep, exercise and chronic hypoxic exposure have not been examined. This study investigated whether exercise exacerbates sleep-related periodic breathing in hypoxia. Methods: Two experimental phases. Short-Term Phase: a laboratory controlled, group-design study in which 16 active, healthy men (age: 25 ± 3 y, height: 1.79 ± 0.06 m, mass: 74 ± 8 kg) were confined to a normobaric hypoxic environment (FIO2 = 0.139 ± 0.003, 4,000 m) for 10 days, after random assignment to a sedentary (control, CON) or cycle-exercise group (EX). Long-Term Phase: conducted at the Concordia Antarctic Research Station (3,800 m equivalent at the Equator) where 14 men (age: 36 ± 9 y, height: 1.77 ± 0.09 m, mass: 75 ± 10 kg) lived for 12–14 months, continuously confined. Participants were stratified post hoc based on self-reported physical activity levels. We quantified apnea-hypopnea index (AHI) and physical activity variables. Results: Short-Term Phase: mean AHI scores were significantly elevated in the EX group compared to CON (Night1 = CON: 39 ± 51, EX: 91 ± 59; Night10 = CON: 32 ± 32, EX: 92 ± 48; P = 0.046). Long-Term Phase: AHI was correlated to mean exercise time (R2 = 0.4857; P = 0.008) and the coefficient of variation in night oxyhemoglobin saturation (SpO2; R2 = 0.3062; P = 0.049). Conclusions: Data indicate that exercise (physical activity) per se affects night SpO2 concentrations and AHI after a minimum of two bouts of moderate-intensity hypoxic exercise, while habitual physical activity in hypobaric hypoxic confinement affects breathing during sleep, up to 13+ months' duration Citation: Tellez HF, Morrison SA, Neyt X, Mairesse O, Piacentini MF, Macdonald-Nethercott E, Pangerc A, Dolenc-Groselj L, Eiken O, Pattyn N, Mekjavic IB, Meeusen R. Exercise during short-term and long-term

  14. Discovery of a new short-period, eclipsing cataclysmic variable

    NASA Technical Reports Server (NTRS)

    Downes, R. A.; Mateo, M.; Szkody, P.; Jenner, D. C.; Margon, B.

    1986-01-01

    Photometry and spectroscopy of a newly recognized 14th mag eclipsing cataclysmic variable, KPD 1911 + 1212 (= SVS 8130, V1315 Agl) are reported. The system exhibits deep (1.7 mag) eclipses with period 0.1397 day. The spectrum is that of a high-excitation old nova and shows dramatic variability of the emission line strengths through the eclipse. The profiles of the Balmer emission lines are also phase-dependent, with prominent absorption cores appearing briefly near the inferior conjunction of the emission line source. There is no direct evidence for the secondary. A preliminary determination of radial velocity variations at modest spectral resolution yields K = 132 + or - 26 km/s for the Balmer emission lines. A model is presented for the system consistent with current data, which implies a mass for the primary and secondary stars of 0.9 and 0.4 solar mass respectively and in inclination of i = 78 deg.

  15. Protein aggregation in E. coli : short term and long term effects of nutrient density.

    PubMed

    Baig, Ulfat I; Bhadbhade, Bharati J; Mariyam, Dincy; Watve, Milind G

    2014-01-01

    During exponential growth some cells of E. coli undergo senescence mediated by asymmetric segregation of damaged components, particularly protein aggregates. We showed previously that functional cell division asymmetry in E. coli was responsive to the nutritional environment. Short term exposure as well as long term selection in low calorie environments led to greater cell division symmetry and decreased frequency of senescent cells as compared to high calorie environments. We show here that long term selection in low nutrient environment decreased protein aggregation as revealed by fluorescence microscopy and proportion of insoluble proteins. Across selection lines protein aggregation was correlated significantly positively with the RNA content, presumably indicating metabolic rate. This suggests that the effects of caloric restriction on cell division symmetry and aging in E. coli may work via altered protein handling mechanisms. The demonstrable effects of long term selection on protein aggregation suggest that protein aggregation is an evolvable phenomenon rather than being a passive inevitable process. The aggregated proteins progressively disappeared on facing starvation indicating degradation and recycling demonstrating that protein aggregation is a reversible process in E. coli. PMID:25210787

  16. Short-term and Long-term Variations of Dose Rate measured by MSL/RAD

    NASA Astrophysics Data System (ADS)

    Guo, Jingnan; Zeitlin, Cary; Rafkin, Scot; Boettcher, Stephan; Reitz, Guenther; Koehler, Jan; Ehresmann, Bent; Martin, Cesar; Burmeister, Soenke; Posner, Arik; Wimmer-Schweingruber, Robert; Hassler, Donald M.; Brinza, David; Boehm, Henning Eckart; Lohf, Henning; Appel, Jan

    The Radiation Assessment Detector (RAD), onboard Mars Science Laboratory’s (MSL) rover Curiosity, measures the spectra of both energetic charged and neutral particles along with radiation dose rate at the surface of Mars. Several effects have been observed for the first time to influence the Galactic Cosmic Ray (GCR)-driven particle radiation on the surface: [a] short-term diurnal variations of the Martian atmospheric pressure caused by daily thermal tides [Rafkin 2014]; [b] long-term seasonal pressure changes in the Martian atmosphere; and [c] the modulation of the primary GCR fluxes by the heliospheric magnetic field, which correlates with long-term solar activities and heliospheric rotation. These concurrent factors affect the dose rate variations measured by RAD on the Martian surface. RAD also recorded the dose rate during the 253-day cruise phase of MSL from the Earth to Mars. The variations of the GCR-induced dose rates during quiet time period without the direct detection of Solar Particle Events (SPE) were solely driven by the changes of heliospheric conditions (i.e. [c]). The RAD cruise and surface dose measurements, along with the surface pressure data and the solar modulation factor, are analysed in order to understand how the long-term influences ([b] and [c]) individually correlate with the measured dose rates.

  17. Predictors of maximal short-term power outputs in basketball players 14-16 years.

    PubMed

    Carvalho, Humberto M; Coelho E Silva, Manuel J; Figueiredo, António J; Gonçalves, Carlos E; Philippaerts, Renaat M; Castagna, Carlo; Malina, Robert M

    2011-05-01

    Relationships between growth, maturation and maximal short-term power outputs were investigated in 94 youth basketball players aged 14-16 years. Data included chronological age (CA), skeletal age (SA), years of training; body dimensions, estimated thigh volume, a running based short-term exercise assessed by the line drill test (LDT), the Bangsbo sprint test (BST) and short-term muscle power outputs with the Wingate anaerobic test (WAnT). Multiple linear regression analyses were used to estimate the effects of CA, skeletal maturity (SA/CA), years of training experience, body size and lower-limb volume on short-term performance in the LDT, BST and WAnT, respectively. Explained variances differed between cycle-ergometry outputs (52-54%) and running test performances (23-46%). The independent effects of predictors were small in the fatigue scores of the WAnT (4%) and the BST (11%). Skeletal maturity, body mass and leg length were primary predictors for all maximal short-term power output measures. Leg length was more relevant as a predictor than stature in the WAnT outputs, while stature and body mass appeared in the model with the running tests as dependent variable. Maximal short-term running abilities were also sensitive to years of training. In summary, skeletal maturation, body size and thigh muscle mass explained moderate to large proportions of the variance on maximal short-term performances of adolescent basketball players. The results highlight the importance of considering maturity status in evaluating the maximal short-term power outputs of adolescent athletes.

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

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

  19. Vitamin D endocrine system after short-term space flight

    NASA Technical Reports Server (NTRS)

    Rhoten, William B. (Principal Investigator); Sergeev, Igor N. (Principal Investigator)

    1996-01-01

    The exposure of the body to microgravity during space flight causes a series of well-documented changes in Ca(2+) metabolism, yet the cellular/molecular mechanisms leading to these changes are poorly understood. There is some evidence for microgravity-induced alterations in the vitamin D endocrine system, which is known to be primarily involved in the regulation of Ca(2+) metabolism. Vitamin D-dependent Ca(2+) binding proteins, or calbindins, are believed to have a significant role in maintaining cellular Ca(2+) homeostasis. We used immunocytochemical, biochemical and molecular approaches to analyze the expression of calbindin-D(sub 28k) and calbindin-D(sub 9k) in kidneys and intestines of rats flown for 9 days aboard the Spacelab 3 mission. The effects of microgravity on calbindins in rats in space vs. 'grounded' animals (synchronous Animal Enclosure Module controls and tail suspension controls) were compared. Exposure to microgravity resulted in a significant decrease in calbindin-D(sub 28k) content in kidneys and calbindin-D(sub 9k) in the intestine of flight and suspended animals, as measured by enzyme-linked immunosorbent assay (ELISA). Immunocytochemistry (ICC) in combination with quantitative computer image analysis was used to measure in situ the expression of calbindins in kidneys and intestine, and insulin in pancreas. There was a large decrease in the distal tubular cell-associated calbindin-D(sub 28k) and absorptive cell-associated calbindin-D(sub 9k) immunoreactivity in the space and suspension kidneys and intestine, as compared with matched ground controls. No consistent differences in pancreatic insulin immunoreactivity between space, suspension and ground controls was observed. There were significant correlations between results by quantitative ICC and ELISA. Western blot analysis showed no consistent changes in the low levels of intestinal and renal vitamin D receptors. These findings suggest that a decreased expression of calbindins after a short-term

  20. Long-term variability of dMe stars

    NASA Technical Reports Server (NTRS)

    Phillips, M. J.; Hartmann, L.

    1978-01-01

    Photographic B magnitudes of the four spot stars BY Dra (dM0e), CC Eri (K7 Ve), AU Mic (dM2.5e), and YZ CMi (dM4.5e) are reported which considerably extend the time baseline of the photoelectric data on these stars. The long-term variation of the stars in yearly mean light is investigated. It is found that both BY Dra and CC Eri exhibit long-term B-magnitude variations with amplitudes of about 0.3 to 0.4 magnitude and times between maximum and minimum light near 30 yr. No apparent variability is observed for AU Mic and YZ CMi. The possibility is discussed that the variability of BY Dra and CC Eri is connected with a starspot cycle, for which the period would be around 60 yr.

  1. Using electrophysiology to demonstrate that cueing affects long-term memory storage over the short term.

    PubMed

    Maxcey, Ashleigh M; Fukuda, Keisuke; Song, Won S; Woodman, Geoffrey F

    2015-10-01

    As researchers who study working memory, we often assume that participants keep a representation of an object in working memory when we present a cue that indicates that the object will be tested in a couple of seconds. This intuitively accounts for how well people can remember a cued object, relative to their memory for that same object presented without a cue. However, it is possible that this superior memory does not purely reflect storage of the cued object in working memory. We tested the hypothesis that cues presented during a stream of objects, followed by a short retention interval and immediate memory test, can change how information is handled by long-term memory. We tested this hypothesis by using a family of frontal event-related potentials believed to reflect long-term memory storage. We found that these frontal indices of long-term memory were sensitive to the task relevance of objects signaled by auditory cues, even when the objects repeated frequently, such that proactive interference was high. Our findings indicate the problematic nature of assuming process purity in the study of working memory, and demonstrate that frequent stimulus repetitions fail to isolate the role of working memory mechanisms.

  2. Dancing Bees Improve Colony Foraging Success as Long-Term Benefits Outweigh Short-Term Costs

    PubMed Central

    Schürch, Roger; Grüter, Christoph

    2014-01-01

    Waggle dancing bees provide nestmates with spatial information about high quality resources. Surprisingly, attempts to quantify the benefits of this encoded spatial information have failed to find positive effects on colony foraging success under many ecological circumstances. Experimental designs have often involved measuring the foraging success of colonies that were repeatedly switched between oriented dances versus disoriented dances (i.e. communicating vectors versus not communicating vectors). However, if recruited bees continue to visit profitable food sources for more than one day, this procedure would lead to confounded results because of the long-term effects of successful recruitment events. Using agent-based simulations, we found that spatial information was beneficial in almost all ecological situations. Contrary to common belief, the benefits of recruitment increased with environmental stability because benefits can accumulate over time to outweigh the short-term costs of recruitment. Furthermore, we found that in simulations mimicking previous experiments, the benefits of communication were considerably underestimated (at low food density) or not detected at all (at medium and high densities). Our results suggest that the benefits of waggle dance communication are currently underestimated and that different experimental designs, which account for potential long-term benefits, are needed to measure empirically how spatial information affects colony foraging success. PMID:25141306

  3. Using electrophysiology to demonstrate that cueing affects long-term memory storage over the short term.

    PubMed

    Maxcey, Ashleigh M; Fukuda, Keisuke; Song, Won S; Woodman, Geoffrey F

    2015-10-01

    As researchers who study working memory, we often assume that participants keep a representation of an object in working memory when we present a cue that indicates that the object will be tested in a couple of seconds. This intuitively accounts for how well people can remember a cued object, relative to their memory for that same object presented without a cue. However, it is possible that this superior memory does not purely reflect storage of the cued object in working memory. We tested the hypothesis that cues presented during a stream of objects, followed by a short retention interval and immediate memory test, can change how information is handled by long-term memory. We tested this hypothesis by using a family of frontal event-related potentials believed to reflect long-term memory storage. We found that these frontal indices of long-term memory were sensitive to the task relevance of objects signaled by auditory cues, even when the objects repeated frequently, such that proactive interference was high. Our findings indicate the problematic nature of assuming process purity in the study of working memory, and demonstrate that frequent stimulus repetitions fail to isolate the role of working memory mechanisms. PMID:25604772

  4. Unveiling long-term variability in XMM-Newton surveys within the EXTraS project

    NASA Astrophysics Data System (ADS)

    Rosen, S.; Read, A.; Law-Green, D.; Watson, M.; Pye, J.; O'Brien, P.

    2016-06-01

    The EXTraS project (Exploring the X-ray transient and variable sky) is an EU/FP7-Cooperation Space framework programme that aims to bring together a diverse set of time-domain analyses of XMM-Newton X-ray data and make them available to the public in a coherent manner. Through a combination of pointed observations and slew scans, XMM-Newton has repeatedly observed many regions of the sky, in a few cases up to ˜50 times, ˜70000 sources being observed more than once. While non-uniformly spaced and often sparse, these snapshots provide scientifically valuable information on the photometric behaviour of sources on longer term (hours to ˜ a decade) timescales. Here we describe the collation of XMM-Newton data for long-term variability from the 3XMM-DR5 catalogue, the slew survey and upper-limit information from the associated XMM-Newton products, and the analysis being performed on the ensuing light curves. We also present emerging examples of some newly identified long-term variable sources to highlight the value of this element of the EXTraS project. These longer baseline light curves can (i) unveil variable sources that appear stable in individual observations, (ii) reveal exotic and transient sources and (iii) complement short-term variability information from elsewhere in the EXTraS project by probing slower physical phenomena.

  5. Health reform in New Zealand: short-term gain but long-term pain?

    PubMed

    Ashton, Toni; Tenbensel, Tim

    2012-10-01

    Following a period of quite radical structural reform during the 1990s, health reform in New Zealand is now more incremental and often 'under the radar' of public scrutiny and debate. However, many changes have been made to the roles and functions of key agencies and this could have a profound effect on the direction and performance of the public health system. In particular, the objective of reform at the national level has shifted away from improving population health and reducing health disparities towards improving the performance of service providers. This article describes some of the reforms that have been introduced in recent years and discusses some implications of these changes. We argue that policy settings that are concerned only with getting the right services to the right people at the right time are inherently short-sighted if they fail to tackle the long-term causes of increasing demand for future health services. PMID:23186398

  6. Distribution of Short-Term and Lifetime Predicted Risks of Cardiovascular Diseases in Peruvian Adults

    PubMed Central

    Quispe, Renato; Bazo-Alvarez, Juan Carlos; Burroughs Peña, Melissa S; Poterico, Julio A; Gilman, Robert H; Checkley, William; Bernabé-Ortiz, Antonio; Huffman, Mark D; Miranda, J Jaime

    2015-01-01

    Background Short-term risk assessment tools for prediction of cardiovascular disease events are widely recommended in clinical practice and are used largely for single time-point estimations; however, persons with low predicted short-term risk may have higher risks across longer time horizons. Methods and Results We estimated short-term and lifetime cardiovascular disease risk in a pooled population from 2 studies of Peruvian populations. Short-term risk was estimated using the atherosclerotic cardiovascular disease Pooled Cohort Risk Equations. Lifetime risk was evaluated using the algorithm derived from the Framingham Heart Study cohort. Using previously published thresholds, participants were classified into 3 categories: low short-term and low lifetime risk, low short-term and high lifetime risk, and high short-term predicted risk. We also compared the distribution of these risk profiles across educational level, wealth index, and place of residence. We included 2844 participants (50% men, mean age 55.9 years [SD 10.2 years]) in the analysis. Approximately 1 of every 3 participants (34% [95% CI 33 to 36]) had a high short-term estimated cardiovascular disease risk. Among those with a low short-term predicted risk, more than half (54% [95% CI 52 to 56]) had a high lifetime predicted risk. Short-term and lifetime predicted risks were higher for participants with lower versus higher wealth indexes and educational levels and for those living in urban versus rural areas (P<0.01). These results were consistent by sex. Conclusions These findings highlight potential shortcomings of using short-term risk tools for primary prevention strategies because a substantial proportion of Peruvian adults were classified as low short-term risk but high lifetime risk. Vulnerable adults, such as those from low socioeconomic status and those living in urban areas, may need greater attention regarding cardiovascular preventive strategies. PMID:26254303

  7. Short-term Ensemble Flood Forecasting Experiments in Brazil

    NASA Astrophysics Data System (ADS)

    Collischonn, Walter; Meller, Adalberto; Fan, Fernando; Moreira, Demerval; Dias, Pedro; Buarque, Diogo; Bravo, Juan

    2013-04-01

    Flood Forecasting and issuing early warnings to communities under risk can help reduce the impacts of those events. However, to be effective, warnings should be given several hours in advance. The best solution to extend the lead time is possibly the use of rainfall-runoff models with input given by rainfall and streamflow observations and by forecasts of future precipitation derived from numerical weather prediction (NWP) models. Recent studies showed that probabilistic or ensemble flood forecasts produced using ensemble precipitation forecasts as input data outperform deterministic flood forecasts in several cases in Europe and the United States, and ensemble flood forecasting systems are increasingly becoming operational in these regions. In Brazil, on the other hand, operational flood warning systems are rare, and often based on simplified river routing or linear transfer function models. However, a large number of global and regional meteorological models is operationally run covering most of the country, and forecasts of those models are available for recent years. We used this available data to conduct experiments of short term ensemble flood forecasting in the Paraopeba River basin (12 thousand km2), located in Southeastern Brazil. Streamflow forecasts were produced using the MGB-IPH hydrological model, using a simple empirical state updating method and using an ensemble of precipitation forecasts generated by several models, with different initial conditions and parameterizations, from several weather forecasting centers. A single deterministic streamflow forecast, based on a quantitative precipitation forecast derived from the optimal combination of several outputs of NWP models was used as a reference to assess the performance of the ensemble streamflow forecasts. Flood forecasts experiments were performed for three rainy seasons (austral summer) between 2008-2011. The results for predictions of dichotomous events, which mean exceeding or not flood

  8. The Short-Term Cooling but Long-Term Global Warming Due to Biomass Burning.

    NASA Astrophysics Data System (ADS)

    Jacobson, Mark Z.

    2004-08-01

    Biomass burning releases gases (e.g., CO2, CO, CH4, NOx, SO2, C2H6, C2H4, C3H8, C3H6) and aerosol particle components (e.g., black carbon, organic matter, K+, Na+, Ca2+, Mg2+, NH4+, H+, Cl-, H2SO4, HSO4-, SO42-, NO3-). To date, the global-scale climate response of controlling emission of these constituents together has not been examined. Here 10-yr global simulations of the climate response of biomass-burning aerosols and short-lived gases are coupled with numerical calculations of the long-term effect of controlling biomass-burning CO2 and CH4 to estimate the net effect of controlling burning over 100 yr. Whereas eliminating biomass-burning particles is calculated to warm temperatures in the short term, this warming may be more than offset after several decades by cooling due to eliminating long-lived CO2, particularly from permanent deforestation. It is also shown analytically that biomass burning always results in CO2 accumulation, even when regrowth fluxes equal emission fluxes and in the presence of fertilization. Further, because burning grassland and cropland yearly, as opposed to every several years, increases CO2, biofuel burning, considered a “renewable” energy source, is only partially renewable, and biomass burning elevates CO2 until it is stopped. Because CO2 from biomass burning is considered recyclable and biomass particles are thought to cool climate, the Kyoto Protocol did not consider biomass-burning controls. If the results here, which apply to a range of scenarios but are subject to uncertainty, are correct, such control may slow global warming, contrary to common perception, and improve human health.


  9. Effects of Short-Term Free-Weight and Semiblock Periodization Resistance Training on Metabolic Syndrome.

    PubMed

    South, Mark A; Layne, Andrew S; Stuart, Charles A; Triplett, N Travis; Ramsey, Michael; Howell, Mary E; Sands, William A; Mizuguchi, Satoshi; Hornsby, W Guy; Kavanaugh, Ashley A; Stone, Michael H

    2016-10-01

    South, MA, Layne, AS, Stuart, CA, Triplett, NT, Ramsey, MW, Howell, ME, Sands, WA, Mizuguchi, S, Hornsby, WG, Kavanaugh, AA, and Stone, MH. Effects of short-term free-weight and semiblock periodization resistance training on metabolic syndrome. J Strength Cond Res 30(10): 2682-2696, 2016-The effects of short-term resistance training on performance and health variables associated with prolonged sedentary lifestyle and metabolic syndrome (MS) were investigated. Resistance training may alter a number of health-related, physiological, and performance variables. As a result, resistance training can be used as a valuable tool in ameliorating the effects of a sedentary lifestyle including those associated with MS. Nineteen previously sedentary subjects (10 with MS and 9 with nonmetabolic syndrome [NMS]) underwent 8 weeks of supervised resistance training. Maximum strength was measured using an isometric midthigh pull and resulting force-time curve. Vertical jump height (JH) and power were measured using a force plate. The muscle cross-sectional area (CSA) and type were examined using muscle biopsy and standard analysis techniques. Aerobic power was measured on a cycle ergometer using a ParvoMedics 2400 Metabolic system. Endurance was measured as time to exhaustion on a cycle ergometer. After training, maximum isometric strength, JH, jump power, and V[Combining Dot Above]O2peak increased by approximately 10% (or more) in both the metabolic and NMS groups (both male and female subjects). Over 8 weeks of training, body mass did not change statistically, but percent body fat decreased in subjects with the MS and in women, and lean body mass increased in all groups (p ≤ 0.05). Few alterations were noted in the fiber type. Men had larger CSAs compared those of with women, and there was a fiber-specific trend toward hypertrophy over time. In summary, 8 weeks of semiblock free-weight resistance training improved several performance variables and some cardiovascular factors

  10. 34 CFR 390.1 - What is the Rehabilitation Short-Term Training program?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... designed for the support of special seminars, institutes, workshops, and other short-term courses in technical matters relating to the vocational, medical, social, and psychological rehabilitation...

  11. 34 CFR 390.1 - What is the Rehabilitation Short-Term Training program?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... designed for the support of special seminars, institutes, workshops, and other short-term courses in technical matters relating to the vocational, medical, social, and psychological rehabilitation...

  12. Circadian Modulation of Short-Term Memory in "Drosophila"

    ERIC Educational Resources Information Center

    Lyons, Lisa C.; Roman, Gregg

    2009-01-01

    Endogenous biological clocks are widespread regulators of behavior and physiology, allowing for a more efficient allocation of efforts and resources over the course of a day. The extent that different processes are regulated by circadian oscillators, however, is not fully understood. We investigated the role of the circadian clock on short-term…

  13. Short- and long-term effects of unemployment on fertility

    PubMed Central

    Currie, Janet; Schwandt, Hannes

    2014-01-01

    Scholars have been examining the relationship between fertility and unemployment for more than a century. Most studies find that fertility falls with unemployment in the short run, but it is not known whether these negative effects persist, because women simply may postpone childbearing to better economic times. Using more than 140 million US birth records for the period 1975–2010, we analyze both the short- and long-run effects of unemployment on fertility. We follow fixed cohorts of US-born women defined by their own state and year of birth, and relate their fertility to the unemployment rate experienced by each cohort at different ages. We focus on conceptions that result in a live birth. We find that women in their early 20s are most affected by high unemployment rates in the short run and that the negative effects on fertility grow over time. A one percentage point increase in the average unemployment rate experienced between the ages of 20 and 24 reduces the short-run fertility of women in this age range by six conceptions per 1,000 women. When we follow these women to age 40, we find that a one percentage point increase in the unemployment rate experienced at ages 20–24 leads to an overall loss of 14.2 conceptions. This long-run effect is driven largely by women who remain childless and thus do not have either first births or higher-order births. PMID:25267622

  14. Short- and long-term effects of unemployment on fertility.

    PubMed

    Currie, Janet; Schwandt, Hannes

    2014-10-14

    Scholars have been examining the relationship between fertility and unemployment for more than a century. Most studies find that fertility falls with unemployment in the short run, but it is not known whether these negative effects persist, because women simply may postpone childbearing to better economic times. Using more than 140 million US birth records for the period 1975-2010, we analyze both the short- and long-run effects of unemployment on fertility. We follow fixed cohorts of US-born women defined by their own state and year of birth, and relate their fertility to the unemployment rate experienced by each cohort at different ages. We focus on conceptions that result in a live birth. We find that women in their early 20s are most affected by high unemployment rates in the short run and that the negative effects on fertility grow over time. A one percentage point increase in the average unemployment rate experienced between the ages of 20 and 24 reduces the short-run fertility of women in this age range by six conceptions per 1,000 women. When we follow these women to age 40, we find that a one percentage point increase in the unemployment rate experienced at ages 20-24 leads to an overall loss of 14.2 conceptions. This long-run effect is driven largely by women who remain childless and thus do not have either first births or higher-order births.

  15. Intelligence as a predictor of outcome in short- and long-term psychotherapy.

    PubMed

    Knekt, Paul; Saari, Taru; Lindfors, Olavi

    2014-12-30

    Intelligence has been suggested as a suitability factor for short-term therapy whereas its possible effect on short-term versus long-term therapy still is unknown. The aim of this study was to compare the prediction of intelligence on the level of psychiatric symptoms and psychosocial functioning in psychotherapies of different lengths. A total of 251 outpatients from the Helsinki Psychotherapy Study, aged 20–46 years, and suffering from mood or anxiety disorders were allocated to two long-term and two short-term therapies. Intelligence was assessed at baseline with the Wechsler Adult Intelligence Scale (WAIS-R). Psychiatric symptoms and psychosocial functioning were assessed 5–10 times during a 5-year follow-up using two primary symptom measures (HDRS and HARS) and one primary measure of psychosocial functioning (GAF). Short-term therapy was more effective than long-term therapy during the first year of follow-up. During the second to fourth follow-up year no differences between short- and long-term therapies or the intelligence groups were found. At the fifth follow-up year, however, long-term psychotherapy showed a statistically significantly larger change in all three primary measures compared to short-term therapy among those with higher intelligence. No differences between therapy groups were noted in those with lower intelligence. People with higher intelligence may benefit more from long-term than from short-term psychotherapy. These findings should be confirmed.

  16. Imminent Suicide: The Illusion of Short-Term Prediction

    ERIC Educational Resources Information Center

    Simon, Robert I.

    2006-01-01

    The concept of imminent suicide is examined. A search of National Electronic Library for Mental Health, the Cochrane Library, PubMed, OVID and MD Consult databases was conducted using the terms "suicide, imminent." The term "imminent" frequently appears in the mental health literature, finding common usage among clinicians. It is also a legal term…

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

    PubMed

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

    2015-06-01

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

  18. In vivo short-term and long-term host reaction to starch-based scaffolds.

    PubMed

    Santos, T C; Marques, A P; Höring, B; Martins, A R; Tuzlakoglu, K; Castro, A G; van Griensven, M; Reis, R L

    2010-11-01

    The implantation of biomaterials may elicit a host response to this foreign body, and the magnitude of that reaction depends on the host and on the implanted material. The aim of this study was to compare the inflammatory response induced by the implantation of starch-based (SPCL) scaffolds in two implantation rat models: subcutaneous (SC) and intramuscular (IM). Moreover, two methodologies, wet spinning (WS) and fibre-bonding (FB), were used to prepare the scaffolds. The short-term inflammatory/immune host reaction was assessed by SC and IM implantations in rats after 1 and 2 weeks, and the long-term host response was addressed after 8 and 12 weeks of SC implantation of both types of SPCL scaffolds in rats. After each time period, the scaffolds, surrounding tissue and nearby lymph nodes were explanted, and used for histological analysis and molecular biology evaluation. The results showed that SPCL-WS scaffolds seem to induce a slight lower inflammatory/immune reaction in both types of implantation models. Nonetheless, comparing the two models, the IM implantation resulted in a slightly higher inflammatory response than the SC implantation with early activation of the lymph nodes. The overall data suggests a good integration of the materials in the host, independently of the tissue location with a normal progress of the reaction for all the conditions.

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

    PubMed

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

    2015-06-01

    All animals need clean water to drink. At the authors' animal facility, drinking water for immunocompromised rodents is filtered by reverse osmosis, acidified during bottling and sterilized in an autoclave. Autoclaved water bottles can be stored in unopened autoclave bags for 7 d or in opened bags for 2 d; if not used during that time, they are emptied, cleaned, refilled and sterilized again. The authors wished to determine whether the storage period of 2-7 d was adequate and necessary to ensure the quality of drinking water. They tested water bottles for pH levels and for the presence of adenosine triphosphate as a measure of organic contamination during short-term and long-term storage. The pH of autoclaved drinking water generally remained stable during storage. Furthermore, no instances of organic contamination were detected in autoclaved water bottles stored for up to 22 d in unopened bags and only one instance was detected in bottles stored for up to 119 d in opened bags in a room with individually ventilated cages. On the basis of these findings, the acceptable storage period for autoclaved water bottles in opened bags at the authors' facility was extended to 21 d. PMID:25989554

  20. Short-term disruption rates and long-term outcomes of a professional parent program.

    PubMed

    Redinger, Robyn

    2012-01-01

    Both traditional and specialized foster care have disruption rates ranging from 36% to 70%. Connecting Children and Families was a professional parent program that provided permanent family placements for children and young adults with significant behavior problems and mental health issues. During the 15 years of the Connecting Children and Families program, the short-term disruption rate was 21%. Long-term positive outcomes (i.e., stability in the family, reunification with birth family, or adoption) occurred for 83% of the children and young adults. This article is a program description of Connecting Children and Families. There were five key elements of this program: (a) The primary treatment was the life itself provided by the professional parents; (b) The parents were paid a significant stipend and they were treated both as professionals and as the parents of the children placed in their home; (c) The program model was one based on continuity of clinical care rather than case management; (d) Treatment interventions were derived from the fields of behaviorism and applied behavior analysis; and (e) The core value of the program was rooted in Wolfensberger's concept of social role valorization. PMID:24205552