WorldWideScience

Sample records for short term fluctuations

  1. Short-term fluctuations in motivation to quit smoking in a sample of smokers in Hawaii.

    Science.gov (United States)

    Herzog, Thaddeus; Pokhrel, Pallav; Kawamoto, Crissy T

    2015-01-01

    Despite its potential for usefulness in informing the development of smoking cessation interventions, short-term fluctuations in motivation to quit is a relatively understudied topic. To assess the prevalence of smokers' day-to-day fluctuations in motivation to quit, and to assess associations of day-to-day fluctuations in motivation to quit with several established cessation-related variables. A cross-sectional survey was administered to smokers in Hawaii (N = 1,567). To assess short-term fluctuations in motivation to quit smoking, participants were asked to respond "True" or "False" to the statement: "My motivation to quit smoking changes from one day to the next." Other items measured desire to quit smoking, intention to quit, confidence in quitting, cigarette dependence, and other cessation-related variables. "My motivation to quit smoking changes from one day to the next" was endorsed as true by 64.7% of smokers, and false by 35.3%. Analyses revealed that smokers who indicated fluctuating motivation were significantly more interested in quitting as compared to smokers without fluctuations. Fluctuations in motivation to quit also were associated with greater confidence in quitting, lesser cigarette dependence, and more recent quitting activity (all p motivation to quit are common. Day-to-day fluctuations in motivation to quit are strongly associated with higher motivation to quit, greater confidence in future quitting, and other positive cessation-relevant trends.

  2. Short-term predictability of crude oil markets: A detrended fluctuation analysis approach

    International Nuclear Information System (INIS)

    Alvarez-Ramirez, Jose; Alvarez, Jesus; Rodriguez, Eduardo

    2008-01-01

    This paper analyzes the auto-correlations of international crude oil prices on the basis of the estimation of the Hurst exponent dynamics for returns over the period from 1987 to 2007. In doing so, a model-free statistical approach - detrended fluctuation analysis - that reduces the effects of non-stationary market trends and focuses on the intrinsic auto-correlation structure of market fluctuations over different time horizons, is used. Tests for time variations of the Hurst exponent indicate that over long horizons the crude oil market is consistent with the efficient market hypothesis. However, meaningful auto-correlations cannot be excluded for time horizons smaller than one month where the Hurst exponent manifests cyclic, non-periodic dynamics. This means that the market exhibits a time-varying short-term inefficient behavior that becomes efficient in the long term. The proposed methodology and its findings are put in perspective with previous studies and results. (author)

  3. Short-term fluctuations in bivalve larvae compared with some environmental factors in a coastal lagoon (South Portugal

    Directory of Open Access Journals (Sweden)

    Luis M.Z. Chícaro

    2000-12-01

    Full Text Available In this study, short-term fluctuations in bivalve larvae were compared with some triggering factors for a period of sixteen months. Data on the abundance of planktonic larvae, collected two to three times a week were related to water temperature, salinity, wind velocity, tidal amplitude and chlorophyll a. Higher densities of planktonic bivalve larvae were caught between May and August, but intense fluctuations in abundance were observed. Planktonic bivalve larvae of eighteen taxa were identified. Larvae of Mytilus galloprovincialis, Cerastoderma edule, Ruditapes decussates and Venerupis spp. were the most abundant. The seasonal fluctuations of bivalve abundance seem to be controlled by temperature, the major factor in the timing of the reproduction of bivalves. Nevertheless, advection may be also a key factor during the planktonic life of bivalve species in coastal systems, such as the Ria Formosa.

  4. Dynamics of cyanobacterial bloom formation during short-term hydrodynamic fluctuation in a large shallow, eutrophic, and wind-exposed Lake Taihu, China.

    Science.gov (United States)

    Wu, Tingfeng; Qin, Boqiang; Zhu, Guangwei; Luo, Liancong; Ding, Yanqing; Bian, Geya

    2013-12-01

    Short-term hydrodynamic fluctuations caused by extreme weather events are expected to increase worldwide because of global climate change, and such fluctuations can strongly influence cyanobacterial blooms. In this study, the cyanobacterial bloom disappearance and reappearance in Lake Taihu, China, in response to short-term hydrodynamic fluctuations, was investigated by field sampling, long-term ecological records, high-frequency sensors and MODIS satellite images. The horizontal drift caused by the dominant easterly wind during the phytoplankton growth season was mainly responsible for cyanobacterial biomass accumulation in the western and northern regions of the lake and subsequent bloom formation over relatively long time scales. The cyanobacterial bloom changed slowly under calm or gentle wind conditions. In contrast, the short-term bloom events within a day were mainly caused by entrainment and disentrainment of cyanobacterial colonies by wind-induced hydrodynamics. Observation of a westerly event in Lake Taihu revealed that when the 30 min mean wind speed (flow speed) exceeded the threshold value of 6 m/s (5.7 cm/s), cyanobacteria in colonies were entrained by the wind-induced hydrodynamics. Subsequently, the vertical migration of cyanobacterial colonies was controlled by hydrodynamics, resulting in thorough mixing of algal biomass throughout the water depth and the eventual disappearance of surface blooms. Moreover, the intense mixing can also increase the chance for forming larger and more cyanobacterial colonies, namely, aggregation. Subsequently, when the hydrodynamics became weak, the cyanobacterial colonies continuously float upward without effective buoyancy regulation, and cause cyanobacterial bloom explosive expansion after the westerly. Furthermore, the results of this study indicate that the strong wind happening frequently during April and October can be an important cause of the formation and expansion of cyanobacterial blooms in Lake Taihu.

  5. Predicting short-term stock fluctuations by using processing fluency

    Science.gov (United States)

    Alter, Adam L.; Oppenheimer, Daniel M.

    2006-01-01

    Three studies investigated the impact of the psychological principle of fluency (that people tend to prefer easily processed information) on short-term share price movements. In both a laboratory study and two analyses of naturalistic real-world stock market data, fluently named stocks robustly outperformed stocks with disfluent names in the short term. For example, in one study, an initial investment of $1,000 yielded a profit of $112 more after 1 day of trading for a basket of fluently named shares than for a basket of disfluently named shares. These results imply that simple, cognitive approaches to modeling human behavior sometimes outperform more typical, complex alternatives. PMID:16754871

  6. Evaluation of short-term tracer fluctuations in groundwater and soil air in a two year study

    Science.gov (United States)

    Jenner, Florian; Mayer, Simon; Aeschbach, Werner; Weissbach, Therese

    2016-04-01

    The application of gas tracers like noble gases (NGs), SF6 or CFCs in groundwater studies such as paleo temperature determination requires a detailed understanding of the dynamics of reactive and inert gases in the soil air with which the infiltrating water equilibrates. Due to microbial gas consumption and production, NG partial pressures in soil air can deviate from atmospheric air, an effect that could bias noble gas temperatures estimates if not taken into account. So far, such an impact on NG contents in groundwater has not been directly demonstrated. We provide the first long-term study of the above mentioned gas tracers and physical parameters in both the saturated and unsaturated soil zone, sampled continuously for more than two years near Mannheim (Germany). NG partial pressures in soil air correlate with soil moisture and the sum value of O2+CO2, with a maximal significant enhancement of 3-6% with respect to atmospheric air during summer time. Observed seasonal fluctuations result in a mass dependent fractionation of NGs in soil air. Concentrations of SF6 and CFCs in soil air are determined by corresponding fluctuations in local atmospheric air, caused by industrial emissions. Arising concentration peaks are damped with increasing soil depth. Shallow groundwater shows short-term NG fluctuations which are smoothed within a few meters below the water table. A correlation between NG contents of soil air and of groundwater is observable during strong recharge events. However, there is no evidence for a permanent influence of seasonal variations of soil air composition on shallow groundwater. Fluctuating NG contents in shallow groundwater are rather determined by variations of soil temperature and water table level. Our data gives evidence for a further temperature driven equilibration of groundwater with entrapped air bubbles within the topmost saturated zone, which permanently occurs even some years after recharge. Local subsurface temperature fluctuations

  7. Does stress affect the joints? Daily stressors, stress vulnerability, immune and HPA axis activity, and short-term disease and symptom fluctuations in rheumatoid arthritis.

    Science.gov (United States)

    Evers, Andrea W M; Verhoeven, Elisabeth W M; van Middendorp, Henriët; Sweep, Fred C G J; Kraaimaat, Floris W; Donders, A Rogier T; Eijsbouts, Agnes E; van Laarhoven, Antoinette I M; de Brouwer, Sabine J M; Wirken, Lieke; Radstake, Timothy R D J; van Riel, Piet L C M

    2014-09-01

    Both stressors and stress vulnerability factors together with immune and hypothalamus-pituitary-adrenal (HPA) axis activity components have been considered to contribute to disease fluctuations of chronic inflammatory diseases, such as rheumatoid arthritis (RA). The aim of the present study was to investigate whether daily stressors and worrying as stress vulnerability factor as well as immune and HPA axis activity markers predict short-term disease activity and symptom fluctuations in patients with RA. In a prospective design, daily stressors, worrying, HPA axis (cortisol) and immune system (interleukin (IL)-1β, IL-6, IL-8, interferon (IFN)-γ, tumour necrosis factor α) markers, clinical and self-reported disease activity (disease activity score in 28 joints, RA disease activity index), and physical symptoms of pain and fatigue were monitored monthly during 6 months in 80 RA patients. Multilevel modelling indicated that daily stressors predicted increased fatigue in the next month and that worrying predicted increased self-reported disease activity, swollen joint count and pain in the next month. In addition, specific cytokines of IL-1β and IFN-γ predicted increased fatigue 1 month later. Overall, relationships remained relatively unchanged after controlling for medication use, disease duration and demographic variables. No evidence was found for immune and HPA axis activity markers as mediators of the stress-disease relationship. Daily stressors and the stress-vulnerability factor worrying predict indicators of the short-term course of RA disease activity and fatigue and pain, while specific cytokines predict short-term fluctuations of fatigue. These stress-related variables and immune markers seem to affect different aspects of disease activity or symptom fluctuations independently in RA. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  8. Short-term stability in refractive status despite large fluctuations in glucose levels in diabetes mellitus type 1 and 2.

    Directory of Open Access Journals (Sweden)

    Byki Huntjens

    Full Text Available PURPOSE: This work investigates how short-term changes in blood glucose concentration affect the refractive components of the diabetic eye in patients with long-term Type 1 and Type 2 diabetes. METHODS: Blood glucose concentration, refractive error components (mean spherical equivalent MSE, J0, J45, central corneal thickness (CCT, anterior chamber depth (ACD, crystalline lens thickness (LT, axial length (AL and ocular aberrations were monitored at two-hourly intervals over a 12-hour period in: 20 T1DM patients (mean age ± SD 38±14 years, baseline HbA1c 8.6±1.9%; 21 T2DM patients (mean age ± SD 56±11 years, HbA1c 7.5±1.8%; and in 20 control subjects (mean age ± SD 49±23 years, HbA1c 5.5±0.5%. The refractive and biometric results were compared with the corresponding changes in blood glucose concentration. RESULTS: Blood glucose concentration at different times was found to vary significantly within (p0.05. Minor changes of marginal statistical or optical significance were observed in some biometric parameters. Similarly there were some marginally significant differences between the baseline biometric parameters of well-controlled and poorly-controlled diabetic subjects. CONCLUSION: This work suggests that normal, short-term fluctuations (of up to about 6 mM/l on a timescale of a few hours in the blood glucose levels of diabetics are not usually associated with acute changes in refractive error or ocular wavefront aberrations. It is therefore possible that factors other than refractive error fluctuations are sometimes responsible for the transient visual problems often reported by diabetic patients.

  9. Panorama 2013 - Short term trends in the gas industry

    International Nuclear Information System (INIS)

    Lecarpentier, Armelle

    2012-10-01

    The outlook for gas industry development in the short term is clouded by uncertainties (impact of the economic slowdown, competition between energies, price fluctuations, etc.). However, as in 2012, many favorable factors in terms of natural gas supply and demand point to sustained and sustainable growth of this energy. (author)

  10. Short-term variability of CYG X-1

    International Nuclear Information System (INIS)

    Oda, M.; Doi, K.; Ogawara, Y.; Takagishi, K.; Wada, M.

    1975-01-01

    The short-term X-ray variability distinguishes Cyg X-1, which is the most likely candidate of the black hole, from other X-ray sources. Present status of our knowledge on this short-term variation mainly from the Uhuru, the MIT and the GSFC observations is reviewed. The nature of impulsive variations which compose the time variation exceeding the statistical fluctuation is discussed. There are indications that the energy spectrum of large pulses is harder than the average spectrum or the large pulses are the characteristics of the hard component of the spectrum if it is composed of two, soft and hard, components. Features of the variations may be partly simulated by the superposition of random short-noise pulses with a fraction of a second duration. However, the autocorrelation analysis and the dynamic spectrum analysis indicate that the correlation lasts for several seconds and in the variation buried are some regularities which exhibit power concentrations in several frequency bands; 0.2 -- 0.3, 0.4 -- 0.5, 0.8, 1.2 -- 1.5 Hz. There are several possible interpretation of these results in terms of: e.g. a) a mixture of short-noise pulses with two or more constant durations, b) the shape of the basic shot-noise pulse, c) bunching of the pulses, d) superposition of wave-packets or temporal oscillations. But we have not yet reached any definite understandings in the nature of the variabilities. The sub-structure of the fluctuations on a time scale of milli-second suggested by two investigations is also discussed. (auth.)

  11. Latitudinal Patterns in European Seagrass Carbon Reserves: Influence of Seasonal Fluctuations versus Short-Term Stress and Disturbance Events

    Directory of Open Access Journals (Sweden)

    Laura M. Soissons

    2018-02-01

    Full Text Available Seagrass meadows form highly productive and valuable ecosystems in the marine environment. Throughout the year, seagrass meadows are exposed to abiotic and biotic variations linked to (i seasonal fluctuations, (ii short-term stress events such as, e.g., local nutrient enrichment, and (iii small-scale disturbances such as, e.g., biomass removal by grazing. We hypothesized that short-term stress events and small-scale disturbances may affect seagrass chance for survival in temperate latitudes. To test this hypothesis we focused on seagrass carbon reserves in the form of starch stored seasonally in rhizomes, as these have been defined as a good indicator for winter survival. Twelve Zostera noltei meadows were monitored along a latitudinal gradient in Western Europe to firstly assess the seasonal change of their rhizomal starch content. Secondly, we tested the effects of nutrient enrichment and/or biomass removal on the corresponding starch content by using a short-term manipulative field experiment at a single latitude in the Netherlands. At the end of the growing season, we observed a weak but significant linear increase of starch content along the latitudinal gradient from south to north. This agrees with the contention that such reserves are essential for regrowth after winter, which is more severe in the north. In addition, we also observed a weak but significant positive relationship between starch content at the beginning of the growing season and past winter temperatures. This implies a lower regrowth potential after severe winters, due to diminished starch content at the beginning of the growing season. Short-term stress and disturbances may intensify these patterns, because our manipulative experiments show that when nutrient enrichment and biomass loss co-occurred at the end of the growing season, Z. noltei starch content declined. In temperate zones, the capacity of seagrasses to accumulate carbon reserves is expected to determine carbon

  12. Latitudinal Patterns in European Seagrass Carbon Reserves: Influence of Seasonal Fluctuations versus Short-Term Stress and Disturbance Events

    Science.gov (United States)

    Soissons, Laura M.; Haanstra, Eeke P.; van Katwijk, Marieke M.; Asmus, Ragnhild; Auby, Isabelle; Barillé, Laurent; Brun, Fernando G.; Cardoso, Patricia G.; Desroy, Nicolas; Fournier, Jerome; Ganthy, Florian; Garmendia, Joxe-Mikel; Godet, Laurent; Grilo, Tiago F.; Kadel, Petra; Ondiviela, Barbara; Peralta, Gloria; Puente, Araceli; Recio, Maria; Rigouin, Loic; Valle, Mireia; Herman, Peter M. J.; Bouma, Tjeerd J.

    2018-01-01

    Seagrass meadows form highly productive and valuable ecosystems in the marine environment. Throughout the year, seagrass meadows are exposed to abiotic and biotic variations linked to (i) seasonal fluctuations, (ii) short-term stress events such as, e.g., local nutrient enrichment, and (iii) small-scale disturbances such as, e.g., biomass removal by grazing. We hypothesized that short-term stress events and small-scale disturbances may affect seagrass chance for survival in temperate latitudes. To test this hypothesis we focused on seagrass carbon reserves in the form of starch stored seasonally in rhizomes, as these have been defined as a good indicator for winter survival. Twelve Zostera noltei meadows were monitored along a latitudinal gradient in Western Europe to firstly assess the seasonal change of their rhizomal starch content. Secondly, we tested the effects of nutrient enrichment and/or biomass removal on the corresponding starch content by using a short-term manipulative field experiment at a single latitude in the Netherlands. At the end of the growing season, we observed a weak but significant linear increase of starch content along the latitudinal gradient from south to north. This agrees with the contention that such reserves are essential for regrowth after winter, which is more severe in the north. In addition, we also observed a weak but significant positive relationship between starch content at the beginning of the growing season and past winter temperatures. This implies a lower regrowth potential after severe winters, due to diminished starch content at the beginning of the growing season. Short-term stress and disturbances may intensify these patterns, because our manipulative experiments show that when nutrient enrichment and biomass loss co-occurred at the end of the growing season, Z. noltei starch content declined. In temperate zones, the capacity of seagrasses to accumulate carbon reserves is expected to determine carbon-based regrowth

  13. Stochastic Optimal Wind Power Bidding Strategy in Short-Term Electricity Market

    DEFF Research Database (Denmark)

    Hu, Weihao; Chen, Zhe; Bak-Jensen, Birgitte

    2012-01-01

    Due to the fluctuating nature and non-perfect forecast of the wind power, the wind power owners are penalized for the imbalance costs of the regulation, when they trade wind power in the short-term liberalized electricity market. Therefore, in this paper a formulation of an imbalance cost...... minimization problem for trading wind power in the short-term electricity market is described, to help the wind power owners optimize their bidding strategy. Stochastic optimization and a Monte Carlo method are adopted to find the optimal bidding strategy for trading wind power in the short-term electricity...... market in order to deal with the uncertainty of the regulation price, the activated regulation of the power system and the forecasted wind power generation. The Danish short-term electricity market and a wind farm in western Denmark are chosen as study cases due to the high wind power penetration here...

  14. Short-term variability of Cyg X-1

    International Nuclear Information System (INIS)

    Oda, M.; Doi, K.; Ogawara, Y.

    1976-01-01

    The short-term X-ray variability distinguishes Cyg X-1, which is the most likely candidate for a black hole, from other X-ray sources. The present status of our knowledge on this short-term variation, mainly from the UHURU, the MIT and the GSFC observations, is reviewed. The nature of impulsive variations which compose the time variation exceeding the statistical fluctuation is discussed. There are indications that the energy spectrum of large pulses is harder than the average spectrum, or that the large pulses are the characteristics of the hard component of the spectrum if it is composed of two, soft and hard, components. Features of the variations may be partly simulated by the superposition of random shot-noise pulses with a fraction of a second duration. However, the autocorrelation analysis and the dynamic spectrum analysis indicate that the correlation lasts for several seconds and in the variation are buried some regularities which exhibit power concentrations in several frequency bands; 0.2-0.3, 0.4-0.5, 0.8, 1.2-1.5 Hz. There are several possible interpretations of these results in terms of; e.g. (a) a mixture of shot-noise pulses with two or more constant durations, (b) the shape of the basic shot-noise pulse, (c) bunching of the pulses, (d) superposition of wave-packets or temporal oscillations. But we have not yet reached any definite understandings in the nature of the variabilities. The substructure of the fluctuations on a time scale of milliseconds suggested by two investigations is also discussed. (Auth.)

  15. Long term persistence in the sea surface temperature fluctuations

    OpenAIRE

    Monetti, Roberto A.; Havlin, Shlomo; Bunde, Armin

    2002-01-01

    We study the temporal correlations in the sea surface temperature (SST) fluctuations around the seasonal mean values in the Atlantic and Pacific oceans. We apply a method that systematically overcome possible trends in the data. We find that the SST persistence, characterized by the correlation $C(s)$ of temperature fluctuations separated by a time period $s$, displays two different regimes. In the short-time regime which extends up to roughly 10 months, the temperature fluctuations display a...

  16. Correlation structures in short-term variabilities of stock indices and exchange rates

    Science.gov (United States)

    Nakamura, Tomomichi; Small, Michael

    2007-09-01

    Financial data usually show irregular fluctuations and some trends. We investigate whether there are correlation structures in short-term variabilities (irregular fluctuations) among financial data from the viewpoint of deterministic dynamical systems. Our method is based on the small-shuffle surrogate method. The data we use are daily closing price of Standard & Poor's 500 and the volume, and daily foreign exchange rates, Euro/US Dollar (USD), British Pound/USD and Japanese Yen/USD. We found that these data are not independent.

  17. Simulation of short-term fluctuations in gamma exposure rate due to radioactive cloud released from nuclear power plant

    International Nuclear Information System (INIS)

    Ichikawa, Yoichi; Shikata, Hiroshi; Ishida, Kenji; Ohba, Tachimori.

    1981-01-01

    The measured γ-exposure rate around nuclear power plants is due mainly to natural causes and radioactive clouds emitted from the plants. An exposure calculation method based on puff model has been already proposed to identify the plant contributions and to estimate values in response to short-term fluctuations of meteorological condition and the release rate. However, the calculation method by this model consumes a lot of computer time, since the calculation requires a three-dimensional integration of the distribution of the concentration from each puff. Hence, we propose a simplified method using approximate polynominal equations and interpolations. The computer time needed for the calculation with the simplified method is reduced to 1/30 of that required by the previous method. The calculation results by simplified method are compared with those by the previous method and with the measured exposure rate less natural background. The results of two different methods are in good agreement. The calculated exposure rate is within the range from half to twice as much as the measured exposure rate less background. (author)

  18. Short-term regulation of hydro powerplants. Studies on the environmental effects

    International Nuclear Information System (INIS)

    Sinisalmi, T.; Riihimaeki, J.; Vehanen, T.; Yrjaenae, T.

    1997-01-01

    The publication is a final report on a project studying effects of short-term regulation of hydro power plants. The project consists of two parts: (1) examining and developing methods for evaluation, (2) applying methods in a case study at the Oulujoki River. The economic value of short-term regulation was studied with a model consisting of an optimization model and a river simulation model. Constraints on water level or discharge variations could be given to the power plants and their economical influence could be studied. Effects on shoreline recreation use due to water level fluctuation were studied with a model where various effects are made commensurable and expressed in monetary terms. A literature survey and field experiments were used to study the methods for assessing effects of short-term regulation on river habitats. The state and development needs of fish stocks and fisheries in large regulated rivers were studied and an environmental classification was made. Remedial measures for the short-term regulated rivers were studied with a literature survey and enquiries. A comprehensive picture of the various effects of short-term regulation was gained in the case study in Oulujoki River (110 km long, 7 power plants). Harmful effects can be reduced with the given recommendations of remedial measures on environment and the usage of the hydro power plants. (orig.) 52 refs

  19. Short-term regulation of hydro powerplants. Studies on the environmental effects

    Energy Technology Data Exchange (ETDEWEB)

    Sinisalmi, T. [ed.; Forsius, J.; Muotka, J.; Soimakallio, H. [Imatran Voima Oy, Vantaa (Finland); Riihimaeki, J. [VTT, Espoo (Finland); Vehanen, T. [Finnish Game and Fisheries Research Inst. (Finland); Yrjaenae, T. [North Ostrobothnia Regional Environmental Centre, Oulu (Finland)

    1997-12-31

    The publication is a final report on a project studying effects of short-term regulation of hydro power plants. The project consists of two parts: (1) examining and developing methods for evaluation, (2) applying methods in a case study at the Oulujoki River. The economic value of short-term regulation was studied with a model consisting of an optimization model and a river simulation model. Constraints on water level or discharge variations could be given to the power plants and their economical influence could be studied. Effects on shoreline recreation use due to water level fluctuation were studied with a model where various effects are made commensurable and expressed in monetary terms. A literature survey and field experiments were used to study the methods for assessing effects of short-term regulation on river habitats. The state and development needs of fish stocks and fisheries in large regulated rivers were studied and an environmental classification was made. Remedial measures for the short-term regulated rivers were studied with a literature survey and enquiries. A comprehensive picture of the various effects of short-term regulation was gained in the case study in Oulujoki River (110 km long, 7 power plants). Harmful effects can be reduced with the given recommendations of remedial measures on environment and the usage of the hydro power plants. (orig.) 52 refs.

  20. Health Effects of Short-Term Fluctuations in Macroeconomic Conditions: The Case of Hypertension for Older Americans.

    Science.gov (United States)

    Angrisani, Marco; Lee, Jinkook

    2016-11-01

    We investigate the health effects of short-term macroeconomic fluctuations as described by changes in unemployment rate, house, and stock market price indexes. The 'Great Recession' provides the opportunity to conduct this analysis as it involved contemporaneous shocks to the labor, housing, and stock markets. Using panel data from the Health and Retirement Study over the period 2004-2010, we relate changes in hypertension status to changes in state-level unemployment rate and house prices and to changes in stock market prices. We consider hypertension, a disease related to stress and of high prevalence among older adults, that has received little attention in the literature linking macroeconomic conditions to individual health. Our analysis exploits self-reports of hypertension diagnosis as well as directly measured blood pressure readings. Using both measures, we find that the likelihood of developing hypertension is negatively related to changes in house prices. Also, decreasing house prices lower the probability of stopping hypertension medication treatment for individuals previously diagnosed with the condition. We do not observe significant associations between hypertension and either changes in unemployment rate or stock market prices. We document heterogeneity in the estimated health effects of the recession by gender, education, asset ownership, and work status. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  1. Long-term competitive dynamics of two cryptic rotifer species: diapause and fluctuating conditions.

    Directory of Open Access Journals (Sweden)

    Carmen Gabaldón

    Full Text Available Life-history traits may have an important role in promoting species coexistence. However, the complexity of certain life cycles makes it difficult to draw conclusions about the conditions for coexistence or exclusion based on the study of short-term competitive dynamics. Brachionus plicatilis and B. manjavacasare two cryptic rotifer species co-occurring in many lakes on the Iberian Peninsula. They have a complex life cycle in which cyclical parthenogenesis occurs with diapausing stages being the result of sexual reproduction. B. plicatilis and B. manjavacasare identical in morphology and size, their biotic niches are broadly overlapping, and they have similar competitive abilities. However, the species differ in life-history traits involving sexual reproduction and diapause, and respond differently to salinity and temperature. As in the case of certain other species that are extremely similar in morphology, a fluctuating environment are considered to be important for their coexistence. We studied the long-term competitive dynamics of B. plicatilis and B. manjavacas under different salinity regimes (constant and fluctuating. Moreover, we focused on the dynamics of the diapausing egg bank to explore how the outcome of the entire life cycle of these rotifers can work to mediate stable coexistence. We demonstrated that these species do not coexist under constant-salinity environment, as the outcome of competition is affected by the level of salinity-at low salinity, B. plicatilis excluded B. manjavacas, and the opposite outcome occurred at high salinity. Competitive dynamics under fluctuating salinity showed that the dominance of one species over the other also tended to fluctuate. The duration of co-occurrence of these species was favoured by salinity fluctuation and perhaps by the existence of a diapausing egg bank. Stable coexistence was not found in our system, which suggests that other factors or other salinity fluctuation patterns might act as

  2. Long-term competitive dynamics of two cryptic rotifer species: diapause and fluctuating conditions.

    Science.gov (United States)

    Gabaldón, Carmen; Carmona, María José; Montero-Pau, Javier; Serra, Manuel

    2015-01-01

    Life-history traits may have an important role in promoting species coexistence. However, the complexity of certain life cycles makes it difficult to draw conclusions about the conditions for coexistence or exclusion based on the study of short-term competitive dynamics. Brachionus plicatilis and B. manjavacasare two cryptic rotifer species co-occurring in many lakes on the Iberian Peninsula. They have a complex life cycle in which cyclical parthenogenesis occurs with diapausing stages being the result of sexual reproduction. B. plicatilis and B. manjavacasare identical in morphology and size, their biotic niches are broadly overlapping, and they have similar competitive abilities. However, the species differ in life-history traits involving sexual reproduction and diapause, and respond differently to salinity and temperature. As in the case of certain other species that are extremely similar in morphology, a fluctuating environment are considered to be important for their coexistence. We studied the long-term competitive dynamics of B. plicatilis and B. manjavacas under different salinity regimes (constant and fluctuating). Moreover, we focused on the dynamics of the diapausing egg bank to explore how the outcome of the entire life cycle of these rotifers can work to mediate stable coexistence. We demonstrated that these species do not coexist under constant-salinity environment, as the outcome of competition is affected by the level of salinity-at low salinity, B. plicatilis excluded B. manjavacas, and the opposite outcome occurred at high salinity. Competitive dynamics under fluctuating salinity showed that the dominance of one species over the other also tended to fluctuate. The duration of co-occurrence of these species was favoured by salinity fluctuation and perhaps by the existence of a diapausing egg bank. Stable coexistence was not found in our system, which suggests that other factors or other salinity fluctuation patterns might act as stabilizing

  3. Medium-term fluctuations and the "Great Ratios" of economic growth

    DEFF Research Database (Denmark)

    Groth, Christian; Madsen, Jakob B.

    2016-01-01

    Evidence for the OECD countries show that the “great ratios”, such as the unemployment rate, factor shares, Tobin’s q and the investment-capital ratio, fluctuate significantly on medium-term frequencies of 10-40 years duration. To explain these medium-term fluctuations, we establish a macro...

  4. A survey of short-term and long-term stability of tube parameters in a mammography unit

    Directory of Open Access Journals (Sweden)

    Praskalo Jovica Ž.

    2014-01-01

    Full Text Available In order to set up a successful mammography screening program in the Republic of Srpska, a Siemens Mammomat 1000 X-ray machine was selected for analysis as the said mammography system is widely used in clinical practice. The variations in tube parameters (specific air kerma, high-voltage accuracy and reproducibility, linearity between exposure and dose exposure time were monitored over a five-year period, from 2008 to 2012. In addition, due to observed daily fluctuations for chosen parameters, a series of measurements were performed three times a day within a single-month period (mainly October 2012. The goal of such an experimental set up is to assess short-term and long-term stability of tube parameters in the given mammography unit and to make a comparison between them. The present paper shows how an early detection of significant parameter fluctuations can help eliminate irregularities and optimize the performance of mammography systems. [Projekat Ministarstva nauke Republike Srbije, br. 171007

  5. Observation of short period fluctuation of CygX-1 with balloon

    International Nuclear Information System (INIS)

    Nakagawa, Michio; Sakurai, Takahisa; Uchida, Masayoshi

    1977-01-01

    CygX-1 presents very complex short period fluctuation of X-ray, therefore the hard X-ray was especially observed in 1972 and 1973 with large balloons, and the data were analyzed. This short period fluctuation and energy spectra of CygX-1 in the normal and flare time bands were compared. The observing apparatuses consisted of the 3 in diameter NaI detector and a high pressure proportional counter. The observing method is to turn the gondora alternately to the directions of source (ON) and background (OFF). As for the data analysis, the events at ON and OFF in the observation data in 1972 and 1973 were plotted for time interval. The background component is in agreement with Poisson's distribution, but source component is not. This difference for Poisson's distribution means the behavior of CygX-1. The power spectrum was analyzed, and the strong power density was observed at 5.4 x 10 -2 Hz in ON, but such power density was not observed in OFF. Accordingly this is presumed to be caused by CygX-1. The events for time interval in flare time are shown. The rise of about 2.9 σ exists at 80 msec. The count rates were compared for photon energy in the normal and flare times. The short period fluctuation of hard X-ray from CygX-1 deviates from Poisson's distribution and is different in the normal and flare times. (Nakai, Y.)

  6. Measuring, Predicting and Visualizing Short-Term Change in Word Representation and Usage in VKontakte Social Network

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Ian B.; Arendt, Dustin L.; Bell, Eric B.; Volkova, Svitlana

    2017-05-17

    Language in social media is extremely dynamic: new words emerge, trend and disappear, while the meaning of existing words can fluctuate over time. This work addresses several important tasks of visualizing and predicting short term text representation shift, i.e. the change in a word’s contextual semantics. We study the relationship between short-term concept drift and representation shift on a large social media corpus – VKontakte collected during the Russia-Ukraine crisis in 2014 – 2015. We visualize short-term representation shift for example keywords and build predictive models to forecast short-term shifts in meaning from previous meaning as well as from concept drift. We show that short-term representation shift can be accurately predicted up to several weeks in advance and that visualization provides insight into meaning change. Our approach can be used to explore and characterize specific aspects of the streaming corpus during crisis events and potentially improve other downstream classification tasks including real-time event forecasting in social media.

  7. Audit of long-term and short-term liabilities

    Directory of Open Access Journals (Sweden)

    Korinko M.D.

    2017-03-01

    Full Text Available The article determines the importance of long-term and short-term liabilities for the management of financial and material resources of an enterprise. It reviews the aim, objects and information generators for realization of audit of short-term and long-term obligations. The organizing and methodical providing of audit of long-term and short-term liabilities of an enterprise are generalized. The authors distinguish the stages of realization of audit of long-term and short-term liabilities, the aim of audit on each of the presented stages, and recommend methodical techniques. It is fixed that it is necessary to conduct the estimation of the systems of internal control and record-keeping of an enterprise by implementation of public accountant procedures for determination of volume and maintenance of selection realization. After estimating the indicated systems, a public accountant determines the methodology for realization of public accountant verification of long-term and short-term liabilities. The analytical procedures that public accountants are expedient to use for realization of audit of short-term and long-term obligations are determined. The authors suggest the classification of the educed defects on the results of the conducted public accountant verification of short-term and long-term obligations.

  8. Short-Term Wind Speed Forecasting Using Decomposition-Based Neural Networks Combining Abnormal Detection Method

    Directory of Open Access Journals (Sweden)

    Xuejun Chen

    2014-01-01

    Full Text Available As one of the most promising renewable resources in electricity generation, wind energy is acknowledged for its significant environmental contributions and economic competitiveness. Because wind fluctuates with strong variation, it is quite difficult to describe the characteristics of wind or to estimate the power output that will be injected into the grid. In particular, short-term wind speed forecasting, an essential support for the regulatory actions and short-term load dispatching planning during the operation of wind farms, is currently regarded as one of the most difficult problems to be solved. This paper contributes to short-term wind speed forecasting by developing two three-stage hybrid approaches; both are combinations of the five-three-Hanning (53H weighted average smoothing method, ensemble empirical mode decomposition (EEMD algorithm, and nonlinear autoregressive (NAR neural networks. The chosen datasets are ten-minute wind speed observations, including twelve samples, and our simulation indicates that the proposed methods perform much better than the traditional ones when addressing short-term wind speed forecasting problems.

  9. Short-term fluctuations in vegetation and phytoplankton during the Middle Eocene greenhouse climate: a 640-kyr record from the Messel oil shale (Germany)

    Science.gov (United States)

    Lenz, Olaf K.; Wilde, Volker; Riegel, Walter

    2011-11-01

    The Palaeogene was the most recent greenhouse period on Earth. Especially for the Late Palaeocene and Early Eocene, several superimposed short-term hyperthermal events have been described, including extremes such as the Palaeocene-Eocene Thermal Maximum. Major faunal and floral turnovers in the marine and terrestrial realms were recorded in association with these events. High-resolution palynological analysis of the early Middle Eocene maar lake sediments at Messel, near Darmstadt, Germany, provides an insight into the dynamics of a climax vegetation during the Middle Eocene greenhouse climate in a time span without significant climatic excursions. Numerical techniques like detrended correspondence analysis and wavelet analysis have been applied to recognize cyclic fluctuations and long-term trends in the vegetation through a time interval of approximately 640 kyr. Based on the numerical zoning of the pollen diagram, three phases in the development of the vegetation may be distinguished. Throughout these phases, the climax vegetation did not change substantially in qualitative composition, but a trend towards noticeably less humid conditions probably in combination with a drop of the water level in the lake may be recognized. A shift in algal population from the freshwater dinoflagellate cyst Messelodinium thielepfeifferae to a dominance of Botryococcus in the uppermost part of the core is interpreted as a response to changes in acidity and nutrient availability within the lake. Time series analyses of pollen assemblages show that variations in the Milankovitch range of eccentricity, obliquity and precession can be distinguished. In addition, fluctuations in the sub-Milankovitch range are indicated. This demonstrates that floral changes during steady depositional conditions in the Middle Eocene of Messel were controlled by orbital forcing.

  10. Hsp70 expression and metabolite composition in response to short-term thermal changes in Folsomia candida (Collembola)

    DEFF Research Database (Denmark)

    Waagner, Dorthe; Heckmann, Lars-Henrik; Malmendal, Anders

    2010-01-01

    In the present study the joint transcriptomic and metabolomic responses in Folsomia candida (Collembola) to temperature changes on a short-term scale were studied. Change in heat tolerance was examined as survival after a 35 degrees C heat shock (2h) in the course of either a fluctuating temperat......In the present study the joint transcriptomic and metabolomic responses in Folsomia candida (Collembola) to temperature changes on a short-term scale were studied. Change in heat tolerance was examined as survival after a 35 degrees C heat shock (2h) in the course of either a fluctuating...... analysed in F. candida using nuclear magnetic resonance spectroscopy ((1)H NMR). A significant metabolomic divergence between pre-treated and control collembolans was evident; partly due to a significantly reduced relative concentration of five free amino acids (arginine, leucine, lysine, phenylalanine...

  11. The short-term impacts of Earned Income Tax Credit disbursement on health.

    Science.gov (United States)

    Rehkopf, David H; Strully, Kate W; Dow, William H

    2014-12-01

    There are conflicting findings regarding long- and short-term effects of income on health. Whereas higher average income is associated with better health, there is evidence that health behaviours worsen in the short-term following income receipt.Prior studies revealing such negative short-term effects of income receipt focus on specific subpopulations and examine a limited set of health outcomes. The United States Earned Income Tax Credit (EITC) is an income supplement tied to work, and is the largest poverty reduction programme in the USA. We utilize the fact that EITC recipients typically receive large cash transfers in the months of February,March and April, in order to examine associated changes in health outcomes that can fluctuate on a monthly basis. We examine associations with 30 outcomes in the categories of diet, food security, health behaviours, cardiovascular biomarkers, metabolic biomarkers and infection and immunity among 6925 individuals from the U.S. National Health and Nutrition Survey. Our research design approximates a natural experiment,since whether individuals were sampled during treatment or non-treatment months is independent of social, demographic and health characteristics that do not vary with time. There are both beneficial and detrimental short-term impacts of income receipt.Although there are detrimental impacts on metabolic factors among women, most other impacts are beneficial, including those for food security, smoking and trying to lose weight. The short-term impacts of EITC income receipt are not universally health promoting, but on balance there are more health benefits than detriments.

  12. A tangential CO{sub 2} laser collective scattering system for measuring short-scale turbulent fluctuations in the EAST superconducting tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Cao, G.M., E-mail: gmcao@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, PO Box 1126, Hefei, Anhui 230031 (China); Li, Y.D. [Institute of Plasma Physics, Chinese Academy of Sciences, PO Box 1126, Hefei, Anhui 230031 (China); Li, Q. [School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Zhang, X.D.; Sun, P.J.; Wu, G.J.; Hu, L.Q. [Institute of Plasma Physics, Chinese Academy of Sciences, PO Box 1126, Hefei, Anhui 230031 (China)

    2014-12-15

    Highlights: • A tangential CO{sub 2} laser collective scattering system was first installed on EAST. • It can measure the short-scale fluctuations in different regions simultaneously. • It can study the broadband fluctuations, QC fluctuations, MHD phenomenon, etc. - Abstract: A tangential CO{sub 2} laser collective scattering system has been first installed on the Experimental Advanced Superconducting Tokamak (EAST) to measure short-scale turbulent fluctuations in EAST plasmas. The system can measure fluctuations with up to four distinct wavenumbers simultaneously ranging from 10 cm{sup −1} to 26 cm{sup −1}, and correspondingly k{sub ⊥}ρ{sub s}∼1.5−4.3. The system is designed based on the oblique propagation of the probe beam with respect to the magnetic field, and thus the enhanced spatial localization can be achieved by taking full advantage of turbulence anisotropy and magnetic field inhomogeneity. The simultaneous measurements of turbulent fluctuations in different regions can be taken by special optical setup. Initial measurements indicate rich short-scale turbulent dynamics in both core and outer regions of EAST plasmas. The system will be a powerful tool for investigating the features of short-scale turbulent fluctuations in EAST plasmas.

  13. Pediatric polytrauma : Short-term and long-term outcomes

    NARCIS (Netherlands)

    vanderSluis, CK; Kingma, J; Eisma, WH; tenDuis, HJ

    Objective: To assess the short-term and long-term outcomes of pediatric polytrauma patients and to analyze the extent to which short-term outcomes can predict long-term outcomes. Materials and Methods: Ail pediatric polytrauma patients (Injury Severity Score of greater than or equal to 16, less than

  14. A Simple Hybrid Model for Short-Term Load Forecasting

    Directory of Open Access Journals (Sweden)

    Suseelatha Annamareddi

    2013-01-01

    Full Text Available The paper proposes a simple hybrid model to forecast the electrical load data based on the wavelet transform technique and double exponential smoothing. The historical noisy load series data is decomposed into deterministic and fluctuation components using suitable wavelet coefficient thresholds and wavelet reconstruction method. The variation characteristics of the resulting series are analyzed to arrive at reasonable thresholds that yield good denoising results. The constitutive series are then forecasted using appropriate exponential adaptive smoothing models. A case study performed on California energy market data demonstrates that the proposed method can offer high forecasting precision for very short-term forecasts, considering a time horizon of two weeks.

  15. Paraconductivity of three-dimensional amorphous superconductors: evidence for a short-wavelength cutoff in the fluctuation spectrum

    International Nuclear Information System (INIS)

    Johnson, W.L.

    1977-10-01

    Measurements of the temperature dependence and magnetic field dependence of the paraconductivity of a three dimensional amorphous superconductor are presented. The data are analyzed in terms of several current theories and are found to give good agreement for low fields and temperatures near T/sub c/. The paraconductivity falls well below predicted theoretical values in the high temperature and high field limits. This is attributed to the reduced role of high wavevector contributions to the paraconductivity. It is shown that the introduction of a short wavelength cutoff in the theoretical fluctuation spectrum provides a phenomelogical account of the discrepancy between theory and experiment

  16. Potential breeding distributions of U.S. birds predicted with both short-term variability and long-term average climate data.

    Science.gov (United States)

    Bateman, Brooke L; Pidgeon, Anna M; Radeloff, Volker C; Flather, Curtis H; VanDerWal, Jeremy; Akçakaya, H Resit; Thogmartin, Wayne E; Albright, Thomas P; Vavrus, Stephen J; Heglund, Patricia J

    2016-12-01

    Climate conditions, such as temperature or precipitation, averaged over several decades strongly affect species distributions, as evidenced by experimental results and a plethora of models demonstrating statistical relations between species occurrences and long-term climate averages. However, long-term averages can conceal climate changes that have occurred in recent decades and may not capture actual species occurrence well because the distributions of species, especially at the edges of their range, are typically dynamic and may respond strongly to short-term climate variability. Our goal here was to test whether bird occurrence models can be predicted by either covariates based on short-term climate variability or on long-term climate averages. We parameterized species distribution models (SDMs) based on either short-term variability or long-term average climate covariates for 320 bird species in the conterminous USA and tested whether any life-history trait-based guilds were particularly sensitive to short-term conditions. Models including short-term climate variability performed well based on their cross-validated area-under-the-curve AUC score (0.85), as did models based on long-term climate averages (0.84). Similarly, both models performed well compared to independent presence/absence data from the North American Breeding Bird Survey (independent AUC of 0.89 and 0.90, respectively). However, models based on short-term variability covariates more accurately classified true absences for most species (73% of true absences classified within the lowest quarter of environmental suitability vs. 68%). In addition, they have the advantage that they can reveal the dynamic relationship between species and their environment because they capture the spatial fluctuations of species potential breeding distributions. With this information, we can identify which species and guilds are sensitive to climate variability, identify sites of high conservation value where climate

  17. Room Volume Estimation Based on Ambiguity of Short-Term Interaural Phase Differences Using Humanoid Robot Head

    Directory of Open Access Journals (Sweden)

    Ryuichi Shimoyama

    2016-07-01

    Full Text Available Humans can recognize approximate room size using only binaural audition. However, sound reverberation is not negligible in most environments. The reverberation causes temporal fluctuations in the short-term interaural phase differences (IPDs of sound pressure. This study proposes a novel method for a binaural humanoid robot head to estimate room volume. The method is based on the statistical properties of the short-term IPDs of sound pressure. The humanoid robot turns its head toward a sound source, recognizes the sound source, and then estimates the ego-centric distance by its stereovision. By interpolating the relations between room volume, average standard deviation, and ego-centric distance experimentally obtained for various rooms in a prepared database, the room volume was estimated by the binaural audition of the robot from the average standard deviation of the short-term IPDs at the estimated distance.

  18. Long-term associative learning predicts verbal short-term memory performance

    OpenAIRE

    Jones, Gary; Macken, Bill

    2017-01-01

    Studies using tests such as digit span and nonword repetition have implicated short-term memory across a range of developmental domains. Such tests ostensibly assess specialized processes for the short-term manipulation and maintenance of information that are often argued to enable long-term learning. However, there is considerable evidence for an influence of long-term linguistic learning on performance in short-term memory tasks that brings into question the role of a specialized short-term...

  19. Long-term associative learning predicts verbal short-term memory performance.

    Science.gov (United States)

    Jones, Gary; Macken, Bill

    2018-02-01

    Studies using tests such as digit span and nonword repetition have implicated short-term memory across a range of developmental domains. Such tests ostensibly assess specialized processes for the short-term manipulation and maintenance of information that are often argued to enable long-term learning. However, there is considerable evidence for an influence of long-term linguistic learning on performance in short-term memory tasks that brings into question the role of a specialized short-term memory system separate from long-term knowledge. Using natural language corpora, we show experimentally and computationally that performance on three widely used measures of short-term memory (digit span, nonword repetition, and sentence recall) can be predicted from simple associative learning operating on the linguistic environment to which a typical child may have been exposed. The findings support the broad view that short-term verbal memory performance reflects the application of long-term language knowledge to the experimental setting.

  20. Preparatory Body State before Reacting to an Opponent: Short-Term Joint Torque Fluctuation in Real-Time Competitive Sports.

    Science.gov (United States)

    Fujii, Keisuke; Yamashita, Daichi; Kimura, Tetsuya; Isaka, Tadao; Kouzaki, Motoki

    2015-01-01

    , irrespective of the outcome. These results indicate that the preparatory body state as explained by short-term joint torque fluctuations before the defensive step would help explain the performance in competitive sports, and will give insights into understanding human adaptive behavior in unpredicted and uncontrolled environments.

  1. The relation between short-term emotion dynamics and psychological well-being: A meta-analysis.

    Science.gov (United States)

    Houben, Marlies; Van Den Noortgate, Wim; Kuppens, Peter

    2015-07-01

    Not only how good or bad people feel on average, but also how their feelings fluctuate across time is crucial for psychological health. The last 2 decades have witnessed a surge in research linking various patterns of short-term emotional change to adaptive or maladaptive psychological functioning, often with conflicting results. A meta-analysis was performed to identify consistent relationships between patterns of short-term emotion dynamics-including patterns reflecting emotional variability (measured in terms of within-person standard deviation of emotions across time), emotional instability (measured in terms of the magnitude of consecutive emotional changes), and emotional inertia of emotions over time (measured in terms of autocorrelation)-and relatively stable indicators of psychological well-being or psychopathology. We determined how such relationships are moderated by the type of emotional change, type of psychological well-being or psychopathology involved, valence of the emotion, and methodological factors. A total of 793 effect sizes were identified from 79 articles (N = 11,381) and were subjected to a 3-level meta-analysis. The results confirmed that overall, low psychological well-being co-occurs with more variable (overall ρ̂ = -.178), unstable (overall ρ̂ = -.205), but also more inert (overall ρ̂ = -.151) emotions. These effect sizes were stronger when involving negative compared with positive emotions. Moreover, the results provided evidence for consistency across different types of psychological well-being and psychopathology in their relation with these dynamical patterns, although specificity was also observed. The findings demonstrate that psychological flourishing is characterized by specific patterns of emotional fluctuations across time, and provide insight into what constitutes optimal and suboptimal emotional functioning. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

  2. Is WTI crude oil market becoming weakly efficient over time? New evidence from multiscale analysis based on detrended fluctuation analysis

    International Nuclear Information System (INIS)

    Wang, Yudong; Liu, Li

    2010-01-01

    This paper extends the work in Tabak and Cajueiro (Are the crude oil markets becoming weakly efficient over time, Energy Economics 29 (2007) 28-36) and Alvarez-Ramirez et al. (Short-term predictability of crude oil markets: a detrended fluctuation analysis approach, Energy Economics 30 (2008) 2645-2656). In this paper, we test for the efficiency of WTI crude oil market through observing the dynamic of local Hurst exponents employing the method of rolling window based on multiscale detrended fluctuation analysis. Empirical results show that short-term, medium-term and long-term behaviors were generally turning into efficient behavior over time. However, in this way, the results also show that the market did not evolve along stable conditions for long times. Multiscale analysis is also implemented based on multifractal detrended fluctuation analysis. We found that the small fluctuations of WTI crude oil market were persistent; however, the large fluctuations had high instability, both in the short- and long-terms. Our discussion is also extended by incorporating arguments from the crude oil market structure for explaining the different correlation dynamics. (author)

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

    Science.gov (United States)

    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.

  4. Evidence for nonuniversal behavior of paraconductivity caused by predominant short-wavelength Gaussian fluctuations in YBa2Cu3O6.9

    International Nuclear Information System (INIS)

    Gauzzi, A.; Pavuna, D.

    1995-01-01

    We report on in-plane paraconductivity measurements in thin YBa 2 Cu 3 O 6.9 films. Our analysis of the data shows that the temperature dependence of paraconductivity is affected by lattice disorder and deviates at all temperatures from the universal power laws predicted by both scaling and mean-field theories. This gives evidence for the absence of critical fluctuations and for the failure of the Aslamazov-Larkin universal relation between critical exponent and dimensionality of the spectrum of Gaussian fluctuations. We account quantitatively for the data within the experimental error by introducing a short-wavelength cutoff into this spectrum. This implies that three-dimensional short-wavelength Gaussian fluctuations dominate in YBa 2 Cu 3 O 6.9 and suggests a rapid attenuation of these fluctuations with decreasing wavelength in short-coherence-length systems as compared to the case of the conventional Ginzburg-Landau theory

  5. BASEL III: long-term impact on economic performance and fluctuations

    OpenAIRE

    Paolo Angelini; Laurent Clerc; Vasco Cúrdia; Leonardo Gambacorta; Andrea Gerali; Alberto Locarno; Roberto Motto; Werner Roeger; Skander J. van den Heuvel; Jan Vlcek

    2011-01-01

    We assess the long-term economic impact of the new regulatory standards (the Basel III reform), answering the following questions: 1) What is the impact of the reform on longterm economic performance? 2) What is the impact of the reform on economic fluctuations? 3) What is the impact of the adoption of countercyclical capital buffers on economic fluctuations? The main results are the following: 1) Each percentage point increase in the capital ratio causes a median 0.09 percent decline in the ...

  6. The Demonstration of Short-Term Consolidation.

    Science.gov (United States)

    Jolicoeur, Pierre; Dell'Acqua, Roberto

    1998-01-01

    Results of seven experiments involving 112 college students or staff using a dual-task approach provide evidence that encoding information into short-term memory involves a distinct process termed short-term consolidation (STC). Results suggest that STC has limited capacity and that it requires central processing mechanisms. (SLD)

  7. Analysis of the fluctuation-induced excess dc conductivity of epitaxial YBa2Cu3O7 films: Influence of a short-wavelength cutoff in the fluctuation spectrum

    International Nuclear Information System (INIS)

    Hopfengaertner, R.; Hensel, B.; Saemann-Ischenko, G.

    1991-01-01

    Measurements of the temperature dependence of the in-plane dc conductivity on various high-quality epitaxial YBa 2 Cu 3 O 7 films are presented. The rounding of the resistivity in the transition region has been analyzed in terms of the anisotropic Aslamazov-Larkin (AL), Lawrence-Doniach (LD), and Maki-Thompson theories. In the framework of the time-dependent Ginzburg-Landau (GL) approach we have investigated the influence of a short-wavelength cutoff parameter in the fluctuation spectrum of the AL and LD term. In both theories this physically reasonable cutoff leads to a considerable reduction of the predicted excess dc conductivity at higher temperatures. Moreover, the three-dimensional anisotropic AL term, taking the cutoff into account, predicts nearly the same excess conductivity as the original LD term, although these two approaches describe different systems. A good agreement between experimental data and LD as well as the modified three-dimensional anisotropic AL term was found in the region 1.01T c ≤T≤1.1T c . The zero-temperature GL coherence length ξ c (0) has been estimated to be about 1.5 A

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

    OpenAIRE

    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 rath...

  9. Short-term memory across eye blinks.

    Science.gov (United States)

    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.

  10. Short-term memory and dual task performance

    Science.gov (United States)

    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.

  11. Detrended fluctuation analysis of short datasets: An application to fetal cardiac data

    Science.gov (United States)

    Govindan, R. B.; Wilson, J. D.; Preißl, H.; Eswaran, H.; Campbell, J. Q.; Lowery, C. L.

    2007-02-01

    Using detrended fluctuation analysis (DFA) we perform scaling analysis of short datasets of length 500-1500 data points. We quantify the long range correlation (exponent α) by computing the mean value of the local exponents αL (in the asymptotic regime). The local exponents are obtained as the (numerical) derivative of the logarithm of the fluctuation function F(s) with respect to the logarithm of the scale factor s:αL=dlog10F(s)/dlog10s. These local exponents display huge variations and complicate the correct quantification of the underlying correlations. We propose the use of the phase randomized surrogate (PRS), which preserves the long range correlations of the original data, to minimize the variations in the local exponents. Using the numerically generated uncorrelated and long range correlated data, we show that performing DFA on several realizations of PRS and estimating αL from the averaged fluctuation functions (of all realizations) can minimize the variations in αL. The application of this approach to the fetal cardiac data (RR intervals) is discussed and we show that there is a statistically significant correlation between α and the gestation age.

  12. Measuring, Predicting and Visualizing Short-Term Change in Word Representation and Usage in VKontakte Social Network

    OpenAIRE

    Stewart, Ian; Arendt, Dustin; Bell, Eric; Volkova, Svitlana

    2017-01-01

    Language in social media is extremely dynamic: new words emerge, trend and disappear, while the meaning of existing words can fluctuate over time. Such dynamics are especially notable during a period of crisis. This work addresses several important tasks of measuring, visualizing and predicting short term text representation shift, i.e. the change in a word's contextual semantics, and contrasting such shift with surface level word dynamics, or concept drift, observed in social media streams. ...

  13. Short-term LNG-markets

    International Nuclear Information System (INIS)

    Eldegard, Tom; Lund, Arne-Christian; Miltersen, Kristian; Rud, Linda

    2005-01-01

    The global Liquefied Natural Gas (LNG) industry has experienced substantial growth in the past decades. In the traditional trade patterns of LNG the product has typically been handled within a dedicated chain of plants and vessels fully committed by long term contracts or common ownership, providing risk sharing of large investments in a non-liquid market. Increasing gas prices and substantial cost reductions in all parts of the LNG chain have made LNG projects viable even if only part of the capacity is secured by long-term contracts, opening for more flexible trade of the remainder. Increasing gas demand, especially in power generation, combined with cost reductions in the cost of LNG terminals, open new markets for LNG. For the LNG supplier, the flexibility of shifting volumes between regions represents an additional value. International trade in LNG has been increasing, now accounting for more than one fifth of the world's cross-border gas trade. Despite traditional vertical chain bonds, increased flexibility has contributed in fact to an increasing LNG spot trade, representing 8% of global trade in 2002. The focus of this paper is on the development of global short-term LNG markets, and their role with respect to efficiency and security of supply in European gas markets. Arbitrage opportunities arising from price differences between regional markets (such as North America versus Europe) are important impetuses for flexible short-term trade. However, the short-term LNG trade may suffer from problems related to market access, e.g. limited access to terminals and regulatory issues, as well as rigidities connected to vertical binding within the LNG chain. Important issues related to the role of short-term LNG-trade in the European gas market are: Competition, flexibility in meeting peak demand, security of supply and consequences of differences in pricing policies (oil-linked prices in Europe and spot market prices in North America). (Author)

  14. Gut microbiome response to short-term dietary interventions in reactive hypoglycemia subjects.

    Science.gov (United States)

    Quercia, Sara; Turroni, Silvia; Fiori, Jessica; Soverini, Matteo; Rampelli, Simone; Biagi, Elena; Castagnetti, Andrea; Consolandi, Clarissa; Severgnini, Marco; Pianesi, Mario; Fallucca, Francesco; Pozzilli, Paolo; Brigidi, Patrizia; Candela, Marco

    2017-11-01

    Reactive hypoglycemia is a metabolic disorder that provokes severe hypoglycemic episodes after meals. Over recent years, the gut microbiota has been recognized as potential target for the control of metabolic diseases, and the possibility to correct gut microbiota dysbioses through diet, favouring the recovery of metabolic homeostasis, has been considered. We investigate the impact of 2 short-term (3-day) nutritional interventions, based on the macrobiotic Ma-Pi 2 diet and a control Mediterranean diet, on the structure and functionality of the gut microbiota in 12 patients affected by reactive hypoglycemia. The gut microbiota composition was characterized by next-generation sequencing of the V3 to V4 region of the 16S rRNA gene, and the ecosystem functionality was addressed by measuring the faecal concentration of short-chain fatty acids (SCFAs). In order to measure the short-term physiological gut microbiota fluctuation, the microbiomes of 7 healthy people were characterized before and after 3 days of constant diet. While no convergence of the gut microbiota compositional profiles was observed, a significant increase in SCFA faecal levels was induced only in the Ma-Pi 2 diet group, suggesting the potential of this diet to support a short-term functional convergence of the gut microbiota, regardless of the individual compositional layout. The Ma-Pi 2 diet, with its high fibre load, was effective in increasing the production of SCFAs by the gut microbiota. Because these metabolites are known for their ability to counterbalance the metabolic deregulation in persons with glucose impairment disorders, their increased bioavailability could be of some relevance in reactive hypoglycemia. Copyright © 2017 John Wiley & Sons, Ltd.

  15. Short-term incentive schemes for hospital managers

    Directory of Open Access Journals (Sweden)

    Lucas Malambe

    2013-10-01

    Full Text Available Orientation: Short-term incentives, considered to be an extrinsic motivation, are commonly used to motivate performance. This study explored hospital managers’ perceptions of short term incentives in maximising performance and retention. Research purpose: The study explored the experiences, views and perceptions of private hospital managers in South Africa regarding the use of short-term incentives to maximise performance and retention, as well as the applicability of the findings to public hospitals. Motivation for the study: Whilst there is an established link between performance reward schemes and organisational performance, there is little understanding of the effects of short term incentives on the performance and retention of hospital managers within the South African context. Research design, approach, and method: The study used a qualitative research design: interviews were conducted with a purposive sample of 19 hospital managers, and a thematic content analysis was performed. Main findings: Short-term incentives may not be the primary motivator for hospital managers, but they do play a critical role in sustaining motivation. Participants indicated that these schemes could also be applicable to public hospitals. Practical/managerial implications: Hospital managers are inclined to be more motivated by intrinsic than extrinsic factors. However, hospital managers (as middle managers also seem to be motivated by short-term incentives. A combination of intrinsic and extrinsic motivators should thus be used to maximise performance and retention. Contribution/value-add: Whilst the study sought to explore hospital managers’ perceptions of short-term incentives, it also found that an adequate balance between internal and external motivators is key to implementing an effective short-term incentive scheme.

  16. Short-Term Intercultural Psychotherapy: Ethnographic Inquiry

    Science.gov (United States)

    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…

  17. Why do short term workers have high mortality?

    DEFF Research Database (Denmark)

    Kolstad, Henrik; Olsen, Jørn

    1999-01-01

    or violence, the rate ratios for short term employment were 2.30 (95% Cl 1.74-3.06) and 1.86 (95% Cl 1.35-2.56), respectively. An unhealthy lifestyle may also be a determinant of short term employment. While it is possible in principle to adjust for lifestyle factors if proper data are collected, the health......Increased mortality is often reported among workers in short term employment. This may indicate either a health-related selection process or the presence of different lifestyle or social conditions among short term workers. The authors studied these two aspects of short term employment among 16...

  18. Short-term mechanisms influencing volumetric brain dynamics

    Directory of Open Access Journals (Sweden)

    Nikki Dieleman

    2017-01-01

    Full Text Available With the use of magnetic resonance imaging (MRI and brain analysis tools, it has become possible to measure brain volume changes up to around 0.5%. Besides long-term brain changes caused by atrophy in aging or neurodegenerative disease, short-term mechanisms that influence brain volume may exist. When we focus on short-term changes of the brain, changes may be either physiological or pathological. As such determining the cause of volumetric dynamics of the brain is essential. Additionally for an accurate interpretation of longitudinal brain volume measures by means of neurodegeneration, knowledge about the short-term changes is needed. Therefore, in this review, we discuss the possible mechanisms influencing brain volumes on a short-term basis and set-out a framework of MRI techniques to be used for volumetric changes as well as the used analysis tools. 3D T1-weighted images are the images of choice when it comes to MRI of brain volume. These images are excellent to determine brain volume and can be used together with an analysis tool to determine the degree of volume change. Mechanisms that decrease global brain volume are: fluid restriction, evening MRI measurements, corticosteroids, antipsychotics and short-term effects of pathological processes like Alzheimer's disease, hypertension and Diabetes mellitus type II. Mechanisms increasing the brain volume include fluid intake, morning MRI measurements, surgical revascularization and probably medications like anti-inflammatory drugs and anti-hypertensive medication. Exercise was found to have no effect on brain volume on a short-term basis, which may imply that dehydration caused by exercise differs from dehydration by fluid restriction. In the upcoming years, attention should be directed towards studies investigating physiological short-term changes within the light of long-term pathological changes. Ultimately this may lead to a better understanding of the physiological short-term effects of

  19. Short-term stability test for thorium soil candidate a reference material

    Energy Technology Data Exchange (ETDEWEB)

    Clain, Almir F.; Fonseca, Adelaide M.G.; Dantas, Vanessa V.D.B.; Braganca, Maura J.C.; Souza, Poliana S., E-mail: almir@ird.gov.br, E-mail: adelaide@ird.gov.br, E-mail: vanessa@ird.gov.br, E-mail: maura@ird.gov.br, E-mail: poliana@bolsista.ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    This work describes a methodology to determine the soil short-term stability after the steps of production in laboratory. The short-term stability of the soil is an essential property to be determined in order to producing a reference material. The soil is a candidate of reference material for chemical analysis of thorium with metrological traceability to be used in environmental analysis, equipment calibration, validation methods, and quality control. A material is considered stable in a certain temperature if the property of interest does not change with time, considering the analytical random fluctuations. Due to this, the angular coefficient from the graphic of Th concentration versus elapsed time must be near to zero. The analytical determinations of thorium concentration were performed by Instrumental Neutron activation Analysis. The slopes and their uncertainties were obtained from the regression lines at temperatures of 20 deg C and 60 deg C, with control temperature of -20 deg C. From the obtained data a t-test was applied. In both temperatures the calculated t-value was lower than the critical value, so we can conclude with 95% confidence level that no significant changes happened during the period studied concerning thorium concentration in soil at temperatures of 20 deg C and 60 deg C, showing stability at these temperatures. (author)

  20. Short-term stability test for thorium soil candidate a reference material

    International Nuclear Information System (INIS)

    Clain, Almir F.; Fonseca, Adelaide M.G.; Dantas, Vanessa V.D.B.; Braganca, Maura J.C.; Souza, Poliana S.

    2015-01-01

    This work describes a methodology to determine the soil short-term stability after the steps of production in laboratory. The short-term stability of the soil is an essential property to be determined in order to producing a reference material. The soil is a candidate of reference material for chemical analysis of thorium with metrological traceability to be used in environmental analysis, equipment calibration, validation methods, and quality control. A material is considered stable in a certain temperature if the property of interest does not change with time, considering the analytical random fluctuations. Due to this, the angular coefficient from the graphic of Th concentration versus elapsed time must be near to zero. The analytical determinations of thorium concentration were performed by Instrumental Neutron activation Analysis. The slopes and their uncertainties were obtained from the regression lines at temperatures of 20 deg C and 60 deg C, with control temperature of -20 deg C. From the obtained data a t-test was applied. In both temperatures the calculated t-value was lower than the critical value, so we can conclude with 95% confidence level that no significant changes happened during the period studied concerning thorium concentration in soil at temperatures of 20 deg C and 60 deg C, showing stability at these temperatures. (author)

  1. Verbal Short-Term Memory Span in Speech-Disordered Children: Implications for Articulatory Coding in Short-Term Memory.

    Science.gov (United States)

    Raine, Adrian; And Others

    1991-01-01

    Children with speech disorders had lower short-term memory capacity and smaller word length effect than control children. Children with speech disorders also had reduced speech-motor activity during rehearsal. Results suggest that speech rate may be a causal determinant of verbal short-term memory capacity. (BC)

  2. Real-time energy resources scheduling considering short-term and very short-term wind forecast

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marco; Sousa, Tiago; Morais, Hugo; Vale, Zita [Polytechnic of Porto (Portugal). GECAD - Knowledge Engineering and Decision Support Research Center

    2012-07-01

    This paper proposes an energy resources management methodology based on three distinct time horizons: day-ahead scheduling, hour-ahead scheduling, and real-time scheduling. In each scheduling process the update of generation and consumption operation and of the storage and electric vehicles storage status are used. Besides the new operation conditions, the most accurate forecast values of wind generation and of consumption using results of short-term and very short-term methods are used. A case study considering a distribution network with intensive use of distributed generation and electric vehicles is presented. (orig.)

  3. The Mind and Brain of Short-Term Memory

    OpenAIRE

    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, w...

  4. Very-long-term and short-term chromatic adaptation: are their influences cumulative?

    Science.gov (United States)

    Belmore, Suzanne C; Shevell, Steven K

    2011-02-09

    Very-long-term (VLT) chromatic adaptation results from exposure to an altered chromatic environment for days or weeks. Color shifts from VLT adaptation are observed hours or days after leaving the altered environment. Short-term chromatic adaptation, on the other hand, results from exposure for a few minutes or less, with color shifts measured within seconds or a few minutes after the adapting light is extinguished; recovery to the pre-adapted state is complete in less than an hour. Here, both types of adaptation were combined. All adaptation was to reddish-appearing long-wavelength light. Shifts in unique yellow were measured following adaptation. Previous studies demonstrate shifts in unique yellow due to VLT chromatic adaptation, but shifts from short-term chromatic adaptation to comparable adapting light can be far greater than from VLT adaptation. The question considered here is whether the color shifts from VLT adaptation are cumulative with large shifts from short-term adaptation or, alternatively, does simultaneous short-term adaptation eliminate color shifts caused by VLT adaptation. The results show the color shifts from VLT and short-term adaptation together are cumulative, which indicates that both short-term and very-long-term chromatic adaptation affect color perception during natural viewing. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. The dependence of the nuclear charge form factor on short range correlations and surface fluctuation effects

    International Nuclear Information System (INIS)

    Massen, S. E.; Garistov, V. P.; Grypeos, M. E.

    1996-01-01

    The effects of nuclear surface fluctuations on harmonic oscillator elastic charge form factor of light nuclei are investigated, simultaneously approximating the short-range correlations through a Jastrow correlation factor. Inclusion of the surface fluctuation effects within this description, by truncating the cluster expansion at the two-body part, is found to improve somewhat the fit to the elastic charge form-factor of 16 O and 40 Ca. However, the convergence of the cluster expansion is expected to deteriorate. An additional finding is that surface-fluctuation correlations produce a drastic change in the asymptotic behaviour of the point-proton form-factor, which now falls off quite slowly (i.e. as const.q -4 ) at large values of the momentum transfer q

  6. FLUCTUATING SELECTION AND THE MAINTENANCE OF INDIVIDUAL AND SEX-SPECIFIC DIET SPECIALIZATION IN FREE-LIVING OYSTERCATCHERS

    NARCIS (Netherlands)

    van de Pol, Martijn; Brouwer, Lyanne; Ens, B; Oosterbeek, Kees; Tinbergen, Joost M.; Candolin, U.

    Fluctuating and disruptive selection are important mechanisms for maintaining intrapopulation trait variation. Nonetheless, few field studies quantify selection pressures over long periods and identify what causes them to fluctuate. Diet specialists in oystercatchers differ in short-term payoffs

  7. Detecting method for crude oil price fluctuation mechanism under different periodic time series

    International Nuclear Information System (INIS)

    Gao, Xiangyun; Fang, Wei; An, Feng; Wang, Yue

    2017-01-01

    Highlights: • We proposed the concept of autoregressive modes to indicate the fluctuation patterns. • We constructed transmission networks for studying the fluctuation mechanism. • There are different fluctuation mechanism under different periodic time series. • Only a few types of autoregressive modes control the fluctuations in crude oil price. • There are cluster effects during the fluctuation mechanism of autoregressive modes. - Abstract: Current existing literatures can characterize the long-term fluctuation of crude oil price time series, however, it is difficult to detect the fluctuation mechanism specifically under short term. Because each fluctuation pattern for one short period contained in a long-term crude oil price time series have dynamic characteristics of diversity; in other words, there exhibit various fluctuation patterns in different short periods and transmit to each other, which reflects the reputedly complicate and chaotic oil market. Thus, we proposed an incorporated method to detect the fluctuation mechanism, which is the evolution of the different fluctuation patterns over time from the complex network perspective. We divided crude oil price time series into segments using sliding time windows, and defined autoregressive modes based on regression models to indicate the fluctuation patterns of each segment. Hence, the transmissions between different types of autoregressive modes over time form a transmission network that contains rich dynamic information. We then capture transmission characteristics of autoregressive modes under different periodic time series through the structure features of the transmission networks. The results indicate that there are various autoregressive modes with significantly different statistical characteristics under different periodic time series. However, only a few types of autoregressive modes and transmission patterns play a major role in the fluctuation mechanism of the crude oil price, and these

  8. Short term variation of Cyg X-1 in the hard x-ray region

    International Nuclear Information System (INIS)

    Doi, Kosei

    1978-01-01

    Cyg X-1 is a peculiar celestial body considered to be a close binary system of a black hole and a blue super-giant star. It is presently known that the time fluctuation of Cyg X-1 is considerably complex, ranging from seconds to days or months. Of these variation, attention has been paid to the short time variation in relation to the black hole theory. Observations of fluctuations in the order of second have been limited to soft X-ray (20 keV or more) so far, because great technical difficulties are involved due to the low intensity of hard X-ray. The present investigation is based on the fluctuations in the order of second in hard X-ray, and was conducted by employing an unprecedented large area X-ray telescope. The text describes on the brief history of the short time fluctuation, explains the experimental plan, X-ray detecting system, flight of a balloon and the analyses and discussions of fluctuation factor by variation function method, and gives the analysis data and conclusion. The observations resulted in the fact that the fluctuations in the order of second were small at 20 to 30 keV, but become large when energy is higher or lower than this value. The most natural explanation available for this result may be that it is essentially spectrum fluctuation, being inverse correlation in higher and lower energies. Physical meaning of such spectrum fluctuation is considered in connection with precipitating disk model around a black hole. (Wakatsuki, Y.)

  9. Short term variation of Cyg X-1 in the hard x-ray region

    Energy Technology Data Exchange (ETDEWEB)

    Doi, Kosei [Tokyo Univ. (Japan). Inst. of Space and Aeronautical Science

    1978-08-01

    Cyg X-1 is a peculiar celestial body considered to be a close binary system of a black hole and a blue super-giant star. It is presently known that the time fluctuation of Cyg X-1 is considerably complex, ranging from seconds to days or months. Of these variation, attention has been paid to the short time variation in relation to the black hole theory. Observations of fluctuations in the order of second have been limited to soft X-ray (20 keV or more) so far, because great technical difficulties are involved due to the low intensity of hard X-ray. The present investigation is based on the fluctuations in the order of second in hard X-ray, and was conducted by employing an unprecedented large area X-ray telescope. The text describes on the brief history of the short time fluctuation, explains the experimental plan, X-ray detecting system, flight of a balloon and the analyses and discussions of fluctuation factor by variation function method, and gives the analysis data and conclusion. The observations resulted in the fact that the fluctuations in the order of second were small at 20 to 30 keV, but become large when energy is higher or lower than this value. The most natural explanation available for this result may be that it is essentially spectrum fluctuation, being inverse correlation in higher and lower energies. Physical meaning of such spectrum fluctuation is considered in connection with precipitating disk model around a black hole.

  10. Short term memory in echo state networks

    OpenAIRE

    Jaeger, H.

    2001-01-01

    The report investigates the short-term memory capacity of echo state recurrent neural networks. A quantitative measure MC of short-term memory capacity is introduced. The main result is that MC 5 N for networks with linear Output units and i.i.d. input, where N is network size. Conditions under which these maximal memory capacities are realized are described. Several theoretical and practical examples demonstrate how the short-term memory capacities of echo state networks can be exploited for...

  11. A comparison of short-term dispersion estimates resulting from various atmospheric stability classification methods

    International Nuclear Information System (INIS)

    Mitchell, A.E. Jr.

    1982-01-01

    Four methods of classifying atmospheric stability class are applied at four sites to make short-term (1-h) dispersion estimates from a ground-level source based on a model consistent with U.S. Nuclear Regulatory Commission practice. The classification methods include vertical temperature gradient, standard deviation of horizontal wind direction fluctuations (sigma theta), Pasquill-Turner, and modified sigma theta which accounts for meander. Results indicate that modified sigma theta yields reasonable dispersion estimates compared to those produced using methods of vertical temperature gradient and Pasquill-Turner, and can be considered as a potential economic alternative in establishing onsite monitoring programs. (author)

  12. Short-term Wind Forecasting at Wind Farms using WRF-LES and Actuator Disk Model

    Science.gov (United States)

    Kirkil, Gokhan

    2017-04-01

    Short-term wind forecasts are obtained for a wind farm on a mountainous terrain using WRF-LES. Multi-scale simulations are also performed using different PBL parameterizations. Turbines are parameterized using Actuator Disc Model. LES models improved the forecasts. Statistical error analysis is performed and ramp events are analyzed. Complex topography of the study area affects model performance, especially the accuracy of wind forecasts were poor for cross valley-mountain flows. By means of LES, we gain new knowledge about the sources of spatial and temporal variability of wind fluctuations such as the configuration of wind turbines.

  13. Short term and medium term power distribution load forecasting by neural networks

    International Nuclear Information System (INIS)

    Yalcinoz, T.; Eminoglu, U.

    2005-01-01

    Load forecasting is an important subject for power distribution systems and has been studied from different points of view. In general, load forecasts should be performed over a broad spectrum of time intervals, which could be classified into short term, medium term and long term forecasts. Several research groups have proposed various techniques for either short term load forecasting or medium term load forecasting or long term load forecasting. This paper presents a neural network (NN) model for short term peak load forecasting, short term total load forecasting and medium term monthly load forecasting in power distribution systems. The NN is used to learn the relationships among past, current and future temperatures and loads. The neural network was trained to recognize the peak load of the day, total load of the day and monthly electricity consumption. The suitability of the proposed approach is illustrated through an application to real load shapes from the Turkish Electricity Distribution Corporation (TEDAS) in Nigde. The data represents the daily and monthly electricity consumption in Nigde, Turkey

  14. A Spatiotemporal Multi-View-Based Learning Method for Short-Term Traffic Forecasting

    Directory of Open Access Journals (Sweden)

    Shifen Cheng

    2018-06-01

    Full Text Available Short-term traffic forecasting plays an important part in intelligent transportation systems. Spatiotemporal k-nearest neighbor models (ST-KNNs have been widely adopted for short-term traffic forecasting in which spatiotemporal matrices are constructed to describe traffic conditions. The performance of the models is closely related to the spatial dependencies, the temporal dependencies, and the interaction of spatiotemporal dependencies. However, these models use distance functions and correlation coefficients to identify spatial neighbors and measure the temporal interaction by only considering the temporal closeness of traffic, which result in existing ST-KNNs that cannot fully reflect the essential features of road traffic. This study proposes an improved spatiotemporal k-nearest neighbor model for short-term traffic forecasting by utilizing a multi-view learning algorithm named MVL-STKNN that fully considers the spatiotemporal dependencies of traffic data. First, the spatial neighbors for each road segment are automatically determined using cross-correlation under different temporal dependencies. Three spatiotemporal views are built on the constructed spatiotemporal closeness, periodic, and trend matrices to represent spatially heterogeneous traffic states. Second, a spatiotemporal weighting matrix is introduced into the ST-KNN model to recognize similar traffic patterns in the three spatiotemporal views. Finally, the results of traffic pattern recognition under these three spatiotemporal views are aggregated by using a neural network algorithm to describe the interaction of spatiotemporal dependencies. Extensive experiments were conducted using real vehicular-speed datasets collected on city roads and expressways. In comparison with baseline methods, the results show that the MVL-STKNN model greatly improves short-term traffic forecasting by lowering the mean absolute percentage error between 28.24% and 46.86% for the city road dataset and

  15. Short-Term Memory and Aphasia: From Theory to Treatment.

    Science.gov (United States)

    Minkina, Irene; Rosenberg, Samantha; Kalinyak-Fliszar, Michelene; Martin, Nadine

    2017-02-01

    This article reviews existing research on the interactions between verbal short-term memory and language processing impairments in aphasia. Theoretical models of short-term memory are reviewed, starting with a model assuming a separation between short-term memory and language, and progressing to models that view verbal short-term memory as a cognitive requirement of language processing. The review highlights a verbal short-term memory model derived from an interactive activation model of word retrieval. This model holds that verbal short-term memory encompasses the temporary activation of linguistic knowledge (e.g., semantic, lexical, and phonological features) during language production and comprehension tasks. Empirical evidence supporting this model, which views short-term memory in the context of the processes it subserves, is outlined. Studies that use a classic measure of verbal short-term memory (i.e., number of words/digits correctly recalled in immediate serial recall) as well as those that use more intricate measures (e.g., serial position effects in immediate serial recall) are discussed. Treatment research that uses verbal short-term memory tasks in an attempt to improve language processing is then summarized, with a particular focus on word retrieval. A discussion of the limitations of current research and possible future directions concludes the review. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  16. A new derivation of Luescher F-term and fluctuations around the giant magnon

    International Nuclear Information System (INIS)

    Heller, Michal P.; Janik, Romuald A.; Lukowski, Tomasz

    2008-01-01

    In this paper we give a new derivation of the generalized Luescher F-term formula from a summation over quadratic fluctuations around a given soliton. The result is very general providing that S-matrix is diagonal and is valid for arbitrary dispersion relation. We then apply this formalism to compute the leading finite size corrections to the giant magnon dispersion relation coming from quantum fluctuations.

  17. Social Welfare and the Psychology of Food Sharing: Short-Term Hunger Increases Support for Social Welfare

    DEFF Research Database (Denmark)

    Petersen, Michael Bang; Aarøe, Lene; Jensen, Niels Holm

    2014-01-01

    Do politically irrelevant events influence important policy opinions? Previous research on social welfare attitudes has emphasized the role of political factors such as economic self-interest and ideology. Here, we demonstrate that attitudes to social welfare are also influenced by short-term flu......—we consistently find that hungry individuals act in a greedier manner but describe themselves as more cooperative and express greater support for social welfare.......Do politically irrelevant events influence important policy opinions? Previous research on social welfare attitudes has emphasized the role of political factors such as economic self-interest and ideology. Here, we demonstrate that attitudes to social welfare are also influenced by short......-term fluctuations in hunger. Using theories in evolutionary psychology, we predict that hungry individuals will be greedier and take more resources from others while also attempting to induce others to share by signaling cooperative intentions and expressing support for sharing, including evolutionarily novel forms...

  18. Excitation of short-scale fluctuations by parametric decay of helicon waves into ion-sound and Trivelpiece-Gould waves

    International Nuclear Information System (INIS)

    Lorenz, B; Kraemer, M; Selenin, V L; Aliev, Yu M

    2005-01-01

    The helicon wave field and the excitation of short-scale electrostatic fluctuations in a helicon-produced plasma are closely related as both the helicon wave damping and the fluctuation level are shown to increase with the launched rf power. Correlation methods using electrostatic probes as well as microwave back-scattering at the upper-hybrid resonance are applied to obtain the dispersion relations of the fluctuations in the low-frequency and high-frequency ranges. The frequency and wavenumber spectra measured for all components of the wave vector allow us to identify the fluctuations as ion-sound and Trivelpiece-Gould waves that originate from parametric decay of the helicon pump wave. The growth rates and thresholds inferred from the evolution of the fluctuations in a wide range of helicon plasma parameters are in good agreement with predictions for the parametric decay instability that takes into account realistic damping rates for the decay waves as well as non-vanishing parallel wavenumber of the helicon pump

  19. Short-term memories with a stochastic perturbation

    International Nuclear Information System (INIS)

    Pontes, Jose C.A. de; Batista, Antonio M.; Viana, Ricardo L.; Lopes, Sergio R.

    2005-01-01

    We investigate short-term memories in linear and weakly nonlinear coupled map lattices with a periodic external input. We use locally coupled maps to present numerical results about short-term memory formation adding a stochastic perturbation in the maps and in the external input

  20. Short-term memory

    Science.gov (United States)

    Toulouse, G.

    This is a rather bold attempt to bridge the gap between neuron structure and psychological data. We try to answer the question: Is there a relation between the neuronal connectivity in the human cortex (around 5,000) and the short-term memory capacity (7±2)? Our starting point is the Hopfield model (Hopfield 1982), presented in this volume by D.J. Amit.

  1. Competitive short-term and long-term memory processes in spatial habituation.

    Science.gov (United States)

    Sanderson, David J; Bannerman, David M

    2011-04-01

    Exposure to a spatial location leads to habituation of exploration such that, in a novelty preference test, rodents subsequently prefer exploring a novel location to the familiar location. According to Wagner's (1981) theory of memory, short-term and long-term habituation are caused by separate and sometimes opponent processes. In the present study, this dual-process account of memory was tested. Mice received a series of exposure training trials to a location before receiving a novelty preference test. The novelty preference was greater when tested after a short, rather than a long, interval. In contrast, the novelty preference was weaker when exposure training trials were separated by a short, rather than a long interval. Furthermore, it was found that long-term habituation was determined by the independent effects of the amount of exposure training and the number of exposure training trials when factors such as the intertrial interval and the cumulative intertrial interval were controlled. A final experiment demonstrated that a long-term reduction of exploration could be caused by a negative priming effect due to associations formed during exploration. These results provide evidence against a single-process account of habituation and suggest that spatial habituation is determined by both short-term, recency-based memory and long-term, incrementally strengthened memory.

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

    Science.gov (United States)

    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. © The Author(s) 2015.

  3. Evaluation of Short Term Memory Span Function In Children

    Directory of Open Access Journals (Sweden)

    Barış ERGÜL

    2016-12-01

    Full Text Available Although details of the information encoded in the short-term memory where it is stored temporarily be recorded in the working memory in the next stage. Repeating the information mentally makes it remain in memory for a long time. Studies investigating the relationship between short-term memory and reading skills that are carried out to examine the relationship between short-term memory processes and reading comprehension. In this study information coming to short-term memory and the factors affecting operation of short term memory are investigated with regression model. The aim of the research is to examine the factors (age, IQ and reading skills that are expected the have an effect on short-term memory in children through regression analysis. One of the assumptions of regression analysis is to examine which has constant variance and normal distribution of the error term. In this study, because the error term is not normally distributed, robust regression techniques were applied. Also, for each technique; coefficient of determination is determined. According to the findings, the increase in age, IQ and reading skills caused the increase in short term memory in children. After applying robust regression techniques, the Winsorized Least Squares (WLS technique gives the highest coefficient of determination.

  4. Evaluation of Short Term Memory Span Function In Children

    OpenAIRE

    Barış ERGÜL; Arzu ALTIN YAVUZ; Ebru GÜNDOĞAN AŞIK

    2016-01-01

    Although details of the information encoded in the short-term memory where it is stored temporarily be recorded in the working memory in the next stage. Repeating the information mentally makes it remain in memory for a long time. Studies investigating the relationship between short-term memory and reading skills that are carried out to examine the relationship between short-term memory processes and reading comprehension. In this study information coming to short-term memory and the factors ...

  5. Short-term Memory as a Processing Shift

    Science.gov (United States)

    Lewis-Smith, Marion Quinn

    1975-01-01

    The series of experiments described here examined the predictions for free recall from sequential models and the shift formulation, focusing on the roles of short- and long-term memory in the primacy/recency shift and on the effects of expectancies on short- and long-term memory. (Author/RK)

  6. On the relationship between short- and long-term memory

    DEFF Research Database (Denmark)

    Sørensen, Thomas Alrik

    James (1890) divided memory into separate stores; primary and secondary – or short-term and long-term memory. The interaction between the two stores often assumes that information initially is represented in volatile short-term store before entering and consolidating in the more durable long-term......, accepted). Counter to popular beliefs this suggest that long-term memory precedes short-term memory and not vice versa....... memory system (e.g. Atkinson & Shiffrin, 1968). Short-term memory seems to provide a surprising processing bottleneck where only a very limited amount of information can be represented at any given moment (Miller, 1956; Cowan, 2001). A number of studies have investigated the nature of this processing...

  7. Journal Afrika Statistika ISSN 0852-0305 Short term forecasting of ...

    African Journals Online (AJOL)

    tion of this research is to propose some procedures to estimate the following ... by Eurostat about six weeks after the end of the reference quarter. .... alized principal components of current values of the variables in the dataset. These factors are designed to remove short-run and variable-specific sources of fluctuation.

  8. Origin of short-period (30-300 s) Doppler frequency fluctuations of lower F region reflections in the equatorial electrojet region

    International Nuclear Information System (INIS)

    Sastri, J.H.; Ramesh, K.B.; Rao, J.V.S.V.; Somayajulu, V.V.

    1991-01-01

    Measurements of phase path P of lower F-region reflections at normal incidence at Kodaikanal revealed the ubiquitous presence of 30-300-s quasi-sinusoidal variations in the time rate of change of phase path, P (Doppler frequency shift) during day time. A study is made of the influence of the irregularities in the equatorial electrojet on the P fluctuations using simultaneous observations of F-region phase path at Kodaikanal and of equatorial electrojet with the VHF-backscatter radar at Thumba. It is shown that the spectral content of the Doppler fluctuations (quantified in terms of variance, sigma squared computed from P time series synthesized through FFT exp -1 (FFT) in the chosen period bands, 30-300 s/30-120 s of the FFT of original P times series) bears a significant positive linear relationship to the horizontal phase velocity of electrojet irregularities (3-m scale size) on a hourly basis. This result is in consonance with earlier findings (Sastri et al., 1990) of a significant linear relationship of sigma squared to the electrojet strength (estimated from H-field data) and a practical cessation of the P fluctuations at times of disappearance of Esq on ionograms (partial/complete counterelectrojet). The present work substantiates the interpretation that the short-period Doppler-frequency fluctuations are due to phase-path changes imposed on lower F region reflections by the refractive-index variations associated with the convective motions of plasma density irregularities (type I and II) in the daytime equatorial electrojet. 49 refs

  9. Short-term memory and long-term memory are still different.

    Science.gov (United States)

    Norris, Dennis

    2017-09-01

    A commonly expressed view is that short-term memory (STM) is nothing more than activated long-term memory. If true, this would overturn a central tenet of cognitive psychology-the idea that there are functionally and neurobiologically distinct short- and long-term stores. Here I present an updated case for a separation between short- and long-term stores, focusing on the computational demands placed on any STM system. STM must support memory for previously unencountered information, the storage of multiple tokens of the same type, and variable binding. None of these can be achieved simply by activating long-term memory. For example, even a simple sequence of digits such as "1, 3, 1" where there are 2 tokens of the digit "1" cannot be stored in the correct order simply by activating the representations of the digits "1" and "3" in LTM. I also review recent neuroimaging data that has been presented as evidence that STM is activated LTM and show that these data are exactly what one would expect to see based on a conventional 2-store view. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  10. Fast Weight Long Short-Term Memory

    OpenAIRE

    Keller, T. Anderson; Sridhar, Sharath Nittur; Wang, Xin

    2018-01-01

    Associative memory using fast weights is a short-term memory mechanism that substantially improves the memory capacity and time scale of recurrent neural networks (RNNs). As recent studies introduced fast weights only to regular RNNs, it is unknown whether fast weight memory is beneficial to gated RNNs. In this work, we report a significant synergy between long short-term memory (LSTM) networks and fast weight associative memories. We show that this combination, in learning associative retrie...

  11. Short-term power plant operation scheduling in thermal systems with long-term boundary conditions

    International Nuclear Information System (INIS)

    Wolter, H.

    1990-01-01

    For the first time, the modeling of long-term quantitative conditions within the short-term planning of the application of power stations is made via their shadow prices. It corresponds to a decomposition of the quantitative conditions by means of the method of the Langrange relaxation. The shadow prices determined by the planning for energy application regarding long- term quantitative conditions pass into the short-term planning for power station application and subsidize or rather punish the application of limited amounts as for as they are not claimed for sufficiently or excessively. The clear advantage of this modeling is that the short-term planning of power station application can deviate from the envisioned energy application regarding the total optimum, because the shadow prices contain all information about the cost effect of the energy shifts in the residual total period, which become necessary due to the deviations in the short-term period to be planned in the current short-term period. (orig./DG) [de

  12. Improving creativity performance by short-term meditation

    Science.gov (United States)

    2014-01-01

    Background One form of meditation intervention, the integrative body-mind training (IBMT) has been shown to improve attention, reduce stress and change self-reports of mood. In this paper we examine whether short-term IBMT can improve performance related to creativity and determine the role that mood may play in such improvement. Methods Forty Chinese undergraduates were randomly assigned to short-term IBMT group or a relaxation training (RT) control group. Mood and creativity performance were assessed by the Positive and Negative Affect Schedule (PANAS) and Torrance Tests of Creative Thinking (TTCT) questionnaire respectively. Results As predicted, the results indicated that short-term (30 min per day for 7 days) IBMT improved creativity performance on the divergent thinking task, and yielded better emotional regulation than RT. In addition, cross-lagged analysis indicated that both positive and negative affect may influence creativity in IBMT group (not RT group). Conclusions Our results suggested that emotion-related creativity-promoting mechanism may be attributed to short-term meditation. PMID:24645871

  13. The Structure and Content of Long-Term and Short-Term Mate Preferences

    Directory of Open Access Journals (Sweden)

    Peter K. Jonason

    2013-12-01

    Full Text Available This study addresses two limitations in the mate preferences literature. First, research all-too-often relies on single-item assessments of mate preferences precluding more advanced statistical techniques like factor analysis. Second, when factor analysis could be done, it exclusively has done for long-term mate preferences, at the exclusion of short-term mate preferences. In this study (N = 401, we subjected 20 items designed to measure short- and long-term mate preferences to both principle components (n = 200 and confirmatory factor analysis (n = 201. In the long-term context, we replicated previous findings that there are three different categories of preferences: physical attractiveness, interpersonal warmth, and social status. In the short-term context, physical attractiveness occupied two parts of the structure, social status dropped out, and interpersonal warmth remained. Across short- and long-term contexts, there were slight changes in what defined the shared dimensions (i.e., physical attractiveness and interpersonal warmth, suggesting prior work that applies the same inventory to each context might be flawed. We also replicated sex differences and similarities in mate preferences and correlates with sociosexuality and mate value. We adopt an evolutionary paradigm to understand our results.

  14. Short-term energy outlook, annual supplement 1994

    International Nuclear Information System (INIS)

    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

  15. Short-term energy outlook annual supplement, 1993

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  16. Fluctuations in substitution type alloys and their analyses. Short-range order structures

    International Nuclear Information System (INIS)

    Iwasaki, Hiroshi; Ohshima, Ken-ichi

    2010-01-01

    This article is the fifth of the serial lecture, microstructures and fluctuations, in this magazine. The formula of X-ray diffuse scattering intensity was derived for binary alloys by introducing short-range order parameters. Diffuse scattering intensities for a single crystal Cu 3 Au were measured above critical temperature for ordering. The short-range parameters were obtained by a three-dimensional Fourier analysis. The long-range pair interaction between atoms was originated from the indirect screening interaction due to conduction electrons. A detailed study was made on short-range-order diffuse scattering from Cu 3 Au in the disordered state by electron diffraction. Fourfold splitting of the diffuse scattering was observed at 110 in the reciprocal lattice, and this result was attributed to the reflection of the form of the Fermi surface. The X-ray diffuse scattering intensity was measured at room temperature for disordered Cu-Pd alloys for the six composition of Pd. Twofold and fourfold splitting of diffuse scattering due to the short-range order (SRO) were observed at 100, 110 and equivalent positions respectively from alloys with more than 13.0at% Pd. The SRO parameters were determined from all the six alloys. For Cu-Pt alloys, the diffuse scattering originated from the correlation between Cu and Pt layers in direction was observed in addition to the one due to the reflection of the Fermi surface imaging. (author)

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

  20. Implementing a short-term loyalty program : case: Bosch Lawn & Garden and the Ventum short-term loyalty program

    OpenAIRE

    Logvinova, Veronika

    2015-01-01

    In 2015, one of the Bosch Home and Garden divisions, Bosch Lawn and Garden, has made a strategic decision to adopt a points-based short-term loyalty program called Ventum LG in the German supermarkets and petrol stations. It was decided that the base of this program will be completed Ventum PT short-term loyalty program which was managed by another division, Bosch Power Tools, and proved to be successful. This thesis aims to evaluate the worthiness of the Ventum LG loyalty program for Bosch L...

  1. Effect of kinesthetic illusion induced by visual stimulation on muscular output function after short-term immobilization.

    Science.gov (United States)

    Inada, Toru; Kaneko, Fuminari; Hayami, Tatsuya

    2016-04-01

    Kinesthetic illusions by visual stimulation (KiNVIS) enhances corticomotor excitability and activates motor association areas. The purpose of this study was to investigate the effect of KiNVIS induction on muscular output function after short-term immobilization. Thirty subjects were assigned to 3 groups: an immobilization group, with the left hand immobilized for 12h (immobilization period); an illusion group, with the left hand immobilized and additionally subjected to KiNVIS of the immobilized part during the immobilization period; and a control group with no manipulation. The maximum voluntary contraction (MVC), fluctuation of force (force fluctuation) during a force modulation task, and twitch force were measured both before (pre-test) and after (post-test) the immobilization period. Data were analyzed by performing two-way (TIME×GROUP) repeated measures ANOVA. The MVC decreased in the immobilization group only (pre-test; 37.8±6.1N, post-test; 32.8±6.9N, p<0.0005) after the immobilization period. The force fluctuation increased only in the immobilization group (pre-test; 2.19±0.54%, post-test; 2.78±0.87%, p=0.007) after the immobilization period. These results demonstrate that induction of KiNVIS prevents negative effect on MVC and force fluctuation after 12h of immobilization. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Decay uncovered in nonverbal short-term memory.

    Science.gov (United States)

    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.

  3. Short-term energy outlook annual supplement, 1993

    International Nuclear Information System (INIS)

    1993-01-01

    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. (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

  4. A novel economy reflecting short-term load forecasting approach

    International Nuclear Information System (INIS)

    Lin, Cheng-Ting; Chou, Li-Der

    2013-01-01

    Highlights: ► We combine MA line of TAIEX and SVR to overcome the load demands over-prediction problems caused by the economic downturn. ► The Taiwan island-wide electricity power system was used as the case study. ► Short- to middle-term MA lines of TAIEX are found to be good economic input variables for load forecasting models. - Abstract: The global economic downturn in 2008 and 2009, which was spurred by the bankruptcy of Lehman Brothers, sharply reduced the demand for electricity load. Conventional load-forecasting approaches were unable to respond to sudden changes in the economy, because these approaches do not consider the effect of economic factors. Therefore, the over-prediction problem occurred. To overcome this problem, this paper proposes a novel, economy-reflecting, short-term load forecasting (STLF) approach based on theories of moving average (MA) line of stock index and machine learning. In this approach, the stock indices decision model is designed to reflect fluctuations in the Taiwan Stock Exchange Capitalization Weighted Stock Index (TAIEX) series, which is selected as an optimal input variable in support vector regression load forecasting model at an appropriate timing. The Taiwan island-wide hourly electricity load demands from 2008 to 2010 are used as the case study for performance benchmarking. Results show that the proposed approach with a 60-day MA of the TAIEX as economic learning pattern achieves good forecasting performance. It outperforms the conventional approach by 29.16% on average during economic downturn-affected days. Overall, the proposed approach successfully overcomes the over-prediction problems caused by the economic downturn. To the best of our knowledge, this paper is the first attempt to apply MA line theory of stock index on STLF.

  5. Short-term variability of Cyg X-1 and the accretion disk temperature fluctuation

    International Nuclear Information System (INIS)

    Doi, K.

    1980-01-01

    Recent theoretical models which have been proposed to explain the observed time-averaged spectrum of Cyg X-1 assume that the hard x-rays are emitted by inverse-Compton mechanism from an optically thin, hot accretion disk around a black hole. Results are reported here of balloon observations (20-68 keV) and compared with previous rocket observations (1.5-25 keV). Using the results an analysis is made of the variability of the source intensity in the hard x-ray range which suggests that the variation is essentially spectral indicating that it originated from temperature fluctuation in an accretive disk. Such a model, which explains the stochastic nature of the variability, its characteristic time scale and spectral features at the same time in the context of the conventional accretion disk model for Cyg X-1, is examined. (U.K.)

  6. Parent-Offspring Conflict over Short-Term Mating Strategies

    Directory of Open Access Journals (Sweden)

    Spyroulla Georgiou

    2011-12-01

    Full Text Available Individuals engage in short-term mating strategies that enable them to obtain fitness benefits from casual relationships. These benefits, however, count for less and cost more to their parents. On this basis three hypotheses are tested. First, parents and offspring are likely to disagree over short-term mating strategies, with the former considering these as less acceptable than the latter. Second, parents are more likely to disapprove of the short-term mating strategies of their daughters than of their sons. Finally, mothers and fathers are expected to agree on how much they disagree over the short-term mating strategies of their children. Evidence from a sample of 148 Greek-Cypriot families (140 mothers, 105 fathers, 119 daughters, 77 sons provides support for the first two hypotheses and partial support for the third hypothesis. The implications of these findings for understanding family dynamics are further discussed.

  7. Circadian modulation of short-term memory in Drosophila.

    Science.gov (United States)

    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 associative memory formation using a negatively reinforced olfactory-learning paradigm in Drosophila melanogaster. We found that memory formation was regulated in a circadian manner. The peak performance in short-term memory (STM) occurred during the early subjective night with a twofold performance amplitude after a single pairing of conditioned and unconditioned stimuli. This rhythm in memory is eliminated in both timeless and period mutants and is absent during constant light conditions. Circadian gating of sensory perception does not appear to underlie the rhythm in short-term memory as evidenced by the nonrhythmic shock avoidance and olfactory avoidance behaviors. Moreover, central brain oscillators appear to be responsible for the modulation as cryptochrome mutants, in which the antennal circadian oscillators are nonfunctional, demonstrate robust circadian rhythms in short-term memory. Together these data suggest that central, rather than peripheral, circadian oscillators modulate the formation of short-term associative memory and not the perception of the stimuli.

  8. The Role of Short-term Consolidation in Memory Persistence

    OpenAIRE

    Timothy J. Ricker

    2015-01-01

    Short-term memory, often described as working memory, is one of the most fundamental information processing systems of the human brain. Short-term memory function is necessary for language, spatial navigation, problem solving, and many other daily activities. Given its importance to cognitive function, understanding the architecture of short-term memory is of crucial importance to understanding human behavior. Recent work from several laboratories investigating the entry of information into s...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  11. Short-term and long-term sick-leave in Sweden

    DEFF Research Database (Denmark)

    Blank, N; Diderichsen, Finn

    1995-01-01

    The primary aim of the study was to analyse similarities and differences between repeated spells of short-term sick-leave (more than 3 spells of less than 7 days' duration in a 12-month period) and long-term absence through sickness (at least 1 spell of more than 59 days' duration in a 12-month p...

  12. Magnetic fluctuations associated with density fluctuations in the tokamak edge

    International Nuclear Information System (INIS)

    Kim, Y.J.; Gentle, K.W.; Ritz, C.P.; Rhodes, T.L.; Bengtson, R.D.

    1989-01-01

    Electrostatic density and potential fluctuations occurring with high amplitude near the edge of a tokamak are correlated with components of the fluctuating magnetic field measured outside the limiter radius. It has been established that this turbulence is associated with fluctuations in current as well as density and potential. The correlation extends for substantial toroidal distances, but only if the probes are displaced approximately along field lines, consistent with the short coherence lengths poloidally but long coherence lengths parallel to the field which are characteristic for this turbulence. Furthermore, the correlation can be found only with density fluctuations measured inside the limiter radius; density fluctuations behind the limiter have no detectable magnetic concomitant for the toroidally spaced probes used here. (author). Letter-to-the-editor. 12 refs, 3 figs

  13. Short-term Consumer Benefits of Dynamic Pricing

    OpenAIRE

    Dupont, Benjamin; De Jonghe, Cedric; Kessels, Kris; Belmans, Ronnie

    2011-01-01

    Consumer benefits of dynamic pricing depend on a variety of factors. Consumer characteristics and climatic circumstances widely differ, which forces a regional comparison. This paper presents a general overview of demand response programs and focuses on the short-term benefits of dynamic pricing for an average Flemish residential consumer. It reaches a methodology to develop a cost reflective dynamic pricing program and to estimate short-term bill savings. Participating in a dynamic pricing p...

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

    Science.gov (United States)

    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…

  15. A least squares approach for efficient and reliable short-term versus long-term optimization

    DEFF Research Database (Denmark)

    Christiansen, Lasse Hjuler; Capolei, Andrea; Jørgensen, John Bagterp

    2017-01-01

    The uncertainties related to long-term forecasts of oil prices impose significant financial risk on ventures of oil production. To minimize risk, oil companies are inclined to maximize profit over short-term horizons ranging from months to a few years. In contrast, conventional production...... optimization maximizes long-term profits over horizons that span more than a decade. To address this challenge, the oil literature has introduced short-term versus long-term optimization. Ideally, this problem is solved by a posteriori multi-objective optimization methods that generate an approximation...... the balance between the objectives, leaving an unfulfilled potential to increase profits. To promote efficient and reliable short-term versus long-term optimization, this paper introduces a natural way to characterize desirable Pareto points and proposes a novel least squares (LS) method. Unlike hierarchical...

  16. Do Short-Term Managerial Objectives Lead to Under- or Over-Investment in Long-Term Projects

    OpenAIRE

    Lucian Arye Bebchuk; Lars A. Stole

    1994-01-01

    This paper studies managerial decisions about investment in long-run projects in the presence of imperfect information (the market knows less about such investments than the firm's managers) and short-term managerial objectives (the managers are concerned about the short-term stock price as well as the long-term stock price). Prior work has suggested that imperfect information and short-term managerial objectives induce managers to underinvest in long-run projects. We show that either underin...

  17. Impact of economic fluctuations on suicide mortality in Canada (1926-2008): Testing the Durkheim, Ginsberg, and Henry and Short theories.

    Science.gov (United States)

    Thibodeau, Lise; Lachaud, James

    2016-01-01

    Three theories have been proposed to explain the relationship between suicide and economic fluctuations, including the Durkheim (nonlinear), Ginsberg (procyclical), and Henry and Short (countercyclical) theories. This study tested the effect of economic fluctuations, measured by unemployment rate, on suicide rates in Canada from 1926 to 2008. Autoregressive integrated moving average time-series models were used. The results showed a significant relationship between suicide and economic fluctuation; this association was positive during the contraction period (1926-1950) and negative in the period of economic expansion (1951-1973). Males and females showed differential effects in the period of moderate unemployment (1974-2008). In addition, the suicide rate of mid-adults (45-64) was most impacted by economic fluctuations. Our study tends to support Durkheim's theory and suggests the need for public health responses in times of economic contraction and expansion.

  18. Sleep Quality, Short-Term and Long-Term CPAP Adherence

    Science.gov (United States)

    Somiah, Manya; Taxin, Zachary; Keating, Joseph; Mooney, Anne M.; Norman, Robert G.; Rapoport, David M.; Ayappa, Indu

    2012-01-01

    Study Objectives: Adherence to CPAP therapy is low in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS). The purpose of the present study was to evaluate the utility of measures of sleep architecture and sleep continuity on the CPAP titration study as predictors of both short- and long-term CPAP adherence. Methods: 93 patients with OSAHS (RDI 42.8 ± 34.3/h) underwent in-laboratory diagnostic polysomnography, CPAP titration, and follow-up polysomnography (NPSG) on CPAP. Adherence to CPAP was objectively monitored. Short-term (ST) CPAP adherence was averaged over 14 days immediately following the titration study. Long-term (LT) CPAP adherence was obtained in 56/93 patients after approximately 2 months of CPAP use. Patients were grouped into CPAP adherence groups for ST ( 4 h) and LT adherence ( 4 h). Sleep architecture, sleep disordered breathing (SDB) indices, and daytime outcome variables from the diagnostic and titration NPSGs were compared between CPAP adherence groups. Results: There was a significant relationship between ST and LT CPAP adherence (r = 0.81, p CPAP adherence groups had significantly lower %N2 and greater %REM on the titration NPSG. A model combining change in sleep efficiency and change in sleep continuity between the diagnostic and titration NPSGs predicted 17% of the variance in LT adherence (p = 0.006). Conclusions: These findings demonstrate that characteristics of sleep architecture, even on the titration NPSG, may predict some of the variance in CPAP adherence. Better sleep quality on the titration night was related to better CPAP adherence, suggesting that interventions to improve sleep on/prior to the CPAP titration study might be used as a therapeutic intervention to improve CPAP adherence. Citation: Somiah M; Taxin Z; Keating J; Mooney AM; Norman RG; Rapoport DM; Ayappa I. Sleep quality, short-term and long-term CPAP adherence. J Clin Sleep Med 2012;8(5):489-500. PMID:23066359

  19. Assessing the associative deficit of older adults in long-term and short-term/working memory.

    Science.gov (United States)

    Chen, Tina; Naveh-Benjamin, Moshe

    2012-09-01

    Older adults exhibit a deficit in associative long-term memory relative to younger adults. However, the literature is inconclusive regarding whether this deficit is attenuated in short-term/working memory. To elucidate the issue, three experiments assessed younger and older adults' item and interitem associative memory and the effects of several variables that might potentially contribute to the inconsistent pattern of results in previous studies. In Experiment 1, participants were tested on item and associative recognition memory with both long-term and short-term retention intervals in a single, continuous recognition paradigm. There was an associative deficit for older adults in the short-term and long-term intervals. Using only short-term intervals, Experiment 2 utilized mixed and blocked test designs to examine the effect of test event salience. Blocking the test did not attenuate the age-related associative deficit seen in the mixed test blocks. Finally, an age-related associative deficit was found in Experiment 3, under both sequential and simultaneous presentation conditions. Even while accounting for some methodological issues, the associative deficit of older adults is evident in short-term/working memory.

  20. Tunneling probe of fluctuating superconductivity in disordered thin films

    Science.gov (United States)

    Dentelski, David; Frydman, Aviad; Shimshoni, Efrat; Dalla Torre, Emanuele G.

    2018-03-01

    Disordered thin films close to the superconductor-insulator phase transition (SIT) hold the key to understanding quantum phase transition in strongly correlated materials. The SIT is governed by superconducting quantum fluctuations, which can be revealed, for example, by tunneling measurements. These experiments detect a spectral gap, accompanied by suppressed coherence peaks, on both sides of the transition. Here we describe the insulating side in terms of a fluctuating superconducting field with finite-range correlations. We perform a controlled diagrammatic resummation and derive analytic expressions for the tunneling differential conductance. We find that short-range superconducting fluctuations suppress the coherence peaks even in the presence of long-range correlations. Our approach offers a quantitative description of existing measurements on disordered thin films and accounts for tunneling spectra with suppressed coherence peaks.

  1. The pedagogy of Short-Term Study-Abroad Programs

    Directory of Open Access Journals (Sweden)

    Jude Gonsalvez

    2013-10-01

    Full Text Available This paper focuses on establishing guidelines on the pedagogy of short term study abroad programs. This study follows 33 students who participated in a short-term study-abroad program to India with the researcher from 2006 through 2011. The study relies heavily on the student reflections and expressions as they experienced them. It is qualitative in nature. Focus groups were the main method of data collection, where participants were invited to reflect, express, and share their experiences with one another. This provided an opportunity for the participants to come together, relive their experiences, and help provide information as to how and what type of an influence this short-term study-abroad program provided.

  2. Genetic deletion of melanin-concentrating hormone neurons impairs hippocampal short-term synaptic plasticity and hippocampal-dependent forms of short-term memory.

    Science.gov (United States)

    Le Barillier, Léa; Léger, Lucienne; Luppi, Pierre-Hervé; Fort, Patrice; Malleret, Gaël; Salin, Paul-Antoine

    2015-11-01

    The cognitive role of melanin-concentrating hormone (MCH) neurons, a neuronal population located in the mammalian postero-lateral hypothalamus sending projections to all cortical areas, remains poorly understood. Mainly activated during paradoxical sleep (PS), MCH neurons have been implicated in sleep regulation. The genetic deletion of the only known MCH receptor in rodent leads to an impairment of hippocampal dependent forms of memory and to an alteration of hippocampal long-term synaptic plasticity. By using MCH/ataxin3 mice, a genetic model characterized by a selective deletion of MCH neurons in the adult, we investigated the role of MCH neurons in hippocampal synaptic plasticity and hippocampal-dependent forms of memory. MCH/ataxin3 mice exhibited a deficit in the early part of both long-term potentiation and depression in the CA1 area of the hippocampus. Post-tetanic potentiation (PTP) was diminished while synaptic depression induced by repetitive stimulation was enhanced suggesting an alteration of pre-synaptic forms of short-term plasticity in these mice. Behaviorally, MCH/ataxin3 mice spent more time and showed a higher level of hesitation as compared to their controls in performing a short-term memory T-maze task, displayed retardation in acquiring a reference memory task in a Morris water maze, and showed a habituation deficit in an open field task. Deletion of MCH neurons could thus alter spatial short-term memory by impairing short-term plasticity in the hippocampus. Altogether, these findings could provide a cellular mechanism by which PS may facilitate memory encoding. Via MCH neuron activation, PS could prepare the day's learning by increasing and modulating short-term synaptic plasticity in the hippocampus. © 2015 Wiley Periodicals, Inc.

  3. Relationship between short and long term radon measurements

    International Nuclear Information System (INIS)

    Martinez, T.; Ramirez, D.; Navarrete, M.; Cabrera, L.; Ramirez, A.; Gonzalez, P.

    2000-01-01

    In this work the radon group of the Faculty of Chemistry at the National University of Mexico presents the results obtained in the establishment of a relation between the short and long term radon measures made with passive electret detectors E-PERM type LLT and HST. The measures were carried out inside single family dwellings (open house condition) located in the southeast of Mexico City (in Xochimilco) during the four seasons of the year 1997. A correlation was established between the short term measures (five days) and those of a long term for every season as well as an annual average, with an equation that relates them. The objective and advantage of this correlation are that with a short term measure it is possible to predict the annual mean radon concentration, that represents a saving of human and economic resources. (author)

  4. Impact of short-term severe accident management actions in a long-term perspective. Final Report

    International Nuclear Information System (INIS)

    2000-03-01

    The present systems for severe accident management are focused on mitigating the consequences of special severe accident phenomena and to reach a safe plant state. However, in the development of strategies and procedures for severe accident management, it is also important to consider the long-term perspective of accident management and especially to secure the safe state of the plant. The main reason for this is that certain short-term actions have an impact on the long-term scenario. Both positive and negative effects from short-term actions on the accident management in the long-term perspective have been included in this paper. Short-term actions are accident management measures taken within about 24 hours after the initiating event. The purpose of short-term actions is to reach a stable status of the plant. The main goal in the long-term perspective is to maintain the reactor in a stable state and prevent uncontrolled releases of activity. The purpose of this short Technical Note, deliberately limited in scope, is to draw attention to potential long-term problems, important to utilities and regulatory authorities, arising from the way a severe accident would be managed during the first hours. Its objective is to encourage discussions on the safest - and maybe also most economical - way to manage a severe accident in the long term by not making the situation worse through inappropriate short-term actions, and on the identification of short-term actions likely to make long-term management easier and safer. The Note is intended as a contribution to the knowledge base put at the disposal of Member countries through international collaboration. The scope of the work has been limited to a literature search. Useful further activities have been identified. However, there is no proposal, at this stage, for more detailed work to be undertaken under the auspices of the CSNI. Plant-specific applications would need to be developed by utilities

  5. Ordered short-term memory differs in signers and speakers: Implications for models of short-term memory

    OpenAIRE

    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, Supalla, Newport, & Bavelier, 2004). Here, we test the hypothesis that this population difference reflects differences in the way speakers and signers maintain temporal order information in short-te...

  6. Short-term and long-term deflection of reinforced hollow core ...

    African Journals Online (AJOL)

    This paper presents a study on different methods of analysis that are currently used by design codes to predict the short-term and long-term deflection of reinforced concrete slab systems and compares the predicted deflections with measured deflections. The experimental work to measure deflections involved the testing of ...

  7. Robust short-term memory without synaptic learning.

    Directory of Open Access Journals (Sweden)

    Samuel Johnson

    Full Text Available 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.

  8. Robust short-term memory without synaptic learning.

    Science.gov (United States)

    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.

  9. Robust Short-Term Memory without Synaptic Learning

    Science.gov (United States)

    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. A multifractal detrended fluctuation analysis of financial market efficiency: Comparison using Dow Jones sector ETF indices

    Science.gov (United States)

    Tiwari, Aviral Kumar; Albulescu, Claudiu Tiberiu; Yoon, Seong-Min

    2017-10-01

    This study challenges the efficient market hypothesis, relying on the Dow Jones sector Exchange-Traded Fund (ETF) indices. For this purpose, we use the generalized Hurst exponent and multifractal detrended fluctuation analysis (MF-DFA) methods, using daily data over the timespan from 2000 to 2015. We compare the sector ETF indices in terms of market efficiency between short- and long-run horizons, small and large fluctuations, and before and after the global financial crisis (GFC). Our findings can be summarized as follows. First, there is clear evidence that the sector ETF markets are multifractal in nature. We also find a crossover in the multifractality of sector ETF market dynamics. Second, the utilities and consumer goods sector ETF markets are more efficient compared with the financial and telecommunications sector ETF markets, in terms of price prediction. Third, there are noteworthy discrepancies in terms of market efficiency, between the short- and long-term horizons. Fourth, the ETF market efficiency is considerably diminished after the global financial crisis.

  11. Short-term memory binding deficits in Alzheimer's disease

    OpenAIRE

    Parra, Mario; Abrahams, S.; Fabi, K.; Logie, R.; Luzzi, S.; Della Sala, Sergio

    2009-01-01

    Alzheimer's disease impairs long term memories for related events (e.g. faces with names) more than for single events (e.g. list of faces or names). Whether or not this associative or ‘binding’ deficit is also found in short-term memory has not yet been explored. In two experiments we investigated binding deficits in verbal short-term memory in Alzheimer's disease. Experiment 1 : 23 patients with Alzheimer's disease and 23 age and education matched healthy elderly were recruited. Participants...

  12. Relationship between short-term sexual strategies and sexual jealousy.

    Science.gov (United States)

    Mathes, Eugene W

    2005-02-01

    In a classic study, Buss, Larson, Westen, and Semmelroth reported that men were more distressed by the thought of a partner's sexual infidelity (sexual jealousy) and women were more distressed by the thought of a partner's emotional infidelity (emotional jealousy). Initially, Buss and his associates explained these results by suggesting that men are concerned about uncertainty of paternity, that is, the possibility of raising another man's child while believing the child is their own. However, later they explained the results in terms of men's preference for short-term sexual strategies. The purpose of this research was to test the explanation of short-term sexual strategies. Men and women subjects were instructed to imagine themselves in a relationship which was either short-term (primarily sexual) or long-term (involving commitment) and then respond to Buss's jealousy items. It was hypothesized that, when both men and women imagined a short-term relationship, they would be more threatened by a partner's sexual infidelity, and, when they imagined a long-term relationship, they would be more threatened by a partner's emotional infidelity. Support was found for this hypothesis.

  13. Impact of long-term and short-term therapies on seminal parameters

    Directory of Open Access Journals (Sweden)

    Jlenia Elia

    2013-04-01

    Full Text Available Aim: The aim of this work was: i to evaluate the prevalence of male partners of subfertile couples being treated with long/short term therapies for non andrological diseases; ii to study their seminal profile for the possible effects of their treatments on spermatogenesis and/or epididymal maturation. Methods: The study group was made up of 723 subjects, aged between 25 and 47 years. Semen analysis was performed according to World Health Organization (WHO guidelines (1999. The Superimposed Image Analysis System (SIAS, which is based on the computerized superimposition of spermatozoa images, was used to assess sperm motility parameters. Results: The prevalence of subjects taking pharmacological treatments was 22.7% (164/723. The prevalence was 3.7% (27/723 for the Short-Term Group and 18.9% (137/723 for the Long-Term Group. The subjects of each group were also subdivided into subgroups according to the treatments being received. Regarding the seminal profile, we did not observe a significant difference between the Long-Term, Short-Term or the Control Group. However, regarding the subgroups, we found a significant decrease in sperm number and progressive motility percentage in the subjects receiving treatment with antihypertensive drugs compared with the other subgroups and the Control Group. Conclusions: In the management of infertile couples, the potential negative impact on seminal parameters of any drugs being taken as Long-Term Therapy should be considered. The pathogenic mechanism needs to be clarified.

  14. Ambiguity Aversion, Asset Prices, and the Welfare Costs of Aggregate Fluctuations

    DEFF Research Database (Denmark)

    Alonso, Irasema; Prado, Mauricio

    2015-01-01

    with a representative agent facing consumption fluctuations calibrated to match U.S. data from 1889 to 2008. Our experiment is to restrict preference parameters in order to as well as possible match some asset-price facts—the average returns on equity and a short-term risk-free bond—and then compute the welfare...

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

    International Nuclear Information System (INIS)

    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

  16. Short-term flow induced crystallization in isotactic polypropylene : how short is short?

    NARCIS (Netherlands)

    Ma, Z.; Balzano, L.; Portale, G.; Peters, G.W.M.

    2013-01-01

    The so-called "short-term flow" protocol is widely applied in experimental flow-induced crystallization studies on polymers in order to separate the nucleation and subsequent growth processes [Liedauer et al. Int. Polym. Proc. 1993, 8, 236–244]. The basis of this protocol is the assumption that

  17. Comparison of Short Term with Long Term Catheterization after Anterior Colporrhaphy Surgery

    Directory of Open Access Journals (Sweden)

    F. Movahed

    2010-07-01

    Full Text Available Introduction & Objective: This belief that overfilling the bladder after anterior colporrhaphy might have a negative influence on surgical outcome, causes routine catheterization after operation. This study was done to compare short term (24h with long term (72h catheterization after anterior colporrhaphy.Materials & Methods: This randomized clinical trial was carried out at Kosar Hospital , Qazvin (Iran in 2005-2006. One hundred cases candidating for anterior colporrhaphy , were divided in two equal groups . In the first group foley catheter was removed 24 hours and in the second group 72 hours after the operation. Before removing catheter, urine sample was obtained for culture . After removal and urination, residual volume was determinded. If the volume exceeded 200 ml or retention occured, the catheter would be fixed for more 72 hours. Need for recatheterization, urinary retention, positive urine culture,and hospital stay were surveyed. The data was analyzed using T and Fisher tests.Results: Residual volume exceeding 200 ml and the need for recatheterization occurred in one case (2% in the short term group but in the long term group none of the subjects needed recatheterization (P=1. Retention was not seen. In the both groups, one case (2% had positive urine culture with no statistically significant difference (P=1. Mean hospital stay was short in the first group (P=0.00.Conclusion: Short term catheterization after anterior colporrhaphy does not cause urinary retention and decreases hospital stay.

  18. Short-term versus long-term market opportunities and financial constraints

    International Nuclear Information System (INIS)

    Ferrari, Angelo

    1999-01-01

    This presentation discusses gas developments in Europe, the European Gas Directive, short term vs. long term, and Snam's new challenges. The European gas market is characterized by (1) The role of gas in meeting the demand for energy, which varies greatly from one country to another, (2) A growing market, (3) Decreasing role of domestic production, and (4) Increasing imports. Within the European Union, the Gas Directive aims to transform single national markets into one integrated European market by introducing third party access to the network for eligible clients as a means of increasing the competition between operators. The Gas Directive would appear to modify the form of the market rather than its size, and in particular the sharing of responsibility and risk among operators. The market in the future will offer operators the possibility to exploit opportunities deriving mainly from demands for increased flexibility. Opportunities linked to entrepreneurial initiatives require long-term investments characteristic of the gas business. Risks and opportunities must be balanced evenly between different operators. If everyone takes on their own risks and responsibilities, this means a wider distribution of the risks of long-term vs. short-term, currently borne by the gas companies that are integrated, into a market that tends to favour the short-term. A gradual liberalization process should allow incumbent operators to gradually diversify their activities in new gas market areas or enter new business activities. They could move beyond their local and European boundaries in pursuit of an international dimension. The market will have to make the transition from the national to the European dimension: as an example, Snam covers 90% of the Italian market, but its share of an integrated European market will be about 15%

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

    Science.gov (United States)

    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)

  20. Frequency-specific insight into short-term memory capacity

    OpenAIRE

    Feurra, Matteo; Galli, Giulia; Pavone, Enea Francesco; Rossi, Alessandro; Rossi, Simone

    2016-01-01

    We provided novel evidence of a frequency-specific effect by transcranial alternating current stimulation (tACS) of the left posterior parietal cortex on short-term memory, during a digit span task. the effect was prominent with stimulation at beta frequency for young and not for middle-aged adults and correlated with age. Our findings highlighted a short-term memory capacity improvement by tACS application.

  1. Reconciling long-term cultural diversity and short-term collective social behavior.

    Science.gov (United States)

    Valori, Luca; Picciolo, Francesco; Allansdottir, Agnes; Garlaschelli, Diego

    2012-01-24

    An outstanding open problem is whether collective social phenomena occurring over short timescales can systematically reduce cultural heterogeneity in the long run, and whether offline and online human interactions contribute differently to the process. Theoretical models suggest that short-term collective behavior and long-term cultural diversity are mutually excluding, since they require very different levels of social influence. The latter jointly depends on two factors: the topology of the underlying social network and the overlap between individuals in multidimensional cultural space. However, while the empirical properties of social networks are intensively studied, little is known about the large-scale organization of real societies in cultural space, so that random input specifications are necessarily used in models. Here we use a large dataset to perform a high-dimensional analysis of the scientific beliefs of thousands of Europeans. We find that interopinion correlations determine a nontrivial ultrametric hierarchy of individuals in cultural space. When empirical data are used as inputs in models, ultrametricity has strong and counterintuitive effects. On short timescales, it facilitates a symmetry-breaking phase transition triggering coordinated social behavior. On long timescales, it suppresses cultural convergence by restricting it within disjoint groups. Moreover, ultrametricity implies that these results are surprisingly robust to modifications of the dynamical rules considered. Thus the empirical distribution of individuals in cultural space appears to systematically optimize the coexistence of short-term collective behavior and long-term cultural diversity, which can be realized simultaneously for the same moderate level of mutual influence in a diverse range of online and offline settings.

  2. Short-Term Robustness of Production Management Systems : New Methodology

    NARCIS (Netherlands)

    Kleijnen, J.P.C.; Gaury, E.G.A.

    2000-01-01

    This paper investigates the short-term robustness of production planning and control systems. This robustness is defined here as the systems ability to maintain short-term service probabilities (i.e., the probability that the fill rate remains within a prespecified range), in a variety of

  3. Differences in health status between long-term and short-term benzodiazepine users.

    NARCIS (Netherlands)

    Zandstra, S.M.; Furer, J.W.; Lisdonk, E.H. van de; Bor, J.H.J.; Zitman, F.G.; Weel, C. van

    2002-01-01

    BACKGROUND: Despite generally accepted advice to keep treatment short, benzodiazepines are often prescibed for more than six months. Prevention of long-term benzodiazepine use could be facilitated by the utilisation of risk indicators for long-term use. However, the characteristics of long-term

  4. The roles of long-term phonotactic and lexical prosodic knowledge in phonological short-term memory.

    Science.gov (United States)

    Tanida, Yuki; Ueno, Taiji; Lambon Ralph, Matthew A; Saito, Satoru

    2015-04-01

    Many previous studies have explored and confirmed the influence of long-term phonological representations on phonological short-term memory. In most investigations, phonological effects have been explored with respect to phonotactic constraints or frequency. If interaction between long-term memory and phonological short-term memory is a generalized principle, then other phonological characteristics-that is, suprasegmental aspects of phonology-should also exert similar effects on phonological short-term memory. We explored this hypothesis through three immediate serial-recall experiments that manipulated Japanese nonwords with respect to lexical prosody (pitch-accent type, reflecting suprasegmental characteristics) as well as phonotactic frequency (reflecting segmental characteristics). The results showed that phonotactic frequency affected the retention not only of the phonemic sequences, but also of pitch-accent patterns, when participants were instructed to recall both the phoneme sequence and accent pattern of nonwords. In addition, accent pattern typicality influenced the retention of the accent pattern: Typical accent patterns were recalled more accurately than atypical ones. These results indicate that both long-term phonotactic and lexical prosodic knowledge contribute to phonological short-term memory performance.

  5. Visual Short-Term Memory Complexity

    DEFF Research Database (Denmark)

    Sørensen, Thomas Alrik

    Several recent studies have explored the nature and limits of visual short-term memory (VSTM) (e.g. Luck & Vogel, 1997). A general VSTM capacity limit of about 3 to 4 letters has been found, thus confirming results from earlier studies (e.g. Cattell, 1885; Sperling, 1960). However, Alvarez...

  6. Brain oscillatory substrates of visual short-term memory capacity.

    Science.gov (United States)

    Sauseng, Paul; Klimesch, Wolfgang; Heise, Kirstin F; Gruber, Walter R; Holz, Elisa; Karim, Ahmed A; Glennon, Mark; Gerloff, Christian; Birbaumer, Niels; Hummel, Friedhelm C

    2009-11-17

    The amount of information that can be stored in visual short-term memory is strictly limited to about four items. Therefore, memory capacity relies not only on the successful retention of relevant information but also on efficient suppression of distracting information, visual attention, and executive functions. However, completely separable neural signatures for these memory capacity-limiting factors remain to be identified. Because of its functional diversity, oscillatory brain activity may offer a utile solution. In the present study, we show that capacity-determining mechanisms, namely retention of relevant information and suppression of distracting information, are based on neural substrates independent of each other: the successful maintenance of relevant material in short-term memory is associated with cross-frequency phase synchronization between theta (rhythmical neural activity around 5 Hz) and gamma (> 50 Hz) oscillations at posterior parietal recording sites. On the other hand, electroencephalographic alpha activity (around 10 Hz) predicts memory capacity based on efficient suppression of irrelevant information in short-term memory. Moreover, repetitive transcranial magnetic stimulation at alpha frequency can modulate short-term memory capacity by influencing the ability to suppress distracting information. Taken together, the current study provides evidence for a double dissociation of brain oscillatory correlates of visual short-term memory capacity.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Impaired short-term memory for pitch in congenital amusia.

    Science.gov (United States)

    Tillmann, Barbara; Lévêque, Yohana; Fornoni, Lesly; Albouy, Philippe; Caclin, Anne

    2016-06-01

    Congenital amusia is a neuro-developmental disorder of music perception and production. The hypothesis is that the musical deficits arise from altered pitch processing, with impairments in pitch discrimination (i.e., pitch change detection, pitch direction discrimination and identification) and short-term memory. The present review article focuses on the deficit of short-term memory for pitch. Overall, the data discussed here suggest impairments at each level of processing in short-term memory tasks; starting with the encoding of the pitch information and the creation of the adequate memory trace, the retention of the pitch traces over time as well as the recollection and comparison of the stored information with newly incoming information. These impairments have been related to altered brain responses in a distributed fronto-temporal network, associated with decreased connectivity between these structures, as well as in abnormalities in the connectivity between the two auditory cortices. In contrast, amusic participants׳ short-term memory abilities for verbal material are preserved. These findings show that short-term memory deficits in congenital amusia are specific to pitch, suggesting a pitch-memory system that is, at least partly, separated from verbal memory. This article is part of a Special Issue entitled SI: Auditory working memory. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. The uranium industry: long-term planning for short-term competition

    International Nuclear Information System (INIS)

    Vottero, X.; Georges Capus, G.

    2001-01-01

    Long term planning for short term competition Today, uranium producers face new challenges in terms of both production (new regulatory, environmental and social constraints) and market conditions (new sources of uranium supply, very low prices and tough competition). In such a context, long-term planning is not just a prerequisite to survive in the nuclear fuel cycle industry. In fact, it also contributes to sustaining nuclear electricity generation facing fierce competition from other energy sources in increasingly deregulated markets. Firstly, the risk of investing in new mining projects in western countries is growing because, on the one hand, of very erratic market conditions and, on the other hand, of increasingly lengthy, complex and unpredictable regulatory conditions. Secondly, the supply of other sources of uranium (uranium derived from nuclear weapons, uranium produced in CIS countries, ...) involve other risks, mainly related to politics and commercial restrictions. Consequently, competitive uranium supply requires not only technical competence but also financial strength and good marketing capabilities in order to anticipate long-term market trends, in terms of both demand and supply. It also requires taking into account new parameters such as politics, environment, regulations, etc. Today, a supplier dedicated to the sustainable production of nuclear electricity must manage a broad range of long-term risks inherent to the procurement of uranium. Taking into account all these parameters in a context of short-term, fast-changing market is a great challenge for the future generation. World Uranium Civilian Supply and Demand. (authors)

  10. Insensitivity of visual short-term memory to irrelevant visual information.

    Science.gov (United States)

    Andrade, Jackie; Kemps, Eva; Werniers, Yves; May, Jon; Szmalec, Arnaud

    2002-07-01

    Several authors have hypothesized that visuo-spatial working memory is functionally analogous to verbal working memory. Irrelevant background speech impairs verbal short-term memory. We investigated whether irrelevant visual information has an analogous effect on visual short-term memory, using a dynamic visual noise (DVN) technique known to disrupt visual imagery (Quinn & McConnell, 1996b). Experiment I replicated the effect of DVN on pegword imagery. Experiments 2 and 3 showed no effect of DVN on recall of static matrix patterns, despite a significant effect of a concurrent spatial tapping task. Experiment 4 showed no effect of DVN on encoding or maintenance of arrays of matrix patterns, despite testing memory by a recognition procedure to encourage visual rather than spatial processing. Serial position curves showed a one-item recency effect typical of visual short-term memory. Experiment 5 showed no effect of DVN on short-term recognition of Chinese characters, despite effects of visual similarity and a concurrent colour memory task that confirmed visual processing of the characters. We conclude that irrelevant visual noise does not impair visual short-term memory. Visual working memory may not be functionally analogous to verbal working memory, and different cognitive processes may underlie visual short-term memory and visual imagery.

  11. Remembering over the short-term: the case against the standard model.

    Science.gov (United States)

    Nairne, James S

    2002-01-01

    Psychologists often assume that short-term storage is synonymous with activation, a mnemonic property that keeps information in an immediately accessible form. Permanent knowledge is activated, as a result of on-line cognitive processing, and an activity trace is established "in" short-term (or working) memory. Activation is assumed to decay spontaneously with the passage of time, so a refreshing process-rehearsal-is needed to maintain availability. Most of the phenomena of immediate retention, such as capacity limitations and word length effects, are assumed to arise from trade-offs between rehearsal and decay. This "standard model" of how we remember over the short-term still enjoys considerable popularity, although recent research questions most of its main assumptions. In this chapter I review the recent research and identify the empirical and conceptual problems that plague traditional conceptions of short-term memory. Increasingly, researchers are recognizing that short-term retention is cue driven, much like long-term memory, and that neither rehearsal nor decay is likely to explain the particulars of short-term forgetting.

  12. Gummed-up memory: chewing gum impairs short-term recall.

    Science.gov (United States)

    Kozlov, Michail D; Hughes, Robert W; Jones, Dylan M

    2012-01-01

    Several studies have suggested that short-term memory is generally improved by chewing gum. However, we report the first studies to show that chewing gum impairs short-term memory for both item order and item identity. Experiment 1 showed that chewing gum reduces serial recall of letter lists. Experiment 2 indicated that chewing does not simply disrupt vocal-articulatory planning required for order retention: Chewing equally impairs a matched task that required retention of list item identity. Experiment 3 demonstrated that manual tapping produces a similar pattern of impairment to that of chewing gum. These results clearly qualify the assertion that chewing gum improves short-term memory. They also pose a problem for short-term memory theories asserting that forgetting is based on domain-specific interference given that chewing does not interfere with verbal memory any more than tapping. It is suggested that tapping and chewing reduce the general capacity to process sequences.

  13. A Short Term Analogue Memory

    DEFF Research Database (Denmark)

    Shah, Peter Jivan

    1992-01-01

    A short term analogue memory is described. It is based on a well-known sample-hold topology in which leakage currents have been minimized partly by circuit design and partly by layout techniques. Measurements on a test chip implemented in a standard 2.4 micron analogue CMOS process show a droop...

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

    Science.gov (United States)

    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.

  15. Comparison of Sugammadex and Neostigmine in Short Term Surgery

    Directory of Open Access Journals (Sweden)

    Fatih Koc

    2014-03-01

    Full Text Available Aim: This study compared the efficacy and cost effectivines of sugammadex and neostigmine for reversal of neuromuscular blockade induced by rocuronium for short term elective surgery. Material and Method: After written informed consent, 33 patients aged 18%u201365, ASA I-III, who were undergoing short term surgery (

  16. Short term fluctuations and succession trends in tropical floodplain vegetation measured by correspondence analysis

    Directory of Open Access Journals (Sweden)

    Anderson Medeiros dos Santos

    2008-08-01

    Full Text Available The aim of this work was to study the aquatic macrophytes community development to distinguish the fluctuations from succession trends at different temporal and spatial scales in the Upper Paraná River floodplain. The samples were collected quarterly from May 2000 to March 2002 in seven lakes with different degrees of connectivity from the main river channel and analyzed by between-class correspondence analysis. It was difficult to establish any pattern of community development at local scale but at a higher level of organization, disconnected lakes were characterized by fluctuation of the floristic composition. Connected lakes showed a straight trajectory, indicating that succession was occurring at these sites. Probably the income of propagules and diaspores from the river into connected lakes was the driving force of the observed change in community composition.Trabalhos sobre sucessão ecológica foram realizados principalmente com ecologia vegetal de plantas terrestres, onde a maioria das teorias foram concebidas. Poucos estudos abordam a vegetação de áreas alagáveis especialmente no Brasil. Este trabalho investigou o desenvolvimento da comunidade de macrófitas aquáticas tentando distinguir flutuações populacionais de tendências sucessionais em diferentes escalas temporal e espacial na planície de inundação do Alto Rio Paraná. As amostras foram coletadas a cada três meses, de maio de 2000 a março de 2002, em 7 lagoas com diferentes graus de conectividade com a calha principal dos rios, e analisadas pela análise de correspondência (CA entre-classes. Foi difícil estabelecer qualquer padrão de desenvolvimento da comunidade sob uma escala local, mas em uma escala mais ampla, as lagoas desconectadas foram caracterizadas pela flutuação da composição florística. As lagoas conectadas apresentaram uma trajetória retilínea no diagrama da CA, indicando que a sucessão estava ocorrendo nestes locais. Provavelmente, o aporte

  17. Short-term memory for scenes with affective content

    OpenAIRE

    Maljkovic, Vera; Martini, Paolo

    2005-01-01

    The emotional content of visual images can be parameterized along two dimensions: valence (pleasantness) and arousal (intensity of emotion). In this study we ask how these distinct emotional dimensions affect the short-term memory of human observers viewing a rapid stream of images and trying to remember their content. We show that valence and arousal modulate short-term memory as independent factors. Arousal influences dramatically the average speed of data accumulation in memory: Higher aro...

  18. LANGUAGE REPETITION AND SHORT-TERM MEMORY: AN INTEGRATIVE FRAMEWORK

    Directory of Open Access Journals (Sweden)

    Steve eMajerus

    2013-07-01

    Full Text Available 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 nonword-, word- and sentence-level as well as of verbal maintenance deficits in case of brain injury.

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

    Science.gov (United States)

    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.

  20. Short-horizon regulation for long-term investors

    NARCIS (Netherlands)

    Shi, Z.; Werker, B.J.M.

    2012-01-01

    We study the effects of imposing repeated short-horizon regulatory constraints on long-term investors. We show that Value-at-Risk and Expected Shortfall constraints, when imposed dynamically, lead to similar optimal portfolios and wealth distributions. We also show that, in utility terms, the costs

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

    Science.gov (United States)

    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.

  2. The stimulation of hematosis on short-term and prolong irradiation

    International Nuclear Information System (INIS)

    Tukhtaev, T.M.

    1978-01-01

    This book studies the stimulation of hematosis on short-term and prolong irradiation, pathogenetic mechanisms of lesion and reconstruction of hematosis at critical radiation sickness, action hematosis stimulators in short-term irradiation conditions

  3. Rapid effects of estrogens on short-term memory: Possible mechanisms.

    Science.gov (United States)

    Paletta, Pietro; Sheppard, Paul A S; Matta, Richard; Ervin, Kelsy S J; Choleris, Elena

    2018-06-01

    Estrogens affect learning and memory through rapid and delayed mechanisms. Here we review studies on rapid effects on short-term memory. Estradiol rapidly improves social and object recognition memory, spatial memory, and social learning when administered systemically. The dorsal hippocampus mediates estrogen rapid facilitation of object, social and spatial short-term memory. The medial amygdala mediates rapid facilitation of social recognition. The three estrogen receptors, α (ERα), β (ERβ) and the G-protein coupled estrogen receptor (GPER) appear to play different roles depending on the task and brain region. Both ERα and GPER agonists rapidly facilitate short-term social and object recognition and spatial memory when administered systemically or into the dorsal hippocampus and facilitate social recognition in the medial amygdala. Conversely, only GPER can facilitate social learning after systemic treatment and an ERβ agonist only rapidly improved short-term spatial memory when given systemically or into the hippocampus, but also facilitates social recognition in the medial amygdala. Investigations into the mechanisms behind estrogens' rapid effects on short term memory showed an involvement of the extracellular signal-regulated kinase (ERK) and the phosphoinositide 3-kinase (PI3K) kinase pathways. Recent evidence also showed that estrogens interact with the neuropeptide oxytocin in rapidly facilitating social recognition. Estrogens can increase the production and/or release of oxytocin and other neurotransmitters, such as dopamine and acetylcholine. Therefore, it is possible that estrogens' rapid effects on short-term memory may occur through the regulation of various neurotransmitters, although more research is need on these interactions as well as the mechanisms of estrogens' actions on short-term memory. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Short-Term Reproducibility of Twenty-Four-Hour Intraocular Pressure Curves in Untreated Patients with Primary Open-Angle Glaucoma and Ocular Hypertension.

    Directory of Open Access Journals (Sweden)

    Shuo Xu

    Full Text Available To assess the short-term day-to-day reproducibility of 24-hour intraocular pressure (IOP curves in various respects in untreated primary open-angle glaucoma (POAG and ocular hypertension (OHT patients.47 subjects with POAG and 34 subjects with OHT underwent IOP measurements every 2 hours in both eyes for consecutive 48 hours by a non-contact tonometer (NCT. IOP values at each time point were recorded. Mean IOP, peak IOP, time difference of peak IOP between two days and IOP fluctuation were also calculated. Intraclass correlation coefficients (ICCs and Bland-Altman plots were used to evaluate reproducibility.ICCs of the entire IOP values for a complete 24-hour curve were 0.577 and 0.561 in POAG and OHT patients, respectively. ICCs of IOP values at different time points ranged from 0.384 (10am to 0.686 (4am in POAG patients and from 0.347 (6am to 0.760 (4am in OHT patients. ICCs of mean IOP, peak IOP and IOP fluctuation were respectively 0.832, 0.704, 0.367 in POAG patients and 0.867, 0.816 0.633 in OHT patients. Only 37.23% and 35.29% of the peak IOP time points appeared within the time difference of 2 hours in POAG and OHT patients, respectively, while 53.19% and 48.53% appeared within 4 hours in POAG and OHT patients, respectively.A 24-hour IOP curve in a single day is not highly reproducible in short-term and has limited use for evaluating individual IOP condition. Mean IOP and peak IOP for a 24-hour IOP curve are useful parameters in clinical follow-up, while IOP value at a certain time point, IOP fluctuation and peak IOP time point should be interpreted with caution.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Short-term and long-term earthquake occurrence models for Italy: ETES, ERS and LTST

    Directory of Open Access Journals (Sweden)

    Maura Murru

    2010-11-01

    Full Text Available This study describes three earthquake occurrence models as applied to the whole Italian territory, to assess the occurrence probabilities of future (M ≥5.0 earthquakes: two as short-term (24 hour models, and one as long-term (5 and 10 years. The first model for short-term forecasts is a purely stochastic epidemic type earthquake sequence (ETES model. The second short-term model is an epidemic rate-state (ERS forecast based on a model that is physically constrained by the application to the earthquake clustering of the Dieterich rate-state constitutive law. The third forecast is based on a long-term stress transfer (LTST model that considers the perturbations of earthquake probability for interacting faults by static Coulomb stress changes. These models have been submitted to the Collaboratory for the Study of Earthquake Predictability (CSEP for forecast testing for Italy (ETH-Zurich, and they were locked down to test their validity on real data in a future setting starting from August 1, 2009.

  7. Category Specific Knowledge Modulate Capacity Limitations of Visual Short-Term Memory

    DEFF Research Database (Denmark)

    Dall, Jonas Olsen; Watanabe, Katsumi; Sørensen, Thomas Alrik

    2016-01-01

    We explore whether expertise can modulate the capacity of visual short-term memory, as some seem to argue that training affects capacity of short-term memory [13] while others are not able to find this modulation [12]. We extend on a previous study [3] demonstrating expertise effects by investiga...... are in line with the theoretical interpretation that visual short-term memory reflects the sum of the reverberating feedback loops to representations in long-term memory.......We explore whether expertise can modulate the capacity of visual short-term memory, as some seem to argue that training affects capacity of short-term memory [13] while others are not able to find this modulation [12]. We extend on a previous study [3] demonstrating expertise effects......), and expert observers (Japanese university students). For both the picture and the letter condition we find no performance difference in memory capacity, however, in the critical hiragana condition we demonstrate a systematic difference relating expertise differences between the groups. These results...

  8. Short-term mechanisms influencing volumetric brain dynamics

    NARCIS (Netherlands)

    Dieleman, Nikki; Koek, Huiberdina L.; Hendrikse, Jeroen

    2017-01-01

    With the use of magnetic resonance imaging (MRI) and brain analysis tools, it has become possible to measure brain volume changes up to around 0.5%. Besides long-term brain changes caused by atrophy in aging or neurodegenerative disease, short-term mechanisms that influence brain volume may exist.

  9. Short-term robustness of production management systems

    NARCIS (Netherlands)

    Kleijnen, J.P.C.; Gaury, E.G.A.

    1998-01-01

    Short-term performance of a production management system for make-to-stock factories may be quantified through the service rate per shift; long-term performance through the average monthly work in process (WIP). This may yield, for example, that WIP is minimized, while the probability of the service

  10. Potentials of short term and long term cryopreserved sperm of the ...

    African Journals Online (AJOL)

    To service the growing demand for male African giant catfish (Clarias gariepinus) broodstock for aquaculture in Nigeria, and to conserve valuable genetic resources, we improved both short-term (in deep freezer at -35°C) and long-term cryopreservation (in liquid nitrogen at -296°C) of catfish sperm. Catfish sperm ...

  11. Forecasting stock return volatility: A comparison between the roles of short-term and long-term leverage effects

    Science.gov (United States)

    Pan, Zhiyuan; Liu, Li

    2018-02-01

    In this paper, we extend the GARCH-MIDAS model proposed by Engle et al. (2013) to account for the leverage effect in short-term and long-term volatility components. Our in-sample evidence suggests that both short-term and long-term negative returns can cause higher future volatility than positive returns. Out-of-sample results show that the predictive ability of GARCH-MIDAS is significantly improved after taking the leverage effect into account. The leverage effect for short-term volatility component plays more important role than the leverage effect for long-term volatility component in affecting out-of-sample forecasting performance.

  12. Effects of massive wind power integration on short-term water resource management in central Chile - a grid-wide study

    Science.gov (United States)

    Haas, J.; Olivares, M. A.; Palma, R.

    2013-12-01

    In central Chile, water from reservoirs and streams is mainly used for irrigation and power generation. Hydropower reservoirs operation is particularly challenging because: i) decisions at each plant impact the entire power system, and ii) the existence of large storage capacity implies inter-temporal ties. An Independent System Operator (ISO) decides the grid-wide optimal allocation of water for power generation, under irrigation-related constraints. To account for the long-term opportunity cost of water, a future cost function is determined and used in the short term planning. As population growth and green policies demand increasing levels of renewable energy in power systems, deployment of wind farms and solar plants is rising quickly. However, their power output is highly fluctuating on short time scales, affecting the operation of power plants, particularly those fast responding units as hydropower reservoirs. This study addresses these indirect consequences of massive introduction of green energy sources on reservoir operations. Short-term reservoir operation, under different wind penetration scenarios, is simulated using a replica of Chile's ISO's scheduling optimization tools. Furthermore, an ongoing study is exploring the potential to augment the capacity the existing hydro-power plants to better cope with the balancing needs due to a higher wind power share in the system. As reservoir releases determine to a great extent flows at downstream locations, hourly time series of turbined flows for 24-hour periods were computed for selected combinations between new wind farms and increased capacity of existing hydropower plants. These time series are compiled into subdaily hydrologic alteration (SDHA) indexes (Zimmerman et al, 2010). The resulting sample of indexes is then analyzed using duration curves. Results show a clear increase in the SDHA for every reservoir of the system as more fluctuating renewables are integrated into the system. High-fluctuation

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

    Science.gov (United States)

    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.

  14. Short-term and working memory impairments in aphasia.

    Science.gov (United States)

    Potagas, Constantin; Kasselimis, Dimitrios; Evdokimidis, Ioannis

    2011-08-01

    The aim of the present study is to investigate short-term memory and working memory deficits in aphasics in relation to the severity of their language impairment. Fifty-eight aphasic patients participated in this study. Based on language assessment, an aphasia score was calculated for each patient. Memory was assessed in two modalities, verbal and spatial. Mean scores for all memory tasks were lower than normal. Aphasia score was significantly correlated with performance on all memory tasks. Correlation coefficients for short-term memory and working memory were approximately of the same magnitude. According to our findings, severity of aphasia is related with both verbal and spatial memory deficits. Moreover, while aphasia score correlated with lower scores in both short-term memory and working memory tasks, the lack of substantial difference between corresponding correlation coefficients suggests a possible primary deficit in information retention rather than impairment in working memory. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Short-Term Contract Work in Adult Education (I) and (II).

    Science.gov (United States)

    Hall, Dorothea; McMath, Patricia

    1986-01-01

    This two-part article discusses short-term project contracts for adult education staff. Part one covers implications of this trend for the service and for the staff involved. Part two looks at short-term contracts from the management viewpoint. (CH)

  16. Short-term Memory of Deep RNN

    OpenAIRE

    Gallicchio, Claudio

    2018-01-01

    The extension of deep learning towards temporal data processing is gaining an increasing research interest. In this paper we investigate the properties of state dynamics developed in successive levels of deep recurrent neural networks (RNNs) in terms of short-term memory abilities. Our results reveal interesting insights that shed light on the nature of layering as a factor of RNN design. Noticeably, higher layers in a hierarchically organized RNN architecture results to be inherently biased ...

  17. Selection on female behaviour fluctuates with offspring environment.

    Science.gov (United States)

    Taylor, R W; Boutin, S; Humphries, M M; McAdam, A G

    2014-11-01

    Temporal variation in selection has long been proposed as a mechanism by which genetic variation could be maintained despite short-term strong directional selection and has been invoked to explain the maintenance of consistent individual differences in behaviour. We tested the hypothesis that ecological changes through time lead to fluctuating selection, which could promote the maintenance of variation in female behavioural traits in a wild population of North American red squirrels. As predicted, linear selection gradients on female aggression and activity significantly fluctuated across years depending on the level of competition among juveniles for vacant territories. This selection acted primarily through juvenile overwinter survival rather than maternal fecundity. Incorporating uncertainty in individual measures of behaviour reduced the magnitude of annual selection gradients and increased uncertainty in these estimates, but did not affect the overall pattern of temporal fluctuations in natural selection that coincided with the intensity of competition for vacant territories. These temporal fluctuations in selection might, therefore, promote the maintenance of heritable individual differences in behaviour in this wild red squirrel population. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  18. Cardioprotective Signature of Short-Term Caloric Restriction.

    Directory of Open Access Journals (Sweden)

    Hossein Noyan

    Full Text Available To understand the molecular pathways underlying the cardiac preconditioning effect of short-term caloric restriction (CR.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.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.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.

  19. The stability of the international oil trade network from short-term and long-term perspectives

    Science.gov (United States)

    Sun, Qingru; Gao, Xiangyun; Zhong, Weiqiong; Liu, Nairong

    2017-09-01

    To examine the stability of the international oil trade network and explore the influence of countries and trade relationships on the trade stability, we construct weighted and unweighted international oil trade networks based on complex network theory using oil trading data between countries from 1996 to 2014. We analyze the stability of international oil trade network (IOTN) from short-term and long-term aspects. From the short-term perspective, we find that the trade volumes play an important role on the stability. Moreover, the weighted IOTN is stable; however, the unweighted networks can better reflect the actual evolution of IOTN. From the long-term perspective, we identify trade relationships that are maintained during the whole sample period to reveal the situation of the whole international oil trade. We provide a way to quantitatively measure the stability of complex network from short-term and long-term perspectives, which can be applied to measure and analyze trade stability of other goods or services.

  20. Dissociating Measures of Consciousness from Measures of Short-Term Memory

    DEFF Research Database (Denmark)

    Sørensen, Thomas Alrik; Ásgeirsson, Árni Gunnar; Staugaard, Camilla Funch

    Often, the contents of consciousness are equated with the contents of short-term memory (or working memory), sometimes to a point where they are treated as identical entities. In the present study we aimed to investigate whether they may be modulated independently and thus dissociated from each...... if conscious content simply can be reduced to a cognitive process like short-term memory. In two experiments, we combined two different measures of short-term memory capacity to investigate how manipulations of set-size affect performance in observers with the Perceptual Awareness Scale (PAS) to measure...... conscious experience of the stimulus in every trial (Ramsøy & Overgaard, 2004; Overgaard & Sørensen, 2004). We trained observers to report their experience of a visual target stimulus on the four-point PAS scale; ranging from “no experience” to “clear experience”. To measure short-term memory we used...

  1. Applicability of short-term accelerated biofouling studies to predict long-term biofouling accumulation in reverse osmosis membrane systems

    KAUST Repository

    Sanawar, Huma

    2018-02-02

    Biofouling studies addressing biofouling control are mostly executed in short-term studies. It is unclear whether data collected from these experiments are representative for long-term biofouling as occurring in full-scale membrane systems. This study investigated whether short-term biofouling studies accelerated by biodegradable nutrient dosage to feed water were predictive for long-term biofouling development without nutrient dosage. Since the presence of a feed spacer has an strong effect on the degree of biofouling, this study employed six geometrically different feed spacers. Membrane fouling simulators (MFSs) were operated with the same (i) membrane, (ii) feed flow and (iii) feed water, but with feed spacers varying in geometry. For the short-term experiment, biofilm formation was enhanced by nutrient dosage to the MFS feed water, whereas no nutrient dosage was applied in the long-term experiment. Pressure drop development was monitored to characterize the extent of biofouling, while the accumulated viable biomass content at the end of the experimental run was quantified by adenosine triphosphate (ATP) measurements. Impact of feed spacer geometry on biofouling was compared for the short-term and long-term biofouling study. The results of the study revealed that the feed spacers exhibited the same biofouling behavior for (i) the short-term (9-d) study with nutrient dosage and (ii) the long-term (96-d) study without nutrient dosage. For the six different feed spacers, the accumulated viable biomass content (pg ATP.cm) was roughly the same, but the biofouling impact in terms of pressure drop increase in time was significantly different. The biofouling impact ranking of the six feed spacers was the same for the short-term and long-term biofouling studies. Therefore, it can be concluded that short-term accelerated biofouling studies in MFSs are a representative and suitable approach for the prediction of biofouling in membrane filtration systems after long-term

  2. Short-term fasting alters cytochrome P450-mediated drug metabolism in humans

    NARCIS (Netherlands)

    Lammers, Laureen A.; Achterbergh, Roos; de Vries, Emmely M.; van Nierop, F. Samuel; Klümpen, Heinz-Josef; Soeters, Maarten R.; Boelen, Anita; Romijn, Johannes A.; Mathôt, Ron A. A.

    2015-01-01

    Experimental studies indicate that short-term fasting alters drug metabolism. However, the effects of short-term fasting on drug metabolism in humans need further investigation. Therefore, the aim of this study was to evaluate the effects of short-term fasting (36 h) on P450-mediated drug

  3. Dissociating Contents of Consciousness from Contents of Short-Term Memory

    DEFF Research Database (Denmark)

    Sørensen, Thomas Alrik; Ásgeirsson, Árni Gunnar; Staugaard, Camilla Funch

    2014-01-01

    The contents of consciousness and of short-term memory are hard to disentangle. As it seems intuitive that we represent attended objects in short-term memory and in experience, to many, it also seems intuitive to equate this content. Here we investigated memory resolution for orientation......” to a “clear experience” of a probed target. To assess memory resolution we used a Landolt-variation on the visual short-term memory (VSTM) resolution paradigm (e.g. Wilken & Ma, 2004). Set-sizes in the memory display were varied between 1, 2, or 4 elements. With increasing set-size we found that both...

  4. Some risks related to the short-term trading of natural gas

    International Nuclear Information System (INIS)

    Ahmed El Hachemi Mazighi

    2004-01-01

    Traditionally guided by long-term contracts, the international natural gas trade is experiencing new methods of operating, based on the short term and more flexibility. Today, indeed, the existence of uncommitted quantities of natural gas, combined with gas price discrepancies among different regions of the world, gives room for the expansion of the spot-trading of gas. The main objective of this paper is to discuss three fundamental risks related to the short-term trading of natural gas: volume risk, price risk and infrastructure risk. The defenders Of globalisation argue that the transition from the long-term to the short-term trading of natural gas is mainly a question of access to gas reserves, decreasing costs of gas liquefaction, the building of liquefied natural gas (LNG) fleets and regasification facilities and third-party access to the infrastructure. This process needs to be as short as possible, so that the risks related to the transition process will disappear rapidly. On the other hand, the detractors of globalisation put the emphasis on the complexity of the gas value chain and on the fact that eliminating long- term contracts increases the risks inherent to the international natural gas business. In this paper, we try to untangle and assess the risks related to the short-term trading of natural gas. Our main conclusions are: the short-term trading of gas is far from riskless; volume risk requires stock-building in both consuming and producing countries. (author)

  5. Holding multiple items in short term memory: a neural mechanism.

    Directory of Open Access Journals (Sweden)

    Edmund T Rolls

    Full Text Available Human short term memory has a capacity of several items maintained simultaneously. We show how the number of short term memory representations that an attractor network modeling a cortical local network can simultaneously maintain active is increased by using synaptic facilitation of the type found in the prefrontal cortex. We have been able to maintain 9 short term memories active simultaneously in integrate-and-fire simulations where the proportion of neurons in each population, the sparseness, is 0.1, and have confirmed the stability of such a system with mean field analyses. Without synaptic facilitation the system can maintain many fewer memories active in the same network. The system operates because of the effectively increased synaptic strengths formed by the synaptic facilitation just for those pools to which the cue is applied, and then maintenance of this synaptic facilitation in just those pools when the cue is removed by the continuing neuronal firing in those pools. The findings have implications for understanding how several items can be maintained simultaneously in short term memory, how this may be relevant to the implementation of language in the brain, and suggest new approaches to understanding and treating the decline in short term memory that can occur with normal aging.

  6. Holding multiple items in short term memory: a neural mechanism.

    Science.gov (United States)

    Rolls, Edmund T; Dempere-Marco, Laura; Deco, Gustavo

    2013-01-01

    Human short term memory has a capacity of several items maintained simultaneously. We show how the number of short term memory representations that an attractor network modeling a cortical local network can simultaneously maintain active is increased by using synaptic facilitation of the type found in the prefrontal cortex. We have been able to maintain 9 short term memories active simultaneously in integrate-and-fire simulations where the proportion of neurons in each population, the sparseness, is 0.1, and have confirmed the stability of such a system with mean field analyses. Without synaptic facilitation the system can maintain many fewer memories active in the same network. The system operates because of the effectively increased synaptic strengths formed by the synaptic facilitation just for those pools to which the cue is applied, and then maintenance of this synaptic facilitation in just those pools when the cue is removed by the continuing neuronal firing in those pools. The findings have implications for understanding how several items can be maintained simultaneously in short term memory, how this may be relevant to the implementation of language in the brain, and suggest new approaches to understanding and treating the decline in short term memory that can occur with normal aging.

  7. Holding Multiple Items in Short Term Memory: A Neural Mechanism

    Science.gov (United States)

    Rolls, Edmund T.; Dempere-Marco, Laura; Deco, Gustavo

    2013-01-01

    Human short term memory has a capacity of several items maintained simultaneously. We show how the number of short term memory representations that an attractor network modeling a cortical local network can simultaneously maintain active is increased by using synaptic facilitation of the type found in the prefrontal cortex. We have been able to maintain 9 short term memories active simultaneously in integrate-and-fire simulations where the proportion of neurons in each population, the sparseness, is 0.1, and have confirmed the stability of such a system with mean field analyses. Without synaptic facilitation the system can maintain many fewer memories active in the same network. The system operates because of the effectively increased synaptic strengths formed by the synaptic facilitation just for those pools to which the cue is applied, and then maintenance of this synaptic facilitation in just those pools when the cue is removed by the continuing neuronal firing in those pools. The findings have implications for understanding how several items can be maintained simultaneously in short term memory, how this may be relevant to the implementation of language in the brain, and suggest new approaches to understanding and treating the decline in short term memory that can occur with normal aging. PMID:23613789

  8. Qualitative similarities in the visual short-term memory of pigeons and people.

    Science.gov (United States)

    Gibson, Brett; Wasserman, Edward; Luck, Steven J

    2011-10-01

    Visual short-term memory plays a key role in guiding behavior, and individual differences in visual short-term memory capacity are strongly predictive of higher cognitive abilities. To provide a broader evolutionary context for understanding this memory system, we directly compared the behavior of pigeons and humans on a change detection task. Although pigeons had a lower storage capacity and a higher lapse rate than humans, both species stored multiple items in short-term memory and conformed to the same basic performance model. Thus, despite their very different evolutionary histories and neural architectures, pigeons and humans have functionally similar visual short-term memory systems, suggesting that the functional properties of visual short-term memory are subject to similar selective pressures across these distant species.

  9. A NEW APPROACH TO DETECT CONGESTIVE HEART FAILURE USING DETRENDED FLUCTUATION ANALYSIS OF ELECTROCARDIOGRAM SIGNALS

    Directory of Open Access Journals (Sweden)

    CHANDRAKAR KAMATH

    2015-02-01

    Full Text Available The aim of this study is to evaluate how far the detrended fluctuation analysis (DFA approach helps to characterize the short-term and intermediate-term fractal correlations in the raw electrocardiogram (ECG signals and thereby discriminate between normal and congestive heart failure (CHF subjects. The DFA-1 calculations were performed on normal and CHF short-term ECG segments, of the order of 20 seconds duration. Differences were found in shortterm and intermediate-term correlation properties and the corresponding scaling exponents of the two groups (normal and CHF. The statistical analyses show that short-term fractal scaling exponent alone is sufficient to distinguish between normal and CHF subjects. The receiver operating characteristic curve (ROC analysis confirms the robustness of this new approach and exhibits an average accuracy that exceeds 98.2%, average sensitivity of about 98.4%, positive predictivity of 98.00%, and average specificity of 98.00%.

  10. Short-term hydropower production planning by stochastic programming

    DEFF Research Database (Denmark)

    Fleten, Stein-Erik; Kristoffersen, Trine

    2008-01-01

    -term production planning a matter of spatial distribution among the reservoirs of the plant. Day-ahead market prices and reservoir inflows are, however, uncertain beyond the current operation day and water must be allocated among the reservoirs in order to strike a balance between current profits and expected......Within the framework of multi-stage mixed-integer linear stochastic programming we develop a short-term production plan for a price-taking hydropower plant operating under uncertainty. Current production must comply with the day-ahead commitments of the previous day which makes short...

  11. Some risks related to the short-term trading of natural gas

    International Nuclear Information System (INIS)

    Mazighi, Ahmed El Hachemi

    2004-01-01

    Traditionally guided by long-term contracts, the international natural gas trade is experiencing new methods of operating, based on the short term and more flexibility. Today, indeed, the existence of uncommitted quantities of natural gas, combined with gas price discrepancies among different regions of the world, gives room for the expansion of the spot-trading of gas. The main objective of this paper is to discuss three fundamental risks related to the short-term trading of natural gas: volume risk, price risk and infrastructure risk. The defenders of globalisation argue that the transition from the long-term to the short-term trading of natural gas is mainly a question of access to gas reserves, decreasing costs of gas liquefaction, the building of liquefied natural gas (LNG) fleets and regasification facilities and third-party access to the infrastructure. This process needs to be as short as possible, so that the risks related to the transition process will disappear rapidly. On the other hand, the detractors of globalisation put the emphasis on the complexity of the gas value chain and on the fact that eliminating long-term contracts increases the risks inherent to the international natural gas business. In this paper, we try to untangle and assess the risks related to the short-term trading of natural gas. Our main conclusions are: the short-term trading of gas is far from riskless; volume risk requires stock-building in both consuming and producing countries; price risk, through the high volatility for gas, induces an increase in options prices; there is no evidence to suggest that money-lenders' appetite for financing gas infrastructure projects will continue in a short-term trading system. This would be a threat to consumers' security of supply. (Author)

  12. Short-term Mobility and Increased Partnership Concurrency among Men in Zimbabwe.

    Directory of Open Access Journals (Sweden)

    Susan Cassels

    Full Text Available Migration has long been understood as an underlying factor for HIV transmission, and sexual partner concurrency has been increasingly studied as an important component of HIV transmission dynamics. However, less work has examined the role of short-term mobility in sexual partner concurrency using a network approach. Short-term mobility may be a risk for HIV for the migrant's partner as well either through the partner's risk behaviors while the migrant is away, such as the partner having additional partners, or via exposure to the return migrant.Using data from the 2010-11 Zimbabwe Demographic and Health Survey, weighted generalized linear regression models were used to investigate the associations between short-term mobility and partnership concurrency at the individual and partnership levels.At the individual level, we find strong evidence of an association between short-term mobility and concurrency. Men who traveled were more likely to have concurrent partnerships compared to men who did not travel and the relationship was non-linear: each trip was associated with a 2% higher probability of concurrency, with a diminishing risk at 60 trips (p<0.001. At the partnership level, short-term mobility by the male only or both partners was associated with male concurrency. Couples in which the female only traveled exhibited less male concurrency.Short-term mobility has the ability to impact population-level transmission dynamics by facilitating partnership concurrency and thus onward HIV transmission. Short-term migrants may be an important population to target for HIV testing, treatment, or social and behavioral interventions to prevent the spread of HIV.

  13. Short-term and long-term effects of violent media on aggression in children and adults.

    Science.gov (United States)

    Bushman, Brad J; Huesmann, L Rowell

    2006-04-01

    To test whether the results of the accumulated studies on media violence and aggressive behavior are consistent with the theories that have evolved to explain the effects. We tested for the existence of both short-term and long-term effects for aggressive behavior. We also tested the theory-driven hypothesis that short-term effects should be greater for adults and long-term effects should be greater for children. Meta-analysis. Children younger than 18 years and adults. Violent media, including TV, movies, video games, music, and comic books. Measures of aggressive behavior, aggressive thoughts, angry feelings, physiological arousal (eg, heart rate, blood pressure), and helping behavior. Effect size estimates were combined using meta-analytic procedures. As expected, the short-term effects of violent media were greater for adults than for children whereas the long-term effects were greater for children than for adults. The results also showed that there were overall modest but significant effect sizes for exposure to media violence on aggressive behaviors, aggressive thoughts, angry feelings, arousal levels, and helping behavior. The results are consistent with the theory that short-term effects are mostly due to the priming of existing well-encoded scripts, schemas, or beliefs, which adults have had more time to encode. In contrast, long-term effects require the learning (encoding) of scripts, schemas, or beliefs. Children can encode new scripts, schemas, and beliefs via observational learning with less interference and effort than adults.

  14. Long term fluctuations of groundwater mine pollution in a sulfide mining district with dry Mediterranean climate: Implications for water resources management and remediation.

    Science.gov (United States)

    Caraballo, Manuel A; Macías, Francisco; Nieto, José Miguel; Ayora, Carlos

    2016-01-01

    Water resources management and restoration strategies, and subsequently ecological and human life quality, are highly influenced by the presence of short and long term cycles affecting the intensity of a targeted pollution. On this respect, a typical acid mine drainage (AMD) groundwater from a sulfide mining district with dry Mediterranean climate (Iberian Pyrite Belt, SW Spain) was studied to unravel the effect of long term weather changes in water flow rate and metal pollutants concentration. Three well differentiated polluting stages were observed and the specific geochemical, mineralogical and hydrological processes involved (pyrite and enclosing rocks dissolution, evaporitic salts precipitation-redisolution and pluviometric long term fluctuations) were discussed. Evidencing the importance of including longer background monitoring stage in AMD management and restoration strategies, the present study strongly advise a minimum 5-years period of AMD continuous monitoring previous to the design of any AMD remediation system in regions with dry Mediterranean climate. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Effects of lattice fluctuations on electronic transmission in metal/conjugated-oligomer/metal structures

    International Nuclear Information System (INIS)

    Yu, Z.G.; Smith, D.L.; Saxena, A.; Bishop, A.R.

    1997-01-01

    The electronic transmission across metal/conjugated-oligomer/metal structures in the presence of lattice fluctuations is studied for short oligomer chains. The lattice fluctuations are approximated by static white noise disorder. Resonant transmission occurs when the energy of an incoming electron coincides with a discrete electronic level of the oligomer. The corresponding transmission peak diminishes in intensity with increasing disorder strength. Because of disorder there is an enhancement of the electronic transmission for energies that lie within the electronic gap of the oligomer. If fluctuations are sufficiently strong, a transmission peak within the gap is found at the midgap energy E=0 for degenerate conjugated oligomers (e.g., trans-polyacetylene) and E≠0 for AB-type degenerate oligomers. These results can be interpreted in terms of soliton-antisoliton states created by lattice fluctuations. copyright 1997 The American Physical Society

  16. Wavelet decomposition and neuro-fuzzy hybrid system applied to short-term wind power

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Jimenez, L.A.; Mendoza-Villena, M. [La Rioja Univ., Logrono (Spain). Dept. of Electrical Engineering; Ramirez-Rosado, I.J.; Abebe, B. [Zaragoza Univ., Zaragoza (Spain). Dept. of Electrical Engineering

    2010-03-09

    Wind energy has become increasingly popular as a renewable energy source. However, the integration of wind farms in the electrical power systems presents several problems, including the chaotic fluctuation of wind flow which results in highly varied power generation from a wind farm. An accurate forecast of wind power generation has important consequences in the economic operation of the integrated power system. This paper presented a new statistical short-term wind power forecasting model based on wavelet decomposition and neuro-fuzzy systems optimized with a genetic algorithm. The paper discussed wavelet decomposition; the proposed wind power forecasting model; and computer results. The original time series, the mean electric power generated in a wind farm, was decomposing into wavelet coefficients that were utilized as inputs for the forecasting model. The forecasting results obtained with the final models were compared to those obtained with traditional forecasting models showing a better performance for all the forecasting horizons. 13 refs., 1 tab., 4 figs.

  17. LISA Pathfinder test-mass charging during galactic cosmic-ray flux short-term variations

    Science.gov (United States)

    Grimani, C.; Fabi, M.; Lobo, A.; Mateos, I.; Telloni, D.

    2015-02-01

    Metal free-floating test masses aboard the future interferometers devoted to gravitational wave detection in space are charged by galactic and solar cosmic rays with energies \\gt 100 MeV/n. This process represents one of the main sources of noise in the lowest frequency band (\\lt 10-3 Hz) of these experiments. We study here the charging of the LISA Pathfinder (LISA-PF) gold-platinum test masses due to galactic cosmic-ray (GCR) protons and helium nuclei with the Fluka Monte Carlo toolkit. Projections of the energy spectra of GCRs during the LISA-PF operations in 2015 are considered. This work was carried out on the basis of the solar activity level and solar polarity epoch expected for LISA-PF. The effects of GCR short-term variations are evaluated here for the first time. Classical Forbush decreases, GCR variations induced by the Sun rotation, and fluctuations in the LISA-PF frequency bandwidth are discussed.

  18. Independence of long-term contextual memory and short-term perceptual hypotheses: Evidence from contextual cueing of interrupted search.

    Science.gov (United States)

    Schlagbauer, Bernhard; Mink, Maurice; Müller, Hermann J; Geyer, Thomas

    2017-02-01

    Observers are able to resume an interrupted search trial faster relative to responding to a new, unseen display. This finding of rapid resumption is attributed to short-term perceptual hypotheses generated on the current look and confirmed upon subsequent looks at the same display. It has been suggested that the contents of perceptual hypotheses are similar to those of other forms of memory acquired long-term through repeated exposure to the same search displays over the course of several trials, that is, the memory supporting "contextual cueing." In three experiments, we investigated the relationship between short-term perceptual hypotheses and long-term contextual memory. The results indicated that long-term, contextual memory of repeated displays neither affected the generation nor the confirmation of short-term perceptual hypotheses for these displays. Furthermore, the analysis of eye movements suggests that long-term memory provides an initial benefit in guiding attention to the target, whereas in subsequent looks guidance is entirely based on short-term perceptual hypotheses. Overall, the results reveal a picture of both long- and short-term memory contributing to reliable performance gains in interrupted search, while exerting their effects in an independent manner.

  19. Questioning short-term memory and its measurement: Why digit span measures long-term associative learning.

    Science.gov (United States)

    Jones, Gary; Macken, Bill

    2015-11-01

    Traditional accounts of verbal short-term memory explain differences in performance for different types of verbal material by reference to inherent characteristics of the verbal items making up memory sequences. The role of previous experience with sequences of different types is ostensibly controlled for either by deliberate exclusion or by presenting multiple trials constructed from different random permutations. We cast doubt on this general approach in a detailed analysis of the basis for the robust finding that short-term memory for digit sequences is superior to that for other sequences of verbal material. Specifically, we show across four experiments that this advantage is not due to inherent characteristics of digits as verbal items, nor are individual digits within sequences better remembered than other types of individual verbal items. Rather, the advantage for digit sequences stems from the increased frequency, compared to other verbal material, with which digits appear in random sequences in natural language, and furthermore, relatively frequent digit sequences support better short-term serial recall than less frequent ones. We also provide corpus-based computational support for the argument that performance in a short-term memory setting is a function of basic associative learning processes operating on the linguistic experience of the rememberer. The experimental and computational results raise questions not only about the role played by measurement of digit span in cognition generally, but also about the way in which long-term memory processes impact on short-term memory functioning. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    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.…

  1. Pigeon visual short-term memory directly compared to primates.

    Science.gov (United States)

    Wright, Anthony A; Elmore, L Caitlin

    2016-02-01

    Three pigeons were trained to remember arrays of 2-6 colored squares and detect which of two squares had changed color to test their visual short-term memory. Procedures (e.g., stimuli, displays, viewing times, delays) were similar to those used to test monkeys and humans. Following extensive training, pigeons performed slightly better than similarly trained monkeys, but both animal species were considerably less accurate than humans with the same array sizes (2, 4 and 6 items). Pigeons and monkeys showed calculated memory capacities of one item or less, whereas humans showed a memory capacity of 2.5 items. Despite the differences in calculated memory capacities, the pigeons' memory results, like those from monkeys and humans, were all well characterized by an inverse power-law function fit to d' values for the five display sizes. This characterization provides a simple, straightforward summary of the fundamental processing of visual short-term memory (how visual short-term memory declines with memory load) that emphasizes species similarities based upon similar functional relationships. By closely matching pigeon testing parameters to those of monkeys and humans, these similar functional relationships suggest similar underlying processes of visual short-term memory in pigeons, monkeys and humans. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Short-term energy outlook: Quarterly projections, Third quarter 1992

    International Nuclear Information System (INIS)

    1992-08-01

    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. (See Short-Term Energy Outlook Annual Supplement, DOE/EIA-0202.) The principal users of the Outlook are managers and energy analysts in private industry and government. The forecast period for this issue of the Outlook extends from the third quarter of 1992 through the fourth quarter of 1993. Values for the second quarter of 1992, 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

  3. Auditory-Cortex Short-Term Plasticity Induced by Selective Attention

    Science.gov (United States)

    Jääskeläinen, Iiro P.; Ahveninen, Jyrki

    2014-01-01

    The ability to concentrate on relevant sounds in the acoustic environment is crucial for everyday function and communication. Converging lines of evidence suggests that transient functional changes in auditory-cortex neurons, “short-term plasticity”, might explain this fundamental function. Under conditions of strongly focused attention, enhanced processing of attended sounds can take place at very early latencies (~50 ms from sound onset) in primary auditory cortex and possibly even at earlier latencies in subcortical structures. More robust selective-attention short-term plasticity is manifested as modulation of responses peaking at ~100 ms from sound onset in functionally specialized nonprimary auditory-cortical areas by way of stimulus-specific reshaping of neuronal receptive fields that supports filtering of selectively attended sound features from task-irrelevant ones. Such effects have been shown to take effect in ~seconds following shifting of attentional focus. There are findings suggesting that the reshaping of neuronal receptive fields is even stronger at longer auditory-cortex response latencies (~300 ms from sound onset). These longer-latency short-term plasticity effects seem to build up more gradually, within tens of seconds after shifting the focus of attention. Importantly, some of the auditory-cortical short-term plasticity effects observed during selective attention predict enhancements in behaviorally measured sound discrimination performance. PMID:24551458

  4. Short-Term Effects of Midseason Coach Turnover on Team Performance in Soccer

    Science.gov (United States)

    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…

  5. Does the Temporal Asymmetry of Short-Term Heart Rate Variability Change during Regular Walking? A Pilot Study of Healthy Young Subjects

    Directory of Open Access Journals (Sweden)

    Xinpei Wang

    2018-01-01

    Full Text Available The acceleration and deceleration patterns in heartbeat fluctuations distribute asymmetrically, which is known as heart rate asymmetry (HRA. It is hypothesized that HRA reflects the balancing regulation of the sympathetic and parasympathetic nervous systems. This study was designed to examine whether altered autonomic balance during exercise can lead to HRA changes. Sixteen healthy college students were enrolled, and each student undertook two 5-min ECG measurements: one in a resting seated position and another while walking on a treadmill at a regular speed of 5 km/h. The two measurements were conducted in a randomized order, and a 30-min rest was required between them. RR interval time series were extracted from the 5-min ECG data, and HRA (short-term was estimated using four established metrics, that is, Porta’s index (PI, Guzik’s index (GI, slope index (SI, and area index (AI, from both raw RR interval time series and the time series after wavelet detrending that removes the low-frequency component of <~0.03 Hz. Our pilot data showed a reduced PI but unchanged GI, SI, and AI during walking compared to resting seated position based on the raw data. Based on the wavelet-detrended data, reduced PI, SI, and AI were observed while GI still showed no significant changes. The reduced PI during walking based on both raw and detrended data which suggests less short-term HRA may underline the belief that vagal tone is withdrawn during low-intensity exercise. GI may not be sensitive to short-term HRA. The reduced SI and AI based on detrended data suggest that they may capture both short- and long-term HRA features and that the expected change in short-term HRA is amplified after removing the trend that is supposed to link to long-term component. Further studies with more subjects and longer measurements are warranted to validate our observations and to examine these additional hypotheses.

  6. Short-term Forecasting Tools for Agricultural Nutrient Management.

    Science.gov (United States)

    Easton, Zachary M; Kleinman, Peter J A; Buda, Anthony R; Goering, Dustin; Emberston, Nichole; Reed, Seann; Drohan, Patrick J; Walter, M Todd; Guinan, Pat; Lory, John A; Sommerlot, Andrew R; Sharpley, Andrew

    2017-11-01

    The advent of real-time, short-term farm management tools is motivated by the need to protect water quality above and beyond the general guidance offered by existing nutrient management plans. Advances in high-performance computing and hydrologic or climate modeling have enabled rapid dissemination of real-time information that can assist landowners and conservation personnel with short-term management planning. This paper reviews short-term decision support tools for agriculture that are under various stages of development and implementation in the United States: (i) Wisconsin's Runoff Risk Advisory Forecast (RRAF) System, (ii) New York's Hydrologically Sensitive Area Prediction Tool, (iii) Virginia's Saturated Area Forecast Model, (iv) Pennsylvania's Fertilizer Forecaster, (v) Washington's Application Risk Management (ARM) System, and (vi) Missouri's Design Storm Notification System. Although these decision support tools differ in their underlying model structure, the resolution at which they are applied, and the hydroclimates to which they are relevant, all provide forecasts (range 24-120 h) of runoff risk or soil moisture saturation derived from National Weather Service Forecast models. Although this review highlights the need for further development of robust and well-supported short-term nutrient management tools, their potential for adoption and ultimate utility requires an understanding of the appropriate context of application, the strategic and operational needs of managers, access to weather forecasts, scales of application (e.g., regional vs. field level), data requirements, and outreach communication structure. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  7. An Artificial Neural Network Based Short-term Dynamic Prediction of Algae Bloom

    Directory of Open Access Journals (Sweden)

    Yao Junyang

    2014-06-01

    Full Text Available This paper proposes a method of short-term prediction of algae bloom based on artificial neural network. Firstly, principal component analysis is applied to water environmental factors in algae bloom raceway ponds to get main factors that influence the formation of algae blooms. Then, a model of short-term dynamic prediction based on neural network is built with the current chlorophyll_a values as input and the chlorophyll_a values in the next moment as output to realize short-term dynamic prediction of algae bloom. Simulation results show that the model can realize short-term prediction of algae bloom effectively.

  8. DYNAMICS OF THE ANXIETY DISORDERS IN THE COURSE OF SHORT-TERM PSYCHOTHERAPY

    Directory of Open Access Journals (Sweden)

    T.N. Hmylova

    2008-06-01

    Full Text Available The tendency of psychotherapy modern concepts referring to the short-term forms having been taken into account, we carried out the research aimed at the study of short-term form personality-oriented psychotherapy effect on the anxiety disorder dynamics. 103 patients with neurotic disorders were examined in the neurosis and psychotherapy department of the Bekhterev Psychoneurological Research Institute. The findings revealed the situational and personal anxiety level to be objectively decreased in the short-term group psychotherapy course. The short-term group psychotherapy was proved to bean effective method in anxiety disorders treatment considering indications and limitations.

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

    OpenAIRE

    DeCamp, Matthew; Rodriguez, Joce; Hecht, Shelby; Barry, Michele; Sugarman, Jeremy

    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 deve...

  10. Narcissism and the Strategic Pursuit of Short-Term Mating

    DEFF Research Database (Denmark)

    Schmitt, David P.; Alcalay, Lidia; Allik, Jüri

    2017-01-01

    Previous studies have documented links between sub-clinical narcissism and the active pursuit of short-term mating strategies (e.g., unrestricted sociosexuality, marital infidelity, mate poaching). Nearly all of these investigations have relied solely on samples from Western cultures. In the curr...... limitations of these cross-culturally universal findings and presents suggestions for future research into revealing the precise psychological features of narcissism that facilitate the strategic pursuit of short-term mating....

  11. Cash Management and Short-Term Investments for Colleges and Universities.

    Science.gov (United States)

    Haag, Leonard H.

    Effective cash management and short-term investing are discussed in this "how to" guide designed to benefit most institutions of higher education. The following premises are examined: proper compensation for effective cash management is not an expense but an investment; effective cash management and short-term investment programs do not depend on…

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

    Science.gov (United States)

    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. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Short-term and long-term plasticity interaction in human primary motor cortex.

    Science.gov (United States)

    Iezzi, Ennio; Suppa, Antonio; Conte, Antonella; Li Voti, Pietro; Bologna, Matteo; Berardelli, Alfredo

    2011-05-01

    Repetitive transcranial magnetic stimulation (rTMS) over primary motor cortex (M1) elicits changes in motor evoked potential (MEP) size thought to reflect short- and long-term forms of synaptic plasticity, resembling short-term potentiation (STP) and long-term potentiation/depression (LTP/LTD) observed in animal experiments. We designed this study in healthy humans to investigate whether STP as elicited by 5-Hz rTMS interferes with LTP/LTD-like plasticity induced by intermittent and continuous theta-burst stimulation (iTBS and cTBS). The effects induced by 5-Hz rTMS and iTBS/cTBS were indexed as changes in MEP size. We separately evaluated changes induced by 5-Hz rTMS, iTBS and cTBS applied alone and those induced by iTBS and cTBS delivered after priming 5-Hz rTMS. Interactions between 5-Hz rTMS and iTBS/cTBS were investigated under several experimental conditions by delivering 5-Hz rTMS at suprathreshold and subthreshold intensity, allowing 1 and 5 min intervals to elapse between 5-Hz rTMS and TBS, and delivering one and ten 5-Hz rTMS trains. We also investigated whether 5-Hz rTMS induces changes in intracortical excitability tested with paired-pulse transcranial magnetic stimulation. When given alone, 5-Hz rTMS induced short-lasting and iTBS/cTBS induced long-lasting changes in MEP amplitudes. When M1 was primed with 10 suprathreshold 5-Hz rTMS trains at 1 min before iTBS or cTBS, the iTBS/cTBS-induced after-effects disappeared. The 5-Hz rTMS left intracortical excitability unchanged. We suggest that STP elicited by suprathreshold 5-Hz rTMS abolishes iTBS/cTBS-induced LTP/LTD-like plasticity through non-homeostatic metaplasticity mechanisms. Our study provides new information on interactions between short-term and long-term rTMS-induced plasticity in human M1. © 2011 The Authors. European Journal of Neuroscience © 2011 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  14. Short-term plasticity as a neural mechanism supporting memory and attentional functions.

    Science.gov (United States)

    Jääskeläinen, Iiro P; Ahveninen, Jyrki; Andermann, Mark L; Belliveau, John W; Raij, Tommi; Sams, Mikko

    2011-11-08

    Based on behavioral studies, several relatively distinct perceptual and cognitive functions have been defined in cognitive psychology such as sensory memory, short-term memory, and selective attention. Here, we review evidence suggesting that some of these functions may be supported by shared underlying neuronal mechanisms. Specifically, we present, based on an integrative review of the literature, a hypothetical model wherein short-term plasticity, in the form of transient center-excitatory and surround-inhibitory modulations, constitutes a generic processing principle that supports sensory memory, short-term memory, involuntary attention, selective attention, and perceptual learning. In our model, the size and complexity of receptive fields/level of abstraction of neural representations, as well as the length of temporal receptive windows, increases as one steps up the cortical hierarchy. Consequently, the type of input (bottom-up vs. top down) and the level of cortical hierarchy that the inputs target, determine whether short-term plasticity supports purely sensory vs. semantic short-term memory or attentional functions. Furthermore, we suggest that rather than discrete memory systems, there are continuums of memory representations from short-lived sensory ones to more abstract longer-duration representations, such as those tapped by behavioral studies of short-term memory. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Short- and long-term reproducibility of radioisotopic examination of gastric emptying

    Energy Technology Data Exchange (ETDEWEB)

    Jonderko, K. (Silesian School of Medicine, Katowice (Poland). Dept. of Gastroenterology)

    1990-01-01

    Reproducibility of gastric emptying (GE) of a radiolabelled solid meal was assessed. The short-term reproducibility was evaluated on the basis of 12 paired GE examinations performed 1-3 days apart. Twelve paired GE examinations taken 3-8 months apart enabled long-term reproducibility assessment. Reproducibility of GE parameters was expressed in terms of the coefficient of variation, CV. No significant between-day variation of solid GE was found either regarding the short-term or the long-term reproducibility. Although slightly higher CV values characterized the long-term reproducibility of the GE parameters considered, the variations of the differences between repeated GE examinations did not differ significantly between short- and long-term GE reproducibility. The results obtained justify the use of radioisotopic GE measurement for the assessment of early and late results of pharmacologic or surgical management. (author).

  16. Short-term and long-term effects of GDP on traffic deaths in 18 OECD countries, 1960-2011.

    Science.gov (United States)

    Dadgar, Iman; Norström, Thor

    2017-02-01

    Research suggests that increases in gross domestic product (GDP) lead to increases in traffic deaths plausibly due to the increased road traffic induced by an expanding economy. However, there also seems to exist a long-term effect of economic growth that is manifested in improved traffic safety and reduced rates of traffic deaths. Previous studies focus on either the short-term, procyclical effect, or the long-term, protective effect. The aim of the present study is to estimate the short-term and long-term effects jointly in order to assess the net impact of GDP on traffic mortality. We extracted traffic death rates for the period 1960-2011 from the WHO Mortality Database for 18 OECD countries. Data on GDP/capita were obtained from the Maddison Project. We performed error correction modelling to estimate the short-term and long-term effects of GDP on the traffic death rates. The estimates from the error correction modelling for the entire study period suggested that a one-unit increase (US$1000) in GDP/capita yields an instantaneous short-term increase in the traffic death rate by 0.58 (pGDP leads to an immediate increase in traffic deaths. However, after the mid-1970s this short-term effect is more than outweighed by a markedly stronger protective long-term effect, whereas the reverse is true for the period before the mid-1970s. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  17. Short-term uranium price formation: a methodology

    International Nuclear Information System (INIS)

    Hsieh, L.Y.; de Graffenried, C.L.

    1987-01-01

    One of the major problems in analyzing the short-term uranium market is the lack of a well-defined spot market price. The two primary sources of price data covering the US uranium market are the series published by the US Dept. of Energy (DOE) and by the Nuclear Exchange Corporation (NUEXCO), a private brokerage firm. Because of the differences in both definition and coverage, these two series are not directly comparable. In this study, an econometric model was developed for analyzing the interrelationship between short-term uranium price (NUEXCO exchange value), supply, demand, and future price expectations formed by market participants. The validity of this model has been demonstrated by the fact that all simulation statistics derived are highly significant. Three forecasting scenarios were developed in this study

  18. Persistent long-term facilitation at an identified synapse becomes labile with activation of short-term heterosynaptic plasticity.

    Science.gov (United States)

    Hu, Jiang-Yuan; Schacher, Samuel

    2014-04-02

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

  19. Behavioural Models of Motor Control and Short-Term Memory

    OpenAIRE

    Imanaka, Kuniyasu; Funase, Kozo; Yamauchi, Masaki

    1995-01-01

    We examined in this review article the behavioural and conceptual models of motor control and short-term memory which have intensively been investigated since the 1970s. First, we reviewed both the dual-storage model of short-term memory in which movement information is stored and a typical model of motor control which emphasizes the importance of efferent factors. We then examined two models of preselection effects: a cognitive model and a cognitive/ efferent model. Following this we reviewe...

  20. Gummed-up memory: Chewing gum impairs short-term recall

    OpenAIRE

    Kozlov, Michail D; Hughes, Robert W; Jones, Dylan M

    2012-01-01

    Several studies have suggested that short-term memory is generally improved by chewing gum. However, we report the first studies to show that chewing gum impairs short-term memory for both item order and item identity. Experiment 1 showed that chewing gum reduces serial recall of letter lists. Experiment 2 indicated that chewing does not simply disrupt vocal-articulatory planning required for order retention: Chewing equally impairs a matched task that required retention of list item identity...

  1. [Short-term memory characteristics of vibration intensity tactile perception on human wrist].

    Science.gov (United States)

    Hao, Fei; Chen, Li-Juan; Lu, Wei; Song, Ai-Guo

    2014-12-25

    In this study, a recall experiment and a recognition experiment were designed to assess the human wrist's short-term memory characteristics of tactile perception on vibration intensity, by using a novel homemade vibrotactile display device based on the spatiotemporal combination vibration of multiple micro vibration motors as a test device. Based on the obtained experimental data, the short-term memory span, recognition accuracy and reaction time of vibration intensity were analyzed. From the experimental results, some important conclusions can be made: (1) The average short-term memory span of tactile perception on vibration intensity is 3 ± 1 items; (2) The greater difference between two adjacent discrete intensities of vibrotactile stimulation is defined, the better average short-term memory span human wrist gets; (3) There is an obvious difference of the average short-term memory span on vibration intensity between the male and female; (4) The mechanism of information extraction in short-term memory of vibrotactile display is to traverse the scanning process by comparison; (5) The recognition accuracy and reaction time performance of vibrotactile display compares unfavourably with that of visual and auditory. The results from this study are important for designing vibrotactile display coding scheme.

  2. Pro short-term procurement - Broker/trader

    International Nuclear Information System (INIS)

    Hoellen, E.E.

    1990-01-01

    The author presents his opinion on the issue of short-term versus long-term procurement of uranium and enrichment and the impact on reliability of supply. The progression of the market has been one of increasing commoditization. Utility buyers have moved towards purchasing uranium on the spot market and linking long-term contracts to spot-market pricing. There is some logic to the argument that utilities and the industry in general would be best served by this approach. Inventories would be worked off much more quickly, and unnecessary supply would be shut off until prices recovered to profitable levels. The result would be a healthier market with no detriment to the reliability of supply

  3. Short-term memory in the service of executive control functions

    Directory of Open Access Journals (Sweden)

    Farshad Alizadeh Mansouri

    2015-12-01

    Full Text Available Short-term memory is a crucial cognitive function for supporting on-going and upcoming behaviours, allowing storage of information across delay periods. The content of this memory may typically include tangible information about features such as the shape, colour or texture of an object, its location and motion relative to the body, or phonological information. The neural correlate of these short-term memories has been found in different brain areas involved in organizing perceptual or motor functions. In particular, neuronal activity in different prefrontal areas encodes task-related information corresponding to short-term memory across delay periods, and lesions in the prefrontal cortex severely affect the ability to hold this type of memory. Recent studies have further expanded the scope and possible role of short-term memory by showing that information of abstract entities such as a behaviour-guiding rule, or the occurrence of a conflict in information processing; can also be maintained in short-term memory and used for adjusting the allocation of executive control in dynamic environments. It has also been shown that neuronal activity in the dorsolateral prefrontal and orbitofrontal cortices encodes information about such abstract entities. These findings suggest that the prefrontal cortex plays crucial roles in organizing goal-directed behaviour by supporting various mnemonic processes that maintain a wide range of information in the service of executive control of on-going or upcoming behaviour.

  4. Implicit short- and long-term memory direct our gaze in visual search.

    Science.gov (United States)

    Kruijne, Wouter; Meeter, Martijn

    2016-04-01

    Visual attention is strongly affected by the past: both by recent experience and by long-term regularities in the environment that are encoded in and retrieved from memory. In visual search, intertrial repetition of targets causes speeded response times (short-term priming). Similarly, targets that are presented more often than others may facilitate search, even long after it is no longer present (long-term priming). In this study, we investigate whether such short-term priming and long-term priming depend on dissociable mechanisms. By recording eye movements while participants searched for one of two conjunction targets, we explored at what stages of visual search different forms of priming manifest. We found both long- and short- term priming effects. Long-term priming persisted long after the bias was present, and was again found even in participants who were unaware of a color bias. Short- and long-term priming affected the same stage of the task; both biased eye movements towards targets with the primed color, already starting with the first eye movement. Neither form of priming affected the response phase of a trial, but response repetition did. The results strongly suggest that both long- and short-term memory can implicitly modulate feedforward visual processing.

  5. Stacking Ensemble Learning for Short-Term Electricity Consumption Forecasting

    Directory of Open Access Journals (Sweden)

    Federico Divina

    2018-04-01

    Full Text Available The ability to predict short-term electric energy demand would provide several benefits, both at the economic and environmental level. For example, it would allow for an efficient use of resources in order to face the actual demand, reducing the costs associated to the production as well as the emission of CO 2 . To this aim, in this paper we propose a strategy based on ensemble learning in order to tackle the short-term load forecasting problem. In particular, our approach is based on a stacking ensemble learning scheme, where the predictions produced by three base learning methods are used by a top level method in order to produce final predictions. We tested the proposed scheme on a dataset reporting the energy consumption in Spain over more than nine years. The obtained experimental results show that an approach for short-term electricity consumption forecasting based on ensemble learning can help in combining predictions produced by weaker learning methods in order to obtain superior results. In particular, the system produces a lower error with respect to the existing state-of-the art techniques used on the same dataset. More importantly, this case study has shown that using an ensemble scheme can achieve very accurate predictions, and thus that it is a suitable approach for addressing the short-term load forecasting problem.

  6. Identity modulates short-term memory for facial emotion.

    Science.gov (United States)

    Galster, Murray; Kahana, Michael J; Wilson, Hugh R; Sekuler, Robert

    2009-12-01

    For some time, the relationship between processing of facial expression and facial identity has been in dispute. Using realistic synthetic faces, we reexamined this relationship for both perception and short-term memory. In Experiment 1, subjects tried to identify whether the emotional expression on a probe stimulus face matched the emotional expression on either of two remembered faces that they had just seen. The results showed that identity strongly influenced recognition short-term memory for emotional expression. In Experiment 2, subjects' similarity/dissimilarity judgments were transformed by multidimensional scaling (MDS) into a 2-D description of the faces' perceptual representations. Distances among stimuli in the MDS representation, which showed a strong linkage of emotional expression and facial identity, were good predictors of correct and false recognitions obtained previously in Experiment 1. The convergence of the results from Experiments 1 and 2 suggests that the overall structure and configuration of faces' perceptual representations may parallel their representation in short-term memory and that facial identity modulates the representation of facial emotion, both in perception and in memory. The stimuli from this study may be downloaded from http://cabn.psychonomic-journals.org/content/supplemental.

  7. Stochastic Short-term High-resolution Prediction of Solar Irradiance and Photovoltaic Power Output

    Energy Technology Data Exchange (ETDEWEB)

    Melin, Alexander M. [ORNL; Olama, Mohammed M. [ORNL; Dong, Jin [ORNL; Djouadi, Seddik M. [ORNL; Zhang, Yichen [University of Tennessee, Knoxville (UTK), Department of Electrical Engineering and Computer Science

    2017-09-01

    The increased penetration of solar photovoltaic (PV) energy sources into electric grids has increased the need for accurate modeling and prediction of solar irradiance and power production. Existing modeling and prediction techniques focus on long-term low-resolution prediction over minutes to years. This paper examines the stochastic modeling and short-term high-resolution prediction of solar irradiance and PV power output. We propose a stochastic state-space model to characterize the behaviors of solar irradiance and PV power output. This prediction model is suitable for the development of optimal power controllers for PV sources. A filter-based expectation-maximization and Kalman filtering mechanism is employed to estimate the parameters and states in the state-space model. The mechanism results in a finite dimensional filter which only uses the first and second order statistics. The structure of the scheme contributes to a direct prediction of the solar irradiance and PV power output without any linearization process or simplifying assumptions of the signal’s model. This enables the system to accurately predict small as well as large fluctuations of the solar signals. The mechanism is recursive allowing the solar irradiance and PV power to be predicted online from measurements. The mechanism is tested using solar irradiance and PV power measurement data collected locally in our lab.

  8. Energy storage system in medium-sized voltage lines for the integration of decentralized fluctuating energy sources; Energiespeicher im Niederspannungsnetz zur Integration dezentraler, fluktuierender Energiequellen

    Energy Technology Data Exchange (ETDEWEB)

    Bodach, M.

    2006-06-30

    The solar radiation fluctuates due to atmospheric and planetary influences. Concerning PV systems, the changes from dark clouds to clear sky result in fast and very deep fluctuations of the time behaviour of the power output fed into the low voltage (LV) network by DC-AC-Converters. On the example of a daily recorded global radiation curve with a very short sampling time (regular interval time 1 s) the paper shows that short-term sags of the solar radiation are possible up to 80% of the previous value as a result of sudden and intensive changes of the density of the clouds. These disturbances of the quality of the generated electric power are directly transformed into the LV grids. If the number of PV systems connected to existing LV networks rises essentially, the fluctuating photovoltaic energy generation will achieve a very high importance and therefore not only the well-known, but also a lot of new problems will occur. They have already been investigated theoretically in different papers and they have also been proven quantitatively by own simulations. Improvements of the energy quality at the point of common coupling will be possible if the grid-coupled PV power plants are supplemented with suitable intelligent storage systems bridging the short-term sags. So the influence of the fluctuating radiation on the generated power can be fundamentally reduced. The developed intelligent short-term storage system smoothes out the generated power of the PV system by means of a storage. It is based on the very high capacity of an electric double layer (UltraCap, produced by EPCOS) and includes a complex electronic control system. The UltraCap has the required storing characteristics and has been adjusted to the system voltage by a highly sophisticated microprocessor controlled DC/DC-converter system. Such an intelligent storage system can also be used for the connection of other decentralised power generation units (e.g. fuel cells, block-unit heating power plant) to the

  9. Short-term and long-term memory in early temporal lobe dysfunction.

    Science.gov (United States)

    Hershey, T; Craft, S; Glauser, T A; Hale, S

    1998-01-01

    Following medial temporal damage, mature humans are impaired in retaining new information over long delays but not short delays. The question of whether a similar dissociation occurs in children was addressed by testing children (ages 7-16) with unilateral temporal lobe epilepsy (TLE) and controls on short- and long-term memory tasks, including a spatial delayed response task (SDR). Early-onset TLE did not affect performance on short delays on SDR, but it did impair performance at the longest delay (60 s), similar to adults with unilateral medial temporal damage. In addition, early-onset TLE affected performance on pattern recall, spatial span, and verbal span with rehearsal interference. No differences were found on story recall or on a response inhibition task.

  10. Distribution of Short-Term and Lifetime Predicted Risks of Cardiovascular Diseases in Peruvian Adults

    Science.gov (United States)

    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 (PPeruvian 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

  11. Short term depression unmasks the ghost frequency.

    Directory of Open Access Journals (Sweden)

    Tjeerd V Olde Scheper

    Full Text Available Short Term Plasticity (STP has been shown to exist extensively in synapses throughout the brain. Its function is more or less clear in the sense that it alters the probability of synaptic transmission at short time scales. However, it is still unclear what effect STP has on the dynamics of neural networks. We show, using a novel dynamic STP model, that Short Term Depression (STD can affect the phase of frequency coded input such that small networks can perform temporal signal summation and determination with high accuracy. We show that this property of STD can readily solve the problem of the ghost frequency, the perceived pitch of a harmonic complex in absence of the base frequency. Additionally, we demonstrate that this property can explain dynamics in larger networks. By means of two models, one of chopper neurons in the Ventral Cochlear Nucleus and one of a cortical microcircuit with inhibitory Martinotti neurons, it is shown that the dynamics in these microcircuits can reliably be reproduced using STP. Our model of STP gives important insights into the potential roles of STP in self-regulation of cortical activity and long-range afferent input in neuronal microcircuits.

  12. Earthquake-induced water-level fluctuations at Yucca Mountain, Nevada, June 1992

    International Nuclear Information System (INIS)

    O'Brien, G.M.

    1993-01-01

    This report presents earthquake-induced water-level and fluid-pressure data for wells in the Yucca Mountain area, Nevada, during June 1992. Three earthquakes occurred which caused significant water-level and fluid-pressure responses in wells. Wells USW H-5 and USW H-6 are continuously monitored to detect short-term responses caused by earthquakes. Two wells, monitored hourly, had significant, longer-term responses in water level following the earthquakes. On June 28, 1992, a 7.5-magnitude earthquake occurred near Landers, California causing an estimated maximum water-level change of 90 centimeters in well USW H-5. Three hours later a 6.6-magnitude earthquake occurred near Big Bear Lake, California; the maximum water-level fluctuation was 20 centimeters in well USW H-5. A 5.6-magnitude earthquake occurred at Little Skull Mountain, Nevada, on June 29, approximately 23 kilometers from Yucca Mountain. The maximum estimated short-term water-level fluctuation from the Little Skull Mountain earthquake was 40 centimeters in well USW H-5. The water level in well UE-25p number-sign 1, monitored hourly, decreased approximately 50 centimeters over 3 days following the Little Skull Mountain earthquake. The water level in UE-25p number-sign 1 returned to pre-earthquake levels in approximately 6 months. The water level in the lower interval of well USW H-3 increased 28 centimeters following the Little Skull Mountain earthquake. The Landers and Little Skull Mountain earthquakes caused responses in 17 intervals of 14 hourly monitored wells, however, most responses were small and of short duration. For several days following the major earthquakes, many smaller magnitude aftershocks occurred causing measurable responses in the continuously monitored wells

  13. Visual dot interaction with short-term memory.

    Science.gov (United States)

    Etindele Sosso, Faustin Armel

    2017-06-01

    Many neurodegenerative diseases have a memory component. Brain structures related to memory are affected by environmental stimuli, and it is difficult to dissociate effects of all behavior of neurons. Here, visual cortex of mice was stimulated with gratings and dot, and an observation of neuronal activity before and after was made. Bandwidth, firing rate and orientation selectivity index were evaluated. A primary communication between primary visual cortex and short-term memory appeared to show an interesting path to train cognitive circuitry and investigate the basics mechanisms of the neuronal learning. The findings also suggested the interplay between primary visual cortex and short-term plasticity. The properties inside a visual target shape the perception and affect the basic encoding. Using visual cortex, it may be possible to train the memory and improve the recovery of people with cognitive disabilities or memory deficit.

  14. Pro short-term procurement - U.S. utility

    International Nuclear Information System (INIS)

    Thompson, R.D.

    1990-01-01

    The author expresses the opinion that rather than focusing market discussions around short-term versus long-term procurement strategies, the parties need to be focusing on how long it is going to take to get to a predominantly market-based price both in uranium and enrichment. Long-term contracts are going to be around and will always be an important part of buyers' and sellers' strategies. It is evident that the annual term contract price renegotiations around the world are resulting in continually lower prices. When these price negotiations finally arrive in the range of the market price, a commodity market that resembles other energy commodity markets can be obtained

  15. Short-Term Memory in Habituation and Dishabituation

    Science.gov (United States)

    Whitlow, Jesse William, Jr.

    1975-01-01

    The present research evaluated the refractorylike response decrement, as found in habituation of auditory evoked peripheral vasoconstriction in rabbits, to determine whether or not it represents a short-term habituation process distinct from effector fatigue or sensory adaptation. (Editor)

  16. What do short-term and long-term relationships look like? Building the relationship coordination and strategic timing (ReCAST) model.

    Science.gov (United States)

    Eastwick, Paul W; Keneski, Elizabeth; Morgan, Taylor A; McDonald, Meagan A; Huang, Sabrina A

    2018-05-01

    Close relationships research has examined committed couples (e.g., dating relationships, marriages) using intensive methods that plot relationship development over time. But a substantial proportion of people's real-life sexual experiences take place (a) before committed relationships become "official" and (b) in short-term relationships; methods that document the time course of relationships have rarely been applied to these contexts. We adapted a classic relationship trajectory-plotting technique to generate the first empirical comparisons between the features of people's real-life short-term and long-term relationships across their entire timespan. Five studies compared long-term and short-term relationships in terms of the timing of relationship milestones (e.g., flirting, first sexual intercourse) and the occurrence/intensity of important relationship experiences (e.g., romantic interest, strong sexual desire, attachment). As romantic interest was rising and partners were becoming acquainted, long-term and short-term relationships were indistinguishable. Eventually, romantic interest in short-term relationships plateaued and declined while romantic interest in long-term relationships continued to rise, ultimately reaching a higher peak. As relationships progressed, participants evidenced more features characteristic of the attachment-behavioral system (e.g., attachment, caregiving) in long-term than short-term relationships but similar levels of other features (e.g., sexual desire, self-promotion, intrasexual competition). These data inform a new synthesis of close relationships and evolutionary psychological perspectives called the Relationship Coordination and Strategic Timing (ReCAST) model. ReCAST depicts short-term and long-term relationships as partially overlapping trajectories (rather than relationships initiated with distinct strategies) that differ in their progression along a normative relationship development sequence. (PsycINFO Database Record (c

  17. Augmented Reality in Informal Learning Environments: Investigating Short-term and Long-term Effects

    DEFF Research Database (Denmark)

    Sommerauer, Peter; Müller, Oliver

    2018-01-01

    field experiment with 24 participants at a mathematics exhibition to measure the effect of AR on acquiring and retaining mathematical knowledge in an informal learning environment, both short-term (i.e., directly after visiting the exhibition) and long-term (i.e., two months after the museum visit). Our...

  18. The complexity of standing postural control in older adults: a modified detrended fluctuation analysis based upon the empirical mode decomposition algorithm.

    Directory of Open Access Journals (Sweden)

    Junhong Zhou

    Full Text Available Human aging into senescence diminishes the capacity of the postural control system to adapt to the stressors of everyday life. Diminished adaptive capacity may be reflected by a loss of the fractal-like, multiscale complexity within the dynamics of standing postural sway (i.e., center-of-pressure, COP. We therefore studied the relationship between COP complexity and adaptive capacity in 22 older and 22 younger healthy adults. COP magnitude dynamics were assessed from raw data during quiet standing with eyes open and closed, and complexity was quantified with a new technique termed empirical mode decomposition embedded detrended fluctuation analysis (EMD-DFA. Adaptive capacity of the postural control system was assessed with the sharpened Romberg test. As compared to traditional DFA, EMD-DFA more accurately identified trends in COP data with intrinsic scales and produced short and long-term scaling exponents (i.e., α(Short, α(Long with greater reliability. The fractal-like properties of COP fluctuations were time-scale dependent and highly complex (i.e., α(Short values were close to one over relatively short time scales. As compared to younger adults, older adults demonstrated lower short-term COP complexity (i.e., greater α(Short values in both visual conditions (p>0.001. Closing the eyes decreased short-term COP complexity, yet this decrease was greater in older compared to younger adults (p<0.001. In older adults, those with higher short-term COP complexity exhibited better adaptive capacity as quantified by Romberg test performance (r(2 = 0.38, p<0.001. These results indicate that an age-related loss of COP complexity of magnitude series may reflect a clinically important reduction in postural control system functionality as a new biomarker.

  19. Distribution of Short-Term and Lifetime Predicted Risks of Cardiovascular Diseases in Peruvian Adults.

    Science.gov (United States)

    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

    2015-08-07

    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. 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 (PPeruvian 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. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2009-02-26

    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. 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. 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. The perceived impact of short-term medical volunteer projects in Guatemala is highly variable and dependent upon the individual project. In this exploratory study, project

  2. Alterations in task-induced activity and resting-state fluctuations in visual and DMN areas revealed in long-term meditators.

    Science.gov (United States)

    Berkovich-Ohana, Aviva; Harel, Michal; Hahamy, Avital; Arieli, Amos; Malach, Rafael

    2016-07-15

    Recently we proposed that the information contained in spontaneously emerging (resting-state) fluctuations may reflect individually unique neuro-cognitive traits. One prediction of this conjecture, termed the "spontaneous trait reactivation" (STR) hypothesis, is that resting-state activity patterns could be diagnostic of unique personalities, talents and life-styles of individuals. Long-term meditators could provide a unique experimental group to test this hypothesis. Using fMRI we found that, during resting-state, the amplitude of spontaneous fluctuations in long-term mindfulness meditation (MM) practitioners was enhanced in the visual cortex and significantly reduced in the DMN compared to naïve controls. Importantly, during a visual recognition memory task, the MM group showed heightened visual cortex responsivity, concomitant with weaker negative responses in Default Mode Network (DMN) areas. This effect was also reflected in the behavioral performance, where MM practitioners performed significantly faster than the control group. Thus, our results uncover opposite changes in the visual and default mode systems in long-term meditators which are revealed during both rest and task. The results support the STR hypothesis and extend it to the domain of local changes in the magnitude of the spontaneous fluctuations. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Qualitative similarities in the visual short-term memory of pigeons and people

    OpenAIRE

    Gibson, Brett; Wasserman, Edward; Luck, Steven J.

    2011-01-01

    Visual short-term memory plays a key role in guiding behavior, and individual differences in visual short-term memory capacity are strongly predictive of higher cognitive abilities. To provide a broader evolutionary context for understanding this memory system, we directly compared the behavior of pigeons and humans on a change detection task. Although pigeons had a lower storage capacity and a higher lapse rate than humans, both species stored multiple items in short-term memory and conforme...

  4. Short-term versus long-term contracting for uranium enrichment services

    International Nuclear Information System (INIS)

    Rudy, G.P.

    1990-01-01

    The US Department of Energy (US DOE) is the world's largest and most experienced supplier of uranium enrichment services. Through the late 1970s and early 1980s, emerging market forces transformed what was once a monopoly into a highly competitive industry. In the early 1980's the DOE lost market share. But as we enter the 1990s, new market forces have emerged. The US DOE believes a responsible balance between long-term and short-term contracting will be the key to success and the key to assuring the long-term health and reliability of the nuclear fuel industry. The US DOE intends to be in this nuclear business for a long time and will continue to offer reliable and responsive services second to none

  5. [Impulsiveness Among Short-Term Prisoners with Antisocial Personality Disorder].

    Science.gov (United States)

    Lang, Fabian U; Otte, Stefanie; Vasic, Nenad; Jäger, Markus; Dudeck, Manuela

    2015-07-01

    The study aimed to investigate the correlation between impulsiveness and the antisocial personality disorder among short-term prisoners. The impulsiveness was diagnosed by the Barratt Impulsiveness Scale (BIS). Short-term prisoners with antisocial personality disorder scored significant higher marks on the BIS total scale than those without any personality disorder. In detail, they scored higher marks on each subscale regarding attentional, motor and nonplanning impulsiveness. Moderate and high effects were calculated. It is to be considered to regard impulsivity as a conceptual component of antisociality. © Georg Thieme Verlag KG Stuttgart · New York.

  6. Reinsurance by short-term reinsurers in South Africa

    Directory of Open Access Journals (Sweden)

    Fernhout, C. L. R.

    2016-02-01

    Full Text Available The short-term reinsurance process usually involves three parties, namely the insurer, the reinsurer and the original policyholder, as the insurer cedes a part of the covered risk of the policyholder to the reinsurer. This research however addresses the perceptions of reinsurers regarding their reinsurance activities, where the reinsurer sells reinsurance to other insurance entities (viz. insurers and reinsurers, as well as buys reinsurance from other insurance entities. The crux of short-term reinsurance is therefore mutually loss sharing between the various insurance entities. The objective of this research focuses on the improvement of financial decision-making regarding the reinsurance operations of the reinsurers. To achieve this objective a literature study was undertaken to provide adequate background to compile a questionnaire for the empirical survey. The primary study embodies the perceptions of the South African short-term reinsurers regarding the following aspects: the various reasons why reinsurance occurs; the contracts / methods of reinsurance; the bases / forms of reinsurance; and the factors which determine the retention levels of a reinsurer. South Africa is classified as a developing economy, is a member of the BRICS countries and has an emerging market economy. The empirical results should therefore also be valuable to other countries which are classified similarly

  7. Frequency-specific insight into short-term memory capacity.

    Science.gov (United States)

    Feurra, Matteo; Galli, Giulia; Pavone, Enea Francesco; Rossi, Alessandro; Rossi, Simone

    2016-07-01

    The digit span is one of the most widely used memory tests in clinical and experimental neuropsychology for reliably measuring short-term memory capacity. In the forward version, sequences of digits of increasing length have to be reproduced in the order in which they are presented, whereas in the backward version items must be reproduced in the reversed order. Here, we assessed whether transcranial alternating current stimulation (tACS) increases the memory span for digits of young and midlife adults. Imperceptibly weak electrical currents in the alpha (10 Hz), beta (20 Hz), theta (5 Hz), and gamma (40 Hz) range, as well as a sham stimulation, were delivered over the left posterior parietal cortex, a cortical region thought to sustain maintenance processes in short-term memory through oscillatory brain activity in the beta range. We showed a frequency-specific effect of beta-tACS that robustly increased the forward memory span of young, but not middle-aged, healthy individuals. The effect correlated with age: the younger the subjects, the greater the benefit arising from parietal beta stimulation. Our results provide evidence of a short-term memory capacity improvement in young adults by online frequency-specific tACS application. Copyright © 2016 the American Physiological Society.

  8. Short-term memory in Down syndrome: applying the working memory model.

    Science.gov (United States)

    Jarrold, C; Baddeley, A D

    2001-10-01

    This paper is divided into three sections. The first reviews the evidence for a verbal short-term memory deficit in Down syndrome. Existing research suggests that short-term memory for verbal information tends to be impaired in Down syndrome, in contrast to short-term memory for visual and spatial material. In addition, problems of hearing or speech do not appear to be a major cause of difficulties on tests of verbal short-term memory. This suggests that Down syndrome is associated with a specific memory problem, which we link to a potential deficit in the functioning of the 'phonological loop' of Baddeley's (1986) model of working memory. The second section considers the implications of a phonological loop problem. Because a reasonable amount is known about the normal functioning of the phonological loop, and of its role in language acquisition in typical development, we can make firm predictions as to the likely nature of the short-term memory problem in Down syndrome, and its consequences for language learning. However, we note that the existing evidence from studies with individuals with Down syndrome does not fit well with these predictions. This leads to the third section of the paper, in which we consider key questions to be addressed in future research. We suggest that there are two questions to be answered, which follow directly from the contradictory results outlined in the previous section. These are 'What is the precise nature of the verbal short-term memory deficit in Down syndrome', and 'What are the consequences of this deficit for learning'. We discuss ways in which these questions might be addressed in future work.

  9. Stability of discrete memory states to stochastic fluctuations in neuronal systems

    Science.gov (United States)

    Miller, Paul; Wang, Xiao-Jing

    2014-01-01

    Noise can degrade memories by causing transitions from one memory state to another. For any biological memory system to be useful, the time scale of such noise-induced transitions must be much longer than the required duration for memory retention. Using biophysically-realistic modeling, we consider two types of memory in the brain: short-term memories maintained by reverberating neuronal activity for a few seconds, and long-term memories maintained by a molecular switch for years. Both systems require persistence of (neuronal or molecular) activity self-sustained by an autocatalytic process and, we argue, that both have limited memory lifetimes because of significant fluctuations. We will first discuss a strongly recurrent cortical network model endowed with feedback loops, for short-term memory. Fluctuations are due to highly irregular spike firing, a salient characteristic of cortical neurons. Then, we will analyze a model for long-term memory, based on an autophosphorylation mechanism of calcium/calmodulin-dependent protein kinase II (CaMKII) molecules. There, fluctuations arise from the fact that there are only a small number of CaMKII molecules at each postsynaptic density (putative synaptic memory unit). Our results are twofold. First, we demonstrate analytically and computationally the exponential dependence of stability on the number of neurons in a self-excitatory network, and on the number of CaMKII proteins in a molecular switch. Second, for each of the two systems, we implement graded memory consisting of a group of bistable switches. For the neuronal network we report interesting ramping temporal dynamics as a result of sequentially switching an increasing number of discrete, bistable, units. The general observation of an exponential increase in memory stability with the system size leads to a trade-off between the robustness of memories (which increases with the size of each bistable unit) and the total amount of information storage (which decreases

  10. Currency speculation and dollar fluctuations

    Directory of Open Access Journals (Sweden)

    Stephan Schulmeister

    1988-12-01

    Full Text Available In this study the reasons behind the wide fluctuations of the dollar exchange rate following the breakdown of the Bretton Woods system, for the most part unexplained by the prevailing exchange rate theories, are explored. To do so, the author investigates the exchange rate between the two most traded currencies, the dollar and the deutschemark, from 1973 to 1988. In the first part, the pattern of the daily exchange rate movements is examined to show that a sequence of upward and downward trends interrupted by non-directional movements is typical of exchange rate dynamics in the short run. Moreover, this pattern is systemically exploited through currency speculation, particularly through the use of “technical analysis”. In the second part, the author focuses on the medium-term, arguing that fluctuations can be explained as the result of interacting disequilibria in the goods and asset markets. Although currency speculation has been systemically profitable for most currencies, it should be considered to be destabilizing since the sequence of price runs caused large and persistent deviations of exchange rates from their equilibrium values (purchasing power parity.

  11. Late Holocene dune mobilizations in the northwestern Negev dunefield, Israel: A response to combined anthropogenic activity and short-term intensified windiness

    Science.gov (United States)

    Roskin, Joel; Katra, Itzhak; Blumberg, Dan G.

    2013-04-01

    The study of the effects of past climates on ancient cultures is usually based on geologic records pertaining to rainfall and temperature fluctuations and shifts. This study proposes a paradigm of anthropogenic activity and windiness fluctuations to explain aeolian sedimentation and dune mobilization in the northwestern (NW) Negev Desert dunefield (Israel). The proposed paradigm contributes a different approach to estimating the effect of climate changes on the unprecedented agricultural and urban settlement expansion during the late Roman to Early Islamic period in the northern and central Negev Desert. This study builds upon the late Holocene cluster of luminescence ages of Roskin et al. (Age, origin and climatic controls on vegetated linear dunes in the northwestern Negev Desert (Israel), Quaternary Science Reviews 30 (2011), 1649-1674) coupled with analysis of archaeological finds and historical texts. We suggest that whereas the NW Negev dunefield was generally stable during the Holocene, intermittent dune mobilization during the late Holocene, at ~1.8 ka and mostly 1.4-1.1 ka (~600-900 CE), are linked to periods of human occupation. The idea that the last glacial dune encroachments alone that formed the NW Negev dunefield is connected to cold-event windy climates that may have intensified East Mediterranean cyclonic winter storms, cannot explain the late Holocene dune mobilizations. We conceptually model a connection between late Holocene dune mobilization, widespread anthropogenic occupation and activity, and windiness. We maintain that historic grazing and uprooting shrubs for fuel in the past by nomads and sedentary populations led to decimation of dune stabilizers, biogenic soil crusts and vegetation, causing dune erodibility and low-grade activity. Short-term events of amplified wind power in conjunction with periods of augmented anthropogenic activity that triggered major events of dune mobilization (elongation) and accretion have been preserved in the

  12. Improving the principles of short-term electric load forecasting of the Irkutsk region

    Directory of Open Access Journals (Sweden)

    Kornilov Vladimir

    2017-01-01

    Full Text Available Forecasting of electric load (EL is an important task for both electric power entities and large consumers of electricity [1]. Large consumers are faced with the need to compose applications for the planned volume of EL, and the deviation of subsequent real consumption from previously announced leads to the appearance of penalties from the wholesale market. In turn, electricity producers are interested in forecasting the demand for electricity for prompt response to its fluctuations and for the purpose of optimal infrastructure development. The most difficult and urgent task is the hourly forecasting of EL, which is extremely important for the successful solution of problems of optimization of generating capacities, minimization of power losses, dispatching control, security assessment of power supply, etc. Ultimately, such forecasts allow optimizing the cash costs for electricity and fuel or water consumption during generation. This paper analyzes the experience of the branch of JSC "SO UPS" Irkutsk Regional Dispatch Office of the procedure for short-term forecasting of the EL of the Irkutsk region.

  13. Effect of zinc supplementation of pregnant rats on short-term and long-term memory of their offspring

    International Nuclear Information System (INIS)

    Ali, M.A.; Ghotbeddin, Z.; Parham, G.H.

    2007-01-01

    To see the dose dependent effects of zinc chloride on the short-term and long-term memory in a shuttle box (rats). Six pair adult wistar rats were taken for this experiment. One group of pregnant rats received a daily oral dose of 20 mg/kg Zn as zinc chloride and the remaining groups received a daily oral dose of (30, 50, 70,100 mg/kg) zinc chloride for two weeks by gavage. One month after birth, a shuttle box was used to test short-term and long-term memory. Two criteria were considered to behavioral test, including latency in entering dark chamber and time spent in the dark chamber. This experiment showed that oral administration of ZnCl/sub 2/ with (20, 30, 50 mg/kg/day) doses after 2 weeks at the stage of pregnancy, can improve the working memory of their offspring (p<0.05). Where as ZnCl/sub 2/ with 30 mg/kg/day dose has been more effective than other doses (p<0.001). But rat which received ZnCl/sub 2/ with 100 mg/kg/day at the stage of pregnancy, has shown significant impairment in working (short-term) memory of their offspring (p<0.05) and there was no significant difference in reference (long-term) memory 3 for any of groups. This study has demonstrated that zinc chloride consumption with 30 mg/kg/day dose for two weeks at the stage of pregnancy in rats, has positive effect on short-term memory on their offspring. But consumption of enhanced zinc 100 mg/kg/day in pregnant rats can cause short-term memory impairment. On the other hand, zinc supplementation such as zinc chloride has no effect on long-term memory. (author)

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

    Science.gov (United States)

    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. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. 34 CFR 664.11 - What is a short-term seminar project?

    Science.gov (United States)

    2010-07-01

    ... short-term seminar project is— (a) Designed to help integrate international studies into an institution... 34 Education 3 2010-07-01 2010-07-01 false What is a short-term seminar project? 664.11 Section 664.11 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF...

  16. Oil price fluctuations and employment in Kern County: A Vector Error Correction approach

    International Nuclear Information System (INIS)

    Michieka, Nyakundi M.; Gearhart, Richard

    2015-01-01

    Kern County is one of the country's largest oil producing regions, in which the oil industry employs a significant fraction of the labor force in the county. In this study, the short- and long-run effects of oil price fluctuations on employment in Kern County are investigated using a Vector Error Correction model (VECM). Empirical results over the period 1990:01 to 2015:03 suggest long-run causality running from both WTI and Brent oil prices to employment. No causality is detected in the short-run. Kern County should formulate appropriate policies, which take into account the fact that changes in oil prices have long-term effects on employment rather than short term. - Highlights: • Kern County is California's largest oil producing region. • Historical data has shown increased employment during periods of high oil prices. • We study the short- and long run effects of oil prices on employment in Kern County. • Results suggest long run causality running from WTI and Brent to employment. • No causality is detected in the short run.

  17. Estimation and analysis of the short-term variations of multi-GNSS receiver differential code biases using global ionosphere maps

    Science.gov (United States)

    Li, Min; Yuan, Yunbin; Wang, Ningbo; Liu, Teng; Chen, Yongchang

    2017-12-01

    Care should be taken to minimize the adverse impact of differential code biases (DCBs) on global navigation satellite systems (GNSS)-derived ionospheric information determinations. For the sake of convenience, satellite and receiver DCB products provided by the International GNSS Service (IGS) are treated as constants over a period of 24 h (Li et al. (2014)). However, if DCB estimates show remarkable intra-day variability, the DCBs estimated as constants over 1-day period will partially account for ionospheric modeling error; in this case DCBs will be required to be estimated over shorter time period. Therefore, it is important to further gain insight into the short-term variation characteristics of receiver DCBs. In this contribution, the IGS combined global ionospheric maps and the German Aerospace Center (DLR)-provided satellite DCBs are used in the improved method to determine the multi-GNSS receiver DCBs with an hourly time resolution. The intra-day stability of the receiver DCBs is thereby analyzed in detail. Based on 1 month of data collected within the multi-GNSS experiment of the IGS, a good agreement within the receiver DCBs is found between the resulting receiver DCB estimates and multi-GNSS DCB products from the DLR at a level of 0.24 ns for GPS, 0.28 ns for GLONASS, 0.28 ns for BDS, and 0.30 ns for Galileo. Although most of the receiver DCBs are relatively stable over a 1-day period, large fluctuations (more than 9 ns between two consecutive hours) within the receiver DCBs can be found. We also demonstrate the impact of the significant short-term variations in receiver DCBs on the extraction of ionospheric total electron content (TEC), at a level of 12.96 TECu (TEC unit). Compared to daily receiver DCB estimates, the hourly DCB estimates obtained from this study can reflect the short-term variations of the DCB estimates more dedicatedly. The main conclusion is that preliminary analysis of characteristics of receiver DCB variations over short-term

  18. Aspects if stochastic models for short-term hydropower scheduling and bidding

    Energy Technology Data Exchange (ETDEWEB)

    Belsnes, Michael Martin [Sintef Energy, Trondheim (Norway); Follestad, Turid [Sintef Energy, Trondheim (Norway); Wolfgang, Ove [Sintef Energy, Trondheim (Norway); Fosso, Olav B. [Dep. of electric power engineering NTNU, Trondheim (Norway)

    2012-07-01

    This report discusses challenges met when turning from deterministic to stochastic decision support models for short-term hydropower scheduling and bidding. The report describes characteristics of the short-term scheduling and bidding problem, different market and bidding strategies, and how a stochastic optimization model can be formulated. A review of approaches for stochastic short-term modelling and stochastic modelling for the input variables inflow and market prices is given. The report discusses methods for approximating the predictive distribution of uncertain variables by scenario trees. Benefits of using a stochastic over a deterministic model are illustrated by a case study, where increased profit is obtained to a varying degree depending on the reservoir filling and price structure. Finally, an approach for assessing the effect of using a size restricted scenario tree to approximate the predictive distribution for stochastic input variables is described. The report is a summary of the findings of Work package 1 of the research project #Left Double Quotation Mark#Optimal short-term scheduling of wind and hydro resources#Right Double Quotation Mark#. The project aims at developing a prototype for an operational stochastic short-term scheduling model. Based on the investigations summarized in the report, it is concluded that using a deterministic equivalent formulation of the stochastic optimization problem is convenient and sufficient for obtaining a working prototype. (author)

  19. 22 CFR 62.21 - Short-term scholars.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Short-term scholars. 62.21 Section 62.21 Foreign Relations DEPARTMENT OF STATE PUBLIC DIPLOMACY AND EXCHANGES EXCHANGE VISITOR PROGRAM Specific... programs, confer on common problems and projects, and promote professional relationships and communications...

  20. Scalable data-driven short-term traffic prediction

    NARCIS (Netherlands)

    Friso, K.; Wismans, L. J.J.; Tijink, M. B.

    2017-01-01

    Short-term traffic prediction has a lot of potential for traffic management. However, most research has traditionally focused on either traffic models-which do not scale very well to large networks, computationally-or on data-driven methods for freeways, leaving out urban arterials completely. Urban

  1. Short-Term Saved Leave Scheme

    CERN Multimedia

    2007-01-01

    As announced at the meeting of the Standing Concertation Committee (SCC) on 26 June 2007 and in http://Bulletin No. 28/2007, the existing Saved Leave Scheme will be discontinued as of 31 December 2007. Staff participating in the Scheme will shortly receive a contract amendment stipulating the end of financial contributions compensated by save leave. Leave already accumulated on saved leave accounts can continue to be taken in accordance with the rules applicable to the current scheme. A new system of saved leave will enter into force on 1 January 2008 and will be the subject of a new implementation procedure entitled "Short-term saved leave scheme" dated 1 January 2008. At its meeting on 4 December 2007, the SCC agreed to recommend the Director-General to approve this procedure, which can be consulted on the HR Department’s website at the following address: https://cern.ch/hr-services/services-Ben/sls_shortterm.asp All staff wishing to participate in the new scheme a...

  2. Short-Term Saved Leave Scheme

    CERN Multimedia

    HR Department

    2007-01-01

    As announced at the meeting of the Standing Concertation Committee (SCC) on 26 June 2007 and in http://Bulletin No. 28/2007, the existing Saved Leave Scheme will be discontinued as of 31 December 2007. Staff participating in the Scheme will shortly receive a contract amendment stipulating the end of financial contributions compensated by save leave. Leave already accumulated on saved leave accounts can continue to be taken in accordance with the rules applicable to the current scheme. A new system of saved leave will enter into force on 1 January 2008 and will be the subject of a new im-plementation procedure entitled "Short-term saved leave scheme" dated 1 January 2008. At its meeting on 4 December 2007, the SCC agreed to recommend the Director-General to approve this procedure, which can be consulted on the HR Department’s website at the following address: https://cern.ch/hr-services/services-Ben/sls_shortterm.asp All staff wishing to participate in the new scheme ...

  3. Maternal haemoglobin and short-term neonatal outcome in preterm neonates.

    Directory of Open Access Journals (Sweden)

    Elodie Savajols

    Full Text Available To determine whether there is a significant association between maternal haemoglobin measured before delivery and short-term neonatal outcome in very preterm neonates.We included prospectively all live births occurring from 25 to 32+6 weeks of gestation in a tertiary care centre between January 1(st 2009 and December 31(st 2011. Outborn infants and infants presenting with lethal malformations were excluded. Three hundred and thirty-nine mothers and 409 infants met the inclusion criteria. For each mother-infant pair a prospective record of epidemiologic data was performed and maternal haemoglobin concentration recorded within 24 hours before delivery was retrospectively researched. Maternal haemoglobin was divided into quartiles with the second and the third one regarded as reference as they were composed of normal haemoglobin values. Short-term outcome was defined as poor in case of death during hospital stay and/or grades III/IV intraventricular haemorrhage and/or periventricular leukomalacia and/or necessity of ventriculoperitoneal shunt.The global rate of poor short-term neonatal outcome was 11.4% and was significantly associated with low maternal haemoglobin values. This association remained significant after adjustment for antenatal corticosteroids therapy, gestational age, parity, mechanism of preterm birth, mode of delivery and birth weight (aOR = 2.97 CI 95% [1.36-6.47]. There was no relation between short-term neonatal outcome and high maternal haemoglobin concentration values.We show that low maternal haemoglobin concentration at delivery is an independent risk factor for poor short-term neonatal outcome in very preterm neonates. This study is one of the first to show such an association within the preterm population.

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

    Science.gov (United States)

    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)

  5. Short-term energy outlook, July 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  6. Short- and long-term memory: differential involvement of neurotransmitter systems and signal transduction cascades

    Directory of Open Access Journals (Sweden)

    MÔNICA R.M. VIANNA

    2000-09-01

    Full Text Available Since William James (1890 first distinguished primary from secondary memory, equivalent to short- and long-term memory, respectively, it has been assumed that short-term memory processes are in charge of cognition while long-term memory is being consolidated. From those days a major question has been whether short-term memory is merely a initial phase of long-term memory, or a separate phenomena. Recent experiments have shown that many treatments with specific molecular actions given into the hippocampus and related brain areas after one-trial avoidance learning can effectively cancel short-term memory without affecting long-term memory formation. This shows that short-term memory and long-term memory involve separate mechanisms and are independently processed. Other treatments, however, influence both memory types similarly, suggesting links between both at the receptor and at the post-receptor level, which should not be surprising as they both deal with nearly the same sensorimotor representations. This review examines recent advances in short- and long-term memory mechanisms based on the effect of intra-hippocampal infusion of drugs acting upon neurotransmitter and signal transduction systems on both memory types.

  7. Dispositional optimism as predictor of outcome in short- and long-term psychotherapy.

    Science.gov (United States)

    Heinonen, Erkki; Heiskanen, Tiia; Lindfors, Olavi; Härkäpää, Kristiina; Knekt, Paul

    2017-09-01

    Dispositional optimism predicts various beneficial outcomes in somatic health and treatment, but has been little studied in psychotherapy. This study investigated whether an optimistic disposition differentially predicts patients' ability to benefit from short-term versus long-term psychotherapy. A total of 326 adult outpatients with mood and/or anxiety disorder were randomized into short-term (solution-focused or short-term psychodynamic) or long-term psychodynamic therapy and followed up for 3 years. Dispositional optimism was assessed by patients at baseline with the self-rated Life Orientation Test (LOT) questionnaire. Outcome was assessed at baseline and seven times during the follow-up, in terms of depressive (BDI, HDRS), anxiety (SCL-90-ANX, HARS), and general psychiatric symptoms (SCL-90-GSI), all seven follow-up points including patients' self-reports and three including interview-based measures. Lower dispositional optimism predicted faster symptom reduction in short-term than in long-term psychotherapy. Higher optimism predicted equally rapid and eventually greater benefits in long-term, as compared to short-term, psychotherapy. Weaker optimism appeared to predict sustenance of problems early in long-term therapy. Stronger optimism seems to best facilitate engaging in and benefiting from a long-term therapy process. Closer research might clarify the psychological processes responsible for these effects and help fine-tune both briefer and longer interventions to optimize treatment effectiveness for particular patients and their psychological qualities. Weaker dispositional optimism does not appear to inhibit brief therapy from effecting symptomatic recovery. Patients with weaker optimism do not seem to gain added benefits from long-term therapy, but instead may be susceptible to prolonged psychiatric symptoms in the early stages of long-term therapy. © 2016 The British Psychological Society.

  8. Deficits in verbal long-term memory and learning in children with poor phonological short-term memory skills.

    Science.gov (United States)

    Gathercole, Susan E; Briscoe, Josie; Thorn, Annabel; Tiffany, Claire

    2008-03-01

    Possible links between phonological short-term memory and both longer term memory and learning in 8-year-old children were investigated in this study. Performance on a range of tests of long-term memory and learning was compared for a group of 16 children with poor phonological short-term memory skills and a comparison group of children of the same age with matched nonverbal reasoning abilities but memory scores in the average range. The low-phonological-memory group were impaired on longer term memory and learning tasks that taxed memory for arbitrary verbal material such as names and nonwords. However, the two groups performed at comparable levels on tasks requiring the retention of visuo-spatial information and of meaningful material and at carrying out prospective memory tasks in which the children were asked to carry out actions at a future point in time. The results are consistent with the view that poor short-term memory function impairs the longer-term retention and ease of learning of novel verbal material.

  9. Insensitivity of visual short-term memory to irrelevant visual information

    OpenAIRE

    Andrade, Jackie; Kemps, Eva; Werniers, Yves; May, Jon; Szmalec, Arnaud

    2002-01-01

    Several authors have hypothesised that visuo-spatial working memory is functionally analogous to verbal working memory. Irrelevant background speech impairs verbal short-term memory. We investigated whether irrelevant visual information has an analogous effect on visual short-term memory, using a dynamic visual noise (DVN) technique known to disrupt visual imagery (Quinn & McConnell, 1996a). Experiment 1 replicated the effect of DVN on pegword imagery. Experiments 2 and 3 showed no effect of ...

  10. Distraction in Verbal Short-Term Memory: Insights from Developmental Differences

    OpenAIRE

    Elliott, Emily; Hughes, Robert W.; Briganti, A; Joseph, Tanya Nicolette; Marsh, John Everett; Macken, William J.

    2016-01-01

    The contribution of two mechanisms of auditory distraction in verbal serial short-term memory-interference with the serial rehearsal processes used to support short-term recall and general attentional diversion-was investigated by exploiting differences in auditory distraction in children and adults. Experiment 1 showed that serial rehearsal plays a role in children's as well as adults' distractibility: Auditory distraction from irrelevant speech was greater for both children and adults as th...

  11. Short-Term and Long-Term Educational Mobility of Families: A Two-Sex Approach.

    Science.gov (United States)

    Song, Xi; Mare, Robert D

    2017-02-01

    We use a multigenerational perspective to investigate how families reproduce and pass their educational advantages to succeeding generations. Unlike traditional mobility studies that have typically focused on one-sex influences from fathers to sons, we rely on a two-sex approach that accounts for interactions between males and females-the process in which males and females mate and have children with those of similar educational statuses and jointly determine the educational status attainment of their offspring. Using data from the Panel Study of Income Dynamics, we approach this issue from both a short-term and a long-term perspective. For the short term, grandparents' educational attainments have a direct association with grandchildren's education as well as an indirect association that is mediated by parents' education and demographic behaviors. For the long term, initial educational advantages of families may benefit as many as three subsequent generations, but such advantages are later offset by the lower fertility of highly educated persons. Yet, all families eventually achieve the same educational distribution of descendants because of intermarriages between families of high- and low-education origin.

  12. The suitability of short-term measurements of radon in the built environment

    International Nuclear Information System (INIS)

    Denman, A.R.; Groves-Kirkby, C.J.; Phillips, P.S.; Crockett, R.G.M.; Woolridge, A.C.

    2008-01-01

    Although domestic and workplace radon concentration levels often show marked diurnal/short-term variation, overall health risk is determined by the long-term average level, and many national protocols advocate the use of long exposure periods, usually three months, to assess long-term risk. Simple passive measurement techniques, e.g. track-etch, activated charcoal and electret, can, however, provide reasonably accurate determinations with exposures as short as one week, and there is pressure from users and stake holders for assessments within this time period. We report evaluation of the effectiveness of one-week, one-month and three-month exposures over a period of one year in a designated Radon Affected Area in the United Kingdom (UK). Although short-term exposures did not compromise measurement accuracy, short-term radon variability rendered one-week measurements less reliable in predicting annual average radon levels via the conventional methodology. Analysis permitted estimation of the maximum and minimum short-term measured domestic radon concentrations at which there was 95% probability of the predicted annual average being below or above the UK Action Level of 200 Bq·m -3 respectively. Between these limits, the short-term result is equivocal, requiring repetition, and the 'equivocal range' for one-week measurements is significantly wider than for three-month exposures. In any geographical area, domestic radon concentrations are distributed log normally, with many properties having low average levels; a small number exhibit excessive levels, and this distribution must be considered when defining exposures for a radon measurement programme. In low-radon areas, where 1% of houses might exceed the Action Level, a one-week assessment will find that fewer outcomes are equivocal. For high-radon areas, with 20% or more houses over the Action Level, more than 50% of one-week outcomes will be equivocal, requiring repeats. The results of this work will be presented

  13. A neuromorphic circuit mimicking biological short-term memory.

    Science.gov (United States)

    Barzegarjalali, Saeid; Parker, Alice C

    2016-08-01

    Research shows that the way we remember things for a few seconds is a different mechanism from the way we remember things for a longer time. Short-term memory is based on persistently firing neurons, whereas storing information for a longer time is based on strengthening the synapses or even forming new neural connections. Information about location and appearance of an object is segregated and processed by separate neurons. Furthermore neurons can continue firing using different mechanisms. Here, we have designed a biomimetic neuromorphic circuit that mimics short-term memory by firing neurons, using biological mechanisms to remember location and shape of an object. Our neuromorphic circuit has a hybrid architecture. Neurons are designed with CMOS 45nm technology and synapses are designed with carbon nanotubes (CNT).

  14. Short-term depression and transient memory in sensory cortex.

    Science.gov (United States)

    Gillary, Grant; Heydt, Rüdiger von der; Niebur, Ernst

    2017-12-01

    Persistent neuronal activity is usually studied in the context of short-term memory localized in central cortical areas. Recent studies show that early sensory areas also can have persistent representations of stimuli which emerge quickly (over tens of milliseconds) and decay slowly (over seconds). Traditional positive feedback models cannot explain sensory persistence for at least two reasons: (i) They show attractor dynamics, with transient perturbations resulting in a quasi-permanent change of system state, whereas sensory systems return to the original state after a transient. (ii) As we show, those positive feedback models which decay to baseline lose their persistence when their recurrent connections are subject to short-term depression, a common property of excitatory connections in early sensory areas. Dual time constant network behavior has also been implemented by nonlinear afferents producing a large transient input followed by much smaller steady state input. We show that such networks require unphysiologically large onset transients to produce the rise and decay observed in sensory areas. Our study explores how memory and persistence can be implemented in another model class, derivative feedback networks. We show that these networks can operate with two vastly different time courses, changing their state quickly when new information is coming in but retaining it for a long time, and that these capabilities are robust to short-term depression. Specifically, derivative feedback networks with short-term depression that acts differentially on positive and negative feedback projections are capable of dynamically changing their time constant, thus allowing fast onset and slow decay of responses without requiring unrealistically large input transients.

  15. Short-term energy outlook. Quarterly projections, first quarter 1995

    International Nuclear Information System (INIS)

    1995-02-01

    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 Short-Term Energy Outlook (Outlook). The forecast period for this issue of the Outlook extends from the first quarter of 1995 through the fourth quarter of 1996. Values for the fourth quarter of 1994, however, are preliminary EIA estimates 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 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. 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. The EIA model is available on computer tape from the National Technical Information Service

  16. Self-reported immature defense style as a predictor of outcome in short-term and long-term psychotherapy.

    Science.gov (United States)

    Laaksonen, Maarit A; Sirkiä, Carlos; Knekt, Paul; Lindfors, Olavi

    2014-07-01

    Identification of pretreatment patient characteristics predictive of psychotherapy outcome could help to guide treatment choices. This study evaluates patients' initial level of immature defense style as a predictor of the outcome of short-term versus long-term psychotherapy. In the Helsinki Psychotherapy Study, 326 adult outpatients with mood or anxiety disorder were randomized to individual short-term (psychodynamic or solution-focused) or long-term (psychodynamic) psychotherapy. Their defense style was assessed at baseline using the 88-item Defense Style Questionnaire and classified as low or high around the median value of the respective score. Both specific (Beck Depression Inventory [BDI], Hamilton Depression Rating Scale [HDRS], Symptom Check List Anxiety Scale [SCL-90-Anx], Hamilton Anxiety Rating Scale [HARS]) and global (Symptom Check List Global Severity Index [SCL-90-GSI], Global Assessment of Functioning Scale [GAF]) psychiatric symptoms were measured at baseline and 3-7 times during a 3-year follow-up. Patients with high use of immature defense style experienced greater symptom reduction in long-term than in short-term psychotherapy by the end of the 3-year follow-up (50% vs. 34%). Patients with low use of immature defense style experienced faster symptom reduction in short-term than in long-term psychotherapy during the first year of follow-up (34% vs. 19%). Knowledge of patients' initial level of immature defense style may potentially be utilized in tailoring treatments. Further research on defense styles as outcome predictors in psychotherapies of different types is needed.

  17. Measuring Short-term Energy Security

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Ensuring energy security has been at the centre of the IEA mission since its inception, following the oil crises of the early 1970s. While the security of oil supplies remains important, contemporary energy security policies must address all energy sources and cover a comprehensive range of natural, economic and political risks that affect energy sources, infrastructures and services. In response to this challenge, the IEA is currently developing a Model Of Short-term Energy Security (MOSES) to evaluate the energy security risks and resilience capacities of its member countries. The current version of MOSES covers short-term security of supply for primary energy sources and secondary fuels among IEA countries. It also lays the foundation for analysis of vulnerabilities of electricity and end-use energy sectors. MOSES contains a novel approach to analysing energy security, which can be used to identify energy security priorities, as a starting point for national energy security assessments and to track the evolution of a country's energy security profile. By grouping together countries with similar 'energy security profiles', MOSES depicts the energy security landscape of IEA countries. By extending the MOSES methodology to electricity security and energy services in the future, the IEA aims to develop a comprehensive policy-relevant perspective on global energy security. This Brochure provides and overview of the analysis and results. Readers interested in an in-depth discussion of methodology are referred to the MOSES Working Paper.

  18. Short-term feeding strategies and pork quality

    NARCIS (Netherlands)

    Geesink, G.H.; Buren, van R.G.C.; Savenije, B.; Verstegen, M.W.A.; Ducro, B.J.; Palen, van der J.G.P.; Hemke, G.

    2004-01-01

    Two experiments were done to determine whether short-term supplementation (5 days pre-slaughter) with magnesium acetate, or a combination of magnesium acetate, tryptophan, vitamin E and vitamin C would improve pork quality. In the first experiment the pigs (Pietrain x Yorkshire, n = 96) were fed a

  19. Combined heat and power production planning in a waste-to-energy plant on a short-term basis

    International Nuclear Information System (INIS)

    Touš, Michal; Pavlas, Martin; Putna, Ondřej; Stehlík, Petr; Crha, Lukáš

    2015-01-01

    In many cases, WtE (waste-to-energy) plants are CHP (combined heat and power) producers. They are often integrated into a central heating system and they also export electricity to the grid. Therefore, they have to plan their operation on a long-term basis (months, years) as well as on a short-term basis (hours, days). Simulation models can effectively support decision making in CHP production planning. In general, CHP production planning on a short-term basis is a challenging task for WtE plants. This article presents a simulation based support. It is demonstrated on an example involving a real WtE plant. Most of the models of relevant WtE sub-systems (boilers, steam turbine) are developed using operational data and applying linear regression and artificial neural network technique. The process randomness given mainly by fluctuating heating value of waste leads to uncertainty in a calculation of CHP production and a stochastic approach is appropriate. The models of the sub-systems are, therefore, extended of a stochastic part and Monte-Carlo simulation is applied. Compared to the current planning strategy in the involved WtE plant, the stochastic simulation based planning provides increased CHP production resulting in better net thermal efficiency and increased revenue. This is demonstrated through a comparison using real operational data. - Highlights: • Introduction of a stochastic model of a CHP production in a waste-to-energy plant. • An application of the model for the next day CHP production planning. • Better net thermal efficiency and therefore increased revenue achieved.

  20. Effect of Short-Term Study Abroad Programs on Students' Cultural Adaptability

    Science.gov (United States)

    Mapp, Susan C.

    2012-01-01

    The number of U.S. students studying abroad has been growing, particularly those participating in short-term trips. However, literature on the effect of these short-term trips is lacking. The purpose of this study was to assess quantitatively the effect on bachelor students' cross-cultural adaptability using a pre-post design. Significant changes…

  1. Robust Short-Term Memory without Synaptic Learning

    OpenAIRE

    Johnson, Samuel; Marro, J.; Torres, Joaquin 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 inf...

  2. PENGARUH KEDALAMAN AIR TERHADAP SHORT TERM MEMORY DAN KONSUMSI ENERGI PADA PENYELAM

    Directory of Open Access Journals (Sweden)

    Rini Dharmastiti

    2012-02-01

    Full Text Available Penelitian ini akan melihat pengaruh kedalaman air terhadap short term memory dan konsumsi energi penyelam. Penelitian ini mengambil sampel 10 mahasiswa pria dan 5 wanita. Pengukuran performansi short term memory dilakukan dengan cara setiap obyek diperlihatkan deretan 7 angka acak yang diberikan selama 5 detik dan setelah 15 detik kemudian dilakukan pemanggilan kembali informasi yang baru saja diberikan. Setiap obyek diuji sebangak 30 kali untuk setiap kedalaman (1 m; 2,5 m; dan 4 m. Pengukuran konsumsi energi dilakukan dengan menghitung denyut jantung menggunakan metode palpasi. Hasil penelitian menunjukkan bahwa semakin meningkat kedalaman air, maka performasi short term memory penyelam tersebut semakin menurun.  Penurunan ini berlaku untuk pria dan wanita. Penambahan kedalaman ini juga meningkatkan konsumsi energi baik pada pria maupun wanita. Perbedaan jenis kelamin mempengaruhi performansi short term memory secara signifikan. Pria memiliki performansi rata-rata short term memory sebesar 91,67% pada kedalaman 1 m, 90,67% pada kedalaman 2,5 m, dan 86,33% pada kedalaman 4 m. Sedangkan wanita memiliki performansi rata-rata sebesar 86% pada kedalaman 1 m, 84% pada kedalaman 2,5 m, dan 80,67% pada kedalaman 4 m. Rata-rata konsumsi energi pria adalah 3,19 kkal, 3,34 kkal, dan 3,65 kkal pada kedalaman 1 m; 2,5 m; dan 4 m berturut-turut. Sedangkan rata-rata konsumsi energi wanita adalah 3,81 kkal, 4,07 kkal, dan 4,54 kkal pada kedalaman yang sama dengan pria.     Kata kunci : tekanan, kedalaman air, performansi short term memory, konsumsi energi.       This research is to observe water depth effects on short term memory and energy expenditure of diver. This research objects are 10 male and 5 female students. Short term memory performance measurement held by every object has been shown 7 random numerics (as information for 5 seconds and after 15 seconds later they write down the information on a paper. Every object got 30 tests for every

  3. Short-term scheduling of an open-pit mine with multiple objectives

    Science.gov (United States)

    Blom, Michelle; Pearce, Adrian R.; Stuckey, Peter J.

    2017-05-01

    This article presents a novel algorithm for the generation of multiple short-term production schedules for an open-pit mine, in which several objectives, of varying priority, characterize the quality of each solution. A short-term schedule selects regions of a mine site, known as 'blocks', to be extracted in each week of a planning horizon (typically spanning 13 weeks). Existing tools for constructing these schedules use greedy heuristics, with little optimization. To construct a single schedule in which infrastructure is sufficiently utilized, with production grades consistently close to a desired target, a planner must often run these heuristics many times, adjusting parameters after each iteration. A planner's intuition and experience can evaluate the relative quality and mineability of different schedules in a way that is difficult to automate. Of interest to a short-term planner is the generation of multiple schedules, extracting available ore and waste in varying sequences, which can then be manually compared. This article presents a tool in which multiple, diverse, short-term schedules are constructed, meeting a range of common objectives without the need for iterative parameter adjustment.

  4. Gluon Green functions free of quantum fluctuations

    Directory of Open Access Journals (Sweden)

    A. Athenodorou

    2016-09-01

    Full Text Available This letter reports on how the Wilson flow technique can efficaciously kill the short-distance quantum fluctuations of 2- and 3-gluon Green functions, remove the ΛQCD scale and destroy the transition from the confining non-perturbative to the asymptotically-free perturbative sector. After the Wilson flow, the behavior of the Green functions with momenta can be described in terms of the quasi-classical instanton background. The same behavior also occurs, before the Wilson flow, at low-momenta. This last result permits applications as, for instance, the detection of instanton phenomenological properties or a determination of the lattice spacing only from the gauge sector of the theory.

  5. Comparative study of short- and long-term indoor radon measurements

    Energy Technology Data Exchange (ETDEWEB)

    Al-Jarallah, M.I. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)], E-mail: mibrahim@kfupm.edu.sa; Fazal-ur-Rehman,; Abdalla, Khalid [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2008-08-15

    Short-term indoor radon measurements are used widely. Therefore, it is interesting to find out a correlation between these measurements and long-term measurements which reflect a better average radon concentration of individual measurement. To find the correlation between the two measurements of indoor radon concentrations at low radon levels, a study was carried out at 34 locations of King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, Saudi Arabia using active and passive methods. In the short-term active method, a radon gas analyzer (AlphaGUARD) was used for a duration of 24 h in each measurement. In the long-term passive method, CR-39 based radon dosimeters were utilized for a period of 6 months, from January 2006 to June 2006. The short-term active measurements showed that the average, minimum and maximum radon concentrations were 19, 8 and 58Bqm{sup -3}, respectively, with a standard deviation of 8.6Bqm{sup -3}. The long-term passive measurements showed that the average, minimum and maximum radon concentrations were 25, 10 and 67Bqm{sup -3}, respectively, with a standard deviation of 12Bqm{sup -3}. The two measurements showed a poor correlation (R{sup 2}=0.38). The long-term measurements showed on the average higher concentrations by a factor of 1.3.

  6. Short-term memory load and pronunciation rate

    Science.gov (United States)

    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.

  7. Implementation of short-term prediction

    Energy Technology Data Exchange (ETDEWEB)

    Landberg, L; Joensen, A; Giebel, G [and others

    1999-03-01

    This paper will giver a general overview of the results from a EU JOULE funded project (`Implementing short-term prediction at utilities`, JOR3-CT95-0008). Reference will be given to specialised papers where applicable. The goal of the project was to implement wind farm power output prediction systems in operational environments at a number of utilities in Europe. Two models were developed, one by Risoe and one by the Technical University of Denmark (DTU). Both prediction models used HIRLAM predictions from the Danish Meteorological Institute (DMI). (au) EFP-94; EU-JOULE. 11 refs.

  8. Short-term indicators. Intensities as a proxy for savings

    Energy Technology Data Exchange (ETDEWEB)

    Boonekamp, P.G.M.; Gerdes, J. [ECN Policy Studies, Petten (Netherlands); Faberi, S. [Institute of Studies for the Integration of Systems ISIS, Rome (Italy)

    2013-12-15

    The ODYSSEE database on energy efficiency indicators (www.odyssee-indicators.org) has been set up to enable the monitoring and evaluation of realised energy efficiency improvements and related energy savings. The database covers the 27 EU countries as well as Norway and Croatia and data are available from 1990 on. This work contributes to the growing need for quantitative monitoring and evaluation of the impacts of energy policies and measures, both at the EU and national level, e.g. due to the Energy Services Directive and the proposed Energy Efficiency Directive. Because the underlying data become available only after some time, the savings figures are not always timely available. This is especially true for the ODEX efficiency indices per sector that rely on a number of indicators. Therefore, there is a need for so-called short-term indicators that become available shortly after the year has passed for which data are needed. The short term indicators do not replace the savings indicators but function as a proxy for the savings in the most recent year. This proxy value is faster available, but will be less accurate than the saving indicators themselves. The short term indicators have to be checked regularly with the ODEX indicators in order to see whether they can function still as a proxy.

  9. Distinct cerebellar engrams in short-term and long-term motor learning.

    Science.gov (United States)

    Wang, Wen; Nakadate, Kazuhiko; Masugi-Tokita, Miwako; Shutoh, Fumihiro; Aziz, Wajeeha; Tarusawa, Etsuko; Lorincz, Andrea; Molnár, Elek; Kesaf, Sebnem; Li, Yun-Qing; Fukazawa, Yugo; Nagao, Soichi; Shigemoto, Ryuichi

    2014-01-07

    Cerebellar motor learning is suggested to be caused by long-term plasticity of excitatory parallel fiber-Purkinje cell (PF-PC) synapses associated with changes in the number of synaptic AMPA-type glutamate receptors (AMPARs). However, whether the AMPARs decrease or increase in individual PF-PC synapses occurs in physiological motor learning and accounts for memory that lasts over days remains elusive. We combined quantitative SDS-digested freeze-fracture replica labeling for AMPAR and physical dissector electron microscopy with a simple model of cerebellar motor learning, adaptation of horizontal optokinetic response (HOKR) in mouse. After 1-h training of HOKR, short-term adaptation (STA) was accompanied with transient decrease in AMPARs by 28% in target PF-PC synapses. STA was well correlated with AMPAR decrease in individual animals and both STA and AMPAR decrease recovered to basal levels within 24 h. Surprisingly, long-term adaptation (LTA) after five consecutive daily trainings of 1-h HOKR did not alter the number of AMPARs in PF-PC synapses but caused gradual and persistent synapse elimination by 45%, with corresponding PC spine loss by the fifth training day. Furthermore, recovery of LTA after 2 wk was well correlated with increase of PF-PC synapses to the control level. Our findings indicate that the AMPARs decrease in PF-PC synapses and the elimination of these synapses are in vivo engrams in short- and long-term motor learning, respectively, showing a unique type of synaptic plasticity that may contribute to memory consolidation.

  10. Effect of short-term hyperglycemia on cerebral function in neurooncological patients

    International Nuclear Information System (INIS)

    Loginov, V.M.; Gnezditskij, V.V.; Emulyushina, O.N.; Mukhamedzhanov, N.Z.

    1991-01-01

    The paper is concerned with the results of investigation of the effect of short-term hyperglycemia on main cerebral functions in 13 neurooncological patients. Taking into account good tolerance of short-term hyperglycemia and the results of its effective use in general oncology, one can recommend it as a modifier in radiation therapy of brain gliomas

  11. Histopathologic characteristics and short-term outcomes of ...

    African Journals Online (AJOL)

    Introduction: Colorectal carcinoma (CRC) is generally a disease of persons older than 40 years. Concerning younger patients, controversies still exist regarding features and prognosis of CRC. We performed this study to characterise CRC in young patients (≤40 years) as well as to evaluate short-term outcome in ...

  12. Short-term memory in the service of executive control functions

    OpenAIRE

    Farshad Alizadeh Mansouri; Marcello eRosa; Nafiseh eAtapour

    2015-01-01

    Short-term memory is a crucial cognitive function for supporting on-going and upcoming behaviours, allowing storage of information across delay periods. The content of this memory may typically include tangible information about features such as the shape, colour or texture of an object, its location and motion relative to the body, or phonological information. The neural correlate of these short-term memories has been found in different brain areas involved in organizing perceptual or motor ...

  13. Short-term clinical experience with hip resurfacing arthroplasty.

    Science.gov (United States)

    Cieliński, Łukasz; Kusz, Damian; Wojciechowski, Piotr; Dziuba, Anna

    2007-01-01

    This paper discusses the authors' experience with hip resurfacing arthroplasty. Although introduced many years ago, the method did not gain wide popularity because of poor long-term outcomes. At present, owing to the introduction of metal-on-metal bearings and hybrid fixation techniques, short- and mid-term results are very good and encourage wider use of this technique, especially in the younger and more active patients whose results with standard total hip replacements would be unsatisfactory. We performed 13 hip resurfacing arthroplasties at our institution between August 1, 2005, and May 1, 2006. Twelve patients reported for the scheduled follow-up and were included in the study. Treatment outcomes were assessed according to the Harris Hip Score. The short-term outcomes of hip resurfacing arthroplasties are encouraging. In the study group there were no intraoperative complications, infections, peripheral nerve palsy, hip dislocations or clinically overt vein thrombosis. All of the patients reported complete or major pain relief. Clinical assessment according to the Harris Hip Score revealed improvement from an average of 57.7 (20.1) points preoperatively to an average of 87.7 (12) points after the surgery. Crutches were used for a maximum of 6 weeks postoperatively. All of the patients are currently able to walk without crutches with full weight-bearing. 1) Hip resurfacing arthroplasty seems to be an advisable method of operative management of younger, active patients, in whom standard THR would be associated with a high risk of failure; it allows THR to be postponed and carried out as a revision surgery with the acetabular component already in place. 2) Despite the good short- and mid-term results, the utility of this method should be evaluated with caution due to the lack of adequate long-term follow-up data.

  14. Short-term wind power prediction based on LSSVM–GSA model

    International Nuclear Information System (INIS)

    Yuan, Xiaohui; Chen, Chen; Yuan, Yanbin; Huang, Yuehua; Tan, Qingxiong

    2015-01-01

    Highlights: • A hybrid model is developed for short-term wind power prediction. • The model is based on LSSVM and gravitational search algorithm. • Gravitational search algorithm is used to optimize parameters of LSSVM. • Effect of different kernel function of LSSVM on wind power prediction is discussed. • Comparative studies show that prediction accuracy of wind power is improved. - Abstract: Wind power forecasting can improve the economical and technical integration of wind energy into the existing electricity grid. Due to its intermittency and randomness, it is hard to forecast wind power accurately. For the purpose of utilizing wind power to the utmost extent, it is very important to make an accurate prediction of the output power of a wind farm under the premise of guaranteeing the security and the stability of the operation of the power system. In this paper, a hybrid model (LSSVM–GSA) based on the least squares support vector machine (LSSVM) and gravitational search algorithm (GSA) is proposed to forecast the short-term wind power. As the kernel function and the related parameters of the LSSVM have a great influence on the performance of the prediction model, the paper establishes LSSVM model based on different kernel functions for short-term wind power prediction. And then an optimal kernel function is determined and the parameters of the LSSVM model are optimized by using GSA. Compared with the Back Propagation (BP) neural network and support vector machine (SVM) model, the simulation results show that the hybrid LSSVM–GSA model based on exponential radial basis kernel function and GSA has higher accuracy for short-term wind power prediction. Therefore, the proposed LSSVM–GSA is a better model for short-term wind power prediction

  15. Response of stream invertebrates to short-term salinization: A mesocosm approach

    International Nuclear Information System (INIS)

    Cañedo-Argüelles, Miguel; Grantham, Theodore E.; Perrée, Isabelle; Rieradevall, Maria; Céspedes-Sánchez, Raquel; Prat, Narcís

    2012-01-01

    Salinization is a major and growing threat to freshwater ecosystems, yet its effects on aquatic invertebrates have been poorly described at a community-level. Here we use a controlled experimental setting to evaluate short-term stream community responses to salinization, under conditions designed to replicate the duration (72 h) and intensity (up to 5 mS cm −1 ) of salinity pulses common to Mediterranean rivers subjected to mining pollution during runoff events. There was a significant overall effect, but differences between individual treatments and the control were only significant for the highest salinity treatment. The community response to salinization was characterized by a decline in total invertebrate density, taxon richness and diversity, an increase in invertebrate drift and loss of the most sensitive taxa. The findings indicate that short-term salinity increases have a significant impact on the stream invertebrate community, but concentrations of 5 mS cm −1 are needed to produce a significant ecological response. - Highlights: ► Short-term salinization has a significant impact on the aquatic invertebrates. ► A significant short-term ecological response is registered at 5 mS cm −1 . ► Salinization causes a decline in invertebrate density, richness and diversity. ► Biotic quality indices decline with increasing salinity and exposure time. - Short-term salinization in a stream mesocosm caused a significant response in the aquatic invertebrate community and led to declines in biological quality indices.

  16. Effect of BRCA1/2 mutation on short-term and long-term breast cancer survival: a systematic review and meta-analysis.

    Science.gov (United States)

    Lee, Eun-Ha; Park, Sue K; Park, Boyoung; Kim, Sung-Won; Lee, Min Hyuk; Ahn, Sei Hyun; Son, Byung Ho; Yoo, Keun-Young; Kang, Daehee

    2010-07-01

    Reports of BRCA genetic mutations and risk of death or recurrence are inconsistent. This study aimed to compare overall and disease-free breast cancer survival rates between BRCA1/2 mutation carriers and non-carriers for short-term and long-term outcomes separately. We searched the PUBMED and EMBASE databases and retrieved 452 articles using keywords that included breast cancer, BRCA mutation, and survival. Seventeen articles were selected for systematic review and among them 11 were included in our meta-analysis. We used the random-effects model to calculate the summary hazard ratio and corresponding 95% confidence interval. BRCA1 mutation carriers had significantly lower short-term and long-term overall survival rates (OSR) relative to non-carriers (HR = 1.92 [95% CI = 1.45-2.53]; 1.33 [1.12-1.58], respectively), while both short-term and long-term OSR of BRCA2 carriers did not differ from non-carriers (HR = 1.30 [95% CI = 0.95-1.76]; 1.12 [95% CI = 0.86-1.45], respectively). For short-term progression-free survival rate (PFSR), BRCA1 mutation carriers had a significantly lower rate than non-carriers (HR = 1.54 [95% CI = 1.12-2.12]), while BRCA2 mutation carriers had a similar PFSR (HR = 1.23 [95% CI = 0.96-1.58]). For long-term PFSRs, we found no significant results. Our results suggest that BRCA1 mutation decreases short-term and long-term OSRs and short-term PFSR, however, BRCA2 mutation does not affect either short-term or long-term survival rate, which is attributed to the different carcinogenic pathways for BRCA1 and BRCA2.

  17. SHORT-TERM AND LONG-TERM WATER LEVEL PREDICTION AT ONE RIVER MEASUREMENT LOCATION

    Directory of Open Access Journals (Sweden)

    Rudolf Scitovski

    2012-12-01

    Full Text Available Global hydrological cycles mainly depend on climate changes whose occurrence is predominantly triggered by solar and terrestrial influence, and the knowledge of the high water regime is widely applied in hydrology. Regular monitoring and studying of river water level behavior is important from several perspectives. On the basis of the given data, by using modifications of general approaches known from literature, especially from investigation in hydrology, the problem of long- and short-term water level forecast at one river measurement location is considered in the paper. Long-term forecasting is considered as the problem of investigating the periodicity of water level behavior by using linear-trigonometric regression and short-term forecasting is based on the modification of the nearest neighbor method. The proposed methods are tested on data referring to the Drava River level by Donji Miholjac, Croatia, in the period between the beginning of 1900 and the end of 2012.

  18. The Global Precipitation Patterns Associated with Short-Term Extratropical Climate Fluctuations

    Science.gov (United States)

    Huffman, George J.; Adler, Robert F.; Bolvin, David T.

    1999-01-01

    Two globally-complete, observation-only precipitation datasets have recently been developed for the Global Precipitation Climatology Project (GPCP). Both depend heavily on a variety of satellite input, as well as gauge data over land. The first, Version 2x79, provides monthly estimates on a 2.5 deg. x 2.5 deg. lat/long grid for the period 1979 through late 1999 (by the time of the conference). The second, the One-Degree Daily (1DD), provides daily estimates on a 1 deg. x l deg. grid for the period 1997 through late 1999 (by the time of the conference). Both are in beta test preparatory to release as official GPCP products. These datasets provide a unique perspective on the hydrological effects of the various atmospheric flow anomalies that have been identified by meteorologists. In this paper we discuss the regional precipitation effects that result from persistent extratropical flow anomalies. We will focus on the Pacific-North America (PNA) and North Atlantic Oscillation (NAO) patterns. Each characteristically becomes established on synoptic time scales, but then persists for periods that can exceed a month. The onset phase of each appears to have systematic mobile features, while the mature phase tend to be more stationary. Accordingly, composites of monthly data for outstanding positive and negative events (separately) contained in the 20-year record reveal the climatological structure of the precipitation during the mature phase. The climatological anomalies of the positive, negative, and (positive-negative) composites show the expected storm-track-related shifts in precipitation, and provide the advantage of putting the known precipitation effects over land in the context of the total pattern over land and ocean. As well, this global perspective points out some unexpected areas of correlation. Day-by-day composites of daily data anchored to the onset date demonstrate the systematic features during the onset. Although the 1DD has a fairly short record, some

  19. Prosodic Similarity Effects in Short-Term Memory in Developmental Dyslexia.

    Science.gov (United States)

    Goswami, Usha; Barnes, Lisa; Mead, Natasha; Power, Alan James; Leong, Victoria

    2016-11-01

    Children with developmental dyslexia are characterized by phonological difficulties across languages. Classically, this 'phonological deficit' in dyslexia has been investigated with tasks using single-syllable words. Recently, however, several studies have demonstrated difficulties in prosodic awareness in dyslexia. Potential prosodic effects in short-term memory have not yet been investigated. Here we create a new instrument based on three-syllable words that vary in stress patterns, to investigate whether prosodic similarity (the same prosodic pattern of stressed and unstressed syllables) exerts systematic effects on short-term memory. We study participants with dyslexia and age-matched and younger reading-level-matched typically developing controls. We find that all participants, including dyslexic participants, show prosodic similarity effects in short-term memory. All participants exhibited better retention of words that differed in prosodic structure, although participants with dyslexia recalled fewer words accurately overall compared to age-matched controls. Individual differences in prosodic memory were predicted by earlier vocabulary abilities, by earlier sensitivity to syllable stress and by earlier phonological awareness. To our knowledge, this is the first demonstration of prosodic similarity effects in short-term memory. The implications of a prosodic similarity effect for theories of lexical representation and of dyslexia are discussed. © 2016 The Authors. Dyslexia published by John Wiley & Sons Ltd. © 2016 The Authors. Dyslexia published by John Wiley & Sons Ltd.

  20. Analysis of the short-term overproduction capability of variable speed wind turbines

    DEFF Research Database (Denmark)

    Hansen, Anca Daniela; Altin, Müfit; Margaris, Ioannis D.

    2014-01-01

    Emphasis in this article is on variable speed wind turbines (VSWTs) capability to provide short-term overproduction and better understanding of VSWTs’ mechanical and electrical limits to deliver such support. VSWTs’ short-term overproduction capability is of primary concern for the transmission...

  1. The right hippocampus participates in short-term memory maintenance of object-location associations

    NARCIS (Netherlands)

    Piekema, C.; Kessels, R.P.C.; Mars, R.B.; Petersson, K.M.; Fernandez, G.S.E.

    2006-01-01

    Doubts have been cast on the strict dissociation between short- and long-term memory systems. Specifically, several neuroimaging studies have shown that the medial temporal lobe, a region almost invariably associated with long-term memory, is involved in active short-term memory maintenance.

  2. The right hippocampus participates in short-term memory maintenance of object-location associations.

    NARCIS (Netherlands)

    Piekema, C.; Kessels, R.P.C.; Mars, R.B.; Petersson, K.M.; Fernandez, G.S.E.

    2006-01-01

    Doubts have been cast on the strict dissociation between short- and long-term memory systems. Specifically, several neuroimaging studies have shown that the medial temporal lobe, a region almost invariably associated with long-term memory, is involved in active short-term memory maintenance.

  3. Short- and Long-Term Outcomes of Student Field Research Experiences in Special Populations.

    Science.gov (United States)

    Soliman, Amr S; Chamberlain, Robert M

    2016-06-01

    Global health education and training of biomedical students in international and minority health research is expending through U.S. academic institutions. This study addresses the short- and long-term outcomes of an NCI-funded R25 short-term summer field research training program. This program is designed for MPH and Ph.D. students in cancer epidemiology and related disciplines, in international and minority settings (special populations) in a recent 7-year period. Positive short-term outcome of 73 students was measured as publishing a manuscript from the field research data and having a job in special populations. Positive long-term outcome was measured as having a post-doc position, being in a doctoral program, and/or employment in special populations at least 3 years from finishing the program. Significant factors associated with both short- and long-term success included resourcefulness of the student and compatibility of personalities and interests between the student and the on-campus and off-campus mentors. Short-term-success of students who conducted international filed research was associated with visits of the on-campus mentor to the field site. Short-term success was also associated with extent of mentorship in the field site and with long-term success. Future studies should investigate how field research sites could enhance careers of students, appropriateness of the sites for specific training competencies, and how to maximize the learning experience of students in international and minority research sites.

  4. CREB binding protein is required for both short-term and long-term memory formation.

    Science.gov (United States)

    Chen, Guiquan; Zou, Xiaoyan; Watanabe, Hirotaka; van Deursen, Jan M; Shen, Jie

    2010-09-29

    CREB binding protein (CBP) is a transcriptional coactivator with histone acetyltransferase activity. Our prior study suggested that CBP might be a key target of presenilins in the regulation of memory formation and neuronal survival. To elucidate the role of CBP in the adult brain, we generated conditional knock-out (cKO) mice in which CBP is completely inactivated in excitatory neurons of the postnatal forebrain. Histological analysis revealed normal neuronal morphology and absence of age-dependent neuronal degeneration in the CBP cKO cerebral cortex. CBP cKO mice exhibited robust impairment in the formation of spatial, associative, and object-recognition memory. In addition to impaired long-term memory, CBP cKO mice also displayed deficits in short-term associative and object-recognition memory. Administration of a histone deacetylase inhibitor, trichostatin A, rescued the reduction of acetylated histones in the CBP cKO cortex but failed to rescue either short- or long-term memory deficits, suggesting that the memory impairment may not be caused by general reduction of histone acetyltransferase activity in CBP cKO mice. Further microarray and Western analysis showed decreased expression of calcium-calmodulin-dependent kinase isoforms and NMDA and AMPA receptor subunits in the cerebral cortex of CBP cKO mice. Collectively, these findings suggest a crucial role for CBP in the formation of both short- and long-term memory.

  5. Short-term supervised inpatient physiotherapy exercise protocol improves cardiac autonomic function after coronary artery bypass graft surgery--a randomised controlled trial.

    Science.gov (United States)

    Mendes, Renata Gonçalves; Simões, Rodrigo Polaquini; De Souza Melo Costa, Fernando; Pantoni, Camila Bianca Falasco; Di Thommazo, Luciana; Luzzi, Sérgio; Catai, Aparecida Maria; Arena, Ross; Borghi-Silva, Audrey

    2010-01-01

    Coronary artery bypass grafting (CABG) is accompanied by severe impairment of cardiac autonomous regulation (CAR). This study aimed to determine whether a short-term physiotherapy exercise protocol post-CABG, during inpatient cardiac rehabilitation (CR), might improve CAR. Seventy-four patients eligible for CABG were recruited and randomised into physiotherapy exercise group (EG) or physiotherapy usual care group (UCG). EG patients underwent a short-term supervised inpatient physiotherapy exercise protocol consisting of an early mobilisation with progressive exercises plus usual care (respiratory exercises). UCG only received respiratory exercises. Forty-seven patients (24 EG and 23 UGC) completed the study. Outcome measures of CAR included linear and non-linear measures of heart rate variability (HRV) assessed before discharge. By hospital discharge, EG presented significantly higher parasympathetic HRV values [rMSSD, high frequency (HF), SD1)], global power (STD RR, SD2), non-linear HRV indexes [detrended fluctuation analysis (DFA)alpha1, DFAalpha2, approximate entropy (ApEn)] and mean RR compared to UCG (pexercise protocol during inpatient CR improves CAR at the time of discharge. Thus, exercise-based inpatient CR might be an effective non-pharmacological tool to improve autonomic cardiac tone in patient's post-CABG.

  6. Verification of“Trend-Volatility Model”in Short-Term Forecast of Grain Production Potential

    Directory of Open Access Journals (Sweden)

    MI Chang-hong

    2016-02-01

    Full Text Available The "trend-volatility model" in short-term forecasting of grain production potential was verified and discussed systematically by using the grain production data from 1949 to 2014, in 16 typical counties and 6 typical districts, and 31 provinces, of China. The results showed as follows:(1 Size of forecast error reflected the precision of short-term production potential, the main reason of large prediction error was a great amount of high yield farmlands were occupied in developed areas and a great increase of vegetable and fruit planted that made grain yield decreased in a short time;(2 The micro-trend amendment method was a necessary part of "trend-volatility model", which could involve the short-term factors such as meteorological factors, science and technology input, social factors and other effects, while macro-trend prediction could not. Therefore, The micro-trend amendment method could improve the forecast precision.(3 In terms of actual situation in recent years in China, the more developed the areas was, the bigger the volatility of short-term production potential was; For the short-term production potential, the stage of increasing-decreasing-recovering also existed in developed areas;(4 In the terms of forecast precision of short-terms production potential, the scale of national was higher than the scale of province, the scale of province was higher than the scale of district, the scale of district was higher than the scale of county. And it was large differences in precision between different provinces, different districts and different counties respectively, which was concerned to the complementarity of domestic climate and the ability of the farmland resistance to natural disasters.

  7. The nature of forgetting from short-term memory

    OpenAIRE

    Muter, Paul

    2001-01-01

    Memory and forgetting are inextricably intertwined. Any account of short-term memory (STM) should address the following question: If three, four, or five chunks are being held in STM, what happens after attention is diverted?

  8. Short-term plasticity in auditory cognition.

    Science.gov (United States)

    Jääskeläinen, Iiro P; Ahveninen, Jyrki; Belliveau, John W; Raij, Tommi; Sams, Mikko

    2007-12-01

    Converging lines of evidence suggest that auditory system short-term plasticity can enable several perceptual and cognitive functions that have been previously considered as relatively distinct phenomena. Here we review recent findings suggesting that auditory stimulation, auditory selective attention and cross-modal effects of visual stimulation each cause transient excitatory and (surround) inhibitory modulations in the auditory cortex. These modulations might adaptively tune hierarchically organized sound feature maps of the auditory cortex (e.g. tonotopy), thus filtering relevant sounds during rapidly changing environmental and task demands. This could support auditory sensory memory, pre-attentive detection of sound novelty, enhanced perception during selective attention, influence of visual processing on auditory perception and longer-term plastic changes associated with perceptual learning.

  9. Fuel consumption: short term and long term price impacts per population type

    International Nuclear Information System (INIS)

    2011-01-01

    This report presents assessments of the price sensitivity of household fuel consumption. After a literature review on price-elasticity assessments and the use of pseudo-panels, the investigation analyses the deciding factors of the household fuel expense and its evolution between 1985 and 2006. It proposes a short term price-elasticity assessment based on the most recent survey, and also proposes price-elasticity assessments for sub-populations, notably in terms of income level or location (rural or urban areas)

  10. Spatiotemporal discrimination in neural networks with short-term synaptic plasticity

    Science.gov (United States)

    Shlaer, Benjamin; Miller, Paul

    2015-03-01

    Cells in recurrently connected neural networks exhibit bistability, which allows for stimulus information to persist in a circuit even after stimulus offset, i.e. short-term memory. However, such a system does not have enough hysteresis to encode temporal information about the stimuli. The biophysically described phenomenon of synaptic depression decreases synaptic transmission strengths due to increased presynaptic activity. This short-term reduction in synaptic strengths can destabilize attractor states in excitatory recurrent neural networks, causing the network to move along stimulus dependent dynamical trajectories. Such a network can successfully separate amplitudes and durations of stimuli from the number of successive stimuli. Stimulus number, duration and intensity encoding in randomly connected attractor networks with synaptic depression. Front. Comput. Neurosci. 7:59., and so provides a strong candidate network for the encoding of spatiotemporal information. Here we explicitly demonstrate the capability of a recurrent neural network with short-term synaptic depression to discriminate between the temporal sequences in which spatial stimuli are presented.

  11. The nature of short-term consolidation in visual working memory.

    Science.gov (United States)

    Ricker, Timothy J; Hardman, Kyle O

    2017-11-01

    Short-term consolidation is the process by which stable working memory representations are created. This process is fundamental to cognition yet poorly understood. The present work examines short-term consolidation using a Bayesian hierarchical model of visual working memory recall to determine the underlying processes at work. Our results show that consolidation functions largely through changing the proportion of memory items successfully maintained until test. Although there was some evidence that consolidation affects representational precision, this change was modest and could not account for the bulk of the consolidation effect on memory performance. The time course of the consolidation function and selective influence of consolidation on specific serial positions strongly indicates that short-term consolidation induces an attentional blink. The blink leads to deficits in memory for the immediately following item when time pressure is introduced. Temporal distinctiveness accounts of the consolidation process are tested and ruled out. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  12. Temporal Prediction Errors Affect Short-Term Memory Scanning Response Time.

    Science.gov (United States)

    Limongi, Roberto; Silva, Angélica M

    2016-11-01

    The Sternberg short-term memory scanning task has been used to unveil cognitive operations involved in time perception. Participants produce time intervals during the task, and the researcher explores how task performance affects interval production - where time estimation error is the dependent variable of interest. The perspective of predictive behavior regards time estimation error as a temporal prediction error (PE), an independent variable that controls cognition, behavior, and learning. Based on this perspective, we investigated whether temporal PEs affect short-term memory scanning. Participants performed temporal predictions while they maintained information in memory. Model inference revealed that PEs affected memory scanning response time independently of the memory-set size effect. We discuss the results within the context of formal and mechanistic models of short-term memory scanning and predictive coding, a Bayes-based theory of brain function. We state the hypothesis that our finding could be associated with weak frontostriatal connections and weak striatal activity.

  13. Short-term treatment outcomes of children starting antiretroviral ...

    African Journals Online (AJOL)

    Short-term treatment outcomes of children starting antiretroviral therapy in the intensive care unit, general medical wards and outpatient HIV clinics at Red Cross War Memorial Children's Hospital, Cape Town, South Africa: A retrospective cohort study.

  14. Evaluation of short-term and long-term stability of emulsions by centrifugation and NMR

    International Nuclear Information System (INIS)

    Tcholakova, S.; Denkov, N.; Ivanov, I.; Marinov, R.

    2004-01-01

    The effect of storage time on the coalescence stability and drop size distribution of egg yolk and whey protein concentrate stabilized emulsions is studied. The emulsion stability is evaluated by centrifugation, whereas the drop size distribution is measured by means of NMR and optical microscopy. The experimental results show that there is no general relation between the emulsion stability and the changes in the mean drop diameter upon shelf-storage of protein emulsions. On the other hand, it is shown that the higher short-term stability, measured by centrifugation immediately after emulsion preparation, corresponds to higher long-term stability (after their self-storage up to 60 days) for emulsions stabilized by the same type of emulsifier. In this way, we are able to obtain information for the long-term stability of emulsions in a relatively short period of time.(authors)

  15. C. elegans positive butanone learning, short-term, and long-term associative memory assays.

    Science.gov (United States)

    Kauffman, Amanda; Parsons, Lance; Stein, Geneva; Wills, Airon; Kaletsky, Rachel; Murphy, Coleen

    2011-03-11

    The memory of experiences and learned information is critical for organisms to make choices that aid their survival. C. elegans navigates its environment through neuron-specific detection of food and chemical odors, and can associate nutritive states with chemical odors, temperature, and the pathogenicity of a food source. Here, we describe assays of C. elegans associative learning and short- and long-term associative memory. We modified an aversive olfactory learning paradigm to instead produce a positive response; the assay involves starving ~400 worms, then feeding the worms in the presence of the AWC neuron-sensed volatile chemoattractant butanone at a concentration that elicits a low chemotactic index (similar to Toroyama et al.). A standard population chemotaxis assay1 tests the worms' attraction to the odorant immediately or minutes to hours after conditioning. After conditioning, wild-type animals' chemotaxis to butanone increases ~0.6 Chemotaxis Index units, its "Learning Index". Associative learning is dependent on the presence of both food and butanone during training. Pairing food and butanone for a single conditioning period ("massed training") produces short-term associative memory that lasts ~2 hours. Multiple conditioning periods with rest periods between ("spaced training") yields long-term associative memory (long-term memory across species. Our protocol also includes image analysis methods for quick and accurate determination of chemotaxis indices. High-contrast images of animals on chemotaxis assay plates are captured and analyzed by worm counting software in MatLab. The software corrects for uneven background using a morphological tophat transformation. Otsu's method is then used to determine a threshold to separate worms from the background. Very small particles are removed automatically and larger non-worm regions (plate edges or agar punches) are removed by manual selection. The software then estimates the size of single worm by ignoring

  16. Short-term versus continuous antimicrobial therapy for asymptomatic bacteriuria in pregnancy.

    Science.gov (United States)

    Whalley, P J; Cunningham, F G

    1977-03-01

    Asymptomatic bacteriuria was identified in 300 pregnant women prior to the 28th week of gestation. In one group of 200 women short-term treatment with either nitrofurantoin or sulfamethizole was given for 14 days, and in another group of 100 women continuous therapy with one of these drugs was given for the remainder of gestation. Weekly urine cultures were obtained from all the women. Of the women treated with short-term therapy, 65% were abacteriuric for the remainder of pregnancy following one course of therapy, 24% became abacteriuric but subsequently relapsed, 2% had reinfection after becoming abacteriuric, and 9% demonstrated no response. Following treatment with a second course of short-term therapy, another 19% of these women were cured for the remainder of their pregnancy, and 3.5% responded to a third course. In the continuous therapy group, 88% of the women became abacteriuric for the remainder of the gestation, 3% demonstrated relapse, 2% developed reinfection, and 7% had no response to the first drug given. These data demonstrate that short-term administration of antimicrobials, when combined with surveillance for recurrent bacteriuria, is effective for the management of the pregnant woman with asymptomatic bacteriuria.

  17. Long-term effects of interference on short-term memory performance in the rat.

    Science.gov (United States)

    Missaire, Mégane; Fraize, Nicolas; Joseph, Mickaël Antoine; Hamieh, Al Mahdy; Parmentier, Régis; Marighetto, Aline; Salin, Paul Antoine; Malleret, Gaël

    2017-01-01

    A distinction has always been made between long-term and short-term memory (also now called working memory, WM). The obvious difference between these two kinds of memory concerns the duration of information storage: information is supposedly transiently stored in WM while it is considered durably consolidated into long-term memory. It is well acknowledged that the content of WM is erased and reset after a short time, to prevent irrelevant information from proactively interfering with newly stored information. In the present study, we used typical WM radial maze tasks to question the brief lifespan of spatial WM content in rodents. Groups of rats were submitted to one of two different WM tasks in a radial maze: a WM task involving the repetitive presentation of a same pair of arms expected to induce a high level of proactive interference (PI) (HIWM task), or a task using a different pair in each trial expected to induce a low level of PI (LIWM task). Performance was effectively lower in the HIWM group than in LIWM in the final trial of each training session, indicative of a "within-session/short-term" PI effect. However, we also observed a different "between-session/long-term" PI effect between the two groups: while performance of LIWM trained rats remained stable over days, the performance of HIWM rats dropped after 10 days of training, and this impairment was visible from the very first trial of the day, hence not attributable to within-session PI. We also showed that a 24 hour-gap across training sessions known to allow consolidation processes to unfold, was a necessary and sufficient condition for the long-term PI effect to occur. These findings suggest that in the HIWM task, WM content was not entirely reset between training sessions and that, in specific conditions, WM content can outlast its purpose by being stored more permanently, generating a long-term deleterious effect of PI. The alternative explanation is that WM content could be transferred and stored

  18. Long-term effects of interference on short-term memory performance in the rat.

    Directory of Open Access Journals (Sweden)

    Mégane Missaire

    Full Text Available A distinction has always been made between long-term and short-term memory (also now called working memory, WM. The obvious difference between these two kinds of memory concerns the duration of information storage: information is supposedly transiently stored in WM while it is considered durably consolidated into long-term memory. It is well acknowledged that the content of WM is erased and reset after a short time, to prevent irrelevant information from proactively interfering with newly stored information. In the present study, we used typical WM radial maze tasks to question the brief lifespan of spatial WM content in rodents. Groups of rats were submitted to one of two different WM tasks in a radial maze: a WM task involving the repetitive presentation of a same pair of arms expected to induce a high level of proactive interference (PI (HIWM task, or a task using a different pair in each trial expected to induce a low level of PI (LIWM task. Performance was effectively lower in the HIWM group than in LIWM in the final trial of each training session, indicative of a "within-session/short-term" PI effect. However, we also observed a different "between-session/long-term" PI effect between the two groups: while performance of LIWM trained rats remained stable over days, the performance of HIWM rats dropped after 10 days of training, and this impairment was visible from the very first trial of the day, hence not attributable to within-session PI. We also showed that a 24 hour-gap across training sessions known to allow consolidation processes to unfold, was a necessary and sufficient condition for the long-term PI effect to occur. These findings suggest that in the HIWM task, WM content was not entirely reset between training sessions and that, in specific conditions, WM content can outlast its purpose by being stored more permanently, generating a long-term deleterious effect of PI. The alternative explanation is that WM content could be

  19. Depletion of serotonin selectively impairs short-term memory without affecting long-term memory in odor learning in the terrestrial slug Limax valentianus.

    Science.gov (United States)

    Shirahata, Takaaki; Tsunoda, Makoto; Santa, Tomofumi; Kirino, Yutaka; Watanabe, Satoshi

    2006-01-01

    The terrestrial slug Limax is able to acquire short-term and long-term memories during aversive odor-taste associative learning. We investigated the effect of the selective serotonergic neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) on memory. Behavioral studies indicated that 5,7-DHT impaired short-term memory but not long-term memory. HPLC (high-performance liquid chromatography) analysis revealed that 5,7-DHT significantly reduced serotonin content in the central nervous system. The present study suggests that acquisition, retention, and/or retrieval of short-term memory involves serotonin, and neither acquisition nor retrieval of long-term memory requires serotonin at a level as high as that required for short-term memory.

  20. The effect of zinc supplementation of lactating rats on short-term and long-term memory of their male offspring.

    Science.gov (United States)

    Karami, Mohammad; Ehsanivostacolaee, Simin; Moazedi, Ali Ahmad; Nosrati, Anahita

    2013-01-01

    In this study the effect of zinc chloride (ZnCl2) administration on the short-term and long-term memory of rats were assessed. We enrolled six groups of adult female and control group of eight Wistar rats in each group. One group was control group with free access to food and water, and five groups drunk zinc chloride in different doses (20, 30, 50, 70 and 100 mg/kg/day) in drinking water for two weeks during lactation .One month after birth, a shuttle box used to short- term and long-term memory and the latency in entering the dark chamber as well. This experiment showed that maternal 70 mg/kg dietary zinc during lactation influenced the working memory of rats' offspring in all groups. Rats received 100 mg/kg/day zinc during lactation so they had significant impairment in working memory (short-term) of their offspring (Plong-term) memory of all groups. Drug consumption below70 mg/kg/day zinc chloride during lactation had no effect. While enhanced 100 mg/ kg/ day zinc in lactating rats could cause short-term memory impairment.

  1. Short-term memory in networks of dissociated cortical neurons.

    Science.gov (United States)

    Dranias, Mark R; Ju, Han; Rajaram, Ezhilarasan; VanDongen, Antonius M J

    2013-01-30

    Short-term memory refers to the ability to store small amounts of stimulus-specific information for a short period of time. It is supported by both fading and hidden memory processes. Fading memory relies on recurrent activity patterns in a neuronal network, whereas hidden memory is encoded using synaptic mechanisms, such as facilitation, which persist even when neurons fall silent. We have used a novel computational and optogenetic approach to investigate whether these same memory processes hypothesized to support pattern recognition and short-term memory in vivo, exist in vitro. Electrophysiological activity was recorded from primary cultures of dissociated rat cortical neurons plated on multielectrode arrays. Cultures were transfected with ChannelRhodopsin-2 and optically stimulated using random dot stimuli. The pattern of neuronal activity resulting from this stimulation was analyzed using classification algorithms that enabled the identification of stimulus-specific memories. Fading memories for different stimuli, encoded in ongoing neural activity, persisted and could be distinguished from each other for as long as 1 s after stimulation was terminated. Hidden memories were detected by altered responses of neurons to additional stimulation, and this effect persisted longer than 1 s. Interestingly, network bursts seem to eliminate hidden memories. These results are similar to those that have been reported from similar experiments in vivo and demonstrate that mechanisms of information processing and short-term memory can be studied using cultured neuronal networks, thereby setting the stage for therapeutic applications using this platform.

  2. A short-term neural network memory

    Energy Technology Data Exchange (ETDEWEB)

    Morris, R.J.T.; Wong, W.S.

    1988-12-01

    Neural network memories with storage prescriptions based on Hebb's rule are known to collapse as more words are stored. By requiring that the most recently stored word be remembered precisely, a new simple short-term neutral network memory is obtained and its steady state capacity analyzed and simulated. Comparisons are drawn with Hopfield's method, the delta method of Widrow and Hoff, and the revised marginalist model of Mezard, Nadal, and Toulouse.

  3. The epidemiology of long- and short-term cancer survivors

    DEFF Research Database (Denmark)

    Jarlbæk, Lene; Christensen, Linda; Bruera, Eduardo

    2014-01-01

    Introduction. In this study, we present data from a population-based cohort of incident cancer patients separated in long- and short-term survivors. Our aim was to procure denominators for use in the planning of rehabilitation and palliative care programs. Material and methods. A registry......-linkage cohort study. All cancer patients, diagnosed from 1993 to 2003 from a 470 000 large population, were followed individually from diagnosis to death or until 31 December 2008. Long-term survivors lived five years or more after the time of the cancer diagnosis (TOCD). Short-term survivors died less than...... and sex. Two-year crude cancer survival seems as a clinically relevant cut point for characterizing potential "denominators" for rehabilitation or palliative care programs. From this cohort of incident cancer patients, and using two-year survival as a cut point, it could be estimated that 54% would...

  4. Daily dynamics of bacterial numbers, CO2 emissions from soil and relationships between their wavelike fluctuations and succession of the microbial community

    Science.gov (United States)

    Semenov, A. M.; Bubnov, I. A.; Semenov, V. M.; Semenova, E. V.; Zelenev, V. V.; Semenova, N. A.

    2013-08-01

    The daily dynamics of the number of copiotrophic and oligotrophic bacteria (in colony-forming units) and CO2 emissions from cultivated soils after short- and long-term disturbances were studied for 25-27 days in a microfield experiment. The relationship of the wavelike fluctuations of the bacterial number and CO2 emission with the succession of the soil microbial community was determined by the polymerase chain reaction method—denaturing gradient gel electrophoresis (PCR-DGGE). Short-term disturbances involved the application of organic or mineral fertilizers, pesticides, and plant residues to the soils of different plots. The long-term effect was a result of using biological and intensive farming systems for three years. The short-term disturbances resulted in increased peaks of the bacterial number, the significance of which was confirmed by harmonics analysis. The daily dynamics of the structure of the soil microbial community, which was studied for 27 days by the DGGE method, also had an oscillatory pattern. Statistical processing of the data (principal components analysis, harmonics and cross-correlation analyses) has revealed significant fluctuations in the structure of microbial communities coinciding with those of the bacterial populations. The structure of the microbial community changed within each peak of the dynamics of the bacterial number (but not from peak to peak), pointing to the cyclical character of the short-term succession. The long-term effects resulted in a less intense response of the microbiota—a lower rate of CO2 emission from the soil cultivated according to the organic farming system.

  5. Effect of Short-Term Hypergravity Treatment on Mouse 2-Cell Embryo Development

    Science.gov (United States)

    Ning, Li-Na; Lei, Xiao-Hua; Cao, Yu-Jing; Zhang, Yun-Fang; Cao, Zhong-Hong; Chen, Qi; Duan, En-Kui

    2015-11-01

    Though there are numerous biological experiments, which have been performed in a space environment, to study the physiological effect of space travel on living organisms, while the potential effect of weightlessness or short-term hypergravity on the reproductive system in most species, particularly in mammalian is still controversial and unclear. In our previous study, we investigated the effect of space microgravity on the development of mouse 4-cell embryos by using Chinese SJ-8. .Unexpectedly, we did not get any developed embryo during the space-flight. Considering that the process of space experiment is quite different from most experiments done on earth in several aspects such as, the vibration and short-term hypergravity during the rock launching and landing. Thus we want to know whether the short-term hypergravity produced by the launch process affect the early embryo development in mice, and howthe early embryos respond to the hypergravity. In present study, we are mimicking the short-term hypergravity during launch by using a centrifuge to investigate its influence on the development of early embryo (2-cell) in mice. We also examined the actin filament distribution in 2-cell embryos by immunostaining to test their potential capacity of development under short-term hypergravity exposure. Our results showed that most 2-cell embryos in the hypergravity exposure groups developed into blastocysts with normal morphology after 72h cultured in vitro, and there is no obvious difference in the development rate of blastocyst formation compared to the control. Moreover, there were no statistically significant differences in birth rates after oviduct transfer of 2-cell mouse embryos exposed on short-term hypergravity compared with 1 g condition. In addition, the well-organized actin distribution appeared in 2-cell embryos after exposed on hypergravity and also in the subsequent developmental blastocysts. Taken together, our data shows that short-term exposure in

  6. Big Five Traits Related to Short-Term Mating: From Personality to Promiscuity across 46 Nations

    Directory of Open Access Journals (Sweden)

    David P. Schmitt

    2008-04-01

    Full Text Available As part of the International Sexuality Description Project, 13,243 participants from 46 nations responded to self-report measures of personality and mating behavior. Several traits showed consistent links with short-term mating. Extraversion positively correlated with interest in short-term mating, unrestricted sociosexuality, having engaged in short-term mate poaching attempts, having succumbed to short-term poaching attempts of others, and lacking relationship exclusivity. Low levels of agreeableness and conscientiousness also related to short-term mating, especially with extra-pair mating. Neuroticism and openness were associated with short-term mating as well, but these links were less consistent across sex and nation. Nation-level links between personality and sexuality replicated within-region findings, such as the strong association between national extraversion and national sociosexuality. Discussion focuses on the origins of personality-sexuality links and their implications across nations.

  7. International Short-Term Countermeasures Survey - 2012 Update

    International Nuclear Information System (INIS)

    Ingham, Grant

    2013-01-01

    Nuclear emergency planning, preparedness, response, and management, in general, are essential elements of any country's nuclear power programme. Part of nuclear emergency planning and preparedness is the implementation of national emergency plans, including detailed procedures for the implementation of short-term countermeasures, before during, and after the release of radioactive substances. The timely and appropriate implementation of short-term countermeasures, such as sheltering, evacuation, and iodine prophylaxis, can, in case of a nuclear emergency with a release of radioactive material, considerably reduce the doses to the public in the vicinity of the nuclear installation. Although international guidelines exist, national procedures and practices may differ due to different national habits, cultural specificity, and societal needs. Different national procedures and practices may, however, in the case of a radioactive release affecting two neighbouring countries, lead to different decisions in the implementation of countermeasures. In order to better understand existing approaches and to facilitate the comparison of national practices, the NEA decided to launch a questionnaire on current practices regarding short-term countermeasures, updating a similar survey performed in 1994 and 2003, as countries' practices have since evolved and been modified. In 2012, it was decided to reevaluate the country approaches in light of the early lessons learnt from the Fukushima Daiichi NPP accident. The information collected may be used to understand the basis for decisions in various countries, and, if deemed appropriate, as a basis for international harmonisation. This may also assist member countries to explain to the public affected by an emergency why the decisions in neighbouring countries may vary. This report summarises the information given by member countries and includes nine sections to explore the different aspects, covering the following topics: member

  8. Resuming growth in Latin America: short and long term policies

    Directory of Open Access Journals (Sweden)

    Julio Lopez G.

    2008-09-01

    Full Text Available The authors of this paper assert that the paralysis of the state generated by the crises of the 1970s and 1980s deprived the economies of the region of an important lever to resume and sustain growth. They thus maintain that to overcome stagnation it will be necessary to reconstruct the state's capacity to implement pro-growth policies. Following Keynes and Kalecki's ideas, but also classical development economists, the authors argue, first, that short-term macroeconomic policies, to reduce unemployment and to increase the degree of capacity utilization, should be used to promote the generation of profits to firms and to wake up entrepreneurs' animal spirits. Short-term expansionary policies should be coupled with measures to improve competitiveness and avoid balance of payments problems. They also claim that alternatives to the liberal programme will fail unless a pro-growth strategy is adopted which includes both short- and long-term policies. They thus propose that long-term policies must complete the package, signaling: a sustained increases of effective demand in the future; and b investment priorities to ensure that capacities will be created in strategic sectors and branches of the economy.

  9. Short- and long-term memory contributions to immediate serial recognition: evidence from serial position effects.

    Science.gov (United States)

    Purser, Harry; Jarrold, Christopher

    2010-04-01

    A long-standing body of research supports the existence of separable short- and long-term memory systems, relying on phonological and semantic codes, respectively. The aim of the current study was to measure the contribution of long-term knowledge to short-term memory performance by looking for evidence of phonologically and semantically coded storage within a short-term recognition task, among developmental samples. Each experimental trial presented 4-item lists. In Experiment 1 typically developing children aged 5 to 6 years old showed evidence of phonologically coded storage across all 4 serial positions, but evidence of semantically coded storage at Serial Positions 1 and 2. In a further experiment, a group of individuals with Down syndrome was investigated as a test case that might be expected to use semantic coding to support short-term storage, but these participants showed no evidence of semantically coded storage and evidenced phonologically coded storage only at Serial Position 4, suggesting that individuals with Down syndrome have a verbal short-term memory capacity of 1 item. Our results suggest that previous evidence of semantic effects on "short-term memory performance" does not reflect semantic coding in short-term memory itself, and provide an experimental method for researchers wishing to take a relatively pure measure of verbal short-term memory capacity, in cases where rehearsal is unlikely.

  10. Short-term effects of simultaneous cardiovascular workout and ...

    African Journals Online (AJOL)

    PMD), has become a growing public health concern, as it may potentially result in the development of hearing difficulties. Objectives: The aim of the study was to determine the differential impact and short-term effects of simultaneous ...

  11. Correlation between Very Short and Short-Term Blood Pressure Variability in Diabetic-Hypertensive and Healthy Subjects.

    Science.gov (United States)

    Casali, Karina R; Schaan, Beatriz D; Montano, Nicola; Massierer, Daniela; M F Neto, Flávio; Teló, Gabriela H; Ledur, Priscila S; Reinheimer, Marilia; Sbruzzi, Graciele; Gus, Miguel

    2018-02-01

    Blood pressure (BP) variability can be evaluated by 24-hour ambulatory BP monitoring (24h-ABPM), but its concordance with results from finger BP measurement (FBPM) has not been established yet. The aim of this study was to compare parameters of short-term (24h-ABPM) with very short-term BP variability (FBPM) in healthy (C) and diabetic-hypertensive (DH) subjects. Cross-sectional study with 51 DH subjects and 12 C subjects who underwent 24h-ABPM [extracting time-rate, standard deviation (SD), coefficient of variation (CV)] and short-term beat-to-beat recording at rest and after standing-up maneuvers [FBPM, extracting BP and heart rate (HR) variability parameters in the frequency domain, autoregressive spectral analysis]. Spearman correlation coefficient was used to correlate BP and HR variability parameters obtained from both FBPM and 24h-ABPM (divided into daytime, nighttime, and total). Statistical significance was set at p ABPM) and LF component of short-term variability (FBPM, total, R = 0.591, p = 0.043); standard deviation (24h-ABPM) with LF component BPV (FBPM, total, R = 0.608, p = 0.036), coefficient of variation (24h-ABPM) with total BPV (FBPM, daytime, -0.585, p = 0.046) and alpha index (FBPM, daytime, -0.592, p = 0.043), time rate (24h-ABPM) and delta LF/HF (FBPM, total, R = 0.636, p = 0.026; daytime R = 0,857, p ABPM (total, daytime) reflect BP and HR variability evaluated by FBPM in healthy individuals. This does not apply for DH subjects.

  12. Nitric oxide affects short-term olfactory memory in the antennal lobe of Manduca sexta.

    Science.gov (United States)

    Gage, Stephanie L; Daly, Kevin C; Nighorn, Alan

    2013-09-01

    Nitric oxide (NO) is thought to play an important neuromodulatory role in olfaction. We are using the hawkmoth Manduca sexta to investigate the function of NO signaling in the antennal lobe (AL; the primary olfactory network in invertebrates). We have found previously that NO is present at baseline levels, dramatically increases in response to odor stimulation, and alters the electrophysiology of AL neurons. It is unclear, however, how these effects contribute to common features of olfactory systems such as olfactory learning and memory, odor detection and odor discrimination. In this study, we used chemical detection and a behavioral approach to further examine the function of NO in the AL. We found that basal levels of NO fluctuate with the daily light cycle, being higher during the nocturnal active period. NO also appears to be necessary for short-term olfactory memory. NO does not appear to affect odor detection, odor discrimination between dissimilar odorants, or learning acquisition. These findings suggest a modulatory role for NO in the timing of olfactory-guided behaviors.

  13. Analysis of Meniscus Fluctuation in a Continuous Casting Slab Mold

    Science.gov (United States)

    Zhang, Kaitian; Liu, Jianhua; Cui, Heng; Xiao, Chao

    2018-03-01

    A water model of slab mold was established to analyze the microscopic and macroscopic fluctuation of meniscus. The fast Fourier transform and wavelet entropy were adopted to analyze the wave amplitude, frequency, and components of fluctuation. The flow patterns under the meniscus were measured by using particle image velocimetry measurement and then the mechanisms of meniscus fluctuation were discussed. The results reflected that wavelet entropy had multi-scale and statistical properties, and it was suitable for the study of meniscus fluctuation details both in time and frequency domain. The basic wave, frequency of which exceeding 1 Hz in the condition of no mold oscillation, was demonstrated in this work. In fact, three basic waves were found: long-wave with low frequency, middle-wave with middle frequency, and short-wave with high frequency. In addition, the upper roll flow in mold had significant effect on meniscus fluctuation. When the position of flow impinged was far from the meniscus, long-wave dominated the fluctuation and the stability of meniscus was enhanced. However, when the velocity of flow was increased, the short-wave dominated the meniscus fluctuation and the meniscus stability was decreased.

  14. Short-term Treatment of Daumone Improves Hepatic Inflammation in Aged Mice.

    Science.gov (United States)

    Park, Jong Hee; Ha, Hunjoo

    2015-05-01

    Chronic inflammation has been proposed as one of the main molecular mechanisms of aging and age-related diseases. Although evidence in humans is limited, short-term calorie restriction (CR) has been shown to have anti-inflammatory effects in aged experimental animals. We reported on the long-term treatment of daumone, a synthetic pheromone secreted by Caenorhabditis elegans in an energy deficient environment, extends the life-span and attenuates liver injury in aged mice. The present study examined whether late onset short-term treatment of daumone exerts anti-inflammatory effects in the livers of aged mice. Daumone was administered orally at doses of 2 or 20 mg/kg/day for 5 weeks to 24-month-old male C57BL/6J mice. Increased liver macrophage infiltration and gene expression of proinflammatory cytokines in aged mice were significantly attenuated by daumone treatment, suggesting that short-term oral administration of daumone may have hepatoprotective effects. Daumone also dose-dependently suppressed tumor necrosis factor-α (TNF-α)-induced nuclear factor-κB (NF-κB) phosphorylation in HepG2 cells. The present data demonstrated that short-term treatment of daumone has anti-inflammatory effects in aged mouse livers possibly through suppression of NF-κB signaling and suggest that daumone may become a lead compound targeting aging and age-associated diseases.

  15. Stimulus-specific suppression preserves information in auditory short-term memory.

    Science.gov (United States)

    Linke, Annika C; Vicente-Grabovetsky, Alejandro; Cusack, Rhodri

    2011-08-02

    Philosophers and scientists have puzzled for millennia over how perceptual information is stored in short-term memory. Some have suggested that early sensory representations are involved, but their precise role has remained unclear. The current study asks whether auditory cortex shows sustained frequency-specific activation while sounds are maintained in short-term memory using high-resolution functional MRI (fMRI). Investigating short-term memory representations within regions of human auditory cortex with fMRI has been difficult because of their small size and high anatomical variability between subjects. However, we overcame these constraints by using multivoxel pattern analysis. It clearly revealed frequency-specific activity during the encoding phase of a change detection task, and the degree of this frequency-specific activation was positively related to performance in the task. Although the sounds had to be maintained in memory, activity in auditory cortex was significantly suppressed. Strikingly, patterns of activity in this maintenance period correlated negatively with the patterns evoked by the same frequencies during encoding. Furthermore, individuals who used a rehearsal strategy to remember the sounds showed reduced frequency-specific suppression during the maintenance period. Although negative activations are often disregarded in fMRI research, our findings imply that decreases in blood oxygenation level-dependent response carry important stimulus-specific information and can be related to cognitive processes. We hypothesize that, during auditory change detection, frequency-specific suppression protects short-term memory representations from being overwritten by inhibiting the encoding of interfering sounds.

  16. Short-Term Multiple Forecasting of Electric Energy Loads for Sustainable Demand Planning in Smart Grids for Smart Homes

    Directory of Open Access Journals (Sweden)

    Adeshina Y. Alani

    2017-10-01

    Full Text Available Energy consumption in the form of fuel or electricity is ubiquitous globally. Among energy types, electricity is crucial to human life in terms of cooking, warming and cooling of shelters, powering of electronic devices as well as commercial and industrial operations. Users of electronic devices sometimes consume fluctuating amounts of electricity generated from smart-grid infrastructure owned by the government or private investors. However, frequent imbalance is noticed between the demand and supply of electricity, hence effective planning is required to facilitate its distribution among consumers. Such effective planning is stimulated by the need to predict future consumption within a short period. Although several interesting classical techniques have been used for such predictions, they still require improvement for the purpose of reducing significant predictive errors when used for short-term load forecasting. This research develops a near-zero cooperative probabilistic scenario analysis and decision tree (PSA-DT model to address the lacuna of enormous predictive error faced by the state-of-the-art models. The PSA-DT is based on a probabilistic technique in view of the uncertain nature of electricity consumption, complemented by a DT to reinforce the collaboration of the two techniques. Based on detailed experimental analytics on residential, commercial and industrial data loads, the PSA-DT model outperforms the state-of-the-art models in terms of accuracy to a near-zero error rate. This implies that its deployment for electricity demand planning will be of great benefit to various smart-grid operators and homes.

  17. Holocene sea-level fluctuation in the southern hemisphere

    Science.gov (United States)

    Isla, Federico Ignacio

    If rising sea levels dominate in the northern hemisphere (NH), falling or fluctuating sea levels predominate in the southern hemisphere (SH). Endogenic processes (tectonics, isostasy or geoidal changes) could explain local or regional mean sea level (MSL) fluctuations but not an hemispherical one. Evidence from South America, Africa, Antarctica, Australia and the Pacific and Indian Oceans suggest that the Holocene transgression rose above the present MSL, in higher latitudes before the tropics. By plotting latitude against the age of MSL arrival at present coasts, good correlation is observed. Oceanic salinity mixing has been already proposed to explain this mid-Holocene sea-level fluctuation. Climate could be the only factor responsible for this hemisphere-wide behavior of MSL. It has been suggested previously that the climate of the SH precedes that of the NH by 3000 years. The climatic optimum, or maximum warmth, occurred predominantly about 6000 BP in the NH, but about 10-9000 BP in the SH. Short-term climatic effects on the sea level (monsoons, southern oscillation/El Niño phenomena) should have significant occurrences during the past in the windiest oceanic hemisphere. This latitudinal trend in former MSL should be considered when using shorelines as reference points for measuring vertical crustal movements.

  18. Managing Transit Ridership with Short-Term Economic Incentives

    Science.gov (United States)

    1982-08-01

    It is the purpose of this booklet to give the reader an overview of the variety, : type, and nature of short-term economic incentive programs that have been : introduced by transit properties over the past few years. 3054k, 55p.

  19. High-intensity exercise and recovery during short-term ...

    African Journals Online (AJOL)

    Objective. To determine the effect of short-term creatine supplementation plus a protein-carbohydrate formula on high-intensity exercise performance and recovery. Design. A repeated-measures, experimental study, employing a randomised, double-blind, placebo-controlled, group comparison design was used.

  20. Short-term versus long-term approaches to the development of tourism-related policies

    OpenAIRE

    Dredge, Dianne

    2015-01-01

    Tourism policy development is an increasingly complex activity involving multiple public sector agencies, industry and community stakeholders and non-government organisations at different scales. This discussion paper examines the implications for tourism of governments adopting short- term versus long-term approaches to the development of tourism related policies and identifies policy considerations to maximize the growth potential of tourism. The key issue is to understand how governments c...

  1. Short term memory for single surface features and bindings in ageing: A replication study.

    Science.gov (United States)

    Isella, Valeria; Molteni, Federica; Mapelli, Cristina; Ferrarese, Carlo

    2015-06-01

    In the present study we replicated a previous experiment investigating visuo-spatial short term memory binding in young and older healthy individuals, in the attempt to verify the pattern of impairment that can be observed in normal elderly for short term memory for single items vs short term memory for bindings. Assessing a larger sample size (25 young and 25 older subjects), using a more appropriate measure of accuracy for a change detection task (A'), and adding the evaluation of speed of performance, we confirmed that old normals show a decline in short term memory for bindings of shape and colour that is of comparable extent, and not major, to the decline in memory for single shapes and single colours. The absence of a specific deficit of short term memory for conjunctions of surface features seems to distinguish cognitive ageing from Alzheimer's Disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Selective potentiation of the antitumor radiation effect by means of short-term hyperglycemia

    International Nuclear Information System (INIS)

    Yarmonenko, S.P.; Shapot, V.S.; Voloshina, E.A.; Gorozhanskaya, Eh.G.; Dyuskaliev, Zh.D.; Krimker, V.M.

    1981-01-01

    Experiments on mice have shown that short-term induced hyperglycemia caused by 5-fold intraperitoneal administration of glucose at a dose of 2.6 and 1.3 g/kg increases notably the radiation injury to a solid type of Ehrlich carcinoma. Short-term induced hyperglycemia is mostly effective after irradiation. During irradiation together with its antitumor effect enhanced in the presence of short-term induced hyperglycemia there is observed selective protection of the normal tissues resulting from a decrease of oxygen pressure in them

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

    Science.gov (United States)

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

    2013-11-06

    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. © 2013 Elsevier B.V. All rights reserved.

  4. Defect production in simulated cascades: Cascade quenching and short-term annealing

    International Nuclear Information System (INIS)

    Heinisch, H.L.

    1983-01-01

    Defect production in displacement cascades in copper has been modeled using the MARLOWE code to generate cascades and the stochastic annealing code ALSOME to simulate cascade quenching and short-term annealing of isolated cascades. Quenching is accomplished by using exaggerated values for defect mobilities and for critical reaction distances in ALSOME for a very short time. The quenched cascades are then short-term annealed with normal parameter values. The quenching parameter values were empirically determined by comparison with results of resistivity measurements. Throughout the collisional, quenching and short-term annealing phases of cascade development, the high energy cascades continue to behave as a collection of independent lower energy lobes. For recoils above about 30 keV the total number of defects and the numbers of free defects scale with the damage energy. As the energy decreases from 30 keV, defect production varies with the changing nature of the cascade configuration, resulting in more defects per unit damage energy. The simulated annealing of a low fluence of interacting cascades revealed an interstitial shielding effect on depleted zones during Stage I recovery. (orig.)

  5. The Effect of Zinc Supplementation of Lactating Rats on Short-Term and Long-Term Memory of Their Male Offspring

    Directory of Open Access Journals (Sweden)

    Mohammad Karami

    2013-12-01

    Full Text Available Background: In this study the effect of zinc chloride (ZnCl2 administration on the short-term and long-term memory of rats were assessed. Methods: We enrolled six groups of adult female and control group of eight Wistar rats in each group. One group was control group with free access to food and water, and five groups drunk zinc chloride in different doses (20, 30, 50, 70 and 100 mg/kg/day in drinking water for two weeks during lactation .One month after birth, a shuttle box used to short- term and long-term memory and the latency in entering the dark chamber as well. Results: This experiment showed that maternal 70 mg/kg dietary zinc during lactation influenced the working memory of rats’ offspring in all groups. Rats received 100 mg/kg/day zinc during lactation so they had significant impairment in working memory (short-term of their offspring (P<0.05. There was no significant difference in reference (long-term memory of all groups. Conclusion: Drug consumption below70 mg/kg/day zinc chloride during lactation had no effect. While enhanced 100 mg/ kg/ day zinc in lactating rats could cause short-term memory impairment.

  6. Integration and segregation of large-scale brain networks during short-term task automatization.

    Science.gov (United States)

    Mohr, Holger; Wolfensteller, Uta; Betzel, Richard F; Mišić, Bratislav; Sporns, Olaf; Richiardi, Jonas; Ruge, Hannes

    2016-11-03

    The human brain is organized into large-scale functional networks that can flexibly reconfigure their connectivity patterns, supporting both rapid adaptive control and long-term learning processes. However, it has remained unclear how short-term network dynamics support the rapid transformation of instructions into fluent behaviour. Comparing fMRI data of a learning sample (N=70) with a control sample (N=67), we find that increasingly efficient task processing during short-term practice is associated with a reorganization of large-scale network interactions. Practice-related efficiency gains are facilitated by enhanced coupling between the cingulo-opercular network and the dorsal attention network. Simultaneously, short-term task automatization is accompanied by decreasing activation of the fronto-parietal network, indicating a release of high-level cognitive control, and a segregation of the default mode network from task-related networks. These findings suggest that short-term task automatization is enabled by the brain's ability to rapidly reconfigure its large-scale network organization involving complementary integration and segregation processes.

  7. Fluctuations, dynamical instabilities and clusterization processes

    International Nuclear Information System (INIS)

    Burgio, G.F.; Chomaz, Ph.; Randrup, J.

    1992-01-01

    Recent progress with regard to the numerical simulation of fluctuations in nuclear dynamics is reported. Cluster formation in unstable nuclear matter is studied within the framework of a Boltzmann-Langevin equation developed to describe large amplitude fluctuations. Through the Fourier analysis of the fluctuating nuclear density in coordinate space, the onset of the clusterization is related to the dispersion relation of harmonic density oscillations. This detailed study on the simple two-dimensional case demonstrates the validity of the general approach. It is also shown, how the inclusion of fluctuations implies a description in terms of ensemble of trajectories and it is discussed why the presence of a stochastic term may cure the intrinsic unpredictability of deterministic theories (such as mean-field approximation) in presence of instabilities and/or chaos. (author) 8 refs., 3 figs

  8. Influence of thermal fluctuations on ligament break-up: a fluctuating lattice Boltzmann study

    Science.gov (United States)

    Xue, Xiao; Biferale, Luca; Sbragaglia, Mauro; Toschi, Federico

    2017-11-01

    Thermal fluctuations are essential ingredients in a nanoscale system, driving Brownian motion of particles and capillary waves at non-ideal interfaces. Here we study the influence of thermal fluctuations on the breakup of liquid ligaments at the nanoscale. We offer quantitative characterization of the effects of thermal fluctuations on the Plateau-Rayleigh mechanism that drives the breakup process of ligaments. Due to thermal fluctuations, the droplet sizes after break-up need to be analyzed in terms of their distribution over an ensemble made of repeated experiments. To this aim, we make use of numerical simulations based on the fluctuating lattice Boltzmann method (FLBM) for multicomponent mixtures. The method allows an accurate and efficient simulation of the fluctuating hydrodynamics equations of a binary mixture, where both stochastic viscous stresses and diffusion fluxes are introduced. This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No 642069.

  9. Anisomycin Injection in Area CA3 of the Hippocampus Impairs Both Short-Term and Long-Term Memories of Contextual Fear

    Science.gov (United States)

    Remaud, Jessica; Ceccom, Johnatan; Carponcy, Julien; Dugué, Laura; Menchon, Gregory; Pech, Stéphane; Halley, Helene; Francés, Bernard; Dahan, Lionel

    2014-01-01

    Protein synthesis is involved in the consolidation of short-term memory into long-term memory. Previous electrophysiological data concerning LTP in CA3 suggest that protein synthesis in that region might also be necessary for short-term memory. We tested this hypothesis by locally injecting the protein synthesis inhibitor anisomycin in hippocampal…

  10. Assessment of short-term memory in Arabic speaking children with specific language impairment.

    Science.gov (United States)

    Kaddah, F A; Shoeib, R M; Mahmoud, H E

    2010-12-15

    Children with Specific Language Impairment (SLI) may have some kind of memory disorder that could increase their linguistic impairment. This study assessed the short-term memory skills in Arabic speaking children with either Expressive Language Impairment (ELI) or Receptive/Expressive Language Impairment (R/ELI) in comparison to controls in order to estimate the nature and extent of any specific deficits in these children that could explain the different prognostic results of language intervention. Eighteen children were included in each group. Receptive, expressive and total language quotients were calculated using the Arabic language test. Assessment of auditory and visual short-term memory was done using the Arabic version of the Illinois Test of Psycholinguistic Abilities. Both groups of SLI performed significantly lower linguistic abilities and poorer auditory and visual short-term memory in comparison to normal children. The R/ELI group presented an inferior performance than the ELI group in all measured parameters. Strong association was found between most tasks of auditory and visual short-term memory and linguistic abilities. The results of this study highlighted a specific degree of deficit of auditory and visual short-term memories in both groups of SLI. These deficits were more prominent in R/ELI group. Moreover, the strong association between the different auditory and visual short-term memories and language abilities in children with SLI must be taken into account when planning an intervention program for these children.

  11. Short-Term International Internship Experiences for Future Teachers and Other Child Development Professionals

    Science.gov (United States)

    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…

  12. Laparoscopic and open subtotal colectomies have similar short-term results.

    Science.gov (United States)

    Hoogenboom, Froukje J; Bosker, Robbert J I; Groen, Henk; Meijerink, Wilhelmus J H J; Lamme, Bas; Pierie, Jean Pierre E N

    2013-01-01

    Laparoscopic subtotal colectomy (STC) is a complex procedure. It is possible that short-term benefits for segmental resections cannot be attributed to this complex procedure. This study aims to assess differences in short-term results for laparoscopic versus open STC during a 15-year single-institute experience. We reviewed consecutive patients undergoing laparoscopic or open elective or subacute STC from January 1997 to December 2012. Fifty-six laparoscopic and 50 open STCs were performed. The operation time was significantly longer in the laparoscopic group, median 266 min (range 121-420 min), compared to 153 min (range 90-408 min) in the open group (p < 0.001). Median hospital stay showed no statistical difference, 14 days (range 1-129 days) in the laparoscopic and 13 days (range 1-85 days) in the open group. Between-group postoperative complications were not statistically different. Laparoscopic STC has short-term results similar to the open procedure, except for a longer operation time. The laparoscopic approach for STC is therefore only advisable in selected patients combined with extensive preoperative counseling. Copyright © 2013 S. Karger AG, Basel.

  13. A Short-Term Longitudinal Study of Memorial Development during Early Grade School.

    Science.gov (United States)

    Kunzinger, Edward L., III

    1985-01-01

    Overt rehearsal and free recall performance was analyzed longitudinally in two experimental testing sessions at 7 and later at 9 years of age. Measures of short- and long-term memory recall, and two measures of input processing were obtained. Significant increases between age levels were exhibited by all variables except short-term memory.…

  14. GF-GC Theory of Human Cognition: Differentiation of Short-Term Auditory and Visual Memory Factors.

    Science.gov (United States)

    McGhee, Ron; Lieberman, Lewis

    1994-01-01

    Study sought to determine whether separate short-term auditory and visual memory factors would emerge given a sufficient number of markers in a factor matrix. A principal component factor analysis with varimax rotation was performed. Short-term visual and short-term auditory memory factors emerged as expected. (RJM)

  15. 13 CFR 107.1240 - Funding of Licensee's draw request through sale to short-term investor.

    Science.gov (United States)

    2010-01-01

    ... through sale to short-term investor. 107.1240 Section 107.1240 Business Credit and Assistance SMALL...'s draw request through sale to short-term investor. (a) Licensee's authorization of SBA to arrange sale of securities to short-term investor. By submitting a request for a draw of Debenture or...

  16. Short-term sleep deprivation stimulates hippocampal neurogenesis in rats following global cerebral ischemia/reperfusion.

    Directory of Open Access Journals (Sweden)

    Oumei Cheng

    Full Text Available Sleep deprivation (SD plays a complex role in central nervous system (CNS diseases. Recent studies indicate that short-term SD can affect the extent of ischemic damage. The aim of this study was to investigate whether short-term SD could stimulate hippocampal neurogenesis in a rat model of global cerebral ischemia/reperfusion (GCIR.One hundred Sprague-Dawley rats were randomly divided into Sham, GCIR and short-term SD groups based on different durations of SD; the short-term SD group was randomly divided into three subgroups: the GCIR+6hSD*3d-treated, GCIR+12hSD-treated and GCIR+12hSD*3d-treated groups. The GCIR rat model was induced via the bilateral occlusion of the common carotid arteries and hemorrhagic hypotension. The rats were sleep-deprived starting at 48 h following GCIR. A Morris water maze test was used to assess learning and memory ability; cell proliferation and differentiation were analyzed via 5-bromodeoxyuridine (BrdU and neuron-specific enolase (NSE, respectively, at 14 and 28 d; the expression of hippocampal BDNF was measured after 7 d.The different durations of short-term SD designed in our experiment exhibited improvement in cognitive function as well as increased hippocampal BDNF expression. Additionally, the short-term SD groups also showed an increased number of BrdU- and BrdU/NSE-positive cells compared with the GCIR group. Of the three short-term SD groups, the GCIR+12hSD*3d-treated group experienced the most substantial beneficial effects.Short-term SD, especially the GCIR+12hSD*3d-treated method, stimulates neurogenesis in the hippocampal dentate gyrus (DG of rats that undergo GCIR, and BDNF may be an underlying mechanism in this process.

  17. Predicting Short-Term Subway Ridership and Prioritizing Its Influential Factors Using Gradient Boosting Decision Trees

    Directory of Open Access Journals (Sweden)

    Chuan Ding

    2016-10-01

    Full Text Available Understanding the relationship between short-term subway ridership and its influential factors is crucial to improving the accuracy of short-term subway ridership prediction. Although there has been a growing body of studies on short-term ridership prediction approaches, limited effort is made to investigate the short-term subway ridership prediction considering bus transfer activities and temporal features. To fill this gap, a relatively recent data mining approach called gradient boosting decision trees (GBDT is applied to short-term subway ridership prediction and used to capture the associations with the independent variables. Taking three subway stations in Beijing as the cases, the short-term subway ridership and alighting passengers from its adjacent bus stops are obtained based on transit smart card data. To optimize the model performance with different combinations of regularization parameters, a series of GBDT models are built with various learning rates and tree complexities by fitting a maximum of trees. The optimal model performance confirms that the gradient boosting approach can incorporate different types of predictors, fit complex nonlinear relationships, and automatically handle the multicollinearity effect with high accuracy. In contrast to other machine learning methods—or “black-box” procedures—the GBDT model can identify and rank the relative influences of bus transfer activities and temporal features on short-term subway ridership. These findings suggest that the GBDT model has considerable advantages in improving short-term subway ridership prediction in a multimodal public transportation system.

  18. Short-term effect of short, intensive speech therapy on articulation and resonance in Ugandan patients with cleft (lip and) palate

    NARCIS (Netherlands)

    Anke Luyten; H. Vermeersch; A. Hodges; K. Bettens; K. van Lierde; G. Galiwango

    2016-01-01

    Objectives: The purpose of the current study was to assess the short-term effectiveness of short and intensive speech therapy provided to patients with cleft (lip and) palate (C(L)P) in terms of articulation and resonance. Methods: Five Ugandan patients (age: 7.3-19.6 years) with non-syndromic C(L)P

  19. Short-term wind power combined forecasting based on error forecast correction

    International Nuclear Information System (INIS)

    Liang, Zhengtang; Liang, Jun; Wang, Chengfu; Dong, Xiaoming; Miao, Xiaofeng

    2016-01-01

    Highlights: • The correlation relationships of short-term wind power forecast errors are studied. • The correlation analysis method of the multi-step forecast errors is proposed. • A strategy selecting the input variables for the error forecast models is proposed. • Several novel combined models based on error forecast correction are proposed. • The combined models have improved the short-term wind power forecasting accuracy. - Abstract: With the increasing contribution of wind power to electric power grids, accurate forecasting of short-term wind power has become particularly valuable for wind farm operators, utility operators and customers. The aim of this study is to investigate the interdependence structure of errors in short-term wind power forecasting that is crucial for building error forecast models with regression learning algorithms to correct predictions and improve final forecasting accuracy. In this paper, several novel short-term wind power combined forecasting models based on error forecast correction are proposed in the one-step ahead, continuous and discontinuous multi-step ahead forecasting modes. First, the correlation relationships of forecast errors of the autoregressive model, the persistence method and the support vector machine model in various forecasting modes have been investigated to determine whether the error forecast models can be established by regression learning algorithms. Second, according to the results of the correlation analysis, the range of input variables is defined and an efficient strategy for selecting the input variables for the error forecast models is proposed. Finally, several combined forecasting models are proposed, in which the error forecast models are based on support vector machine/extreme learning machine, and correct the short-term wind power forecast values. The data collected from a wind farm in Hebei Province, China, are selected as a case study to demonstrate the effectiveness of the proposed

  20. Social evolution and genetic interactions in the short and long term.

    Science.gov (United States)

    Van Cleve, Jeremy

    2015-08-01

    The evolution of social traits remains one of the most fascinating and feisty topics in evolutionary biology even after half a century of theoretical research. W.D. Hamilton shaped much of the field initially with his 1964 papers that laid out the foundation for understanding the effect of genetic relatedness on the evolution of social behavior. Early theoretical investigations revealed two critical assumptions required for Hamilton's rule to hold in dynamical models: weak selection and additive genetic interactions. However, only recently have analytical approaches from population genetics and evolutionary game theory developed sufficiently so that social evolution can be studied under the joint action of selection, mutation, and genetic drift. We review how these approaches suggest two timescales for evolution under weak mutation: (i) a short-term timescale where evolution occurs between a finite set of alleles, and (ii) a long-term timescale where a continuum of alleles are possible and populations evolve continuously from one monomorphic trait to another. We show how Hamilton's rule emerges from the short-term analysis under additivity and how non-additive genetic interactions can be accounted for more generally. This short-term approach reproduces, synthesizes, and generalizes many previous results including the one-third law from evolutionary game theory and risk dominance from economic game theory. Using the long-term approach, we illustrate how trait evolution can be described with a diffusion equation that is a stochastic analogue of the canonical equation of adaptive dynamics. Peaks in the stationary distribution of the diffusion capture classic notions of convergence stability from evolutionary game theory and generally depend on the additive genetic interactions inherent in Hamilton's rule. Surprisingly, the peaks of the long-term stationary distribution can predict the effects of simple kinds of non-additive interactions. Additionally, the peaks

  1. Short-Term Monocular Deprivation Enhances Physiological Pupillary Oscillations

    Directory of Open Access Journals (Sweden)

    Paola Binda

    2017-01-01

    Full Text Available Short-term monocular deprivation alters visual perception in adult humans, increasing the dominance of the deprived eye, for example, as measured with binocular rivalry. This form of plasticity may depend upon the inhibition/excitation balance in the visual cortex. Recent work suggests that cortical excitability is reliably tracked by dilations and constrictions of the pupils of the eyes. Here, we ask whether monocular deprivation produces a systematic change of pupil behavior, as measured at rest, that is independent of the change of visual perception. During periods of minimal sensory stimulation (in the dark and task requirements (minimizing body and gaze movements, slow pupil oscillations, “hippus,” spontaneously appear. We find that hippus amplitude increases after monocular deprivation, with larger hippus changes in participants showing larger ocular dominance changes (measured by binocular rivalry. This tight correlation suggests that a single latent variable explains both the change of ocular dominance and hippus. We speculate that the neurotransmitter norepinephrine may be implicated in this phenomenon, given its important role in both plasticity and pupil control. On the practical side, our results indicate that measuring the pupil hippus (a simple and short procedure provides a sensitive index of the change of ocular dominance induced by short-term monocular deprivation, hence a proxy for plasticity.

  2. Short-term and long-term effects of violent media on aggression in children and adults

    NARCIS (Netherlands)

    Bushman, B.J.; Huesmann, L.R.

    2006-01-01

    Objectives: To test whether the results of the accumulated studies on media violence and aggressive behavior are consistent with the theories that have evolved to explain the effects. We tested for the existence of both short-term and long-term effects for aggressive behavior. We also tested the

  3. A new ensemble model for short term wind power prediction

    DEFF Research Database (Denmark)

    Madsen, Henrik; Albu, Razvan-Daniel; Felea, Ioan

    2012-01-01

    As the objective of this study, a non-linear ensemble system is used to develop a new model for predicting wind speed in short-term time scale. Short-term wind power prediction becomes an extremely important field of research for the energy sector. Regardless of the recent advancements in the re-search...... of prediction models, it was observed that different models have different capabilities and also no single model is suitable under all situations. The idea behind EPS (ensemble prediction systems) is to take advantage of the unique features of each subsystem to detain diverse patterns that exist in the dataset...

  4. Forward-backward multiplicity fluctuation and longitudinal harmonics in high-energy nuclear collisions

    Science.gov (United States)

    Jia, Jiangyong; Radhakrishnan, Sooraj; Zhou, Mingliang; Huo, Peng

    2016-12-01

    Forward-backward (FB) multiplicity fluctuation in high-energy nuclear collisions can be quantified by two-particle pseudo-rapidity correlation function and its expansion into Legendre polynomials. The corresponding coefficients represent different fluctuation modes in longitudinal direction. The leading term corresponds to the asymmetry of numbers of the participants from the two colliding nuclei. This method is tested in events generated from AMPT and HIJING model. The an signal are found to be strongly dampened in AMPT than in HIJIGN, due to weaker short-range correlaitons and final-state effects in AMPT. Two-particle correlation also reveals an intresting shallow minimum around Δη ≈ 0 in AMPT events, which is absent in HIJING results. The method opens a new avenue to elucidate the particle production mechanism and early time dynamics in heavy-ion collisions.

  5. The effects of observational correlated noises on multifractal detrended fluctuation analysis

    Science.gov (United States)

    Gulich, Damián; Zunino, Luciano

    2012-08-01

    We have numerically investigated the effects that observational correlated noises have on the generalized Hurst exponents, h(q), estimated by using the multifractal generalization of detrended fluctuation analysis (MF-DFA). More precisely, artificially generated stochastic binomial multifractals with increased amount of colored noises were analyzed via MF-DFA. It has been recently shown that for moderate additions of white noise, the generalized Hurst exponents are significantly underestimated for qeffects of additive noise, short- term memory and periodic trends, Physica A 390 (2011) 2480-2490]. In this paper, we have found that h(q) with q≥2 are also affected when correlated noises are considered. This is due to the fact that the spurious correlations influence the scaling behaviors associated to large fluctuations. The results obtained are significant for practical situations, where noises with different correlations are inherently present.

  6. Algorithmic modeling of the irrelevant sound effect (ISE) by the hearing sensation fluctuation strength.

    Science.gov (United States)

    Schlittmeier, Sabine J; Weissgerber, Tobias; Kerber, Stefan; Fastl, Hugo; Hellbrück, Jürgen

    2012-01-01

    Background sounds, such as narration, music with prominent staccato passages, and office noise impair verbal short-term memory even when these sounds are irrelevant. This irrelevant sound effect (ISE) is evoked by so-called changing-state sounds that are characterized by a distinct temporal structure with varying successive auditory-perceptive tokens. However, because of the absence of an appropriate psychoacoustically based instrumental measure, the disturbing impact of a given speech or nonspeech sound could not be predicted until now, but necessitated behavioral testing. Our database for parametric modeling of the ISE included approximately 40 background sounds (e.g., speech, music, tone sequences, office noise, traffic noise) and corresponding performance data that was collected from 70 behavioral measurements of verbal short-term memory. The hearing sensation fluctuation strength was chosen to model the ISE and describes the percept of fluctuations when listening to slowly modulated sounds (f(mod) background sounds, the algorithm estimated behavioral performance data in 63 of 70 cases within the interquartile ranges. In particular, all real-world sounds were modeled adequately, whereas the algorithm overestimated the (non-)disturbance impact of synthetic steady-state sounds that were constituted by a repeated vowel or tone. Implications of the algorithm's strengths and prediction errors are discussed.

  7. Short-Range Electron Transfer in Reduced Flavodoxin: Ultrafast Nonequilibrium Dynamics Coupled with Protein Fluctuations.

    Science.gov (United States)

    Kundu, Mainak; He, Ting-Fang; Lu, Yangyi; Wang, Lijuan; Zhong, Dongping

    2018-05-03

    Short-range electron transfer (ET) in proteins is an ultrafast process on the similar timescales as local protein-solvent fluctuations thus the two dynamics are coupled. Here, we use semiquinone flavodoxin and systematically characterized the photoinduced redox cycle with eleven mutations of different aromatic electron donors (tryptophan and tyrosine) and local residues to change redox properties. We observed the forward and backward ET dynamics in a few picoseconds, strongly following a stretched behavior resulting from a coupling between local environment relaxations and these ET processes. We further observed the hot vibrational-state formation through charge recombination and the subsequent cooling dynamics also in a few picoseconds. Combined with the ET studies in oxidized flavodoxin, these results coherently reveal the evolution of the ET dynamics from single to stretched exponential behaviors and thus elucidate critical timescales for the coupling. The observed hot vibration-state formation is robust and should be considered in all photoinduced back ET processes in flavoproteins.

  8. A POSTSYNAPTIC ROLE FOR SHORT-TERM NEURONAL FACILITATION IN DENDRITIC SPINES

    Directory of Open Access Journals (Sweden)

    Sunggu Yang

    2016-09-01

    Full Text Available Synaptic plasticity is a fundamental component of information processing in the brain. Presynaptic facilitation in response to repetitive stimuli, often referred to as paired-pulse facilitation (PPF, is a dominant form of short-term synaptic plasticity. Recently, an additional cellular mechanism for short-term facilitation (short-term postsynaptic plasticity has been proposed. While a dendritic mechanism was described in hippocampus, its expression has not yet been demonstrated at the levels of the spine. Furthermore, it is unknown whether the mechanism can be expressed in other brain regions, such as sensory cortex. Here, we demonstrated that a postsynaptic response can be facilitated by prior spine excitation in both hippocampal and cortical neurons, using 3D digital holography and two-photon calcium imaging. The coordinated action of pre- and post-synaptic plasticity may provide a more thorough account of information processing in the brain.

  9. Short-term treatment with flumazenil restores long-term object memory in a mouse model of Down syndrome.

    Science.gov (United States)

    Colas, Damien; Chuluun, Bayarsaikhan; Garner, Craig C; Heller, H Craig

    2017-04-01

    Down syndrome (DS) is a common genetic cause of intellectual disability yet no pro-cognitive drug therapies are approved for human use. Mechanistic studies in a mouse model of DS (Ts65Dn mice) demonstrate that impaired cognitive function is due to excessive neuronal inhibitory tone. These deficits are normalized by chronic, short-term low doses of GABA A receptor (GABA A R) antagonists in adult animals, but none of the compounds investigated are approved for human use. We explored the therapeutic potential of flumazenil (FLUM), a GABA A R antagonist working at the benzodiazepine binding site that has FDA approval. Long-term memory was assessed by the Novel Object Recognition (NOR) testing in Ts65Dn mice after acute or short-term chronic treatment with FLUM. Short-term, low, chronic dose regimens of FLUM elicit long-lasting (>1week) normalization of cognitive function in both young and aged mice. FLUM at low dosages produces long lasting cognitive improvements and has the potential of fulfilling an unmet therapeutic need in DS. Copyright © 2017. Published by Elsevier Inc.

  10. Quantum fluctuations and inflation

    International Nuclear Information System (INIS)

    Bardeen, J.M.; Bublik, G.J.

    1986-05-01

    We study the effect of quantum fluctuations on the roll-down rate of the inflation field in a semiclassical approximation; this is done by treating the inflation field as a classical random field. The quantum fluctuations are simulated by a noise term in the equation of motion. We consider two different inflationary scenarios (new and chaotic inflation) and find that the roll-down rate of the median value of the inflation field is increased by the quantum fluctuations. Non-linear effects may become important in the later stages of the inflationary regime. 8 refs., 2 figs

  11. Quantum fluctuations and inflation

    International Nuclear Information System (INIS)

    Bardeen, J.M.; Bublik, G.J.

    1987-01-01

    The authors study the effect of quantum fluctuations on the roll-down rate of the inflation field in a semiclassical approximation; this is done by treating the inflation field as a classical random field. The quantum fluctuations are simulated by a noise term in the equation of motion. Two different inflationary scenarios (new and chaotic inflation) are considered and it is found that the roll-down rate of the median value of the inflation field is increased by the quantum fluctuations. Non-linear effects may become important in the later stages of the inflationary regime. (author)

  12. Panorama 2012 - Short-term trends in the gas industry

    International Nuclear Information System (INIS)

    Lecarpentier, Armelle

    2011-12-01

    Against the background of an energy market beset by the Fukushima crisis, the Arab spring and economic uncertainty, 2011 saw dynamic growth in demand for natural gas, although developments varied widely from region to region. New trends are emerging in the gas market, and these will have both short-term and longer-term impacts on how the industry develops. (author)

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

    Directory of Open Access Journals (Sweden)

    Kristina M Visscher

    2007-03-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  15. Short-Term Expectation Formation Versus Long-Term Equilibrium Conditions: The Danish Housing Market

    Directory of Open Access Journals (Sweden)

    Andreas Hetland

    2017-09-01

    Full Text Available The primary contribution of this paper is to establish that the long-swings behavior observed in the market price of Danish housing since the 1970s can be understood by studying the interplay between short-term expectation formation and long-run equilibrium conditions. We introduce an asset market model for housing based on uncertainty rather than risk, which under mild assumptions allows for other forms of forecasting behavior than rational expectations. We test the theory via an I(2 cointegrated VAR model and find that the long-run equilibrium for the housing price corresponds closely to the predictions from the theoretical framework. Additionally, we corroborate previous findings that housing markets are well characterized by short-term momentum forecasting behavior. Our conclusions have wider relevance, since housing prices play a role in the wider Danish economy, and other developed economies, through wealth effects.

  16. Influence of short-term memory on achievement of pupils in special schools

    OpenAIRE

    Podrazilová, Jana

    2010-01-01

    a klíčová slova diplomové práce v anglickém jazyce Key words: Memory - short - term memory - learning Pedagogy - special pedagogy Game - didactic game - mathematic - geometrical pexeso - arithmetic environment of stepping Annotation My master thesis is focused on the analysis of influence of motivation on short-term memory and in consequence on long-term memory in education of mathematics in second and third class of practical and special elementary schools. I have considered the influence of...

  17. An Overview of Short-term Statistical Forecasting Methods

    DEFF Research Database (Denmark)

    Elias, Russell J.; Montgomery, Douglas C.; Kulahci, Murat

    2006-01-01

    An overview of statistical forecasting methodology is given, focusing on techniques appropriate to short- and medium-term forecasts. Topics include basic definitions and terminology, smoothing methods, ARIMA models, regression methods, dynamic regression models, and transfer functions. Techniques...... for evaluating and monitoring forecast performance are also summarized....

  18. Simulation of Mechanical Processes in Gas Storage Caverns for Short-Term Energy Storage

    Science.gov (United States)

    Böttcher, Norbert; Nagel, Thomas; Kolditz, Olaf

    2015-04-01

    In recent years, Germany's energy management has started to be transferred from fossil fuels to renewable and sustainable energy carriers. Renewable energy sources such as solar and wind power are subjected by fluctuations, thus the development and extension of energy storage capacities is a priority in German R&D programs. This work is a part of the ANGUS+ Project, funded by the federal ministry of education and research, which investigates the influence of subsurface energy storage on the underground. The utilization of subsurface salt caverns as a long-term storage reservoir for fossil fuels is a common method, since the construction of caverns in salt rock is inexpensive in comparison to solid rock formations due to solution mining. Another advantage of evaporate as host material is the self-healing behaviour of salt rock, thus the cavity can be assumed to be impermeable. In the framework of short-term energy storage (hours to days), caverns can be used as gas storage reservoirs for natural or artificial fuel gases, such as hydrogen, methane, or compressed air, where the operation pressures inside the caverns will fluctuate more frequently. This work investigates the influence of changing operation pressures at high frequencies on the stability of the host rock of gas storage caverns utilizing numerical models. Therefore, we developed a coupled Thermo-Hydro-Mechanical (THM) model based on the finite element method utilizing the open-source software platform OpenGeoSys. The salt behaviour is described by well-known constitutive material models which are capable of predicting creep, self-healing, and dilatancy processes. Our simulations include the thermodynamic behaviour of gas storage process, temperature development and distribution on the cavern boundary, the deformation of the cavern geometry, and the prediction of the dilatancy zone. Based on the numerical results, optimal operation modes can be found for individual caverns, so the risk of host rock damage

  19. Morphological processing with deficient phonological short-term memory.

    Science.gov (United States)

    Kavé, Gitit; Ze'ev, Hagit Bar; Lev, Anita

    2007-07-01

    This paper investigates the processing of Hebrew derivational morphology in an individual (S.E.) with deficient phonological short-term memory. In comparison to 10 age- and education-matched men, S.E. was impaired on digit span tasks and demonstrated no recency effect in word list recall. S.E. had low word retention span, but he exhibited phonological similarity and word length effects. His ability to make lexical decisions was intact. In a paired-associate test S.E. successfully learned semantically and morphologically related pairs but not phonologically related pairs, and his learning of nonwords was facilitated by the presence of Hebrew consonant roots. Semantic and morphological similarity enhanced immediate word recall. Results show that S.E. is capable of conducting morphological decomposition of Hebrew-derived words despite his phonological deficit, suggesting that transient maintenance of morphological constituents is independent of temporary storage and rehearsal of phonological codes, and that each is processed separately within short-term memory.

  20. Fluoroscopically guided caudal epidural steroid injection for management of degenerative lumbar spinal stenosis: short-term and long-term results

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joon Woo; Myung, Jae Sung; Kang, Heung Sik [Seoul National University Bundang Hospital, Department of Radiology, Seong Nam, Gyeongi-do (Korea); Park, Kun Woo; Yeom, Jin S. [Seoul National University Bundang Hospital, Department of Orthopaedic Surgery, Seong Nam, Gyeongi-do (Korea); Kim, Ki-Jeong; Kim, Hyun-Jib [Seoul National University Bundang Hospital, Department of Neurosurgery, Seong Nam, Gyeongi-do (Korea)

    2010-07-15

    To evaluate the short-term and long-term effects of fluoroscopically guided caudal epidural steroid injection (ESI) for the management of degenerative lumbar spinal stenosis (DLSS) and to analyze outcome predictors. All patients who underwent caudal ESI in 2006 for DLSS were included in the study. Response was based on chart documentation (aggravated, no change, slightly improved, much improved, no pain). In June 2009 telephone interviews were conducted, using formatted questions including the North American Spine Society (NASS) patient satisfaction scale. For short-term and long-term effects, age difference was evaluated by the Mann-Whitney U test, and gender, duration of symptoms, level of DLSS, spondylolisthesis, and previous operations were evaluated by Fisher's exact test. Two hundred and sixteen patients (male: female = 75:141; mean age 69.2 years; range 48{proportional_to}91 years) were included in the study. Improvements (slightly improved, much improved, no pain) were seen in 185 patients (85.6%) after an initial caudal ESI and in 189 patients (87.5%) after a series of caudal ESIs. Half of the patients (89/179, 49.8%) replied positively to the NASS patient satisfaction scale (1 or 2). There were no significant outcome predictors for either the short-term or the long-term responses. Fluoroscopically guided caudal ESI was effective for the management of DLSS (especially central canal stenosis) with excellent short-term and good long-term results, without significant outcome predictors. (orig.)

  1. Generalized noise terms for the quantized fluctuational electrodynamics

    DEFF Research Database (Denmark)

    Partanen, Mikko; Hayrynen, Teppo; Tulkki, Jukka

    2017-01-01

    position-dependent quantum models for the photon number in resonant structures have only been formulated very recently and only for dielectric media. Here we present a general position-dependent quantized fluctuational electrodynamics (QFED) formalism that extends the consistent field quantization...

  2. Electric Field Fluctuations in Water

    Science.gov (United States)

    Thorpe, Dayton; Limmer, David; Chandler, David

    2013-03-01

    Charge transfer in solution, such as autoionization and ion pair dissociation in water, is governed by rare electric field fluctuations of the solvent. Knowing the statistics of such fluctuations can help explain the dynamics of these rare events. Trajectories short enough to be tractable by computer simulation are virtually certain not to sample the large fluctuations that promote rare events. Here, we employ importance sampling techniques with classical molecular dynamics simulations of liquid water to study statistics of electric field fluctuations far from their means. We find that the distributions of electric fields located on individual water molecules are not in general gaussian. Near the mean this non-gaussianity is due to the internal charge distribution of the water molecule. Further from the mean, however, there is a previously unreported Bjerrum-like defect that stabilizes certain large fluctuations out of equilibrium. As expected, differences in electric fields acting between molecules are gaussian to a remarkable degree. By studying these differences, though, we are able to determine what configurations result not only in large electric fields, but also in electric fields with long spatial correlations that may be needed to promote charge separation.

  3. Short-term effect of antibiotics on human gut microbiota.

    Directory of Open Access Journals (Sweden)

    Suchita Panda

    Full Text Available 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.

  4. Are there multiple visual short-term memory stores?

    NARCIS (Netherlands)

    Sligte, I.G.; Scholte, H.S.; Lamme, V.A.F.

    2008-01-01

    Background: Classic work on visual short-term memory (VSTM) suggests that people store a limited amount of items for subsequent report. However, when human observers are cued to shift attention to one item in VSTM during retention, it seems as if there is a much larger representation, which keeps

  5. Memory for relations in the short term and the long term after medial temporal lobe damage.

    Science.gov (United States)

    Squire, Larry R

    2017-05-01

    A central idea about the organization of declarative memory and the function of the hippocampus is that the hippocampus provides for the coding of relationships between items. A question arises whether this idea refers to the process of forming long-term memory or whether, as some studies have suggested, memory for relations might depend on the hippocampus even at short retention intervals and even when the task falls within the province of short-term (working) memory. The latter formulation appears to place the operation of relational memory into conflict with the idea that working memory is independent of medial temporal lobe (MTL) structures. In this report, the concepts of relational memory and working memory are discussed in the light of a simple demonstration experiment. Patients with MTL lesions successfully learned and recalled two word pairs when tested directly after learning but failed altogether when tested after a delay. The results do not contradict the idea that the hippocampus has a fundamental role in relational memory. However, there is a need for further elaboration and specification of the idea in order to explain why patients with MTL lesions can establish relational memory in the short term but not in long-term memory. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  6. Structuring spot, short and long term gas contracts

    International Nuclear Information System (INIS)

    Gretener, N.M.

    1996-01-01

    A review of the core clauses of the modern natural gas purchase and sales contracts, was presented. There exists a wide variety of terms which can be used by a seller and a buyer to customize such a contract to suit particular circumstances. On the basis of length of term, gas contracts may classified as spot contracts having a term of 30 days or less, short term contracts having a term of 30 days to one to two years, and long term contracts having terms greater than two years. The three key elements which are applicable to all gas sales contracts are the contract price, the seller's obligation to deliver, and the buyer's obligation to accept. Other provisions that may be included in any gas sales contract in addition to the basic three were reviewed, including market pricing, load factor incentive pricing, seasonal pricing, pipeline demand charges, market shares, and the seller's right to decontract

  7. Short-Term Photovoltaic Power Generation Forecasting Based on Multivariable Grey Theory Model with Parameter Optimization

    Directory of Open Access Journals (Sweden)

    Zhifeng Zhong

    2017-01-01

    Full Text Available Owing to the environment, temperature, and so forth, photovoltaic power generation volume is always fluctuating and subsequently impacts power grid planning and operation seriously. Therefore, it is of great importance to make accurate prediction of the power generation of photovoltaic (PV system in advance. In order to improve the prediction accuracy, in this paper, a novel particle swarm optimization algorithm based multivariable grey theory model is proposed for short-term photovoltaic power generation volume forecasting. It is highlighted that, by integrating particle swarm optimization algorithm, the prediction accuracy of grey theory model is expected to be highly improved. In addition, large amounts of real data from two separate power stations in China are being employed for model verification. The experimental results indicate that, compared with the conventional grey model, the mean relative error in the proposed model has been reduced from 7.14% to 3.53%. The real practice demonstrates that the proposed optimization model outperforms the conventional grey model from both theoretical and practical perspectives.

  8. Prevention of mammary carcinogenesis by short-term estrogen and progestin treatments

    International Nuclear Information System (INIS)

    Rajkumar, Lakshmanaswamy; Guzman, Raphael C; Yang, Jason; Thordarson, Gudmundur; Talamantes, Frank; Nandi, Satyabrata

    2004-01-01

    Women who have undergone a full-term pregnancy before the age of 20 have one-half the risk of developing breast cancer compared with women who have never gone through a full-term pregnancy. This protective effect is observed universally among women of all ethnic groups. Parity in rats and mice also protects them against chemically induced mammary carcinogenesis. Seven-week-old virgin Lewis rats were given N-methyl-N-nitrosourea. Two weeks later the rats were treated with natural or synthetic estrogens and progestins for 7–21 days by subcutaneous implantation of silastic capsules. In our current experiment, we demonstrate that short-term sustained exposure to natural or synthetic estrogens along with progestins is effective in preventing mammary carcinogenesis in rats. Treatment with 30 mg estriol plus 30 mg progesterone for 3 weeks significantly reduced the incidence of mammary cancer. Short-term exposure to ethynyl estradiol plus megesterol acetate or norethindrone was effective in decreasing the incidence of mammary cancers. Tamoxifen plus progesterone treatment for 3 weeks was able to confer only a transient protection from mammary carcinogenesis, while 2-methoxy estradiol plus progesterone was effective in conferring protection against mammary cancers. The data obtained in the present study demonstrate that, in nulliparous rats, long-term protection against mammary carcinogenesis can be achieved by short-term treatments with natural or synthetic estrogen and progesterone combinations

  9. Short-term energy outlook, January 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  10. The many faces of working memory and short-term storage.

    Science.gov (United States)

    Cowan, Nelson

    2017-08-01

    The topic of working memory (WM) is ubiquitous in research on cognitive psychology and on individual differences. According to one definition, it is a small amount of information kept in a temporary state of heightened accessibility; it is used in most types of communication and problem solving. Short-term storage has been defined as the passive (i.e., non-attention-based, nonstrategic) component of WM or, alternatively, as a passive store separate from an attention-based WM. Here I note that much confusion has been created by the use by various investigators of many, subtly different definitions of WM and short-term storage. The definitions are sometimes made explicit and sometimes implied. As I explain, the different definitions may have stemmed from the use of a wide variety of techniques to explore WM, along with differences in theoretical orientation. By delineating nine previously used definitions of WM and explaining how additional ones may emerge from combinations of these nine, I hope to improve scientific discourse on WM. The potential advantages of clarity about definitions of WM and short-term storage are illustrated with respect to several ongoing research controversies.

  11. Short-term load forecasting by a neuro-fuzzy based approach

    Energy Technology Data Exchange (ETDEWEB)

    Ruey-Hsun Liang; Ching-Chi Cheng [National Yunlin University of Science and Technology (China). Dept. of Electrical Engineering

    2002-02-01

    An approach based on an artificial neural network (ANN) combined with a fuzzy system is proposed for short-term load forecasting. This approach was developed in order to reach the desired short-term load forecasting in an efficient manner. Over the past few years, ANNs have attained the ability to manage a great deal of system complexity and are now being proposed as powerful computational tools. In order to select the appropriate load as the input for the desired forecasting, the Pearson analysis method is first applied to choose two historical record load patterns that are similar to the forecasted load pattern. These two load patterns and the required weather parameters are then fuzzified and input into a neural network for training or testing the network. The back-propagation (BP) neural network is applied to determine the preliminary forecasted load. In addition, the rule base for the fuzzy inference machine contains important linguistic membership function terms with knowledge in the form of fuzzy IF-THEN rules. This produces the load correction inference from the historical information and past forecasted load errors to obtain an inferred load error. Adding the inferred load error to the preliminary forecasted load, we can obtain the finial forecasted load. The effectiveness of the proposed approach to the short-term load-forecasting problem is demonstrated using practical data from the Taiwan Power Company (TPC). (Author)

  12. The effect of retraining of nurses on cardiopulmonary resuscitationsuccess rate and short-term and long-term survival in patients revived

    Directory of Open Access Journals (Sweden)

    Dahi M

    2015-02-01

    Full Text Available Background and Objective: Cardiopulmonary resuscitation (CPR is performed in order to restore the functioning of two most important body organs the heart and brain. The present study was performed to investigate the effect of retraining of nurses on CPR success rate and short-term and long-term CPR survival. Materials and Method: The study population of the present quasi-experimental study consisted of all nurses of Taleghani Hospital affiliated with Shahid Beheshti University, Tehran, Iran, in 2011. The study subjects (n = 400 were selected using convenience and purposive sampling method. The patient survival rate during the first 24 hours (short-term survival and discharge from the hospital (long-term survival after CPR were reported. Then, the study subjects, in groups of 20, participated in CPR training courses. Short-term (24 hours and long-term (discharge from hospital in good mental status survival subsequent to CPR were reevaluated and compared with pre-training results. Data were analyzed using SPSS software version 20, and t-test and chi-square test. Results: Retraining promoted CPR success rates. This increase in the short-term success rate was not significant, but the increase in long-term success rate was statistically significant (P = 0.007. Conclusion: Periodic retraining of nurses may improve CPR success rate particularly long-term survival or discharge from hospital. Therefore, further studies on long-term success of CPR considering confounding factors are recommended

  13. Chances of short-term cooling trends over Canada for the next decades

    Science.gov (United States)

    Grenier, Patrick; de Elia, Ramon; Chaumont, Diane

    2014-05-01

    As climate services continue to develop in Quebec, Canada, an increasing number of requests are made for providing information relevant for the near term. As a response, one approach has been to consider short-term cooling trends as a basis for climate products. This project comprises different aspects: technical steps, knowledge transfer, and societal use. Each step does represent a different challenge. The technical part, i.e. producing probabilistic distributions of short-term temperature trends, involves relatively complex scenario construction methods including bias-related post-processing, and access to wide simulation and observation databases. Calculations are performed on 60 CMIP5-based scenarios on a grid covering Canada during the period 2006-2035, and for 5, 10, 15, 20 and 25-year trend durations. Knowledge transfer implies overcoming misinterpretation, given that probabilistic projections based on simulation ensembles are not perfectly related to real-Earth possible outcomes. Finally, societal use of this information remains the biggest challenge. On the one hand, users clearly state their interest in near-term relevant information, and intuitively it seems clear that short-term cooling trends embedded within the long-term warming path should be considered in adaptation plans, for avoiding over-adaptation. On the other hand, the exact way of incorporating such information within a decision-making process has proven not to be obvious. Irrespective of that, the study and communication of short-term cooling chances is necessary for preventing decision-makers to infer from the eventual occurrence of such a trend that global warming isn't happening. The presentation will discuss the three aspects aforementioned.

  14. Short-Term Wind Speed Forecasting for Power System Operations

    KAUST Repository

    Zhu, Xinxin; Genton, Marc G.

    2012-01-01

    some statistical short-term wind speed forecasting models, including traditional time series approaches and more advanced space-time statistical models. It also discusses the evaluation of forecast accuracy, in particular, the need for realistic loss

  15. Fragile visual short-term memory is an object-based and location-specific store

    NARCIS (Netherlands)

    Pinto, Y.; Sligte, I.G.; Shapiro, K.L.; Lamme, V.A.F.

    2013-01-01

    Fragile visual short-term memory (FM) is a recently discovered form of visual short-term memory. Evidence suggests that it provides rich and high-capacity storage, like iconic memory, yet it exists, without interference, almost as long as visual working memory. In the present study, we sought to

  16. Intelligent and robust prediction of short term wind power using genetic programming based ensemble of neural networks

    International Nuclear Information System (INIS)

    Zameer, Aneela; Arshad, Junaid; Khan, Asifullah; Raja, Muhammad Asif Zahoor

    2017-01-01

    Highlights: • Genetic programming based ensemble of neural networks is employed for short term wind power prediction. • Proposed predictor shows resilience against abrupt changes in weather. • Genetic programming evolves nonlinear mapping between meteorological measures and wind-power. • Proposed approach gives mathematical expressions of wind power to its independent variables. • Proposed model shows relatively accurate and steady wind-power prediction performance. - Abstract: The inherent instability of wind power production leads to critical problems for smooth power generation from wind turbines, which then requires an accurate forecast of wind power. In this study, an effective short term wind power prediction methodology is presented, which uses an intelligent ensemble regressor that comprises Artificial Neural Networks and Genetic Programming. In contrast to existing series based combination of wind power predictors, whereby the error or variation in the leading predictor is propagated down the stream to the next predictors, the proposed intelligent ensemble predictor avoids this shortcoming by introducing Genetical Programming based semi-stochastic combination of neural networks. It is observed that the decision of the individual base regressors may vary due to the frequent and inherent fluctuations in the atmospheric conditions and thus meteorological properties. The novelty of the reported work lies in creating ensemble to generate an intelligent, collective and robust decision space and thereby avoiding large errors due to the sensitivity of the individual wind predictors. The proposed ensemble based regressor, Genetic Programming based ensemble of Artificial Neural Networks, has been implemented and tested on data taken from five different wind farms located in Europe. Obtained numerical results of the proposed model in terms of various error measures are compared with the recent artificial intelligence based strategies to demonstrate the

  17. Dopamine Modulation of Reunion Behavior in Short and Long Term Marmoset Pairs

    Directory of Open Access Journals (Sweden)

    Sarah B. Carp

    2018-05-01

    Full Text Available One major neurobiological substrate regulating social processes is dopamine (DA. DA is implicated in social behavior in species as diverse as fish and birds, and has an established role in regulating relationships between mates in socially monogamous rodents. Marmoset monkeys display traits associated with social monogamy including high rates of affiliation, biparental care, distress upon separation, and aggression toward strangers; several of these behavioral patterns change throughout the development of relationships. This temporal change may represent changing demands, as pairs are likely to jointly face new experiences (e.g., parenthood throughout pairing. We investigated the role of DA and pairing length on social behavior during reunion after separation from the mate. Marmosets were removed from their home environment and treated with agonists and antagonists for the D1 and D2 receptor subtypes. They were exposed to a novel environment containing an opposite-sex stranger and their pair mate, and then reunited with their mate in the home enclosure. Marmosets in long term pairs exhibited higher levels of food sharing during reunion than marmosets in short term pairs, with females in long term pairs sharing food more than males; no sex difference was observed in short term pairs. Subjects in short term pairs spent more time grooming their mate than receiving grooming during reunion, while marmosets in long term pairs displayed similar amounts of both initiated and received grooming. DA treatment altered pair-level behavior. When females received either a D2 agonist or antagonist, short term pairs spent less time in proximity, compared to when males received the same treatments. In long term pairs, treatment of females with either a D1 agonist or antagonist resulted in pairs spending less time in social proximity than when males were treated. These findings suggest that the function of the DA system in mate behavior may be similar between

  18. Ministers of Health: short-term tenure for long-term goals?

    Science.gov (United States)

    Ferraz, Marcos Bosi; Azevedo, Rafael Teixeira

    2011-03-01

    Healthcare investments should consider short and long-term demands. The objectives here were to compare the average tenures of ministers of health in Brazil and in another 22 countries and to evaluate the relationship between ministers' tenures and a number of indicators. Descriptive study conducted at Centro Paulista de Economia da Saúde (CPES). Twenty-two countries with the highest Human Development Indices (HDIs) and Brazil were included. The number of ministers over the past 20 years was investigated through each country's Ministry of Health website. Pearson's correlation coefficient was used to compare the number of ministers in each country with that country's indicators. The Mann-Whitney test was used to compare ministers' tenures in Brazil and other countries. The mean tenure (standard deviation, SD) of Brazilian ministers of health was 15 (12) months, a period that is statistically significantly shorter than the mean tenure of 33 (18) months in the other 22 countries (P < 0.05). There was a moderate and statistically significant positive correlation between the number of ministers and mortality rates for several conditions. The number of ministers also presented moderate and statistically significant negative correlations with per capita total healthcare expenditure (r = -0.567) and with per capita government healthcare expenditure (r = -0.530). On average, ministers of health have extremely short tenures. There is an urgent need to think and plan healthcare systems from a long-term perspective.

  19. Quality of rearing practices as predictor of short-term outcome in adolescent anorexia nervosa.

    Science.gov (United States)

    Castro, J; Toro, J; Cruz, M

    2000-01-01

    Studies of family relationships in anorexia nervosa have produced conflicting results. Some authors claim that family factors are related to short-term outcomes. Perceived rearing practices, as measured by the EMBU (Egna Minnen Betraffande Uppfostran: 'My memories of Upbringing') were examined in a sample (N = 158) of adolescents with anorexia nervosa and compared with the perceptions of adolescents (N = 159) from the general population. A further comparison was made between the groups of patients with good and bad short-term outcomes. Logistic regression analysis was performed to evaluate the predictive value of different variables on short-term outcome. Overall, small differences were observed in the perceptions of rearing practices as expressed by the controls and the anorexic patients. Patients with bad short-term outcome perceived more rejection and control-overprotection from both parents than those with good outcome. In the logistic regression analysis only Rejection from father and the EAT (Eating Attitudes Test) total score gave independent prediction of treatment response. Taken as a whole, these results do not support the idea of altered rearing practices in anorexic patients, at least in young patients with a short evolution of the disease. Perceived rearing practices, especially 'rejection', appear to have an appreciable effect on the short-term outcome.

  20. Short-term memory binding deficits in Alzheimer's disease.

    Science.gov (United States)

    Parra, Mario A; Abrahams, Sharon; Fabi, Katia; Logie, Robert; Luzzi, Simona; Della Sala, Sergio

    2009-04-01

    Alzheimer's disease impairs long term memories for related events (e.g. faces with names) more than for single events (e.g. list of faces or names). Whether or not this associative or 'binding' deficit is also found in short-term memory has not yet been explored. In two experiments we investigated binding deficits in verbal short-term memory in Alzheimer's disease. Experiment 1: 23 patients with Alzheimer's disease and 23 age and education matched healthy elderly were recruited. Participants studied visual arrays of objects (six for healthy elderly and four for Alzheimer's disease patients), colours (six for healthy elderly and four for Alzheimer's disease patients), unbound objects and colours (three for healthy elderly and two for Alzheimer's disease patients in each of the two categories), or objects bound with colours (three for healthy elderly and two for Alzheimer's disease patients). They were then asked to recall the items verbally. The memory of patients with Alzheimer's disease for objects bound with colours was significantly worse than for single or unbound features whereas healthy elderly's memory for bound and unbound features did not differ. Experiment 2: 21 Alzheimer's disease patients and 20 matched healthy elderly were recruited. Memory load was increased for the healthy elderly group to eight items in the conditions assessing memory for single or unbound features and to four items in the condition assessing memory for the binding of these features. For Alzheimer's disease patients the task remained the same. This manipulation permitted the performance to be equated across groups in the conditions assessing memory for single or unbound features. The impairment in Alzheimer's disease patients in recalling bound objects reported in Experiment 1 was replicated. The binding cost was greater than that observed in the healthy elderly group, who did not differ in their performance for bound and unbound features. Alzheimer's disease grossly impairs the

  1. Adult neurogenesis supports short-term olfactory memory.

    Science.gov (United States)

    Arenkiel, Benjamin R

    2010-06-01

    Adult neurogenesis has captivated neuroscientists for decades, with hopes that understanding the programs underlying this phenomenon may provide unique insight toward avenues for brain repair. Interestingly, however, despite intense molecular and cellular investigation, the evolutionary roles and biological functions for ongoing neurogenesis have remained elusive. Here I review recent work published in the Journal of Neuroscience that reveals a functional role for continued neurogenesis toward forming short-term olfactory memories.

  2. Handling geological and economic uncertainties in balancing short-term and long-term objectives in waterflooding optimization

    NARCIS (Netherlands)

    Siraj, M.M.; Van Den Hof, P.M.J.; Jansen, J.D.

    2017-01-01

    Model-based economic optimization of oil production has a significant scope to increase financial life-cycle performance. The net-present-value (NPV) objective in this optimization, because of its nature, focuses on long-term gains, whereas short-term production is not explicitly addressed. At the

  3. Short-term memory deficits correlate with hippocampal-thalamic functional connectivity alterations following acute sleep restriction.

    Science.gov (United States)

    Chengyang, Li; Daqing, Huang; Jianlin, Qi; Haisheng, Chang; Qingqing, Meng; Jin, Wang; Jiajia, Liu; Enmao, Ye; Yongcong, Shao; Xi, Zhang

    2017-08-01

    Acute sleep restriction heavily influences cognitive function, affecting executive processes such as attention, response inhibition, and memory. Previous neuroimaging studies have suggested a link between hippocampal activity and short-term memory function. However, the specific contribution of the hippocampus to the decline of short-term memory following sleep restriction has yet to be established. In the current study, we utilized resting-state functional magnetic resonance imaging (fMRI) to examine the association between hippocampal functional connectivity (FC) and the decline of short-term memory following total sleep deprivation (TSD). Twenty healthy adult males aged 20.9 ± 2.3 years (age range, 18-24 years) were enrolled in a within-subject crossover study. Short-term memory and FC were assessed using a Delay-matching short-term memory test and a resting-state fMRI scan before and after TSD. Seed-based correlation analysis was performed using fMRI data for the left and right hippocampus to identify differences in hippocampal FC following TSD. Subjects demonstrated reduced alertness and a decline in short-term memory performance following TSD. Moreover, fMRI analysis identified reduced hippocampal FC with the superior frontal gyrus (SFG), temporal regions, and supplementary motor area. In addition, an increase in FC between the hippocampus and bilateral thalamus was observed, the extent of which correlated with short-term memory performance following TSD. Our findings indicate that the disruption of hippocampal-cortical connectivity is linked to the decline in short-term memory observed after acute sleep restriction. Such results provide further evidence that support the cognitive impairment model of sleep deprivation.

  4. Short-term outcome of patients with closed comminuted femoral ...

    African Journals Online (AJOL)

    Short-term outcome of patients with closed comminuted femoral shaft fracture treated with locking intramedullary sign nail at Muhimbili Orthopaedic Institute in Tanzania. Billy T. Haonga, Felix S. Mrita, Edmundo E. Ndalama, Jackline E. Makupa ...

  5. The human hippocampal formation mediates short-term memory of colour-location associations.

    Science.gov (United States)

    Finke, Carsten; Braun, Mischa; Ostendorf, Florian; Lehmann, Thomas-Nicolas; Hoffmann, Karl-Titus; Kopp, Ute; Ploner, Christoph J

    2008-01-31

    The medial temporal lobe (MTL) has long been considered essential for declarative long-term memory, whereas the fronto-parietal cortex is generally seen as the anatomical substrate of short-term memory. This traditional dichotomy is questioned by recent studies suggesting a possible role of the MTL for short-term memory. In addition, there is no consensus on a possible specialization of MTL sub-regions for memory of associative information. Here, we investigated short-term memory for single features and feature associations in three humans with post-surgical lesions affecting the right hippocampal formation and in 10 healthy controls. We used three delayed-match-to-sample tasks with two delays (900/5000 ms) and three set sizes (2/4/6 items). Subjects were instructed to remember either colours, locations or colour-location associations. In colour-only and location-only conditions, performance of patients did not differ from controls. By contrast, a significant group difference was found in the association condition at 5000 ms delay. This difference was largely independent of set size, thus suggesting that it cannot be explained by the increased complexity of the association condition. These findings show that the hippocampal formation plays a significant role for short-term memory of simple visuo-spatial associations, and suggest a specialization of MTL sub-regions for associative memory.

  6. Study on Short-term Variability of Ship Responses in Waves

    DEFF Research Database (Denmark)

    Nielsen, Ulrik Dam; Iseki, Toshio

    2015-01-01

    Short-term variability of ship responses is investigated by cross-spectrum analysis. In a steady state condition, it is well known that a certain length of sampled data is required for stable results of the spectral analysis. However, the phase lag between responses, in terms of the phase angle o...

  7. Depletion of Serotonin Selectively Impairs Short-Term Memory without Affecting Long-Term Memory in Odor Learning in the Terrestrial Slug "Limax Valentianus"

    Science.gov (United States)

    Santa, Tomofumi; Kirino, Yutaka; Watanabe, Satoshi; Shirahata, Takaaki; Tsunoda, Makoto

    2006-01-01

    The terrestrial slug "Limax" is able to acquire short-term and long-term memories during aversive odor-taste associative learning. We investigated the effect of the selective serotonergic neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) on memory. Behavioral studies indicated that 5,7-DHT impaired short-term memory but not long-term memory. HPLC…

  8. Case series: Two cases of eyeball tattoos with short-term complications.

    Science.gov (United States)

    Duarte, Gonzalo; Cheja, Rashel; Pachón, Diana; Ramírez, Carolina; Arellanes, Lourdes

    2017-04-01

    To report two cases of eyeball tattoos with short-term post procedural complications. Case 1 is a 26-year-old Mexican man that developed orbital cellulitis and posterior scleritis 2 h after an eyeball tattoo. Patient responded satisfactorily to systemic antibiotic and corticosteroid treatment. Case 2 is a 17-year-old Mexican man that developed two sub-episcleral nodules in the ink injection sites immediately after the procedure. Eyeball tattoos are performed by non-ophthalmic trained personnel. There are a substantial number of short-term risks associated with this procedure. Long-term effects on the eyes and vision are still unknown, but in a worst case scenario could include loss of vision or permanent damage to the eyes.

  9. Role of fluctuations in the phase transitions of coupled plaquette spin models of glasses

    Directory of Open Access Journals (Sweden)

    Giulio Biroli, Charlotte Rulquin, Gilles Tarjus, Marco Tarzia

    2016-10-01

    Full Text Available We study the role of fluctuations on the thermodynamic glassy properties of plaquette spin models, more specifically on the transition involving an overlap order parameter in the presence of an attractive coupling between different replicas of the system. We consider both short-range fluctuations associated with the local environment on Bethe lattices and long-range fluctuations that distinguish Euclidean from Bethe lattices with the same local environment. We find that the phase diagram in the temperature-coupling plane is very sensitive to the former but, at least for the $3$-dimensional (square pyramid model, appears qualitatively or semi-quantitatively unchanged by the latter. This surprising result suggests that the mean-field theory of glasses provides a reasonable account of the glassy thermodynamics of models otherwise described in terms of the kinetically constrained motion of localized defects and taken as a paradigm for the theory of dynamic facilitation. We discuss the possible implications for the dynamical behavior.

  10. Long-term contracts vs. short-term trade of natural gas - a European perspective

    International Nuclear Information System (INIS)

    Neuhoff, Karsten; Hirschhausen, Christian von

    2005-01-01

    This paper analyses the economics of long-term gas contracts under changing institutional conditions, mainly gas sector liberalisation. The paper is motivated by the increasingly tense debate in continental Europe, UK and the US on the security of long-term gas supply. We discuss the main issues regarding long-term contracts, i.e. the changing role of the flexibility clause, the effect of abandoning the destination clause, and the strategic behaviour of producers between long-term sales and spot-sales. The literature suggests consumers and producers benefit from risk hedging through long-term contracts. Furthermore long-term contracts may reduce exercise of market power. Our analysis adds an additional benefit if the long-run demand elasticity is significantly lower than the short-run elasticity, both strategic producers and consumers benefit from lower prices and larger market volume. Some policy implications of the findings are also discussed. (Author)

  11. Get the gist? The effects of processing depth on false recognition in short-term and long-term memory

    OpenAIRE

    Flegal, Kristin E.; Reuter-Lorenz, Patricia A.

    2014-01-01

    Gist-based processing has been proposed to account for robust false memories in the converging-associates task. The deep-encoding processes known to enhance verbatim memory also strengthen gist memory and increase distortions of long-term memory (LTM). Recent research has demonstrated that compelling false memory illusions are relatively delay-invariant, also occurring under canonical short-term memory (STM) conditions. To investigate the contributions of gist to false memory at short and lon...

  12. Working memory, short-term memory and reading proficiency in school-age children with cochlear implants.

    Science.gov (United States)

    Bharadwaj, Sneha V; Maricle, Denise; Green, Laura; Allman, Tamby

    2015-10-01

    The objective of the study was to examine short-term memory and working memory through both visual and auditory tasks in school-age children with cochlear implants. The relationship between the performance on these cognitive skills and reading as well as language outcomes were examined in these children. Ten children between the ages of 7 and 11 years with early-onset bilateral severe-profound hearing loss participated in the study. Auditory and visual short-term memory, auditory and visual working memory subtests and verbal knowledge measures were assessed using the Woodcock Johnson III Tests of Cognitive Abilities, the Wechsler Intelligence Scale for Children-IV Integrated and the Kaufman Assessment Battery for Children II. Reading outcomes were assessed using the Woodcock Reading Mastery Test III. Performance on visual short-term memory and visual working memory measures in children with cochlear implants was within the average range when compared to the normative mean. However, auditory short-term memory and auditory working memory measures were below average when compared to the normative mean. Performance was also below average on all verbal knowledge measures. Regarding reading outcomes, children with cochlear implants scored below average for listening and passage comprehension tasks and these measures were positively correlated to visual short-term memory, visual working memory and auditory short-term memory. Performance on auditory working memory subtests was not related to reading or language outcomes. The children with cochlear implants in this study demonstrated better performance in visual (spatial) working memory and short-term memory skills than in auditory working memory and auditory short-term memory skills. Significant positive relationships were found between visual working memory and reading outcomes. The results of the study provide support for the idea that WM capacity is modality specific in children with hearing loss. Based on these

  13. Short-term effects of radiation in gliolalstoma spheroids

    DEFF Research Database (Denmark)

    Petterson, Stine Asferg; Jakobsen, Ida Pind; Jensen, Stine Skov

    2016-01-01

    was to investigate the short-term effects of radiation of spheroids containing tumor-initiating stem-like cells. We used a patient-derived glioblastoma stem cell enriched culture (T76) and the standard glioblastoma cell line U87. Primary spheroids were irradiated with doses between 2 and 50 Gy and assessed after two...

  14. Attentional priorities and access to short-term memory

    DEFF Research Database (Denmark)

    Gillebert, Celine; Dyrholm, Mads; Vangkilde, Signe Allerup

    2012-01-01

    The intraparietal sulcus (IPS) has been implicated in selective attention as well as visual short-term memory (VSTM). To contrast mechanisms of target selection, distracter filtering, and access to VSTM, we combined behavioral testing, computational modeling and functional magnetic resonance......, thereby displaying a significant interaction between the two factors. The interaction between target and distracter set size in IPS could not be accounted for by a simple explanation in terms of number of items accessing VSTM. Instead, it led us to a model where items accessing VSTM receive differential...

  15. Short-term plasticity as a neural mechanism supporting memory and attentional functions

    OpenAIRE

    Jääskeläinen, Iiro P.; Ahveninen, Jyrki; Andermann, Mark L.; Belliveau, John W.; Raij, Tommi; Sams, Mikko

    2011-01-01

    Based on behavioral studies, several relatively distinct perceptual and cognitive functions have been defined in cognitive psychology such as sensory memory, short-term memory, and selective attention. Here, we review evidence suggesting that some of these functions may be supported by shared underlying neuronal mechanisms. Specifically, we present, based on an integrative review of the literature, a hypothetical model wherein short-term plasticity, in the form of transient center-excitatory ...

  16. Short-Term Market Risks Implied by Weekly Options

    DEFF Research Database (Denmark)

    Andersen, Torben Gustav; Fusari, Nicola; Todorov, Viktor

    a direct way to study volatility and jump risks. Unlike longer-dated options, they are largely insensitive to the risk of intertemporal shifts in the economic environment. Adopting a novel semi-nonparametric approach, we uncover variation in the negative jump tail risk which is not spanned by market......We study short-term market risks implied by weekly S&P 500 index options. The introduction of weekly options has dramatically shifted the maturity profile of traded options over the last five years, with a substantial proportion now having expiry within one week. Such short-dated options provide......" by the level of market volatility and elude standard asset pricing models....

  17. The difference in subjective and objective complexity in the visual short-term memory

    DEFF Research Database (Denmark)

    Dall, Jonas Olsen; Sørensen, Thomas Alrik

    Several studies discuss the influence of complexity on the visual short term memory; some have demonstrated that short-term memory is surprisingly stable regardless of content (e.g. Luck & Vogel, 1997) where others have shown that memory can be influenced by the complexity of stimulus (e.g. Alvarez...... characters. On the contrary expertise or word frequency may reflect what could be termed subjective complexity, as this relate directly to the individual mental categories established. This study will be able to uncover more details on how we should define complexity of objects to be encoded into short-term....... & Cavanagh, 2004). But the term complexity is often not clearly defined. Sørensen (2008; see also Dall, Katsumi, & Sørensen, 2016) suggested that complexity can be related to two different types; objective and subjective complexity. This distinction is supported by a number of studies on the influence...

  18. Model and economic uncertainties in balancing short-term and long-term objectives in water-flooding optimization.

    NARCIS (Netherlands)

    Siraj, M.M.; Hof, Van den P.M.J.; Jansen, J.D.

    2015-01-01

    Model-based optimization of oil production has a significant scope to increase ultimate recovery or financial life-cycle performance. The Net Present Value (NPV) objective in such an optimization framework, because of its nature, focuses on the long-term gains while the short-term production is not

  19. Word-length effect in verbal short-term memory in individuals with Down's syndrome.

    Science.gov (United States)

    Kanno, K; Ikeda, Y

    2002-11-01

    Many studies have indicated that individuals with Down's syndrome (DS) show a specific deficit in short-term memory for verbal information. The aim of the present study was to investigate the influence of the length of words on verbal short-term memory in individuals with DS. Twenty-eight children with DS and 10 control participants matched for memory span were tested on verbal serial recall and speech rate, which are thought to involve rehearsal and output speed. Although a significant word-length effect was observed in both groups for the recall of a larger number of items with a shorter spoken duration than for those with a longer spoken duration, the number of correct recalls in the group with DS was reduced compared to the control subjects. The results demonstrating poor short-term memory in children with DS were irrelevant to speech rate. In addition, the proportion of repetition-gained errors in serial recall was higher in children with DS than in control subjects. The present findings suggest that poor access to long-term lexical knowledge, rather than overt articulation speed, constrains verbal short-term memory functions in individuals with DS.

  20. The case against specialized visual-spatial short-term memory.

    Science.gov (United States)

    Morey, Candice C

    2018-05-24

    The dominant paradigm for understanding working memory, or the combination of the perceptual, attentional, and mnemonic processes needed for thinking, subdivides short-term memory (STM) according to whether memoranda are encoded in aural-verbal or visual formats. This traditional dissociation has been supported by examples of neuropsychological patients who seem to selectively lack STM for either aural-verbal, visual, or spatial memoranda, and by experimental research using dual-task methods. Though this evidence is the foundation of assumptions of modular STM systems, the case it makes for a specialized visual STM system is surprisingly weak. I identify the key evidence supporting a distinct verbal STM system-patients with apparent selective damage to verbal STM and the resilience of verbal short-term memories to general dual-task interference-and apply these benchmarks to neuropsychological and experimental investigations of visual-spatial STM. Contrary to the evidence on verbal STM, patients with apparent visual or spatial STM deficits tend to experience a wide range of additional deficits, making it difficult to conclude that a distinct short-term store was damaged. Consistently with this, a meta-analysis of dual-task visual-spatial STM research shows that robust dual-task costs are consistently observed regardless of the domain or sensory code of the secondary task. Together, this evidence suggests that positing a specialized visual STM system is not necessary. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  2. Short-term forecasting model for aggregated regional hydropower generation

    International Nuclear Information System (INIS)

    Monteiro, Claudio; Ramirez-Rosado, Ignacio J.; Fernandez-Jimenez, L. Alfredo

    2014-01-01

    Highlights: • Original short-term forecasting model for the hourly hydropower generation. • The use of NWP forecasts allows horizons of several days. • New variable to represent the capacity level for generating hydroelectric energy. • The proposed model significantly outperforms the persistence model. - Abstract: This paper presents an original short-term forecasting model of the hourly electric power production for aggregated regional hydropower generation. The inputs of the model are previously recorded values of the aggregated hourly production of hydropower plants and hourly water precipitation forecasts using Numerical Weather Prediction tools, as well as other hourly data (load demand and wind generation). This model is composed of three modules: the first one gives the prediction of the “monthly” hourly power production of the hydropower plants; the second module gives the prediction of hourly power deviation values, which are added to that obtained by the first module to achieve the final forecast of the hourly hydropower generation; the third module allows a periodic adjustment of the prediction of the first module to improve its BIAS error. The model has been applied successfully to the real-life case study of the short-term forecasting of the aggregated hydropower generation in Spain and Portugal (Iberian Peninsula Power System), achieving satisfactory results for the next-day forecasts. The model can be valuable for agents involved in electricity markets and useful for power system operations

  3. Procedure for the delivering of personal short-term visitor dosimeters

    CERN Document Server

    2016-01-01

    Update of the administrative procedure for delivering a personal short-term visitor dosimeter to associated members of CERN’s personnel.   Associated members of the CERN personnel may request a short term visitor dosimeter if working only in Supervised Radiation Areas and for a period of less than two months in a calendar year. Such a dosimeter is delivered without the need to provide the usual regular documents: radiation passport, certificate from the home institute or medical certificate. Periodic verification will ensure that holders of these personal dosimeters do not exceed the maximum allowed personal dose for this type of dosimeter, which is the same as the limit for members of the public at 1 mSv per year. From now on, the two-month period can be spread over a calendar year, offering greater flexibility to users coming to CERN for multiple short periods. Please return unused dosimeters Persons leaving CERN for a period of more than one month should return their dosimeter to the D...

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

    Science.gov (United States)

    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. Long-term and short-term action-effect links and their impact on effect monitoring.

    Science.gov (United States)

    Wirth, Robert; Steinhauser, Robert; Janczyk, Markus; Steinhauser, Marco; Kunde, Wilfried

    2018-04-23

    People aim to produce effects in the environment, and according to ideomotor theory, actions are selected and executed via anticipations of their effects. Further, to ensure that an action has been successful and an effect has been realized, we must be able to monitor the consequences of our actions. However, action-effect links might vary between situations, some might apply for a majority of situations, while others might only apply to special occasions. With a combination of behavioral and electrophysiological markers, we show that monitoring of self-produced action effects interferes with other tasks, and that the length of effect monitoring is determined by both, long-term action-effect links that hold for most situations, and short-term action-effect links that emerge from a current setting. Effect monitoring is fast and frugal when these action-effect links allow for valid anticipation of action effects, but otherwise effect monitoring takes longer and delays a subsequent task. Specific influences of long-term and short-term links on the P1/N1 and P3a further allow to dissect the temporal dynamics of when these links interact for the purpose of effect monitoring. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  6. Short-term energy outlook. Quarterly projections, 2nd quarter 1994

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Short-Term Wind Speed Forecasting for Power System Operations

    KAUST Repository

    Zhu, Xinxin

    2012-04-01

    The emphasis on renewable energy and concerns about the environment have led to large-scale wind energy penetration worldwide. However, there are also significant challenges associated with the use of wind energy due to the intermittent and unstable nature of wind. High-quality short-term wind speed forecasting is critical to reliable and secure power system operations. This article begins with an overview of the current status of worldwide wind power developments and future trends. It then reviews some statistical short-term wind speed forecasting models, including traditional time series approaches and more advanced space-time statistical models. It also discusses the evaluation of forecast accuracy, in particular, the need for realistic loss functions. New challenges in wind speed forecasting regarding ramp events and offshore wind farms are also presented. © 2012 The Authors. International Statistical Review © 2012 International Statistical Institute.

  8. Short-term fasting protects mice against γ ray radiation

    International Nuclear Information System (INIS)

    Zhu Shengnan; Gu Xiuling; Song Lian; Tong Jian; Li Jianxiang

    2012-01-01

    Objective: To investigate the antagonistic effects of short-term fasting against 60 Co γ ray radiation. Methods: After fasting ICR mice were irradiated for 3 min at a dose rate of 2.5 Gy/min and then returned to normal diet. General situation, body weight changes, food consumption and toxic status were observed. WBC, organ index and anti-oxidative ability (ROS, SOD, MDA, T-AOC) were analyzed. Results: After 60 Co γ ray radiation, the mice exhibited severe toxic symptoms before death. The survival rates were 0 for control and 12 h group, 12.5% for 48 h group and 50% for 72 h group respectively. ROS production of 72 h group was reduced compared with 0 h group (P<0.05). Conclusion: Short-term fasting may attenuate radiation induced injuries, evidenced by a significant increase in mice survival rate. (authors)

  9. Short-Term Study Abroad: Culture and the Path of Least Resistance

    Science.gov (United States)

    Lemmons, Kelly

    2015-01-01

    American universities are decreasing the length of study abroad programs in an effort to send more students abroad. Recent publications find that "short-term" programs struggle to increase participants' cultural understanding. However, these research findings fail to offer an explanation as to why shorter programs are falling short. This…

  10. Road safety performance measures and AADT uncertainty from short-term counts.

    Science.gov (United States)

    Milligan, Craig; Montufar, Jeannette; Regehr, Jonathan; Ghanney, Bartholomew

    2016-12-01

    The objective of this paper is to enable better risk analysis of road safety performance measures by creating the first knowledge base on uncertainty surrounding annual average daily traffic (AADT) estimates when the estimates are derived by expanding short-term counts with the individual permanent counter method. Many road safety performance measures and performance models use AADT as an input. While there is an awareness that the input suffers from uncertainty, the uncertainty is not well known or accounted for. The paper samples data from a set of 69 permanent automatic traffic recorders in Manitoba, Canada, to simulate almost 2 million short-term counts over a five year period. These short-term counts are expanded to AADT estimates by transferring temporal information from a directly linked nearby permanent count control station, and the resulting AADT values are compared to a known reference AADT to compute errors. The impacts of five factors on AADT error are considered: length of short-term count, number of short-term counts, use of weekday versus weekend counts, distance from a count to its expansion control station, and the AADT at the count site. The mean absolute transfer error for expanded AADT estimates is 6.7%, and this value varied by traffic pattern group from 5% to 10.5%. Reference percentiles of the error distribution show that almost all errors are between -20% and +30%. Error decreases substantially by using a 48-h count instead of a 24-h count, and only slightly by using two counts instead of one. Weekday counts are superior to weekend counts, especially if the count is only 24h. Mean absolute transfer error increases with distance to control station (elasticity 0.121, p=0.001), and increases with AADT (elasticity 0.857, proad safety performance measures that use AADT as inputs. Analytical frameworks for such analysis exist but are infrequently used in road safety because the evidence base on AADT uncertainty is not well developed. Copyright

  11. Association between Early Attention-Deficit/Hyperactivity Symptoms and Current Verbal and Visuo-Spatial Short-Term Memory

    Science.gov (United States)

    Gau, Susan Shur-Fen; Chiang, Huey-Ling

    2013-01-01

    Deficits in short-term memory are common in adolescents with attention-deficit/hyperactivity disorder (ADHD), but their current ADHD symptoms cannot well predict their short-term performance. Taking a developmental perspective, we wanted to clarify the association between ADHD symptoms at early childhood and short-term memory in late childhood and…

  12. Short-term versus long-term heart rate variability in ischemic cardiomyopathy risk stratification

    Directory of Open Access Journals (Sweden)

    Andreas eVoss

    2013-12-01

    Full Text Available In industrialized countries with aging populations, heart failure affects 0.3%-2% of the general population. The investigation of 24h-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 30min short-term HRV analysis is sufficient for comparable risk stratification in IHF in comparison to 24h-HRV analysis. From 256 IHF patients (221 at low risk (IHFLR and 35 at high risk (IHFHR a 24h beat-to-beat time series b the first 30min segment c the 30min most stationary day segment and d the 30min 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 hours and for each 30min 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

  13. Retrospective attention in short-term memory has a lasting effect on long-term memory across age.

    Science.gov (United States)

    Strunk, Jonathan; Morgan, Lauren; Reaves, Sarah; Verhaeghen, Paul; Duarte, Audrey

    2018-04-13

    Declines in both short- and long-term memory are typical of healthy aging. Recent findings suggest that retrodictive attentional cues ("retro-cues") that indicate the location of to-be-probed items in short-term memory (STM) have a lasting impact on long-term memory (LTM) performance in young adults. Whether older adults can also use retro-cues to facilitate both STM and LTM is unknown. Young and older adults performed a visual STM task in which spatially informative retro-cues or non-informative neutral-cues were presented during STM maintenance of real-world objects. We tested participants' memory at both STM and LTM delays for objects that were previously cued with retrodictive or neutral cues during STM order to measure the lasting impact of retrospective attention on LTM. Older adults showed reduced STM and LTM capacity compared to young adults. However, they showed similar magnitude retro-cue memory benefits as young adults at both STM and LTM delays. To the best of our knowledge, this is the first study to investigate whether retro-cues in STM facilitate the encoding of objects into LTM such that they are more likely to be subsequently retrieved by older adults. Our results support the idea that retrospective attention can be an effective means by which older adults can improve their short and long-term memory performance, even in the context of reduced memory capacity.

  14. SHORT-TERM EFFECT OF DIESEL OIL ON PHYTOPLANKTON

    African Journals Online (AJOL)

    PROF. EKWEME

    Short-term effect of Nigerian diesel oil was tested on the phytoplankton species in Great Kwa River ... aquatic environment. Plant life is the basis of all food web in nature and hence constitutes the makes this fundamental contribution by photosynthesis, utilizing radiant energy to .... (2 cells/ml) re-colonized the area. The three ...

  15. Short-term marginal costs in French agriculture

    OpenAIRE

    Latruffe, Laure; LETORT, Elodie

    2011-01-01

    The paper investigates short-term marginal costs in French agriculture for field cropping, beef cattle, and dairy farms during the period 1995-2006. The multi-input multi-output Symmetric Generalised MacFadden cost function is used, with three variable inputs (crop-specific, animal-specific, energy costs), four outputs and three quasi-fixed inputs. Results indicate that marginal costs are on average lower for crop farms than for livestock samples. However, for crop farms, Common Agricultural ...

  16. How visual short-term memory maintenance modulates subsequent visual aftereffects.

    Science.gov (United States)

    Saad, Elyana; Silvanto, Juha

    2013-05-01

    Prolonged viewing of a visual stimulus can result in sensory adaptation, giving rise to perceptual phenomena such as the tilt aftereffect (TAE). However, it is not known if short-term memory maintenance induces such effects. We examined how visual short-term memory (VSTM) maintenance modulates the strength of the TAE induced by subsequent visual adaptation. We reasoned that if VSTM maintenance induces aftereffects on subsequent encoding of visual information, then it should either enhance or reduce the TAE induced by a subsequent visual adapter, depending on the congruency of the memory cue and the adapter. Our results were consistent with this hypothesis and thus indicate that the effects of VSTM maintenance can outlast the maintenance period.

  17. Mercury simulations within GMOS: Analysis of short-term observational episodes

    Directory of Open Access Journals (Sweden)

    Travnikov O.

    2013-04-01

    Full Text Available A number of contemporary chemical transport models for mercury are applied within the framework of the EU GMOS project to study principal processes of mercury transport and transformations in the atmosphere. Each model is involved in simulation of short-term episodes corresponding to particular Hg measurement campaigns in Europe and other regions. In order to evaluate different physical and chemical mechanisms the models perform sensitivity runs with various parameterizations and/or combinations of considered processes. The modeling results are compared to detailed measurements of Hg species (Hg0/TGM, RGM, HgP with high temporal resolution (hours aiming at reproduction of short-term temporal variability of Hg air concentration.

  18. Addendum to ''Density fluctuations in liquid rubidium''

    International Nuclear Information System (INIS)

    Haan, S.W.; Mountain, R.D.; Hsu, C.S.; Rahman, A.

    1980-01-01

    We performed molecular-dynamics simulations of liquid rubidium and the Lennard-Jones fluid at several densities and temperatures, and of a system whose pair potential is the repulsive core of the rubidium potential. In all cases, propagating density fluctuations occurred in the rubidiumlike systems at much shorter wavelengths than in the Lennard-Jones system. This indicates that the repulsive part of the pair potential is the dominant factor in determining the relaxation of short-wavelength density fluctuations

  19. Toxicological Effects of Caco-2 Cells Following Short-Term and Long-Term Exposure to Ag Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ni Chen

    2016-06-01

    Full Text Available Extensive utilization increases the exposure of humans to Ag nanoparticles (NPs via the oral pathway. To comprehensively address the action of Ag NPs to the gastrointestinal systems in real situations, i.e., the long-term low-dose exposure, we evaluated and compared the toxicity of three Ag NPs (20–30 nm with different surface coatings to the human intestine cell Caco-2 after 1-day and 21-day exposures, using various biological assays. In both the short- and long-term exposures, the variety of surface coating predominated the toxicity of Ag NPs in a descending order of citrate-coated Ag NP (Ag-CIT, bare Ag NP (Ag-B, and poly (N-vinyl-2-pyrrolidone-coated Ag NP (Ag-PVP. The short-term exposure induced cell growth inhibition and death. The cell viability loss appeared after cells were exposed to 0.7 μg/mL Ag-CIT, 0.9 μg/mL Ag-B or >1.0 μg/mL Ag-PVP for 24 h. The short-term and higher-dose exposure also induced reactive oxygen species (ROS generation, mitochondrial damage, cell membrane leakage, apoptosis, and inflammation (IL-8 level. The long-term exposure only inhibited the cell proliferation. After 21-day exposure to 0.4 μg/mL Ag-CIT, the cell viability dropped to less than 50%, while cells exposed to 0.5 μg/mL Ag-PVP remained normal as the control. Generally, 0.3 μg/mL is the non-toxic dose for the long-term exposure of Caco-2 cells to Ag NPs in this study. However, cells presented inflammation after exposure to Ag NPs with the non-toxic dose in the long-term exposure.

  20. Effects of age, gender, and stimulus presentation period on visual short-term memory.

    Science.gov (United States)

    Kunimi, Mitsunobu

    2016-01-01

    This study focused on age-related changes in visual short-term memory using visual stimuli that did not allow verbal encoding. Experiment 1 examined the effects of age and the length of the stimulus presentation period on visual short-term memory function. Experiment 2 examined the effects of age, gender, and the length of the stimulus presentation period on visual short-term memory function. The worst memory performance and the largest performance difference between the age groups were observed in the shortest stimulus presentation period conditions. The performance difference between the age groups became smaller as the stimulus presentation period became longer; however, it did not completely disappear. Although gender did not have a significant effect on d' regardless of the presentation period in the young group, a significant gender-based difference was observed for stimulus presentation periods of 500 ms and 1,000 ms in the older group. This study indicates that the decline in visual short-term memory observed in the older group is due to the interaction of several factors.

  1. Circulating sclerostin is elevated in short-term and reduced in long-term SCI.

    Science.gov (United States)

    Battaglino, Ricardo A; Sudhakar, Supreetha; Lazzari, Antonio A; Garshick, Eric; Zafonte, Ross; Morse, Leslie R

    2012-09-01

    Spinal cord injury (SCI) causes profound bone loss due to muscle paralysis resulting in the inability to walk. Sclerostin, a Wnt signaling pathway antagonist produced by osteocytes, is a potent inhibitor of bone formation. Short-term studies in rodent models have demonstrated increased sclerostin in response to mechanical unloading that is reversed with reloading. Although sclerostin inhibition has been proposed as a potential therapy for bone loss, it is not known if sclerostin levels vary with duration of SCI in humans. We analyzed circulating sclerostin in 155 men with varying degrees of SCI who were 1 year or more post-injury. We report that sclerostin levels are greatest in subjects with short-term SCI (≤5 years post-injury) and decrease significantly over the first 5 years post-injury. There was no association between sclerostin and injury duration in subjects with long-term SCI (>5 years post-injury). In subjects with long-term SCI, sclerostin levels were positively associated with lower extremity bone density and bone mineral content. These data suggest that sclerostin levels are initially increased after SCI in response to mechanical unloading. This response is time-limited and as bone loss progresses, circulating sclerostin is lowest in subjects with severe osteoporosis. These findings support a dual role for sclerostin after SCI: a therapeutic target in acute SCI, and a biomarker of osteoporosis severity in chronic SCI. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Net charge fluctuations and local charge compensation

    International Nuclear Information System (INIS)

    Fu Jinghua

    2006-01-01

    We propose net charge fluctuation as a measure of local charge correlation length. It is demonstrated that, in terms of a schematic multiperipheral model, net charge fluctuation satisfies the same Quigg-Thomas relation as satisfied by charge transfer fluctuation. Net charge fluctuations measured in finite rapidity windows depend on both the local charge correlation length and the size of the observation window. When the observation window is larger than the local charge correlation length, the net charge fluctuation only depends on the local charge correlation length, while forward-backward charge fluctuations always have strong dependence on the observation window size. Net charge fluctuations and forward-backward charge fluctuations measured in the present heavy ion experiments show characteristic features similar to those from multiperipheral models. But the data cannot all be understood within this simple model

  3. Some fundamental aspects of fluctuations and coherence in charged-particle beams in storage rings

    International Nuclear Information System (INIS)

    Chattopadhyay, S.

    1984-01-01

    A conceptual survey and exposition is presented of some fundamental aspects of fluctuations and coherence, as well as the interplay between the two, in coasting charged-particle beams - both continuous and bunched - in storage rings. A detailed study is given of the spectral properties of the incoherent phase-space Schottky fluctuations, their propagation as waves in the beam, and the analytic complex coherent beam electromagnetic response or transfer function. The modification or distortion of these by collective interactions is examined in terms of simple regeneration mechanisms. Collective or coherent forces in the beam-storage-ring system are described by defining suitable impedance functions or propagators, and a brief discussion of the coherent collective modes and their stability is provided, including a general and rigorous description of the Nyquist stability criterion. The nature of the critical fluctuations near an instability threshold is explored. The concept of Landau damping and its connection with phase-mixing within the beam is outlined. The important connection between the incoherent fluctuations and the beam response, namely the Fluctuation-Dissipation relation, is revealed. A brief discussion is given of the information degrees of freedom, and effective temperature of the fluctuation signals. Appendices provide a short resume of some general aspects of various interactions in a charged-particle beam-environment system in a storage ring and a general introduction to kinetic theory as applied to particle beams. (orig.)

  4. Short-term Preoperative Octreotide for Thyrotropin-secreting Pituitary Adenoma

    Directory of Open Access Journals (Sweden)

    Hong-Juan Fang

    2017-01-01

    Conclusions: OCT can control hormone levels and damage the ultrastructure of tumor cells and organelles. Short-term response to OCT may be related to SSTR5 expression. Preoperative SST analog treatment for TSHoma could be considered as a combination therapy.

  5. Prospective testing of Coulomb short-term earthquake forecasts

    Science.gov (United States)

    Jackson, D. D.; Kagan, Y. Y.; Schorlemmer, D.; Zechar, J. D.; Wang, Q.; Wong, K.

    2009-12-01

    Earthquake induced Coulomb stresses, whether static or dynamic, suddenly change the probability of future earthquakes. Models to estimate stress and the resulting seismicity changes could help to illuminate earthquake physics and guide appropriate precautionary response. But do these models have improved forecasting power compared to empirical statistical models? The best answer lies in prospective testing in which a fully specified model, with no subsequent parameter adjustments, is evaluated against future earthquakes. The Center of Study of Earthquake Predictability (CSEP) facilitates such prospective testing of earthquake forecasts, including several short term forecasts. Formulating Coulomb stress models for formal testing involves several practical problems, mostly shared with other short-term models. First, earthquake probabilities must be calculated after each “perpetrator” earthquake but before the triggered earthquakes, or “victims”. The time interval between a perpetrator and its victims may be very short, as characterized by the Omori law for aftershocks. CSEP evaluates short term models daily, and allows daily updates of the models. However, lots can happen in a day. An alternative is to test and update models on the occurrence of each earthquake over a certain magnitude. To make such updates rapidly enough and to qualify as prospective, earthquake focal mechanisms, slip distributions, stress patterns, and earthquake probabilities would have to be made by computer without human intervention. This scheme would be more appropriate for evaluating scientific ideas, but it may be less useful for practical applications than daily updates. Second, triggered earthquakes are imperfectly recorded following larger events because their seismic waves are buried in the coda of the earlier event. To solve this problem, testing methods need to allow for “censoring” of early aftershock data, and a quantitative model for detection threshold as a function of

  6. Botulinum toxin type A in simple motor tics: short-term and long-term treatment-effects.

    Science.gov (United States)

    Rath, Judith J G; Tavy, Dénes L J; Wertenbroek, Agnes A A C M; van Woerkom, Theodoor C A M; de Bruijn, Sebastiaan F T M

    2010-08-01

    To determine the short-term and long-term treatment-effects of botulinum toxin type A in simple motor tics, we analyzed 15 consecutive patients (18 tics) with simple motor tics that were treated every 3 months with injections of BTX-A. Efficacy (rated on a 4-level scale) and duration of effect of the first 2 and last 2 (if treated 5 times or more) treatments were recorded, as well as latency of response, changes of premonitory urges (PMUs) and possible side effects. Total number of treatments for each tic varied from 2 to 50 (mean 11, median 6). In 16 of 18 tics (89%) short-term efficacy was reported successful (good or moderate). Long-term efficacy was reported in 12 tics of which 11 showed similar or even increased beneficial effects. Premonitory urge (PMU) was reported in 8 patients (53%). PMU, if present, lessened or disappeared after treatment with BTX-A. A permanent remission of the treated tic was seen in 3 patients with a maximum follow-up of 10 years. BTX-A appears a safe and effective treatment for simple motor tics and retains its efficacy after long-term treatment. BTX may also induce permanent remission of the treated tics and effects of BTX are not restricted to merely motor behaviour.

  7. Accounting ethics – an empirical investigation of managing short-term earnings

    Directory of Open Access Journals (Sweden)

    Leonie Jooste

    2011-05-01

    Full Text Available Short-term earnings are managed in most, if not all, companies. The management of short-term earnings is vulnerable to misinterpretation, manipulation or deliberate deception even if these misleading accounting practices are prohibited by accounting regulations. Hence, the problem with managing short-term earnings is that it becomes an ethical practice, regardless of who is or may be affected by the practice or the information that flows from it. As a result of the publicity received by Enron and WorldCom on financial failures and fraud, and the subsequent legislation, the Sarbanes-Oxley Act in 2002, students are expected to understand the morality issues of earnings-management practices. Therefore, the ethics of earnings-management practices affects the accounting educator. Accounting students and business managers were surveyed and the findings indicated that there is no significant difference between gender regarding the ethicality of twenty earning management practices. The results, however, show that there is a significant difference between the perceptions of business managers and students regarding the morality of earnings-management practices. However, no significant differences were found between genders.

  8. Modelling the short term herding behaviour of stock markets

    International Nuclear Information System (INIS)

    Shapira, Yoash; Berman, Yonatan; Ben-Jacob, Eshel

    2014-01-01

    Modelling the behaviour of stock markets has been of major interest in the past century. The market can be treated as a network of many investors reacting in accordance to their group behaviour, as manifested by the index and effected by the flow of external information into the system. Here we devise a model that encapsulates the behaviour of stock markets. The model consists of two terms, demonstrating quantitatively the effect of the individual tendency to follow the group and the effect of the individual reaction to the available information. Using the above factors we were able to explain several key features of the stock market: the high correlations between the individual stocks and the index; the Epps effect; the high fluctuating nature of the market, which is similar to real market behaviour. Furthermore, intricate long term phenomena are also described by this model, such as bursts of synchronized average correlation and the dominance of the index as demonstrated through partial correlation. (paper)

  9. The Precategorical Nature of Visual Short-Term Memory

    Science.gov (United States)

    Quinlan, Philip T.; Cohen, Dale J.

    2016-01-01

    We conducted a series of recognition experiments that assessed whether visual short-term memory (VSTM) is sensitive to shared category membership of to-be-remembered (tbr) images of common objects. In Experiment 1 some of the tbr items shared the same basic level category (e.g., hand axe): Such items were no better retained than others. In the…

  10. Verbal Short-Term Memory Span in Children: Long-Term Modality Dependent Effects of Intrauterine Growth Restriction

    Science.gov (United States)

    Geva, R.; Eshel, R.; Leitner, Y.; Fattal-Valevski, A.; Harel, S.

    2008-01-01

    Background: Recent reports showed that children born with intrauterine growth restriction (IUGR) are at greater risk of experiencing verbal short-term memory span (STM) deficits that may impede their learning capacities at school. It is still unknown whether these deficits are modality dependent. Methods: This long-term, prospective design study…

  11. Influence of fluctuating strain on exciton reflection spectra

    DEFF Research Database (Denmark)

    Skettrup, Torben

    1982-01-01

    The influence of an internal distribution of strain on the exciton reflection spectra is investigated. The resulting fluctuating optical constants give rise to a fluctuating phase of reflectivity. The standard deviation σ of these phase fluctuations is the quantity which can be observed...... to derive the dependence of the phase of reflectivity on the direction of the fluctuating optical axis. The results obtained for σ are compared with the experimental depolarization spectra of ZnO. The only fitting parameter is the common standard deviation of the strain components. It is found......, for example, between crossed polarizers or from ellipsometric measurements. Assuming the phase fluctuations to obey a Gaussian distribution, σ can be expressed in a simple way in terms of the degree of polarization or the depolarization of the reflected light. σ is then derived in terms of the standard...

  12. The Interdependence of Long- and Short-Term Components in Unmasked Repetition Priming: An Indication of Shared Resources.

    Science.gov (United States)

    Merema, Matt R; Speelman, Craig P

    2015-01-01

    It has been suggested that unmasked repetition priming is composed of distinct long-and short-term priming components. The current study sought to clarify the relationship between these components by examining the relationship between them. A total of 60 people (45 females, 15 males) participated in a computer-based lexical decision task designed to measure levels of short-term priming across different levels of long-term priming. The results revealed an interdependent relationship between the two components, whereby an increase in long-term priming prompted a decrease in short-term priming. Both long-term and short-term priming were accurately captured by a single power function over seven minutes post repetition, suggesting the two components may draw on the same resources. This interdependence between long- and short-term priming may serve to improve fluency in reading.

  13. The Interdependence of Long- and Short-Term Components in Unmasked Repetition Priming: An Indication of Shared Resources.

    Directory of Open Access Journals (Sweden)

    Matt R Merema

    Full Text Available It has been suggested that unmasked repetition priming is composed of distinct long-and short-term priming components. The current study sought to clarify the relationship between these components by examining the relationship between them. A total of 60 people (45 females, 15 males participated in a computer-based lexical decision task designed to measure levels of short-term priming across different levels of long-term priming. The results revealed an interdependent relationship between the two components, whereby an increase in long-term priming prompted a decrease in short-term priming. Both long-term and short-term priming were accurately captured by a single power function over seven minutes post repetition, suggesting the two components may draw on the same resources. This interdependence between long- and short-term priming may serve to improve fluency in reading.

  14. Respondence Between Electrochemical Fluctuations and Phenomenon for Localized Corrosion of Less-Noble Metals

    International Nuclear Information System (INIS)

    Itoi, Yasuhiko; Take, Seisho; Tsuru, Tooru

    2008-01-01

    We have been studying application of electrochemical noise (Fluctuation) analysis for localized corrosion. Foils of Zinc, Aluminum and Magnesium were used as specimens for electrochemical cell simulating localized corrosion. These specimens were dipped in sodium chloride solutions adjusted to each exponent of hydrogen ion concentration (pH) condition of 5.5, 10, 12 respectively. Time variations of potential and current were measured in those solutions, and simultaneously the surfaces of specimens were observed using microscope with television monitor. Two types of electrochemical cells were arranged for experiments simulated localized corrosion. The fluctuations on trendy component of short-circuited potential and short-circuited current were appeared in synchronization. It was seemed that these fluctuations result from hydrogen evolution on the aluminum active site in the crevice from the microscopic observation. In the case of zinc and magnesium, fluctuations appeared on the trendy component of the corrosion potential. Two types fluctuation were detected. First one is the fluctuation varied periodically. The second one is the random fluctuation. It was seemed that these fluctuations result from generation of corrosion products and hydrogen evolution on the active site in the crevice of zinc and magnesium from the microscopic observation

  15. Short-term use of antiepileptic drugs is neurotoxic to the immature brain

    Directory of Open Access Journals (Sweden)

    Yu Liu

    2015-01-01

    Full Text Available Previous studies have shown that the long-term use of antiepileptic drugs can cause nervous system damage. However, short-term antiepileptic drug treatment is frequently given to infants, especially neonates, to control seizure. Whether the short-term use of antiepileptic drugs is neurotoxic remains unclear. In the present study, immature rats, 3-21 days of age, were intraperitoneally injected with phenobarbital and/or topiramate for 3 consecutive days. Hematoxylin-eosin and immunohistochemical staining revealed that phenobarbital and topiramate, individually or in combination, were cytotoxic to hippocampal CA1 neurons and inhibited the expression of GluR1 and NR2B, excitatory glutamate receptor subunits. Furthermore, the combination of the two drugs caused greater damage than either drug alone. The results demonstrate that the short-term use of antiepileptic drugs damages neurons in the immature brain and that the combined use of antiepileptic drugs exacerbates damage. Our findings suggest that clinicians should consider the potential neurotoxic risk associated with the combined use of antiepileptic drugs in the treatment of seizure.

  16. Predicting short-term weight loss using four leading health behavior change theories

    Directory of Open Access Journals (Sweden)

    Barata José T

    2007-04-01

    Full Text Available Abstract Background This study was conceived to analyze how exercise and weight management psychosocial variables, derived from several health behavior change theories, predict weight change in a short-term intervention. The theories under analysis were the Social Cognitive Theory, the Transtheoretical Model, the Theory of Planned Behavior, and Self-Determination Theory. Methods Subjects were 142 overweight and obese women (BMI = 30.2 ± 3.7 kg/m2; age = 38.3 ± 5.8y, participating in a 16-week University-based weight control program. Body weight and a comprehensive psychometric battery were assessed at baseline and at program's end. Results Weight decreased significantly (-3.6 ± 3.4%, p Conclusion The present models were able to predict 20–30% of variance in short-term weight loss and changes in weight management self-efficacy accounted for a large share of the predictive power. As expected from previous studies, exercise variables were only moderately associated with short-term outcomes; they are expected to play a larger explanatory role in longer-term results.

  17. Effects of Short-term Hypergravity Exposure on Germination, Growth and Photosynthesis of Triticum aestivum L.

    Science.gov (United States)

    Vidyasagar, Pandit B.; Jagtap, Sagar S.; Dixit, Jyotsana P.; Kamble, Shailendra M.; Dhepe, Aarti P.

    2014-12-01

    Numerous studies have been carried out to investigate the hypergravity effect on plants, where seedlings (4-5 days old) were continuously exposed and grown under hypergravity condition. Here, we have used a novel `shortterm hypergravity exposure experimental method' where imbibed caryopses (instead of seedlings) were exposed to higher hypergravity values ranging from 500 g to 2500 g for a short interval time of 10 minutes and post short-term hypergravity treated caryopses were grown under 1 g conditions for five days. Changing patterns in caryopsis germination and growth, along with various photosynthetic and biochemical parameters were studied. Results revealed the significant inhibition of caryopsis germination and growth in short-term hypergravity treated seeds over control. Photosynthesis parameters such as chlorophyll content, rate of photosynthesis (PN), transpiration rate (Evap) and stomatal conductance (Gs), along with intracellular CO2 concentration (Cint) were found to be affected significantly in 5 days old seedlings exposed to short-term hypergravity treatment. In order to investigate the cause of observed inhibition, we examined the α-amylase activity and antioxidative enzyme activities. α-amylase activity was found to be inhibited, along with the reduction of sugars necessary for germination and earlier growth in short-term hypergravity treated caryopses. The activities of antioxidant enzymes such as catalase and guaiacol peroxidase were increased in short-term hypergravity treated caryopses, suggesting that caryopses might have experienced oxidative stress upon short-term hypergravity exposure.

  18. Seasonal variation in short-term mortality after surgery for colorectal cancer?

    DEFF Research Database (Denmark)

    Iversen, L H; Nielsen, H; Pedersen, L

    2010-01-01

    Comorbidity has a major impact on short-term and long-term survival of colorectal cancer (CRC) and many CRC patients suffer from comorbidities. Mortality rates for comorbidities like cardio-respiratory diseases exhibit distinct seasonal variations with highest rates in the winter. Therefore, we...

  19. Rapid, labile, and protein synthesis-independent short-term memory in conditioned taste aversion.

    Science.gov (United States)

    Houpt, T A; Berlin, R

    1999-01-01

    Short-term memory is a rapid, labile, and protein-synthesis-independent phase of memory. The existence of short-term memory in conditioned taste aversion (CTA) learning has not been demonstrated formally. To determine the earliest time at which a CTA is expressed, we measured intraoral intake of sucrose at 15 min, 1 hr, 6 hr, or 48 h after contingent pairing of an intraoral infusion of 5% sucrose (6.6 ml over 6 min) and toxic lithium chloride injection (76 mg/kg). Rats were implanted with intraoral catheters to allow presentation of taste solutions at arbitrary times. Intraoral intake was measured under conditions of long-delay, single-trial learning typical of CTA. Rats decreased intraoral intake of sucrose at 15 min after contingent pairing of sucrose and LiCl, but not after noncontingent LiCl or sucrose. Thus CTA learning can be expressed rapidly. To determine if short-term CTA memory is labile and decays in the absence of long-term memory, we measured intraoral intake of sucrose after pairing sucrose with low doses of LiCl. Rats received an intraoral infusion of 5% sucrose (6 ml/6 min); 30 min later LiCl was injected at three different doses (19, 38, or 76 mg/kg). A second intraoral infusion of sucrose was administered 15 min, 1 hr, 3 hr, 4.5 hr, 6 hr, or 48 hr later. The formation of long-term CTA memory was dependent on the dose of LiCl paired with sucrose during acquisition. Low doses of LiCl induced a CTA that decayed within 6 hr after pairing. Central administration of the protein synthesis inhibitor cycloheximide prior to LiCl injection blocked long-term CTA expression at 6 and 48 hr, but not short-term CTA expression at 1 hr. Thus, short-term memory for CTA learning exists that is acquired rapidly and independent of protein synthesis, but labile in the absence of long-term memory formation.

  20. Synaptic scaling enables dynamically distinct short- and long-term memory formation.

    Directory of Open Access Journals (Sweden)

    Christian Tetzlaff

    2013-10-01

    Full Text Available Memory storage in the brain relies on mechanisms acting on time scales from minutes, for long-term synaptic potentiation, to days, for memory consolidation. During such processes, neural circuits distinguish synapses relevant for forming a long-term storage, which are consolidated, from synapses of short-term storage, which fade. How time scale integration and synaptic differentiation is simultaneously achieved remains unclear. Here we show that synaptic scaling - a slow process usually associated with the maintenance of activity homeostasis - combined with synaptic plasticity may simultaneously achieve both, thereby providing a natural separation of short- from long-term storage. The interaction between plasticity and scaling provides also an explanation for an established paradox where memory consolidation critically depends on the exact order of learning and recall. These results indicate that scaling may be fundamental for stabilizing memories, providing a dynamic link between early and late memory formation processes.

  1. Synaptic scaling enables dynamically distinct short- and long-term memory formation.

    Science.gov (United States)

    Tetzlaff, Christian; Kolodziejski, Christoph; Timme, Marc; Tsodyks, Misha; Wörgötter, Florentin

    2013-10-01

    Memory storage in the brain relies on mechanisms acting on time scales from minutes, for long-term synaptic potentiation, to days, for memory consolidation. During such processes, neural circuits distinguish synapses relevant for forming a long-term storage, which are consolidated, from synapses of short-term storage, which fade. How time scale integration and synaptic differentiation is simultaneously achieved remains unclear. Here we show that synaptic scaling - a slow process usually associated with the maintenance of activity homeostasis - combined with synaptic plasticity may simultaneously achieve both, thereby providing a natural separation of short- from long-term storage. The interaction between plasticity and scaling provides also an explanation for an established paradox where memory consolidation critically depends on the exact order of learning and recall. These results indicate that scaling may be fundamental for stabilizing memories, providing a dynamic link between early and late memory formation processes.

  2. Short term braking capability during power interruptions for integrated matrix converter

    DEFF Research Database (Denmark)

    Klumpner, Christian; Blaabjerg, Frede

    2004-01-01

    attractive. Sinusoidal input currents and bi-directional power flow are other advantages of the matrix converter, but it is less immune to power grid disturbances compared to a standard ASD. In hoisting applications, short-term braking capability during a power outage is needed until the mechanical brake...... engages or to perform more effective a combined braking. This paper proposes a new method to provide short-term braking capability during a power outage for matrix converters. A braking chopper is needed in the clamp circuit, which allows for a drastically reduction of the capacitor size. The power flow...

  3. Soil phosphorus redistribution among iron-bearing minerals under redox fluctuation

    Science.gov (United States)

    Lin, Y.; Bhattacharyya, A.; Campbell, A.; Nico, P. S.; Pett-Ridge, J.; Silver, W. L.

    2016-12-01

    Phosphorus (P) is a key limiting nutrient in tropical forests that governs primary production, litter decomposition, and soil respiration. A large proportion of P in these highly weathered soils is bound to short-range ordered or poorly crystalline iron (Fe) minerals. It is well-documented that these Fe minerals are redox-sensitive; however, little is known about how Fe-redox interactions affect soil P turnover. We evaluated the impacts of oxic/anoxic fluctuation on soil P fractions and reactive Fe species in a laboratory incubation experiment. Soils from a humid tropical forest were amended with plant biomass and incubated for up to 44 days under four redox regimes: static oxic, static anoxic, high frequency fluctuating (4-day oxic/4-day anoxic), and low frequency fluctuating (8-day oxic/4-day anoxic). We found that the static anoxic treatment induced a 10-fold increase in Fe(II) (extracted by hydrochloric acid) and a 1.5-fold increase in poorly crystalline Fe (extracted by ammonium oxalate), suggesting that anoxic conditions drastically increased Fe(III) reduction and the formation of amorphous Fe minerals. Static anoxic conditions also increased Fe-bound P (extracted by sodium hydroxide) and increased the oxalate-extractable P by up to 110% relative to static oxic conditions. In two fluctuating treatments, Fe(II) and oxalate-extractable Fe and P were all increased by short-term reduction events after 30 minutes, but fell back to their initial levels after 3 hours. These results suggest that reductive dissolution of Fe(III) minerals mobilized a significant amount of P; however, this P could be rapidly re-adsorbed. Furthermore, bioavailable P extracted by sodium bicarbonate solution was largely unaffected by redox regimes and was only increased by static anoxic conditions after 20 days. Overall, our data demonstrate that a significant amount of soil P may be liberated and re-adsorbed by Fe minerals during redox fluctuation. Even though bioavailable P appears to be

  4. Investigating domain-general short-term memory for order versus specific item memory in developmental dyslexia

    OpenAIRE

    Hachmann, Wibke Maria

    2012-01-01

    Recent findings suggest that people with dyslexia experience difficulties with the learning of serial order information during the transition from short- to long-term memory. At the same time, models of short-term memory increasingly incorporate a distinction of order and item processing. This work aims to investigate whether serial order processing deficiencies in dyslexia can be traced back to a selective impairment of short-term memory for serial order, and whether this impairment also aff...

  5. The Australian Dollar's Long-Term Fluctuations and Trend: The Commodity Prices-cum-Economic Cycles Hypothesis

    OpenAIRE

    Sanidas, Elias

    2005-01-01

    The Australian dollar’s exchange rate (mainly in relation to the American dollar) has received a considerable attention in research and several models have been proposed to explain its trend and fluctuations. Thus, as a conclusion of this research we can say that this commodity currency very much depends on the terms of trade which in turn depend on commodity prices. The present paper is based on this conclusion and hence proposes the possibility that the Australian dollar’s behavior is overw...

  6. Auditory short-term memory in the primate auditory cortex

    OpenAIRE

    Scott, Brian H.; Mishkin, Mortimer

    2015-01-01

    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 sho...

  7. Short- and Long-Term Effects of Adolescent Alcohol Access: Evidence from Denmark

    DEFF Research Database (Denmark)

    Gupta, Nabanita Datta; Nilsson, Anton

    We exploit changes in minimum legal alcohol purchasing ages in Denmark in order to estimate effects on short- and long-term health outcomes, as well as on human capital formation. Employing a difference-in-differences approach for immediate outcomes and a “regression kink design” for long......-term outcomes, we bring comprehensive evidence on the health and education effects of three reforms, which affected alcohol availability along different dimensions and margins – 1) establishing an off-premise alcohol purchase age of 15 (1998), 2) raising the off-premise alcohol purchase age to 16 (2004), and 3......) increasing the purchase age of beverages exceeding 16.5% in alcohol content from 16 to 18 (2011). Our findings show significant short-term effects of the first and third reforms in terms of reducing injuries and alcohol-related conditions, and some long-term effects of the first reform in terms of reducing...

  8. Errors in nonword repetition: bridging short- and long-term memory.

    Science.gov (United States)

    Santos, F H; Bueno, O F A; Gathercole, S E

    2006-03-01

    According to the working memory model, the phonological loop is the component of working memory specialized in processing and manipulating limited amounts of speech-based information. The Children's Test of Nonword Repetition (CNRep) is a suitable measure of phonological short-term memory for English-speaking children, which was validated by the Brazilian Children's Test of Pseudoword Repetition (BCPR) as a Portuguese-language version. The objectives of the present study were: i) to investigate developmental aspects of the phonological memory processing by error analysis in the nonword repetition task, and ii) to examine phoneme (substitution, omission and addition) and order (migration) errors made in the BCPR by 180 normal Brazilian children of both sexes aged 4-10, from preschool to 4th grade. The dominant error was substitution [F(3,525) = 180.47; P long than in short items, was observed [F(3,519) = 108.36; P long-term memory contributes to holding memory trace. The findings were discussed in terms of distinctiveness, clustering and redintegration hypotheses.

  9. Laparoscopic colectomy for transverse colon cancer: comparative analysis of short- and long-term outcomes.

    Science.gov (United States)

    Sheng, Weizheng; Zhang, Bo; Chen, Weifeng; Gu, Dayong; Gao, Weidong

    2015-01-01

    This study evaluated the short- and long-term outcomes of laparoscopic colectomy compared with open colectomy for patients with transverse colon cancer by matched-pair analysis. This study enrolled 59 patients who underwent laparoscopic colectomy and compared them with 59 matched patients who underwent open colectomy for transverse colon cancer. The following parameters were matched: clinical stage and type of resection. Both short- and long-term outcomes of laparoscopic colectomy were compared with those of open colectomy. No difference was observed between the two groups in terms of age, gender, ASA score, comorbidity, clinical stage and operative procedures. Regarding short-term outcomes, blood loss, time to first flatus, time to liquid diet and postoperative stay were significantly shorter in the laparoscopy group than in the open group, while operation time was significantly longer in the laparoscopy group than in the open group. Postoperative complication was similar between the two groups. With respect to long-term outcomes, the two groups did not differ significantly in terms of 5-year overall and disease-free survival. In summary, laparoscopic colectomy is a safe and feasible option for selected patients with transverse colon cancer. The short- and long-term outcomes of laparoscopic colectomy are considered to be acceptable.

  10. Short-term memory predictions across the lifespan: monitoring span before and after conducting a task.

    Science.gov (United States)

    Bertrand, Julie Marilyne; Moulin, Chris John Anthony; Souchay, Céline

    2017-05-01

    Our objective was to explore metamemory in short-term memory across the lifespan. Five age groups participated in this study: 3 groups of children (4-13 years old), and younger and older adults. We used a three-phase task: prediction-span-postdiction. For prediction and postdiction phases, participants reported with a Yes/No response if they could recall in order a series of images. For the span task, they had to actually recall such series. From 4 years old, children have some ability to monitor their short-term memory and are able to adjust their prediction after experiencing the task. However, accuracy still improves significantly until adolescence. Although the older adults had a lower span, they were as accurate as young adults in their evaluation, suggesting that metamemory is unimpaired for short-term memory tasks in older adults. •We investigate metamemory for short-term memory tasks across the lifespan. •We find younger children cannot accurately predict their span length. •Older adults are accurate in predicting their span length. •People's metamemory accuracy was related to their short-term memory span.

  11. Short-Term Wind Speed Prediction Using EEMD-LSSVM Model

    Directory of Open Access Journals (Sweden)

    Aiqing Kang

    2017-01-01

    Full Text Available Hybrid Ensemble Empirical Mode Decomposition (EEMD and Least Square Support Vector Machine (LSSVM is proposed to improve short-term wind speed forecasting precision. The EEMD is firstly utilized to decompose the original wind speed time series into a set of subseries. Then the LSSVM models are established to forecast these subseries. Partial autocorrelation function is adopted to analyze the inner relationships between the historical wind speed series in order to determine input variables of LSSVM models for prediction of every subseries. Finally, the superposition principle is employed to sum the predicted values of every subseries as the final wind speed prediction. The performance of hybrid model is evaluated based on six metrics. Compared with LSSVM, Back Propagation Neural Networks (BP, Auto-Regressive Integrated Moving Average (ARIMA, combination of Empirical Mode Decomposition (EMD with LSSVM, and hybrid EEMD with ARIMA models, the wind speed forecasting results show that the proposed hybrid model outperforms these models in terms of six metrics. Furthermore, the scatter diagrams of predicted versus actual wind speed and histograms of prediction errors are presented to verify the superiority of the hybrid model in short-term wind speed prediction.

  12. Intact short-term memory and impaired executive functions in obsessive compulsive disorder.

    Science.gov (United States)

    Demeter, Gyula; Racsmány, Mihály; Csigó, Katalin; Harsányi, András; Németh, Attila; Döme, László

    2013-01-30

    Previous neuropsychological studies produced inconsistent results with tasks tapping short-term verbal and visual-spatial memory and executive functions in obsessive compulsive disorder (OCD). The aim of this study was to investigate the presence of deficits in these cognitive domains. A further goal was to describe the distribution of patients in different impairment ranges for all functions, and clarify the relationship between symptom severity and cognitive impairments. Thirty patients with OCD (DSM-IV) and 30 healthy volunteers were compared using well-known neuropsychological tasks. We assessed short-term verbal memory with the Digit Span Forward and Digit Span Backward Tasks, short-term visual-spatial memory with the Corsi Block Tapping Task, while we measured the level of executive functions with the StroopTask and the Wisconsin Card Sorting Test (WCST). Compared with a matched healthy control group, the performance of OCD patients was in the impaired range only in the two executive tasks. We find a significant positive correlations between the Y-BOCS (Yale-Brown Obsessive Compulsive Scale) total scores and the number of perseverative responses (r(28) = 0.409, p short-term memory is intact in OCD. This is in line with neuropsychological model of OCD that the deficit of cognitive and behavioral inhibition are responsible for the main cognitive findings of this disorder, most prevalently the deficit in set shifting and prepotent response inhibition.

  13. Variability of breast density assessment in short-term reimaging with digital mammography

    International Nuclear Information System (INIS)

    Kim, Won Hwa; Moon, Woo Kyung; Kim, Sun Mi; Yi, Ann; Chang, Jung Min; Koo, Hye Ryoung; Lee, Su Hyun; Cho, Nariya

    2013-01-01

    Objective: To evaluate the variability of breast density assessments in short-term reimaging with digital mammography. Materials and methods: In 186 women, short term (mean interval, 27.6 days) serial digital mammograms including CC and MLO views were obtained without any treatment. Mammographic density assessments were performed by three blinded radiologists for Breast Imaging Report and Data System (BI-RADS, grades 1–4) and visual percentage density (PD) estimation, and by one radiologist for computer-aided PD estimation. The variability of assessments was analyzed according to the age, breast density, and mammography types by multivariate logistic regression. Results: In BI-RADS assessments, 29% (161 of 558) of breast density categories were assessed differently after short-term reimaging and the mean absolute difference in PD for CC and MLO view was 7.6% and 8.1% for visual assessments, and 7.4% and 6.4% for computer-aided assessments, respectively. Among all computer-aided assessments, 29% (54 of 186) of CC view and 22% (41 of 186) of MLO view assessments had discrepancy over 10% in PD. Younger age (<50), greater breast density (grades 3 and 4), and different mammography types were significantly associated with the variability. Conclusion: Considerable variability in breast density assessments occurred in short-term reimaging with digital mammography, particularly in women with younger age and greater breast density and when examined using different types of mammography

  14. Variability of breast density assessment in short-term reimaging with digital mammography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won Hwa [Department of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Moon, Woo Kyung, E-mail: moonwk@snu.ac.kr [Department of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Kim, Sun Mi [Department of Radiology, Seoul National University Bundang Hospital, Gyeonggi-do (Korea, Republic of); Yi, Ann [Department of Radiology, Seoul Metropolitan Government Seoul National University, Boramae Medical Center, Seoul (Korea, Republic of); Chang, Jung Min; Koo, Hye Ryoung; Lee, Su Hyun; Cho, Nariya [Department of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2013-10-01

    Objective: To evaluate the variability of breast density assessments in short-term reimaging with digital mammography. Materials and methods: In 186 women, short term (mean interval, 27.6 days) serial digital mammograms including CC and MLO views were obtained without any treatment. Mammographic density assessments were performed by three blinded radiologists for Breast Imaging Report and Data System (BI-RADS, grades 1–4) and visual percentage density (PD) estimation, and by one radiologist for computer-aided PD estimation. The variability of assessments was analyzed according to the age, breast density, and mammography types by multivariate logistic regression. Results: In BI-RADS assessments, 29% (161 of 558) of breast density categories were assessed differently after short-term reimaging and the mean absolute difference in PD for CC and MLO view was 7.6% and 8.1% for visual assessments, and 7.4% and 6.4% for computer-aided assessments, respectively. Among all computer-aided assessments, 29% (54 of 186) of CC view and 22% (41 of 186) of MLO view assessments had discrepancy over 10% in PD. Younger age (<50), greater breast density (grades 3 and 4), and different mammography types were significantly associated with the variability. Conclusion: Considerable variability in breast density assessments occurred in short-term reimaging with digital mammography, particularly in women with younger age and greater breast density and when examined using different types of mammography.

  15. A novel TRNSYS type for short-term borehole heat exchanger simulation: B2G model

    International Nuclear Information System (INIS)

    De Rosa, Mattia; Ruiz-Calvo, Félix; Corberán, José M.; Montagud, Carla; Tagliafico, Luca A.

    2015-01-01

    Highlights: • A novel dynamic borehole heat exchanger model is presented. • Theoretical approach for model parameters calculation is described. • The short-term model is validated against experimental data of a real GSHP. • Strong dynamic conditions due to the ON–OFF regulation are investigated. - Abstract: Models of ground source heat pump (GSHP) systems are used as an aid for the correct design and optimization of the system. For this purpose, it is necessary to develop models which correctly reproduce the dynamic thermal behavior of each component in a short-term basis. Since the borehole heat exchanger (BHE) is one of the main components, special attention should be paid to ensuring a good accuracy on the prediction of the short-term response of the boreholes. The BHE models found in literature which are suitable for short-term simulations usually present high computational costs. In this work, a novel TRNSYS type implementing a borehole-to-ground (B2G) model, developed for modeling the short-term dynamic performance of a BHE with low computational cost, is presented. The model has been validated against experimental data from a GSHP system located at Universitat Politècnica de València, Spain. Validation results show the ability of the model to reproduce the short-term behavior of the borehole, both for a step-test and under normal operating conditions

  16. Short-term mindfulness intervention reduces the negative attentional effects associated with heavy media multitasking.

    Science.gov (United States)

    Gorman, Thomas E; Green, C Shawn

    2016-04-18

    Recent research suggests that frequently switching between various forms of media (i.e. 'media multitasking') is associated with diminished attentional abilities, a disconcerting result given the prevalence of media multitasking in today's society. In the present study, we sought to investigate the extent to which the deficits associated with frequent media multitasking can be temporarily ameliorated via a short-term mindfulness intervention previously shown to produce beneficial effects on the attentional abilities of normally functioning individuals. Consistent with previous work, we found: (1) that heavy media multitaskers showed generally poorer attentional abilities than light media multitaskers and (2) that all participants showed benefits from the short-term mindfulness intervention. Furthermore, we found that the benefits of the short-term mindfulness intervention were not equivalently large across participants. Instead, these benefits were disproportionately large in the heavy media multitaskers. While the positive outcomes were short-lived, this opens the possibility of performing long-term interventions with the goal of realizing lasting gains in this population.

  17. Determinants of Short-Term Export Performance in Pakistan

    OpenAIRE

    Subhani, Muhammad Imtiaz; Osman, Ms.Amber; Habib, Sukaina

    2010-01-01

    This research investigates the interdependency between independent (Increase of pricing strategy adaptation, Increase of export intensity, Firm's commitment to exporting, Export market development, Export market competition, Past Pricing Strategy Adaptation, Past Export Performance Satisfaction, Past Export Intensity, Export market distance) and dependent variables (i.e. Expected Short-Term Export Performance improvement) of export performance. The framework is tested via a survey through que...

  18. Short-term stress enhances cellular immunity and increases early resistance to squamous cell carcinoma.

    Science.gov (United States)

    Dhabhar, Firdaus S; Saul, Alison N; Daugherty, Christine; Holmes, Tyson H; Bouley, Donna M; Oberyszyn, Tatiana M

    2010-01-01

    In contrast to chronic/long-term stress that suppresses/dysregulates immune function, an acute/short-term fight-or-flight stress response experienced during immune activation can enhance innate and adaptive immunity. Moderate ultraviolet-B (UV) exposure provides a non-invasive system for studying the naturalistic emergence, progression and regression of squamous cell carcinoma (SCC). Because SCC is an immunoresponsive cancer, we hypothesized that short-term stress experienced before UV exposure would enhance protective immunity and increase resistance to SCC. Control and short-term stress groups were treated identically except that the short-term stress group was restrained (2.5h) before each of nine UV-exposure sessions (minimum erythemal dose, 3-times/week) during weeks 4-6 of the 10-week UV exposure protocol. Tumors were measured weekly, and tissue collected at weeks 7, 20, and 32. Chemokine and cytokine gene expression was quantified by real-time PCR, and CD4+ and CD8+ T cells by flow cytometry and immunohistochemistry. Compared to controls, the short-term stress group showed greater cutaneous T-cell attracting chemokine (CTACK)/CCL27, RANTES, IL-12, and IFN-gamma gene expression at weeks 7, 20, and 32, higher skin infiltrating T cell numbers (weeks 7 and 20), lower tumor incidence (weeks 11-20) and fewer tumors (weeks 11-26). These results suggest that activation of short-term stress physiology increased chemokine expression and T cell trafficking and/or function during/following UV exposure, and enhanced Type 1 cytokine-driven cell-mediated immunity that is crucial for resistance to SCC. Therefore, the physiological fight-or-flight stress response and its adjuvant-like immuno-enhancing effects, may provide a novel and important mechanism for enhancing immune system mediated tumor-detection/elimination that merits further investigation.

  19. Effects of Cortisol on Short and Long Term Diet and Morphology

    DEFF Research Database (Denmark)

    Peiman, Kathryn S.; Birnie-Gauvin, Kim; Larsen, Martin Hage

    2017-01-01

    Glucocorticoids such as cortisol are released during stressful events. However, many of the effects of cortisol on animals in the wild are still poorly documented. We evaluated the effects of artificially elevated cortisol on diet and morphology over the short term (2 weeks) and long term (4 months......) using a wild population of juvenile semi-anadromous brown trout (Salmo trutta) in Denmark. We caught, tagged and manipulated juvenile fish while in their natal freshwater streams in the fall. Manipulations consisted of an exogenous intracoelomic injection of cortisol suspended in vegetable shortening...... using geometric morphometrics. Cortisol affected carbon stable isotope signatures but had minimal effects on nitrogen isotopes and morphology. Irrespective of treatment, carbon and nitrogen stable isotope values increased over time. This study shows that cortisol can have both short and long term...

  20. Patterns of Change in Interpersonal Problems During and After Short-term and Long-term Psychodynamic Group Therapy: A Randomized Clinical Trial.

    Science.gov (United States)

    Fjeldstad, Anette; Høglend, Per; Lorentzen, Steinar

    2017-05-01

    In this study, we compared the patterns of change in interpersonal problems between short-term and long-term psychodynamic group therapy. A total of 167 outpatients with mixed diagnoses were randomized to 20 or 80 weekly sessions of group therapy. Interpersonal problems were assessed with the Inventory of Interpersonal Problems at six time points during the 3-year study period. Using linear mixed models, change was linearly modelled in two steps. Earlier (within the first 6 months) and later (during the last 2.5 years) changes in five subscales were estimated. Contrary to what we expected, short-term therapy induced a significantly larger early change than long-term therapy on the cold subscale and there was a trend on the socially avoidant subscale, using a Bonferroni-adjusted alpha. There was no significant difference between short-term and long-term group therapy for improving problems in the areas cold, socially avoidant, nonassertive, exploitable, and overly nurturant over the 3 years.

  1. Short term scheduling of multiple grid-parallel PEM fuel cells for microgrid applications

    Energy Technology Data Exchange (ETDEWEB)

    El-Sharkh, M.Y.; Rahman, A.; Alam, M.S. [Dept. of Electrical and Computer Engineering, University of South Alabama, Mobile, AL 36688 (United States)

    2010-10-15

    This paper presents a short term scheduling scheme for multiple grid-parallel PEM fuel cell power plants (FCPPs) connected to supply electrical and thermal energy to a microgrid community. As in the case of regular power plants, short term scheduling of FCPP is also a cost-based optimization problem that includes the cost of operation, thermal power recovery, and the power trade with the local utility grid. Due to the ability of the microgrid community to trade power with the local grid, the power balance constraint is not applicable, other constraints like the real power operating limits of the FCPP, and minimum up and down time are therefore used. To solve the short term scheduling problem of the FCPPs, a hybrid technique based on evolutionary programming (EP) and hill climbing technique (HC) is used. The EP is used to estimate the optimal schedule and the output power from each FCPP. The HC technique is used to monitor the feasibility of the solution during the search process. The short term scheduling problem is used to estimate the schedule and the electrical and thermal power output of five FCPPs supplying a maximum power of 300 kW. (author)

  2. Quantifying and Reducing Uncertainty in Correlated Multi-Area Short-Term Load Forecasting

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yannan; Hou, Zhangshuan; Meng, Da; Samaan, Nader A.; Makarov, Yuri V.; Huang, Zhenyu

    2016-07-17

    In this study, we represent and reduce the uncertainties in short-term electric load forecasting by integrating time series analysis tools including ARIMA modeling, sequential Gaussian simulation, and principal component analysis. The approaches are mainly focusing on maintaining the inter-dependency between multiple geographically related areas. These approaches are applied onto cross-correlated load time series as well as their forecast errors. Multiple short-term prediction realizations are then generated from the reduced uncertainty ranges, which are useful for power system risk analyses.

  3. Optimal shifting of Photovoltaic and load fluctuations from fuel cell and electrolyzer to lead acid battery in a Photovoltaic/hydrogen standalone power system for improved performance and life time

    Science.gov (United States)

    Tesfahunegn, S. G.; Ulleberg, Ø.; Vie, P. J. S.; Undeland, T. M.

    Cost reduction is very critical in the pursuit of realizing more competitive clean and sustainable energy systems. In line with this goal a control method that enables minimization of the cost associated with performance and life time degradation of fuel cell and electrolyzer, and cost of battery replacement in PV/hydrogen standalone power systems is developed. The method uses the advantage of existing peak shaving battery to suppress short-term PV and load fluctuations while reducing impact on the cycle life of the battery itself. This is realized by diverting short-term cyclic charge/discharge events induced by PV/load power fluctuations to the upper band of the battery state of charge regime while operating the fuel cell and electrolyzer systems along stable (smooth) power curves. Comparative studies of the developed method with two other reference cases demonstrate that the proposed method fares better with respect to defined performance indices as fluctuation suppression rate and mean state of charge. Modeling of power electronics and design of controllers used in the study are also briefly discussed in Appendix A.

  4. Short-term and long-term ethanol administration inhibits the placental uptake and transport of valine in rats

    International Nuclear Information System (INIS)

    Patwardhan, R.V.; Schenker, S.; Henderson, G.I.; Abou-Mourad, N.N.; Hoyumpa, A.M. Jr.

    1981-01-01

    Ethanol ingestion during pregnancy causes a pattern of fetal/neonatal dysfunction called the FAS. The effects of short- and long-term ethanol ingestion on the placental uptake and maternal-fetal transfer of valine were studied in rats. The in vivo placental uptake and fetal uptake were estimated after injection of 0.04 micromol of /sub 14/C-valine intravenously on day 20 of gestation in Sprague-Dawley rats. Short-term ethanol ingestion (4 gm/kg) caused a significant reduction in the placental uptake of /sub 14/C-valine by 33%, 60%, and 30%, and 31% at 2.5, 5, 10, and 15 min after valine administration, respectively (p less than 0.01), and a similar significant reduction occurred in the fetal uptake of /sub 14/C-valine (p less than 0.01). Long-term ethanol ingestion prior to and throughout gestation resulted in a 47% reduction in placental valine uptake (p less than 0.01) and a 46% reduction in fetal valine uptake (p less than 0.01). Long-term ethanol feeding from day 4 to day 20 of gestation caused a 32% reduction in placental valine uptake (p less than 0.01) and a 26% reduction in fetal valine uptake (p less than 0.01). We conclude that both short- and long-term ingestion of ethanol inhibit the placental uptake and maternal-fetal transfer of an essential amino acid--valine. An alteration of placental function may contribute to the pathogenesis of the FAS

  5. Short-term memory for tactile and temporal stimuli in a shared-attention recall task.

    Science.gov (United States)

    Bowers, R L; Mollenhauer, M S; Luxford, J

    1990-06-01

    The present study examined short-term memory for tactile and temporal stimuli. Subjects were required to touch three-dimensional sample objects of different shapes and textures, presented for three durations: short, medium, or long. After the sample duration elapsed, a retention interval (5 sec.-20 sec.) occurred followed by a recall test for one of the sample dimensions of shape, texture, or time, across trials. Analysis showed that accuracy for shape and texture was high throughout testing (95-99%), but memory for perceived duration was relatively poor (60%). Further analysis indicated that poor recall on the time dimension was isolated to the medium and long samples; accuracy for short durations was consistently high (90%). In addition, a reliable response bias emerged; subjects recalled durations shorter than the actual duration presented. The results were discussed in terms of two lines of research, one indicating that haptic short-term memory is strong relative to other memory systems, and the other suggesting that the choose-short bias occurs across species.

  6. Reduced short-term memory capacity in Alzheimer's disease: the role of phonological, lexical, and semantic processing.

    Science.gov (United States)

    Caza, Nicole; Belleville, Sylvie

    2008-05-01

    Individuals with Alzheimer's disease (AD) are often reported to have reduced verbal short-term memory capacity, typically attributed to their attention/executive deficits. However, these individuals also tend to show progressive impairment of semantic, lexical, and phonological processing which may underlie their low short-term memory capacity. The goals of this study were to assess the contribution of each level of representation (phonological, lexical, and semantic) to immediate serial recall performance in 18 individuals with AD, and to examine how these linguistic effects on short-term memory were modulated by their reduced capacity to manipulate information in short-term memory associated with executive dysfunction. Results showed that individuals with AD had difficulty recalling items that relied on phonological representations, which led to increased lexicality effects relative to the control group. This finding suggests that patients have a greater reliance on lexical/semantic information than controls, possibly to make up for deficits in retention and processing of phonological material. This lexical/semantic effect was not found to be significantly correlated with patients' capacity to manipulate verbal material in short-term memory, indicating that language processing and executive deficits may independently contribute to reducing verbal short-term memory capacity in AD.

  7. Short- and long-term cognitive effects of chronic cannabinoids administration in late-adolescence rats.

    Directory of Open Access Journals (Sweden)

    Hila Abush

    Full Text Available The use of cannabis can impair cognitive function, especially short-term memory. A controversial question is whether long-term cannabis use during the late-adolescence period can cause irreversible deficits in higher brain function that persist after drug use stops. In order to examine the short- and long-term effects of chronic exposure to cannabinoids, rats were administered chronic i.p. treatment with the CB1/CB2 receptor agonist WIN55,212-2 (WIN; 1.2 mg/kg for two weeks during the late adolescence period (post-natal days 45-60 and tested for behavioral and electrophysiological measures of cognitive performance 24 hrs, 10 and 30 days after the last drug injection. The impairing effects of chronic WIN on short-term memory in the water maze and the object recognition tasks as well as long-term potentiation (LTP in the ventral subiculum (vSub-nucleus accumbens (NAc pathway were temporary as they lasted only 24 h or 10 d after withdrawal. However, chronic WIN significantly impaired hippocampal dependent short-term memory measured in the object location task 24 hrs, 10, 30, and 75 days after the last drug injection. Our findings suggest that some forms of hippocampal-dependent short-term memory are sensitive to chronic cannabinoid administration but other cognitive impairments are temporary and probably result from a residue of cannabinoids in the brain or acute withdrawal effects from cannabinoids. Understanding the effects of cannabinoids on cognitive function may provide us with tools to overcome these impairments and for cannabinoids to be more favorably considered for clinical use.

  8. Short-Term Memory and Its Biophysical Model

    Science.gov (United States)

    Wang, Wei; Zhang, Kai; Tang, Xiao-wei

    1996-12-01

    The capacity of short-term memory has been studied using an integrate-and-fire neuronal network model. It is found that the storage of events depend on the manner of the correlation between the events, and the capacity is dominated by the value of after-depolarization potential. There is a monotonic increasing relationship between the value of after-depolarization potential and the memory numbers. The biophysics relevance of the network model is discussed and different kinds of the information processes are studied too.

  9. Regional cerebral blood flow in Alzheimer's disease. Comparison between short and long-term donepezil therapy

    International Nuclear Information System (INIS)

    Ushijima, Yo; Okuyama, Chio; Kubota, Takao; Nakai, Takako; Nishimura, Tsunehiko; Mori, Satoru

    2006-01-01

    Treatment with donepezil improves cognitive function of patients with Alzheimer's disease (AD) when compared to a placebo-controlled group. The purpose of this study was to investigate changes in regional cerebral blood flow (rCBF) of AD patients in short-term and long-term treatment with donepezil. rCBF was measured by N-isopropyl-p- 123 I-iodoamphetamine (IMP) autoradiography method. CBF measurements were performed in 17 AD patients before treatment and after 3 months (short-term therapy) and 1 year (long-term therapy). Regions of interest were set at cerebral cortex and cerebellar hemisphere. We used absolute CBF and relative CBF expressed as ratio to cerebellar CBF. Significant increases in relative rCBF were noted in the frontal, parietal and temporal lobes at the end of short-term therapy. rCBF was decreased after the long-term therapy, whereas rCBF was still increased to a slight extent, as compared with the pre-treatment levels. Absolute rCBF showed minimal change and a tendency to decline. Relative rCBF significantly increased in the short-term donepezil therapy, while following the long-term therapy, rCBF decreased to the pre-treatment level. (author)

  10. Feature-Based Visual Short-Term Memory Is Widely Distributed and Hierarchically Organized.

    Science.gov (United States)

    Dotson, Nicholas M; Hoffman, Steven J; Goodell, Baldwin; Gray, Charles M

    2018-06-15

    Feature-based visual short-term memory is known to engage both sensory and association cortices. However, the extent of the participating circuit and the neural mechanisms underlying memory maintenance is still a matter of vigorous debate. To address these questions, we recorded neuronal activity from 42 cortical areas in monkeys performing a feature-based visual short-term memory task and an interleaved fixation task. We find that task-dependent differences in firing rates are widely distributed throughout the cortex, while stimulus-specific changes in firing rates are more restricted and hierarchically organized. We also show that microsaccades during the memory delay encode the stimuli held in memory and that units modulated by microsaccades are more likely to exhibit stimulus specificity, suggesting that eye movements contribute to visual short-term memory processes. These results support a framework in which most cortical areas, within a modality, contribute to mnemonic representations at timescales that increase along the cortical hierarchy. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Cyclosporine therapy in inflammatory bowel disease: short-term and long-term results.

    Science.gov (United States)

    Gurudu, S R; Griffel, L H; Gialanella, R J; Das, K M

    1999-09-01

    Intravenous cyclosporine therapy followed by oral cyclosporine therapy reduce the need for urgent surgery in steroid-refractory inflammatory bowel disease (IBD). Our objective is to report short- and long-term results of cyclosporine therapy in IBD patients. Thirteen patients with steroid-refractory IBD, seven patients with ulcerative colitis (UC), and six patients with Crohn's disease (CD) were treated with intravenous cyclosporine (4 mg/kg/day) for a mean period of 11.4+/-2.8 days (range, 4-15 days). Subsequently the patients were started on oral cyclosporine (8 mg/kg/day) and followed for a mean of 10.3+/-10 months (range, 1-30 months). Twelve patients responded to intravenous cyclosporine therapy. One patient with UC developed sepsis on the fourth day of intravenous cyclosporine therapy and needed urgent colectomy. Nine of 12 initial responders (6 patients with UC and 3 patients with CD) relapsed during follow-up despite oral cyclosporine and underwent elective surgery. One patient with CD relapsed 3 months after discontinuation of oral cyclosporine. Only two patients with CD are in long-term remission. There were no long-term side effects in any of the 13 treated patients. In conclusion, intravenous cyclosporine was effective in inducing remission or significant improvement in 12 of 13 patients with steroid-refractory IBD. However, with subsequent oral cyclosporine the remission could be maintained only for a short while. Each of the six patients with UC needed colectomy and three of the five patients with CD had intestinal resection within 12 months despite oral cyclosporine therapy.

  12. Short-term memory, executive control, and children's route learning

    OpenAIRE

    Purser, H. R.; Farran, E. K.; Courbois, Y.; Lemahieu, A.; Mellier, D.; Sockeel, P.; Blades, M.

    2012-01-01

    The aim of this study was to investigate route-learning ability in 67 children aged 5 to 11years 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 visuospatial long-term memory; the route-learning task was conducted using a maze in a virtual environment. In contrast to previous research, correlation...

  13. SHORT-TERM STRESS ENHANCES CELLULAR IMMUNITY AND INCREASES EARLY RESISTANCE TO SQUAMOUS CELL CARCINOMA

    OpenAIRE

    Dhabhar, Firdaus S.; Saul, Alison N.; Daugherty, Christine; Holmes, Tyson H.; Bouley, Donna M.; Oberyszyn, Tatiana M.

    2009-01-01

    In contrast to chronic/long-term stress that suppresses/dysregulates immune function, an acute/short-term fight-or-flight stress response experienced during immune activation can enhance innate and adaptive immunity. Moderate ultraviolet-B (UV) exposure provides a non-invasive system for studying the naturalistic emergence, progression and regression of squamous cell carcinoma (SCC). Because SCC is an immunoresponsive cancer, we hypothesized that short-term stress experienced before UV exposu...

  14. Prediction of short-term and long-term VOC emissions from SBR bitumen-backed carpet under different temperatures

    NARCIS (Netherlands)

    Yang, X.; Chen, Q.; Bluyssen, P.M.

    1998-01-01

    This paper presents two models for volatile organic compound (VOC) emissions from carpet. One is a numerical model using the computational fluid dynamics (CFD) tech-nique for short-term predictions, the other an analytical model for long-term predictions. The numerical model can (1) deal with

  15. Is visual short-term memory depthful?

    Science.gov (United States)

    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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Functional diversity of Collembola is reduced in soils subjected to short-term, but not long-term, geothermal warming

    DEFF Research Database (Denmark)

    Holmstrup, Martin; Ehlers, Bodil K.; Slotsbo, Stine

    2018-01-01

    the extent of such effects in long-term field-based experiments. In this study we make use of both recent (short-term) and long-term geothermal warming of Icelandic soils to examine the responses of Collembola, an ecologically important group of soil invertebrates, to warming. 2. On the basis of metabolic...

  17. Temporal grouping effects in musical short-term memory.

    Science.gov (United States)

    Gorin, Simon; Mengal, Pierre; Majerus, Steve

    2018-07-01

    Recent theoretical accounts of verbal and visuo-spatial short-term memory (STM) have proposed the existence of domain-general mechanisms for the maintenance of serial order information. These accounts are based on the observation of similar behavioural effects across several modalities, such as temporal grouping effects. Across two experiments, the present study aimed at extending these findings, by exploring a STM modality that has received little interest so far, STM for musical information. Given its inherent rhythmic, temporal and serial organisation, the musical domain is of interest for investigating serial order STM processes such as temporal grouping. In Experiment 1, the data did not allow to determine the presence or the absence of temporal grouping effects. In Experiment 2, we observed that temporal grouping of tone sequences during encoding improves short-term recognition for serially presented probe tones. Furthermore, the serial position curves included micro-primacy and micro-recency effects, which are the hallmark characteristic of temporal grouping. Our results suggest that the encoding of serial order information in musical STM may be supported by temporal positional coding mechanisms similar to those reported in the verbal domain.

  18. Short-Term Lifestyle Strategies for Sustaining Cognitive Status

    Directory of Open Access Journals (Sweden)

    Elizabeth P. Howard

    2016-01-01

    Full Text Available Cognitive decline impacts older adults, particularly their independence. The goal of this project was to increase understanding of how short-term, everyday lifestyle options, including physical activity, help an older adult sustain cognitive independence. Using a secondary analysis of lifestyle choices, we drew on a dataset of 4,620 community-dwelling elders in the US, assessed at baseline and one year later using 2 valid and reliable tools, the interRAI Community Health Assessment and the interRAI Wellness tool. Decline or no decline on the Cognitive Performance Scale was the dependent variable. We examined sustaining one’s status on this measure over a one-year period in relation to key dimensions of wellness through intellectual, physical, emotional, social, and spiritual variables. Engaging in physical activity, formal exercise, and specific recreational activities had a favorable effect on short-term cognitive decline. Involvement with computers, crossword puzzles, handicrafts, and formal education courses also were protective factors. The physical and intellectual domains of wellness are prominent aspects in protection from cognitive decline. Inherent in these two domains are mutable factors suitable for targeted efforts to promote older adult health and well-being.

  19. Short-Term Lifestyle Strategies for Sustaining Cognitive Status

    Science.gov (United States)

    Morris, John N.; Steel, Knight; Strout, Kelley A.; Fries, Brant E.; Moore, Alice; Garms-Homolová, Vjenka

    2016-01-01

    Cognitive decline impacts older adults, particularly their independence. The goal of this project was to increase understanding of how short-term, everyday lifestyle options, including physical activity, help an older adult sustain cognitive independence. Using a secondary analysis of lifestyle choices, we drew on a dataset of 4,620 community-dwelling elders in the US, assessed at baseline and one year later using 2 valid and reliable tools, the interRAI Community Health Assessment and the interRAI Wellness tool. Decline or no decline on the Cognitive Performance Scale was the dependent variable. We examined sustaining one's status on this measure over a one-year period in relation to key dimensions of wellness through intellectual, physical, emotional, social, and spiritual variables. Engaging in physical activity, formal exercise, and specific recreational activities had a favorable effect on short-term cognitive decline. Involvement with computers, crossword puzzles, handicrafts, and formal education courses also were protective factors. The physical and intellectual domains of wellness are prominent aspects in protection from cognitive decline. Inherent in these two domains are mutable factors suitable for targeted efforts to promote older adult health and well-being. PMID:27891520

  20. Defect production in simulated cascades: cascade quenching and short-term annealing

    International Nuclear Information System (INIS)

    Heinisch, H.L.

    1982-01-01

    Defect production in high energy displacement cascades has been modeled using the computer code MARLOWE to generate the cascades and the stochastic computer code ALSOME to simulate the cascade quenching and short-term annealing of isolated cascades. The quenching is accomplished by using ALSOME with exaggerated values for defect mobilities and critical reaction distanes for recombination and clustering, which are in effect until the number of defect pairs is equal to the value determined from resistivity experiments at 4K. Then normal mobilities and reaction distances are used during short-term annealing to a point representative of Stage III recovery. Effects of cascade interactions at low fluences are also being investigated. The quenching parameter values were empirically determined for 30 keV cascades. The results agree well with experimental information throughout the range from 1 keV to 100 keV. Even after quenching and short-term annealing the high energy cascades behave as a collection of lower energy subcascades and lobes. Cascades generated in a crystal having thermal displacements were found to be in better agreement with experiments after quenching and annealing than those generated in a non-thermal crystal