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Sample records for specific impulse values

  1. Existence of solutions to boundary value problem of fractional differential equations with impulsive

    Directory of Open Access Journals (Sweden)

    Weihua JIANG

    2016-12-01

    Full Text Available In order to solve the boundary value problem of fractional impulsive differential equations with countable impulses and integral boundary conditions on the half line, the existence of solutions to the boundary problem is specifically studied. By defining suitable Banach spaces, norms and operators, using the properties of fractional calculus and applying the contraction mapping principle and Krasnoselskii's fixed point theorem, the existence of solutions for the boundary value problem of fractional impulsive differential equations with countable impulses and integral boundary conditions on the half line is proved, and examples are given to illustrate the existence of solutions to this kind of equation boundary value problems.

  2. State-dependent impulses boundary value problems on compact interval

    CERN Document Server

    Rachůnková, Irena

    2015-01-01

    This book offers the reader a new approach to the solvability of boundary value problems with state-dependent impulses and provides recently obtained existence results for state dependent impulsive problems with general linear boundary conditions. It covers fixed-time impulsive boundary value problems both regular and singular and deals with higher order differential equations or with systems that are subject to general linear boundary conditions. We treat state-dependent impulsive boundary value problems, including a new approach giving effective conditions for the solvability of the Dirichlet problem with one state-dependent impulse condition and we show that the depicted approach can be extended to problems with a finite number of state-dependent impulses. We investigate the Sturm–Liouville boundary value problem for a more general right-hand side of a differential equation. Finally, we offer generalizations to higher order differential equations or differential systems subject to general linear boundary...

  3. STRICT STABILITY OF IMPULSIVE SET VALUED DIFFERENTIAL EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In this paper, we develop strict stability concepts of ODE to impulsive hybrid set valued differential equations. By Lyapunov’s original method, we get some basic strict stability criteria of impulsive hybrid set valued equations.

  4. Ultrahigh Specific Impulse Nuclear Thermal Propulsion

    Energy Technology Data Exchange (ETDEWEB)

    Anne Charmeau; Brandon Cunningham; Samim Anghaie

    2009-02-09

    Research on nuclear thermal propulsion systems (NTP) have been in forefront of the space nuclear power and propulsion due to their design simplicity and their promise for providing very high thrust at reasonably high specific impulse. During NERVA-ROVER program in late 1950's till early 1970's, the United States developed and ground tested about 18 NTP systems without ever deploying them into space. The NERVA-ROVER program included development and testing of NTP systems with very high thrust (~250,000 lbf) and relatively high specific impulse (~850 s). High thrust to weight ratio in NTP systems is an indicator of high acceleration that could be achieved with these systems. The specific impulse in the lowest mass propellant, hydrogen, is a function of square root of absolute temperature in the NTP thrust chamber. Therefor optimizing design performance of NTP systems would require achieving the highest possible hydrogen temperature at reasonably high thrust to weight ratio. High hydrogen exit temperature produces high specific impulse that is a diret measure of propellant usage efficiency.

  5. Project NEO Specific Impulse Testing Solutions

    Science.gov (United States)

    Baffa, Bill

    2018-01-01

    The Neo test stand is currently configured to fire a horizontally mounted rocket motor with up to 6500 lbf thrust. Currently, the Neo test stand can measure flow of liquid propellant and oxidizer, pressures residing in the closed system up to the combustion chamber. The current configuration does not have the ability to provide all data needed to compute specific impulse. This presents three methods to outfit the NEO test fixture with instrumentation allowing for calculation of specific impulse.

  6. Unique aspects of impulsive traits in substance use and overeating: specific contributions of common assessments of impulsivity.

    Science.gov (United States)

    Beaton, Derek; Abdi, Hervé; Filbey, Francesca M

    2014-11-01

    Abstract Background: Impulsivity is a complex trait often studied in substance abuse and overeating disorders, but the exact nature of impulsivity traits and their contribution to these disorders are still debated. Thus, understanding how to measure impulsivity is essential for comprehending addictive behaviors. Identify unique impulsivity traits specific to substance use and overeating. Impulsive Sensation Seeking (ImpSS) and Barratt's Impulsivity scales (BIS) Scales were analyzed with a non-parametric factor analytic technique (discriminant correspondence analysis) to identify group-specific traits on 297 individuals from five groups: Marijuana (n = 88), Nicotine (n = 82), Overeaters (n = 27), Marijuauna + Nicotine (n = 63), and CONTROLs (n = 37). A significant overall factor structure revealed three components of impulsivity that explained respectively 50.19% (pperm Overeating: lacks focus, but plans (short and long term). Our results reveal impulsivity traits specific to each group. This may provide better criteria to define spectrums and trajectories - instead of categories - of symptoms for substance use and eating disorders. Defining symptomatic spectrums could be an important step forward in diagnostic strategies.

  7. Domain-Specific Impulsivity in School-Age Children

    Science.gov (United States)

    Tsukayama, Eli; Duckworth, Angela Lee; Kim, Betty

    2013-01-01

    Impulsivity is a salient individual difference in children with well-established predictive validity for life outcomes. The current investigation proposes that impulsive behaviors vary systematically by domain. In a series of studies with ethnically and socioeconomically diverse samples of middle school students, we find that schoolwork-related and interpersonal-related impulsivity, as observed by teachers, parents, and the students themselves, are distinct, moderately correlated behavioral tendencies. Each demonstrates differentiated relationships with dimensions of childhood temperament, Big Five personality factors, and outcomes, such as sociometric popularity, report card grades, and classroom conduct. Implications for theoretical conceptions of impulsivity as well as for practical applications (e.g., domain-specific interventions) are discussed. PMID:24118714

  8. Vestibulo-ocular reflex gain values in the suppression head impulse test of healthy subjects.

    Science.gov (United States)

    Rey-Martinez, Jorge; Thomas-Arrizabalaga, Izaskun; Espinosa-Sanchez, Juan Manuel; Batuecas-Caletrio, Angel; Trinidad-Ruiz, Gabriel; Matiño-Soler, Eusebi; Perez-Fernandez, Nicolas

    2018-02-15

    To assess whether there are differences in vestibulo-ocular reflex (VOR) gain for suppression head impulse (SHIMP) and head impulse (HIMP) video head impulse test paradigms, and if so, what are their causes. Prospective multicenter observational double-blind nonrandomized clinical study was performed by collecting 80 healthy subjects from four reference hospitals. SHIMP data was postprocessed to eliminate impulses in which early SHIMP saccades were detected. Differences between HIMP and SHIMP VOR gain values were statistically evaluated. Head impulse maximum velocity, gender, age, direction of impulse, and hospital center were considered as possible influential factors. A small significant statistical difference between HIMP and SHIMP VOR gain values was found on repeated measures analysis of variance (-0.05 ± 0.006, P gain values and did not find influence between gain values differences and maximum head impulse velocity. Both HIMP and SHIMP VOR gain values were significant lower (-0.09, P gain values not adequately explained by known gain modification factors. The persistence of this slight but significant difference indicates that there are more factors causing lower SHIMP VOR gain values. This difference must to be considered in further studies as well as in the clinical SHIMP testing protocols. We hypothesized that VOR phasic response inhibition could be the underlying cause of this difference. IIb. Laryngoscope, 2018. © 2018 The American Laryngological, Rhinological and Otological Society, Inc.

  9. m-POINT BOUNDARY VALUE PROBLEM FOR SECOND ORDER IMPULSIVE DIFFERENTIAL EQUATION AT RESONANCE

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    In his paper,we obtain a general theorem concerning the existence of solutions to an m-point boundary value problem for the second-order differential equation with impulses.Moreover,the result can also be applied to study the usual m-point boundary value problem at resonance without impulses.

  10. Domain-Specific Relationships in Sexual Measures of Impulsive Behavior.

    Science.gov (United States)

    Mahoney, Colin T; Lawyer, Steven R

    2018-04-25

    Impulsivity is an important construct for understanding sexual behaviors, but behavioral and self-report measures of impulsivity often are not correlated. One possible explanation for this is that there is little shared variance in the measures because behavioral measures index impulsivity by asking questions about monetary preferences, while self-report measures index impulsivity by asking about a broad range of real-world outcomes (including those of a sexual nature) largely unrelated to money-related preferences. Undergraduate students (total N = 105; female n = 77, male n = 28) completed laboratory measures-delay discounting (DD) and probability discounting (PD)-for two different outcomes-money and sexual activity. Participants also completed the Delaying Gratification Inventory (DGI), which measures difficulty with delaying gratification (i.e., impulsivity) across different domains, including money and physical pleasures. Findings indicated that DD and PD for money were not related to any of the DGI subscales. However, DD for sexual activity was significantly related to the DGI Physical Pleasures subscale, but not other subscales. These findings suggest that the relationship between behavioral and self-report measures of impulsive choice may be stronger when both are measuring domain-specific rather than domain-general behavioral patterns, but further research is warranted.

  11. Development and characterization of high-efficiency, high-specific impulse xenon Hall thrusters

    Science.gov (United States)

    Hofer, Richard Robert

    This dissertation presents research aimed at extending the efficient operation of 1600 s specific impulse Hall thruster technology to the 2000--3000 s range. While recent studies of commercially developed Hall thrusters demonstrated greater than 4000 s specific impulse, maximum efficiency occurred at less than 3000 s. It was hypothesized that the efficiency maximum resulted as a consequence of modern magnetic field designs, optimized for 1600 s, which were unsuitable at high-specific impulse. Motivated by the industry efforts and mission studies, the aim of this research was to develop and characterize xenon Hall thrusters capable of both high-specific impulse and high-efficiency operation. The research divided into development and characterization phases. During the development phase, the laboratory-model NASA-173M Hall thrusters were designed with plasma lens magnetic field topographies and their performance and plasma characteristics were evaluated. Experiments with the NASA-173M version 1 (v1) validated the plasma lens design by showing how changing the magnetic field topography at high-specific impulse improved efficiency. Experiments with the NASA-173M version 2 (v2) showed there was a minimum current density and optimum magnetic field topography at which efficiency monotonically increased with voltage. Between 300--1000 V, total specific impulse and total efficiency of the NASA-173Mv2 operating at 10 mg/s ranged from 1600--3400 s and 51--61%, respectively. Comparison of the thrusters showed that efficiency can be optimized for specific impulse by varying the plasma lens design. During the characterization phase, additional plasma properties of the NASA-173Mv2 were measured and a performance model was derived accounting for a multiply-charged, partially-ionized plasma. Results from the model based on experimental data showed how efficient operation at high-specific impulse was enabled through regulation of the electron current with the magnetic field. The

  12. Understanding Impulsivity among Children with Specific Learning Disabilities in Inclusion Schools

    Science.gov (United States)

    Al-Dababneh, Kholoud Adeeb; Al-Zboon, Eman K.

    2018-01-01

    Impulsive behavior is a characteristic of children with specific learning disabilities (SLD), and is related to learning ability. The present study aims to identify impulsivity behavior in children with SLD who attend inclusion schools, from their resource room teachers' perspectives. A 31-item questionnaire that addressed four subscales was…

  13. Overweight in adolescent, psychiatric inpatients: A problem of general or food-specific impulsivity?

    Science.gov (United States)

    Deux, Natalie; Schlarb, Angelika A; Martin, Franziska; Holtmann, Martin; Hebebrand, Johannes; Legenbauer, Tanja

    2017-05-01

    Adolescent psychiatric patients are vulnerable to weight problems and show an overrepresentation of overweight compared to the healthy population. One potential factor that can contribute to the etiology of overweight is higher impulsivity. As of yet, it is unclear whether it is a general impulse control deficit or weight-related aspects such as lower impulse control in response to food that have an impact on body weight. As this may have therapeutic implications, the current study investigated differences between overweight and non-overweight adolescent psychiatric inpatients (N = 98; aged 12-20) in relation to trait impulsivity and behavioral inhibition performance. The Barratt Impulsiveness Scale and two go/no-go paradigms with neutral and food-related stimulus materials were applied. Results indicated no significant differences concerning trait impulsivity, but revealed that overweight inpatients had significantly more difficulties in inhibition performance (i.e. they reacted more impulsively) in response to both food and neutral stimuli compared to non-overweight inpatients. Furthermore, no specific inhibition deficit for high-caloric vs. low-caloric food cues emerged in overweight inpatients, whereas non-overweight participants showed significantly lower inhibition skills in response to high-caloric than low-caloric food stimuli. The results highlight a rather general, non-food-specific reduced inhibition performance in an overweight adolescent psychiatric population. Further research is necessary to enhance the understanding of the role of impulsivity in terms of body weight status in this high-risk group of adolescent inpatients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Sex differences in impulsive action and impulsive choice.

    Science.gov (United States)

    Weafer, Jessica; de Wit, Harriet

    2014-11-01

    Here, we review the evidence for sex differences in behavioral measures of impulsivity for both humans and laboratory animals. We focus on two specific components of impulsivity: impulsive action (i.e., difficulty inhibiting a prepotent response) and impulsive choice (i.e., difficulty delaying gratification). Sex differences appear to exist on these measures, but the direction and magnitude of the differences vary. In laboratory animals, impulsive action is typically greater in males than females, whereas impulsive choice is typically greater in females. In humans, women discount more steeply than men, but sex differences on measures of impulsive action depend on tasks and subject samples. We discuss implications of these findings as they relate to drug addiction. We also point out the major gaps in this research to date, including the lack of studies designed specifically to examine sex differences in behavioral impulsivity, and the lack of consideration of menstrual or estrous phase or sex hormone levels in the studies. © 2013.

  15. Effect of ITE and nozzle exit cone erosion on specific impulse of solid rocket motors

    Science.gov (United States)

    Smith-Kent, Randall; Ridder, Jeffrey P.; Loh, Hai-Tien; Abel, Ralph

    1993-06-01

    Specific impulse loss due to the use of a slowly eroding integral throat entrance, or a throat insert, with a faster eroding nozzle exit cone is studied. It is suggested that an oblique shock wave produced by step-off erosion results in loss of specific impulse. This is studied by use of a shock capturing CFD method. The shock loss predictions for first-stage Peacekeeper and Castor 25 motors are found to match the trends of the test data. This work suggests that a loss mechanism, previously unaccounted, should be considered in the specific impulse prediction procedure for nozzles with step-off exit cone erosion.

  16. Dysfunctional decision-making in pathological gambling: pattern specificity and the role of impulsivity.

    Science.gov (United States)

    Kräplin, Anja; Dshemuchadse, Maja; Behrendt, Silke; Scherbaum, Stefan; Goschke, Thomas; Bühringer, Gerhard

    2014-03-30

    Dysfunctional decision-making in individuals with pathological gambling (PGs) may result from dominating reward-driven processes, indicated by higher impulsivity. In the current study we examined (1) if PGs show specific decision-making impairments related to dominating reward-driven processes rather than to strategic planning deficits and (2) whether these impairments are related to impulsivity. Nineteen PGs according to DSM-IV and 19 matched control subjects undertook the Cambridge Gambling Task (CGT) to assess decision-making. The delay discounting paradigm (DDP) as well as the UPPS Impulsive Behavior Scale (measuring urgency, premeditation, perseverance and sensation seeking) were administered as multidimensional measures of impulsivity. Results revealed that (1) PGs exhibited higher risk seeking and an immediate reward focus in the CGT and, in contrast, comparable strategic planning to the control group. (2) Decision-making impairments were related to more severe delay discounting and, specifically, to increased urgency and less premeditation. Our findings suggest (1) the necessity to disentangle decision-making components in order to improve etiological models of PGs, and (2) that urgency and premeditation are specifically related to disadvantageous decision-making and should be tackled in intervention strategies focusing on emotion tolerance and control strategies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  17. Sex differences in impulsive action and impulsive choice

    OpenAIRE

    Weafer, Jessica; de Wit, Harriet

    2013-01-01

    Here, we review the evidence for sex differences in behavioral measures of impulsivity for both humans and laboratory animals. We focus on two specific components of impulsivity: impulsive action (i.e., difficulty inhibiting a prepotent response) and impulsive choice (i.e., difficulty delaying gratification). Sex differences appear to exist on these measures, but the direction and magnitude of the differences vary. In laboratory animals, impulsive action is typically greater in males than fem...

  18. Coaxial plasma thrusters for high specific impulse propulsion

    Science.gov (United States)

    Schoenberg, Kurt F.; Gerwin, Richard A.; Barnes, Cris W.; Henins, Ivars; Mayo, Robert; Moses, Ronald, Jr.; Scarberry, Richard; Wurden, Glen

    1991-01-01

    A fundamental basis for coaxial plasma thruster performance is presented and the steady-state, ideal MHD properties of a coaxial thruster using an annular magnetic nozzle are discussed. Formulas for power usage, thrust, mass flow rate, and specific impulse are acquired and employed to assess thruster performance. The performance estimates are compared with the observed properties of an unoptimized coaxial plasma gun. These comparisons support the hypothesis that ideal MHD has an important role in coaxial plasma thruster dynamics.

  19. Gender-specific mediational links between parenting styles, parental monitoring, impulsiveness, drinking control, and alcohol-related problems.

    Science.gov (United States)

    Patock-Peckham, Julie A; King, Kevin M; Morgan-Lopez, Antonio A; Ulloa, Emilio C; Moses, Jennifer M Filson

    2011-03-01

    Recently, it has been suggested that traits may dynamically change as conditions change. One possible mechanism that may influence impulsiveness is parental monitoring. Parental monitoring reflects a knowledge regarding one's offspring's whereabouts and social connections. The aim of this investigation was to examine potential gender-specific parental influences to impulsiveness (general behavioral control), control over one's own drinking (specific behavioral control), and alcohol-related problems among individuals in a period of emerging adulthood. Direct and mediational links between parenting styles (permissive, authoritarian, and authoritative), parental monitoring, impulsiveness, drinking control, and alcohol-related problems were investigated. A multiple-group, SEM model with (316 women, 265 men) university students was examined. In general, the overall pattern among male and female respondents was distinct. For daughters, perceptions of a permissive father were indirectly linked to more alcohol-related problems through lower levels of monitoring by fathers and more impulsive symptoms. Perceptions of an authoritative father were also indirectly linked to fewer impulsive symptoms through higher levels of monitoring by fathers among daughters. For men, perceptions of a permissive mother were indirectly linked to more alcohol-related problems through lower levels of monitoring by mothers and more impulsive symptoms. For sons, perceptions of mother authoritativeness were indirectly linked to fewer alcohol-related problems through more monitoring by mothers and fewer impulsive symptoms. Monitoring by an opposite-gender parent mediated the link between parenting styles (i.e., permissive, authoritative) on impulsiveness.

  20. Clinical application value of impulse oscillometry in geriatric patients with COPD

    Directory of Open Access Journals (Sweden)

    Liu Z

    2017-03-01

    specificity were 0.789 and 0.931, respectively, and the cutoff values were similar in geriatric and advanced elderly patients. Conclusion: IOS demonstrated good relevance compared with spirometry for geriatric patients with COPD. IOS may serve as an alternative method for spirometry in elderly subjects for the evaluation of the state of COPD. Keywords: COPD, impulse oscillometry, spirometry, geriatric patients

  1. A path model of different forms of impulsivity with externalizing and internalizing psychopathology: Towards greater specificity.

    Science.gov (United States)

    Johnson, Sheri L; Tharp, Jordan A; Peckham, Andrew D; Carver, Charles S; Haase, Claudia M

    2017-09-01

    A growing empirical literature indicates that emotion-related impulsivity (compared to impulsivity that is unrelated to emotion) is particularly relevant for understanding a broad range of psychopathologies. Recent work, however, has differentiated two forms of emotion-related impulsivity: A factor termed Pervasive Influence of Feelings captures tendencies for emotions (mostly negative emotions) to quickly shape thoughts, and a factor termed Feelings Trigger Action captures tendencies for positive and negative emotions to quickly and reflexively shape behaviour and speech. This study used path modelling to consider links from emotion-related and non-emotion-related impulsivity to a broad range of psychopathologies. Undergraduates completed self-report measures of impulsivity, depression, anxiety, aggression, and substance use symptoms. A path model (N = 261) indicated specificity of these forms of impulsivity. Pervasive Influence of Feelings was related to anxiety and depression, whereas Feelings Trigger Action and non-emotion-related impulsivity were related to aggression and substance use. The findings of this study suggest that emotion-relevant impulsivity could be a potentially important treatment target for a set of psychopathologies. Recent work has differentiated two forms of emotion-related impulsivity. This study tests a multivariate path model linking emotion-related and non-emotion-related impulsivity with multiple forms of psychopathology. Impulsive thoughts in response to negative emotions were related to anxiety and depression. Impulsive actions in response to emotions were related to aggression and substance use, as did non-emotion-related impulsivity. The study was limited by the reliance on self-report measures of impulsivity and psychopathology. There is a need for longitudinal work on how these forms of impulsivity predict the onset and course of psychopathology. © 2017 The British Psychological Society.

  2. Master-slave exponential synchronization of delayed complex-valued memristor-based neural networks via impulsive control.

    Science.gov (United States)

    Li, Xiaofan; Fang, Jian-An; Li, Huiyuan

    2017-09-01

    This paper investigates master-slave exponential synchronization for a class of complex-valued memristor-based neural networks with time-varying delays via discontinuous impulsive control. Firstly, the master and slave complex-valued memristor-based neural networks with time-varying delays are translated to two real-valued memristor-based neural networks. Secondly, an impulsive control law is constructed and utilized to guarantee master-slave exponential synchronization of the neural networks. Thirdly, the master-slave synchronization problems are transformed into the stability problems of the master-slave error system. By employing linear matrix inequality (LMI) technique and constructing an appropriate Lyapunov-Krasovskii functional, some sufficient synchronization criteria are derived. Finally, a numerical simulation is provided to illustrate the effectiveness of the obtained theoretical results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Self-reported impulsivity, but not behavioral choice or response impulsivity, partially mediates the effect of stress on drinking behavior.

    Science.gov (United States)

    Hamilton, Kristen R; Ansell, Emily B; Reynolds, Brady; Potenza, Marc N; Sinha, Rajita

    2013-01-01

    Stress and impulsivity contribute to alcohol use, and stress may also act via impulsivity to increase drinking behavior. Impulsivity represents a multi-faceted construct and self-report and behavioral assessments may effectively capture distinct clinically relevant factors. The present research investigated whether aspects of impulsivity mediate the effect of stress on alcohol use. A community-based sample of 192 men and women was assessed on measures of cumulative stress, alcohol use, self-reported impulsivity, and behavioral choice and response impulsivity. Data were analyzed using regression and bootstrapping techniques to estimate indirect effects of stress on drinking via impulsivity. Cumulative adversity exhibited both direct effects and indirect effects (via self-reported impulsivity) on drinking behavior. Additional models examining specific types of stress indicated direct and indirect effects of trauma and recent life events, and indirect effects of major life events and chronic stressors on drinking behavior. Overall, cumulative stress was associated with increased drinking behavior, and this effect was partially mediated by self-reported impulsivity. Self-reported impulsivity also mediated the effects of different types of stress on drinking behavior. These findings highlight the value of mediation models to examine the pathways through which different types of stress increase drinking behavior. Treatment and prevention strategies should focus on enhancing stress management and self-control.

  4. Angular distributions of plasma edge velocity and integrated intensity: Update on specific impulse for Ablative Laser Propulsion

    Science.gov (United States)

    Lin, Jun; Pakhomov, Andrew V.

    2005-04-01

    This work concludes our discussion of the image processing technique developed earlier for determination of specific impulse (Isp) for Ablative Laser Propulsion (ALP). The plasma plumes are recorded with a time-resolved intensified charge-coupled device (ICCD) camera. The plasma was formed in vacuum (˜ 3×10-3 Torr) by focusing output pulses of a laser system (100-ps pulsewidth at 532 nm wavelength and ˜35 mJ energy) on surfaces of C (graphite), Al, Si, Fe, Cu, Zn, Sn, and Pb elements. Angular profiles for integrated intensity and plasma expansion velocity were determined for the tested elements. Such profiles were used further for assessment of specific impulse. Specific impulses derived from angular distributions of plasma expansion velocity and integral intensity appeared in excellent agreement with the data derived earlier from force measurements.

  5. Angular distributions of plasma edge velocity and integrated intensity: Update on specific impulse for Ablative Laser Propulsion

    International Nuclear Information System (INIS)

    Lin Jun; Pakhomov, Andrew V.

    2005-01-01

    This work concludes our discussion of the image processing technique developed earlier for determination of specific impulse (Isp) for Ablative Laser Propulsion (ALP). The plasma plumes are recorded with a time-resolved intensified charge-coupled device (ICCD) camera. The plasma was formed in vacuum (∼ 3x10-3 Torr) by focusing output pulses of a laser system (100-ps pulsewidth at 532 nm wavelength and ∼35 mJ energy) on surfaces of C (graphite), Al, Si, Fe, Cu, Zn, Sn, and Pb elements. Angular profiles for integrated intensity and plasma expansion velocity were determined for the tested elements. Such profiles were used further for assessment of specific impulse. Specific impulses derived from angular distributions of plasma expansion velocity and integral intensity appeared in excellent agreement with the data derived earlier from force measurements

  6. Adaptive iterated function systems filter for images highly corrupted with fixed - Value impulse noise

    Science.gov (United States)

    Shanmugavadivu, P.; Eliahim Jeevaraj, P. S.

    2014-06-01

    The Adaptive Iterated Functions Systems (AIFS) Filter presented in this paper has an outstanding potential to attenuate the fixed-value impulse noise in images. This filter has two distinct phases namely noise detection and noise correction which uses Measure of Statistics and Iterated Function Systems (IFS) respectively. The performance of AIFS filter is assessed by three metrics namely, Peak Signal-to-Noise Ratio (PSNR), Mean Structural Similarity Index Matrix (MSSIM) and Human Visual Perception (HVP). The quantitative measures PSNR and MSSIM endorse the merit of this filter in terms of degree of noise suppression and details/edge preservation respectively, in comparison with the high performing filters reported in the recent literature. The qualitative measure HVP confirms the noise suppression ability of the devised filter. This computationally simple noise filter broadly finds application wherein the images are highly degraded by fixed-value impulse noise.

  7. Integral boundary-value problem for impulsive fractional functional differential equations with infinite delay

    Directory of Open Access Journals (Sweden)

    Archana Chauhan

    2012-12-01

    Full Text Available In this article, we establish a general framework for finding solutions for impulsive fractional integral boundary-value problems. Then, we prove the existence and uniqueness of solutions by applying well known fixed point theorems. The obtained results are illustrated with an example for their feasibility.

  8. Investigation of solutions of state-dependent multi-impulsive boundary value problems

    Czech Academy of Sciences Publication Activity Database

    Rontó, András; Rachůnková, I.; Rontó, M.; Rachůnek, L.

    2017-01-01

    Roč. 24, č. 2 (2017), s. 287-312 ISSN 1072-947X R&D Projects: GA ČR(CZ) GA14-06958S Institutional support: RVO:67985840 Keywords : state-dependent multi-impulsive systems * non-linear boundary value problem * parametrization technique Subject RIV: BA - General Mathematics OBOR OECD: Applied mathematics Impact factor: 0.290, year: 2016 https://www.degruyter.com/view/j/gmj.2017.24.issue-2/gmj-2016-0084/gmj-2016-0084. xml

  9. Investigation of solutions of state-dependent multi-impulsive boundary value problems

    Czech Academy of Sciences Publication Activity Database

    Rontó, András; Rachůnková, I.; Rontó, M.; Rachůnek, L.

    2017-01-01

    Roč. 24, č. 2 (2017), s. 287-312 ISSN 1072-947X R&D Projects: GA ČR(CZ) GA14-06958S Institutional support: RVO:67985840 Keywords : state-dependent multi-impulsive systems * non-linear boundary value problem * parametrization technique Subject RIV: BA - General Mathematics OBOR OECD: Applied mathematics Impact factor: 0.290, year: 2016 https://www.degruyter.com/view/j/gmj.2017.24.issue-2/gmj-2016-0084/gmj-2016-0084.xml

  10. A centre-triggered magnesium fuelled cathodic arc thruster uses sublimation to deliver a record high specific impulse

    Science.gov (United States)

    Neumann, Patrick R. C.; Bilek, Marcela; McKenzie, David R.

    2016-08-01

    The cathodic arc is a high current, low voltage discharge that operates in vacuum and provides a stream of highly ionised plasma from a solid conducting cathode. The high ion velocities, together with the high ionisation fraction and the quasineutrality of the exhaust stream, make the cathodic arc an attractive plasma source for spacecraft propulsion applications. The specific impulse of the cathodic arc thruster is substantially increased when the emission of neutral species is reduced. Here, we demonstrate a reduction of neutral emission by exploiting sublimation in cathode spots and enhanced ionisation of the plasma in short, high-current pulses. This, combined with the enhanced directionality due to the efficient erosion profiles created by centre-triggering, substantially increases the specific impulse. We present experimentally measured specific impulses and jet power efficiencies for titanium and magnesium fuels. Our Mg fuelled source provides the highest reported specific impulse for a gridless ion thruster and is competitive with all flight rated ion thrusters. We present a model based on cathode sublimation and melting at the cathodic arc spot explaining the outstanding performance of the Mg fuelled source. A further significant advantage of an Mg-fuelled thruster is the abundance of Mg in asteroidal material and in space junk, providing an opportunity for utilising these resources in space.

  11. Multiple positive solutions for second order impulsive boundary value problems in Banach spaces

    Directory of Open Access Journals (Sweden)

    Zhi-Wei Lv

    2010-06-01

    Full Text Available By means of the fixed point index theory of strict set contraction operators, we establish new existence theorems on multiple positive solutions to a boundary value problem for second-order impulsive integro-differential equations with integral boundary conditions in a Banach space. Moreover, an application is given to illustrate the main result.

  12. Overlapping and disease specific aspects of impulsivity in children and adolescents with schizophrenia spectrum disorders or Attention-Deficit/Hyperactivity Disorder

    DEFF Research Database (Denmark)

    Jepsen, Jens Richardt Møllegaard; Rydkjær, Jacob; Fagerlund, Birgitte

    Objectives: To identify disease specific and overlapping aspects of impulsivity in children and adolescents with early-onset schizophrenia spectrum disorders or ADHD. Methods: Motor impulsivity (Stop Signal Task), reflection impulsivity (Information Sampling Task), and trait impulsivity (Barratt ...... their decision making to gather more information in a condition with a conflict between reward and certainty. The reduced information sampling may also reflect an increased conviction in the decision at a point of relative uncertainty....

  13. Random Valued Impulse Noise Removal Using Region Based Detection Approach

    Directory of Open Access Journals (Sweden)

    S. Banerjee

    2017-12-01

    Full Text Available Removal of random valued noisy pixel is extremely challenging when the noise density is above 50%. The existing filters are generally not capable of eliminating such noise when density is above 70%. In this paper a region wise density based detection algorithm for random valued impulse noise has been proposed. On the basis of the intensity values, the pixels of a particular window are sorted and then stored into four regions. The higher density based region is considered for stepwise detection of noisy pixels. As a result of this detection scheme a maximum of 75% of noisy pixels can be detected. For this purpose this paper proposes a unique noise removal algorithm. It was experimentally proved that the proposed algorithm not only performs exceptionally when it comes to visual qualitative judgment of standard images but also this filter combination outsmarts the existing algorithm in terms of MSE, PSNR and SSIM comparison even up to 70% noise density level.

  14. Overlapping and disease specific trait, response, and reflection impulsivity in adolescents with first-episode schizophrenia spectrum disorders or attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Jepsen, J R M; Rydkjaer, J; Fagerlund, B; Pagsberg, A K; Jespersen, R Av F; Glenthøj, B Y; Oranje, B

    2018-03-01

    Schizophrenia and attention-deficit/hyperactivity disorder (ADHD) are developmental disorders with shared clinical characteristics such as cognitive impairments and impulsivity. Impulsivity is a core feature of ADHD and an important factor in aggression, violence, and substance use in schizophrenia. Based on the hypothesis that schizophrenia and ADHD represent a continuum of neurodevelopmental impairments, the aim was to identify overlapping and disease specific forms of impulsivity. Adolescents between 12 and 17 years of age were assessed with the Schedule for Affective Disorders and Schizophrenia for School-aged Children - Present and Lifetime Version. Subjects with early-onset, first-episode schizophrenia spectrum disorders (EOS) (N = 29) or ADHD (N = 29) and healthy controls (N = 45) were compared on two performance measures (Information Sampling Task, Stop Signal Task) and a subjective personality trait measure of impulsivity (Barratt Impulsiveness Scale, Version 11 (BIS-11)). Significantly increased reflection impulsivity was observed in ADHD but not in the EOS group. No significant response inhibition deficits (stop signal reaction time) were found in the two clinical groups. The ADHD and the EOS group showed significantly increased motor, attentional, and non-planning subtraits of impulsivity. Impaired pre-decisional information gathering appeared to be specific for ADHD while the information gathering was not significantly reduced in subjects with EOS. Neither the ADHD nor EOS group showed impaired response inhibition but shared increased personality subtraits of attentional, non-planning, and motor impulsivity although the latter was significantly more pronounced in ADHD. These increased subtraits of impulsivity may reflect diagnostic non-specific neurodevelopmental impairments in ADHD and EOS in adolescence.

  15. Test-retest reliability of behavioral measures of impulsive choice, impulsive action, and inattention.

    Science.gov (United States)

    Weafer, Jessica; Baggott, Matthew J; de Wit, Harriet

    2013-12-01

    Behavioral measures of impulsivity are widely used in substance abuse research, yet relatively little attention has been devoted to establishing their psychometric properties, especially their reliability over repeated administration. The current study examined the test-retest reliability of a battery of standardized behavioral impulsivity tasks, including measures of impulsive choice (i.e., delay discounting, probability discounting, and the Balloon Analogue Risk Task), impulsive action (i.e., the stop signal task, the go/no-go task, and commission errors on the continuous performance task), and inattention (i.e., attention lapses on a simple reaction time task and omission errors on the continuous performance task). Healthy adults (n = 128) performed the battery on two separate occasions. Reliability estimates for the individual tasks ranged from moderate to high, with Pearson correlations within the specific impulsivity domains as follows: impulsive choice (r range: .76-.89, ps reliable measures and thus can be confidently used to assess various facets of impulsivity as intermediate phenotypes for drug abuse.

  16. Impulsive differential inclusions a fixed point approach

    CERN Document Server

    Ouahab, Abdelghani; Henderson, Johnny

    2013-01-01

    Impulsive differential equations have been developed in modeling impulsive problems in physics, population dynamics, ecology, biotechnology, industrial robotics, pharmacokinetics, optimal control, etc. The questions of existence and stability of solutions for different classes of initial values problems for impulsive differential equations and inclusions with fixed and variable moments are considered in detail. Attention is also given to boundary value problems and relative questions concerning differential equations. This monograph addresses a variety of side issues that arise from its simple

  17. The clinical assessment of impulsivity

    Directory of Open Access Journals (Sweden)

    Nagesh Brahmavar Pai

    2018-01-01

    Full Text Available The term impulsivity is often used to describe behavior that is both spontaneous and detrimental. Impulsivity is multidimensional and derives from personality, general psychopathology as well as specific mental disorders. Thus, the construct of impulsivity is important as it is associated with numerous mental disorders as well as socially deviant behaviors ranging from behaviors targeted towards others such as aggression, to behaviors targeted toward oneself, for example, self-harm and suicide. As a clinical construct impulsivity is highly predictive of poor prognosis thus further emphasizing its clinical relevance. Therefore, the need exists for impulsivity to be clinically assessed and this assessment should take place at the same time as the assessment of risk. As risk and impulsivity are interrelated and interact. Although there are existing self-report rating scales for trait-based impulsivity, a dearth exists in regards to assessment of impulsivity in clinical practice that is focused and pragmatic. Thus, a pragmatic rubric to guide the individualized assessment of impulsivity in a clinical population is proposed. The quadrants espoused will assist both with the formulation of questions and categorization of responses to determine the most appropriate interventions for the client.

  18. Reliability and comparison of gain values with occurrence of saccades in the EyeSeeCam video head impulse test (vHIT)

    DEFF Research Database (Denmark)

    Hviid Korsager, Leise Elisabeth; Schmidt, Jesper Hvass; Faber, Christian

    2016-01-01

    . There is a lack of knowledge regarding the reliability of the two parameters. The objective was to investigate the reliability of vHIT by comparing gain values between examiners on the same subjects, and to see how differences affected the occurrence of saccades. SUBJECTS: 25 subjects who had undergone cochlear...... coefficient (ICC) of the gain values between examiners ranged from 0.62 to 0.70. Differences in gain values amongst examiners did not seem to affect the occurrence of saccades in the same patient. The occurrence of saccades, therefore, seems to be more reliable than the gain value in the evaluation......The vHIT (video head impulse test) investigates the vestibular function in two ways: a VOR (vestibulo-ocular reflex) gain value and a head impulse diagram. From the diagram covert and overt saccades can be detected. Evaluation of the vestibular function based on vHIT depends on both parameters...

  19. Impulsivity and Cluster B Personality Disorders.

    Science.gov (United States)

    Turner, Daniel; Sebastian, Alexandra; Tüscher, Oliver

    2017-03-01

    Impulsivity is a multifaceted construct and an important personality trait in various mental health conditions. Among personality disorders (PDs), especially cluster B PDs are affected. The aims of this review are to summarize the relevant findings of the past 3 years concerning impulsivity in cluster B PDs and to identify those subcomponents of self-reported impulsivity and experimentally measured impulse control that are most affected in these disorders. All studies referred to antisocial (ASPD) or borderline PD (BPD), and none were found for narcissistic or histrionic PD. In ASPD as well as BPD, self-report scales primarily revealed heightened impulsivity compared to healthy controls. In experimental tasks, ASPD patients showed impairments in response inhibition, while fewer deficits were found in delay discounting. BPD patients showed specific impairments in delay discounting and proactive interference, while response inhibition was less affected. However, after inducing high levels of stress, deficits in response inhibition could also be observed in BPD patients. Furthermore, negative affect led to altered brain activation patterns in BPD patients during impulse control tasks, but no behavioral impairments were found. As proposed by the DSM-5 alternative model for personality disorders, heightened impulsivity is a core personality trait in BPD and ASPD, which is in line with current research findings. However, different components of experimentally measured impulse control are affected in BPD and ASPD, and impulsivity occurring in negative emotional states or increased distress seems to be specific for BPD. Future research could be focused on measures that assess impulsive behaviors on a momentary basis as this is a promising approach especially for further ecological validation and transfer into clinical practice.

  20. A study of variable thrust, variable specific impulse trajectories for solar system exploration

    Science.gov (United States)

    Sakai, Tadashi

    A study has been performed to determine the advantages and disadvantages of variable thrust and variable Isp (specific impulse) trajectories for solar system exploration. There have been several numerical research efforts for variable thrust, variable Isp, power-limited trajectory optimization problems. All of these results conclude that variable thrust, variable Isp (variable specific impulse, or VSI) engines are superior to constant thrust, constant Isp (constant specific impulse; or CSI) engines. However, most of these research efforts assume a mission from Earth to Mars, and some of them further assume that these planets are circular and coplanar. Hence they still lack the generality. This research has been conducted to answer the following questions: (1) Is a VSI engine always better than a CSI engine or a high thrust engine for any mission to any planet with any time of flight considering lower propellant mass as the sole criterion? (2) If a planetary swing-by is used for a VSI trajectory, is the fuel savings of a VSI swing-by trajectory better than that of a CSI swing-by or high thrust swing-by trajectory? To support this research, an unique, new computer-based interplanetary trajectory calculation program has been created. This program utilizes a calculus of variations algorithm to perform overall optimization of thrust, Isp, and thrust vector direction along a trajectory that minimizes fuel consumption for interplanetary travel. It is assumed that the propulsion system is power-limited, and thus the compromise between thrust and Isp is a variable to be optimized along the flight path. This program is capable of optimizing not only variable thrust trajectories but also constant thrust trajectories in 3-D space using a planetary ephemeris database. It is also capable of conducting planetary swing-bys. Using this program, various Earth-originating trajectories have been investigated and the optimized results have been compared to traditional CSI and high

  1. Impulsivity, impulsive and reflective processes and the development of alcohol use and misuse in adolescents and young adults

    Directory of Open Access Journals (Sweden)

    Reinout Wiers

    2010-09-01

    Full Text Available This paper contrasts dual-process and personality approaches in the prediction of addictive behaviors and related risk behaviors. In dual-process models, behavior is described as the joint outcome of qualitatively different “impulsive” (or associative and “reflective” processes. There are important individual differences regarding both types of processes, and the relative strength of both in a specific situation is influenced by prior behavior and state variables (e.g., fatigue, alcohol use. From this perspective, a specific behavior (e.g., alcohol misuse can be predicted by the combined indices of the behavior-related impulsive processes (e.g., associations with alcohol, and reflective processes, including the ability to refrain from a motivationally salient action. Personality approaches have reported that general traits such as impulsivity predict addictive behaviors. Here we contrast these two approaches, with supplementary analyses on four datasets. We hypothesized that trait impulsivity can predict specific risky behaviors, but that its predictive power disappears once specific behavior-related associations, indicators of executive functioning, and their interaction are entered into the equation. In all four studies the observed interaction between specific associations and Executive Control (EC was robust: trait impulsivity did not diminish the prediction of alcohol use by the interaction. Trait impulsivity was not always related to alcohol use, and when it was, the predictive power disappeared after entering the interaction between behavior-specific associations and EC in one study, but not in the other. These findings are interpreted in relation to the validity of the measurements used, which leads to a more refined hypothesis.

  2. Beyond discounting: possible experimental models of impulse control.

    Science.gov (United States)

    Monterosso, J; Ainslie, G

    1999-10-01

    Animal studies of impulsivity have typically used one of three models: a delay of reward procedure, a differential reinforcement for low rate responding (DRL) procedure, or an autoshaping procedure. In each of these paradigms, we argue, measurement of impulsivity is implicitly or explicitly equated with the effect delay has on the value of reward. The steepness by which delay diminishes value (the temporal discount function) is treated as an index of impulsivity. In order to provide a better analog of human impulsivity, this model needs to be expanded to include the converse of impulsivity - self-control. Through mechanisms such as committing to long range interests before the onset of temptation, or through bundling individual choices into classes of choices that are made at once, human decision-making can often look far less myopic than single trial experiments predict. For people, impulsive behavior may be more often the result of the breakdown of self-control mechanisms than of steep discount functions. Existing animal models of self-control are discussed, and future directions are suggested for psychopharmacological research.

  3. Minimal Time Problem with Impulsive Controls

    Energy Technology Data Exchange (ETDEWEB)

    Kunisch, Karl, E-mail: karl.kunisch@uni-graz.at [University of Graz, Institute for Mathematics and Scientific Computing (Austria); Rao, Zhiping, E-mail: zhiping.rao@ricam.oeaw.ac.at [Austrian Academy of Sciences, Radon Institute of Computational and Applied Mathematics (Austria)

    2017-02-15

    Time optimal control problems for systems with impulsive controls are investigated. Sufficient conditions for the existence of time optimal controls are given. A dynamical programming principle is derived and Lipschitz continuity of an appropriately defined value functional is established. The value functional satisfies a Hamilton–Jacobi–Bellman equation in the viscosity sense. A numerical example for a rider-swing system is presented and it is shown that the reachable set is enlargered by allowing for impulsive controls, when compared to nonimpulsive controls.

  4. Regulated expression of the neural cell adhesion molecule L1 by specific patterns of neural impulses.

    Science.gov (United States)

    Itoh, K; Stevens, B; Schachner, M; Fields, R D

    1995-11-24

    Development of the mammalian nervous system is regulated by neural impulse activity, but the molecular mechanisms are not well understood. If cell recognition molecules [for example, L1 and the neural cell adhesion molecule (NCAM)] were influenced by specific patterns of impulse activity, cell-cell interactions controlling nervous system structure could be regulated by nervous system function at critical stages of development. Low-frequency electrical pulses delivered to mouse sensory neurons in culture (0.1 hertz for 5 days) down-regulated expression of L1 messenger RNA and protein (but not NCAM). Fasciculation of neurites, adhesion of neuroblastoma cells, and the number of Schwann cells on neurites was reduced after 0.1-hertz stimulation, but higher frequencies or stimulation after synaptogenesis were without effect.

  5. Impulse: Memory System Support for Scientific Applications

    Directory of Open Access Journals (Sweden)

    John B. Carter

    1999-01-01

    Full Text Available Impulse is a new memory system architecture that adds two important features to a traditional memory controller. First, Impulse supports application‐specific optimizations through configurable physical address remapping. By remapping physical addresses, applications control how their data is accessed and cached, improving their cache and bus utilization. Second, Impulse supports prefetching at the memory controller, which can hide much of the latency of DRAM accesses. Because it requires no modification to processor, cache, or bus designs, Impulse can be adopted in conventional systems. In this paper we describe the design of the Impulse architecture, and show how an Impulse memory system can improve the performance of memory‐bound scientific applications. For instance, Impulse decreases the running time of the NAS conjugate gradient benchmark by 67%. We expect that Impulse will also benefit regularly strided, memory‐bound applications of commercial importance, such as database and multimedia programs.

  6. Ultrasonic hydrometer. [Specific gravity of electrolyte

    Science.gov (United States)

    Swoboda, C.A.

    1982-03-09

    The disclosed ultrasonic hydrometer determines the specific gravity (density) of the electrolyte of a wet battery, such as a lead-acid battery. The hydrometer utilizes a transducer that when excited emits an ultrasonic impulse that traverses through the electrolyte back and forth between spaced sonic surfaces. The transducer detects the returning impulse, and means measures the time t between the initial and returning impulses. Considering the distance d between the spaced sonic surfaces and the measured time t, the sonic velocity V is calculated with the equation V = 2d/t. The hydrometer also utilizes a thermocouple to measure the electrolyte temperature. A hydrometer database correlates three variable parameters including sonic velocity in and temperature and specific gravity of the electrolyte, for temperature values between 0 and 40/sup 0/C and for specific gravity values between 1.05 and 1.30. Upon knowing two parameters (the calculated sonic velocity and the measured temperature), the third parameter (specific gravity) can be uniquely found in the database. The hydrometer utilizes a microprocessor for data storage and manipulation.

  7. Diet-induced impulsivity: Effects of a high-fat and a high-sugar diet on impulsive choice in rats.

    Science.gov (United States)

    Steele, Catherine C; Pirkle, Jesseca R A; Kirkpatrick, Kimberly

    2017-01-01

    Impulsive choice is a common charactertistic among individuals with gambling problems, obesity, and substance abuse issues. Impulsive choice has been classified as a trans-disease process, and understanding the etiology of trait impulsivity could help to understand how diseases and disorders related to impulsive choice are manifested. The Western diet is a possible catalyst of impulsive choice as individuals who are obese and who eat diets high in fat and sugar are typically more impulsive. However, such correlational evidence is unable to discern the direction and causal nature of the relationship. The present study sought to determine how diet may directly contribute to impulsive choice. After 8 weeks of dietary exposure (high-fat, high-sugar, chow), the rats were tested on an impulsive choice task, which presented choices between a smaller-sooner reward (SS) and a larger-later reward (LL). Then, the rats were transferred to a chow diet and retested on the impulsive choice task. The high-sugar and high-fat groups made significantly more impulsive choices than the chow group. Both groups became more self-controlled when they were off the diet, but there were some residual effects of the diet on choice behavior. These results suggest that diet, specifically one high in processed fat or sugar, induces impulsive choice. This diet-induced impulsivity could be a precursor to other disorders that are characterized by impulsivity, such as diet-induced obesity, and could offer potential understanding of the trans-disease nature of impulsive choice.

  8. Specific cognitive-neurophysiological processes predict impulsivity in the childhood attention-deficit/hyperactivity disorder combined subtype.

    Science.gov (United States)

    Bluschke, A; Roessner, V; Beste, C

    2016-04-01

    Attention-deficit/hyperactivity disorder (ADHD) is one of the most prevalent neuropsychiatric disorders in childhood. Besides inattention and hyperactivity, impulsivity is the third core symptom leading to diverse and serious problems. However, the neuronal mechanisms underlying impulsivity in ADHD are still not fully understood. This is all the more the case when patients with the ADHD combined subtype (ADHD-C) are considered who are characterized by both symptoms of inattention and hyperactivity/impulsivity. Combining high-density electroencephalography (EEG) recordings with source localization analyses, we examined what information processing stages are dysfunctional in ADHD-C (n = 20) compared with controls (n = 18). Patients with ADHD-C made more impulsive errors in a Go/No-go task than healthy controls. Neurophysiologically, different subprocesses from perceptual gating to attentional selection, resource allocation and response selection processes are altered in this patient group. Perceptual gating, stimulus-driven attention selection and resource allocation processes were more pronounced in ADHD-C, are related to activation differences in parieto-occipital networks and suggest attentional filtering deficits. However, only response selection processes, associated with medial prefrontal networks, predicted impulsive errors in ADHD-C. Although the clinical picture of ADHD-C is complex and a multitude of processing steps are altered, only a subset of processes seems to directly modulate impulsive behaviour. The present findings improve the understanding of mechanisms underlying impulsivity in patients with ADHD-C and might help to refine treatment algorithms focusing on impulsivity.

  9. Antiperiodic Boundary Value Problems for Second-Order Impulsive Ordinary Differential Equations

    Directory of Open Access Journals (Sweden)

    2009-02-01

    Full Text Available We consider a second-order ordinary differential equation with antiperiodic boundary conditions and impulses. By using Schaefer's fixed-point theorem, some existence results are obtained.

  10. Impulsivity and Suicidality in Adolescent Inpatients.

    Science.gov (United States)

    Auerbach, Randy P; Stewart, Jeremy G; Johnson, Sheri L

    2017-01-01

    Suicide is the second leading cause of death among adolescents, and impulsivity has emerged as a promising marker of risk. The present study tested whether distinct domains of impulsivity are differentially associated with suicide ideation, plans, and attempts. Adolescents (n = 381; boys = 106, girls = 275) aged 13-19 years (M = 15.62, SD = 1.41) were recruited from an acute, residential treatment program. Within 48 h of admission to the hospital, participants were administered structured clinical interviews assessing mental health disorders and suicidality. Following these interviews, participants completed self-report questionnaires assessing symptom severity and impulsivity. Consistent with past research, an exploratory factor analysis of our 90-item impulsivity instrument resulted in a three-factor solution: Pervasive Influence of Feelings, Feelings Trigger Action, and Lack of Follow-Through. Concurrent analysis of these factors confirmed hypotheses of unique associations with suicide ideation and attempts in the past month. Specifically, whereas Pervasive Influence of Feelings (i.e., tendency for emotions to shape thoughts about the self and the future) is uniquely associated with greater suicidal ideation, Feelings Trigger Action (i.e., impulsive behavioral reactivity to emotions) is uniquely associated with the occurrence of suicide attempts, even after controlling for current psychiatric diagnoses and symptoms. Exploratory gender analyses revealed that these effects were significant in female but not male adolescents. These findings provide new insight about how specific domains of impulsivity differentially increase risk for suicide ideation and attempts. Implications for early identification and prevention of youth suicide are discussed.

  11. Measurement of the spatial specific impulse distribution due to buried high explosive charge detonation

    Directory of Open Access Journals (Sweden)

    V. Denefeld

    2017-06-01

    The momentum transfer to a vehicle depends on a number of influencing factors such as: charge mass, embedding material (e.g. sand, gravel, clay, density, water content, saturation, depth of burial, ground clearance and vehicle shape. The presented technology is applied to quantify the influence of the embedding material (alluvial sand, quartz sand, the burial depth and the water content on the local specific impulse distribution. The obtained data can be used as initial condition for the numerical simulation of occupant safety assessment and as input for empirical modeling of momentum transfer on structures.

  12. Parkinson's Impulse-Control Scale for the Severity Rating of Impulse-Control Behaviors in Parkinson's Disease: A Semistructured Clinical Assessment Tool.

    Science.gov (United States)

    Okai, David; Askey-Jones, Sally; Mack, Joel; Martin, Anne; Chaudhuri, Kallol Ray; Samuel, Michael; David, Anthony S; Brown, Richard G

    2016-01-01

    Impulse-control behaviors (ICBs) are increasingly recognized in Parkinson's disease (PD) as drug-related effects of dopaminergic mediation that occur in 15% to 35% of patients with PD. The authors describe the design and evaluation of a new, clinician-rated severity scale for the assessment of syndromal and subsyndromal forms of impulse-control disorders (ICDs), simple (punding) and complex (hobbyism) repetitive behaviors, and compulsive overuse of medication (dopamine dysregulation syndrome). The Parkinson's Impulse-Control Scale (PICS), the first PD-specific, semistructured interview to cover the full range of PD-related ICBs, is described along with initial evidence on its clinimetric properties including interrater reliability, discriminant validity and sensitivity to change. A convenience sample of PD patients with ICBs and those without were administered a semistructured interview (n = 92). The scale distinguished between those with and without clinically detected ICBs and between patients with syndromal ICD and subsyndromal ICB (receiver operating characteristic areas under the curve, 92%-95%). Cutoff values were suggested, and substantial agreement was reported on weighted kappa (Κ) values for clinician-clinician rating of severity (Κ = 0.92). Significant improvements were detected on the scale after a randomized controlled trial of cognitive-behavioral therapy and medication adjustment ( t [22] = 5.47; P < 0.001). The PICS appears to be a reliable measure of the full range of PD ICBs with good levels of interrater reliability. It may provide a useful measure to assess the severity of ICBs and monitor change in clinical and research settings; although, given the specialized centers used for recruitment of this sample, further psychometric evaluation is required.

  13. Neuroanatomical and Neurochemical Basis of Impulsivity

    Directory of Open Access Journals (Sweden)

    Kemal Yazici

    2010-08-01

    tis paradigm, the tendency to prefer small immediate rewards over larger, more delayed reinforcers is measured. İmpulsive choice is defined by a greater tendency to value or choose smaller, more immediate reinforcers. Impulsivity is a multi-faceted behaviour. This behaviour may be studied by subdividing it into different processes neuroanatomically and neurochemically. Neuroanatomical data support the suggestion that behavioral disinhibition (impulsive action / motoric impulsivity and delay-discounting (impulsive choice / decision making differ in the degree to which various components of frontostriatal loops are implicated in their regulation. The dorsal prefrontal cortex does not appear to be involved in mediating impulsive choice, yet does have some role in regulating inhibitory processes. In contrast, there appears to be a pronounced role for the orbitofrontal cortex and basolateral amygdala in controlling impulsive choice. Other structures, however, such as the nucleus accumbens and subthalamic nucleus may be common to both circuits. From the neurochemical perspective, dopamine system and dopamine- 2 (D2 receptors in particular, seems to be closely involved in making impulsive choice. When the noradrenaline system does not function optimally, it might contribute to increased impulsivity. Serotonin might act upon prefrontal cortex to decrease impulsive choices. Interactions between the serotonin and the dopamine systems are important in the regulation of impulsive behaviour. It is possible that various receptor subtypes of the serotonin system may exert differing and even contrasting effects on impulsive behaviour. Although it is very informative to study neurotransmitter systems separately, it should be kept in mind that there are very intimate interactions between the neurotransmitter systems mentioned above. Based on the fact that impulsivity is regulated through multiple neurotransmitters and even more receptors, one may suggest that pharmacotherapy of

  14. Impulsive stabilization and impulsive synchronization of discrete-time delayed neural networks.

    Science.gov (United States)

    Chen, Wu-Hua; Lu, Xiaomei; Zheng, Wei Xing

    2015-04-01

    This paper investigates the problems of impulsive stabilization and impulsive synchronization of discrete-time delayed neural networks (DDNNs). Two types of DDNNs with stabilizing impulses are studied. By introducing the time-varying Lyapunov functional to capture the dynamical characteristics of discrete-time impulsive delayed neural networks (DIDNNs) and by using a convex combination technique, new exponential stability criteria are derived in terms of linear matrix inequalities. The stability criteria for DIDNNs are independent of the size of time delay but rely on the lengths of impulsive intervals. With the newly obtained stability results, sufficient conditions on the existence of linear-state feedback impulsive controllers are derived. Moreover, a novel impulsive synchronization scheme for two identical DDNNs is proposed. The novel impulsive synchronization scheme allows synchronizing two identical DDNNs with unknown delays. Simulation results are given to validate the effectiveness of the proposed criteria of impulsive stabilization and impulsive synchronization of DDNNs. Finally, an application of the obtained impulsive synchronization result for two identical chaotic DDNNs to a secure communication scheme is presented.

  15. Value of impulse oscillometry in evaluating the illness in children with asthma and analysis of its correlation with serum indicators

    Directory of Open Access Journals (Sweden)

    Cui-Fen Bai

    2016-05-01

    Full Text Available Objective: To Value of impulse oscillometry in evaluating the illness in children with asthma and its correlation with serum indicators. Methods: Children with asthma attack, children with asthma remission and healthy children were selected for study, impulse oscillometry was conducted to obtain related parameters, and serum and peripheral blood were collected to detect related indicators. Results: Zrs, R5, R20, R5-R20, absolute value of X5 and Fres of asthma attack group and asthma remission group were higher than those of control group, eosinophil, YKL-40, Hes-1, Cyr61, Eotaxin, IgE, IgG4, LT-B4, LT-C4, LT-D4 and Cys-LT contents in peripheral blood were higher than those of control group, positive proportion of Th2, Th17, cTfh and Th19 in peripheral blood were higher than those of control group, and positive proportion of Th1 and Treg in peripheral blood were lower than those of control group; the changes of above indicators of asthma attack group were more significant than those of asthma remission group; Zrs, R5, R20, R5-R20, absolute value of X5 and Fres were positively correlated with eosinophil, YKL-40, Hes-1, Cyr61, Eotaxin, IgE, IgG4, LT-B4, LT-C4, LTD4 and Cys-LT contents in peripheral blood as well as positive proportion of Th2, Th17, cTfh and Th19 in peripheral blood, and negatively correlated with positive proportion of Th1 and Treg in peripheral blood. Conclusion: Impulse oscillometry detection can provide evidence for diagnosis of bronchial asthma and judgment of its illness, and IOS-related parameters can judge the abnormal degree of inflammatory response and immune response.

  16. [Letter: Work of the impulse section of the horseshoe bat echolocator].

    Science.gov (United States)

    Livshits, M S

    1975-01-01

    Peculiarities of location impulse of Rhinolophidae bring about a distinctive combination of dopler and impulse parts working almost independently, in its locator. In particular the range of the effect of impulse locator connected with the presence of LFM splash in the end of location cry is determined by the value of the period of its repetition. The existence of a long monofrequent part of locaion impulse providing the work of acholocator dopler part due to its narrow bands presents only a comparatively small obstacle to the impulse locator.

  17. Overlapping and disease specific trait, response, and reflection impulsivity in adolescents with first-episode schizophrenia spectrum disorders or attention-deficit/hyperactivity disorder

    DEFF Research Database (Denmark)

    Jepsen, J. R.M.; Rydkjaer, J.; Fagerlund, B.

    2018-01-01

    and Schizophrenia for School-aged Children – Present and Lifetime Version. Subjects with early-onset, first-episode schizophrenia spectrum disorders (EOS) (N = 29) or ADHD (N = 29) and healthy controls (N = 45) were compared on two performance measures (Information Sampling Task, Stop Signal Task) and a subjective......Background: Schizophrenia and attention-deficit/hyperactivity disorder (ADHD) are developmental disorders with shared clinical characteristics such as cognitive impairments and impulsivity. Impulsivity is a core feature of ADHD and an important factor in aggression, violence, and substance use...... in schizophrenia. Based on the hypothesis that schizophrenia and ADHD represent a continuum of neurodevelopmental impairments, the aim was to identify overlapping and disease specific forms of impulsivity. Methods: Adolescents between 12 and 17 years of age were assessed with the Schedule for Affective Disorders...

  18. Impulse sales cooler. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, Per Henrik (DTI, Taastrup (Denmark))

    2010-11-15

    In the past years, the use of impulse coolers has increased considerably and it is estimated that at least 30.000 are installed in shops in Denmark. In addition, there are many small barrel-shaped can coolers. Most impulse coolers are open, which results in a large consumption of energy, and the refrigeration systems are often quite inefficient. A typical impulse cooler uses app. 5 - 8 kWh/day corresponding to a consumption of energy in the magnitude of 60 GWh/year. For several years, the Danish company Vestfrost A/S has produced an impulse sales cooler in the high-efficiency end and the energy consumption of the cooler is measured to be 4.15 kWh/day. The POS72 cooler formed the baseline of this project. At the start-up meeting in 2008, several ideas were discussed with the objective to reduce energy consumption and to use natural refrigerants. Among the ideas were better air curtains, removable lids, better condensers, use of R600a refrigeration system and better insulation. Three generations of prototypes were built and tested in a climate chamber at Danish Technological Institute and the third generation showed very good performance: the energy consumption was measured to 2.215 kWh/day, which is a 47% reduction compared to the baseline. That was achieved by: 1) Improving the cold air cycling system including the air curtain. 2) Using the natural refrigerant R600a (isobutane) and the Danfoss NLE9KTK compressor, which has better efficiency compared to the compressor in the baseline product. 3) Using a box type condenser without fins (preventing dust build-up) and with a relatively high surface area. 4) Improving the insulation value of the plastic cabinet by reducing turbulence in the air gap between the plastic walls and improving the insulation value of the EPS moulded insulation surrounding the refrigeration system at the bottom of the cooler. 5) Preventing short-circuit of warm air around the condenser. 6) The improvements are cost efficient and will not add

  19. Does impulsivity predict outcome in treatment for binge eating disorder? A multimodal investigation.

    Science.gov (United States)

    Manasse, Stephanie M; Espel, Hallie M; Schumacher, Leah M; Kerrigan, Stephanie G; Zhang, Fengqing; Forman, Evan M; Juarascio, Adrienne S

    2016-10-01

    Multiple dimensions of impulsivity (e.g., affect-driven impulsivity, impulsive inhibition - both general and food-specific, and impulsive decision-making) are associated with binge eating pathology cross-sectionally, yet the literature on whether impulsivity predicts treatment outcome is limited. The present pilot study explored impulsivity-related predictors of 20-week outcome in a small open trial (n = 17) of a novel treatment for binge eating disorder. Overall, dimensions of impulsivity related to emotions (i.e., negative urgency) and food cues emerged as predictors of treatment outcomes (i.e., binge eating frequency and global eating pathology as measured by the Eating Disorders Examination), while more general measures of impulsivity were statistically unrelated to global eating pathology or binge frequency. Specifically, those with higher levels of negative urgency at baseline experienced slower and less pronounced benefit from treatment, and those with higher food-specific impulsivity had more severe global eating pathology at baseline that was consistent at post-treatment and follow-up. These preliminary findings suggest that patients high in negative urgency and with poor response inhibition to food cues may benefit from augmentation of existing treatments to achieve optimal outcomes. Future research will benefit from replication with a larger sample, parsing out the role of different dimensions of impulsivity in treatment outcome for eating disorders, and identifying how treatment can be improved to accommodate higher levels of baseline impulsivity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Reconsidering the link between impulsivity and suicidal behavior.

    Science.gov (United States)

    Anestis, Michael D; Soberay, Kelly A; Gutierrez, Peter M; Hernández, Theresa D; Joiner, Thomas E

    2014-11-01

    It is widely accepted that suicidal behavior often occurs with little planning. We propose, however, that suicidal behavior is rarely if ever impulsive-that it is too frightening and physically distressing to engage in without forethought-and that suicidal behavior in impulsive individuals is accounted for by painful and fearsome behaviors capable of enhancing their capacity for suicide. We conducted a meta-analysis of the association between trait impulsivity and suicidal behavior and a critical review of research considering the impulsiveness of specific suicide attempts. Meta-analytic results suggest the relationship between trait impulsivity and suicidal behavior is small. Furthermore, studies examining a mediating role of painful and provocative behaviors have uniformly supported our model. Results from our review suggest that researchers have been unable to adequately measure impulsivity of attempts and that measures sensitive to episodic planning must be developed to further our understanding of this phenomenon. © 2014 by the Society for Personality and Social Psychology, Inc.

  1. The persistence in a Lotka-Volterra competition systems with impulsive

    International Nuclear Information System (INIS)

    Zhen Jin; Han Maoan; Li Guihua

    2005-01-01

    In this paper, a nonautonomous two-dimensional competitive Lotka-Volterra system with impulsive is considered. we study the persistence and extinction, giving two inequalities involving averages of the growth rates and impulsive value, which guarantees persistence of the system. An extension of the principle of competition exclusion is obtained in this paper. Moreover, several examples are also worked out, they show that the impulsive can change the persistence of the system

  2. A constructive approach to boundary value problems with state-dependent impulses

    Czech Academy of Sciences Publication Activity Database

    Rachůnková, I.; Rachůnek, L.; Rontó, András; Rontó, M.

    2016-01-01

    Roč. 274, February (2016), s. 726-744 ISSN 0096-3003 Institutional support: RVO:67985840 Keywords : non-linear system of differential equation * impulse effect * parameterization * successive approximations Subject RIV: BA - General Mathematics Impact factor: 1.738, year: 2016 http://www.sciencedirect.com/science/article/pii/S0096300315015234

  3. Impulsive Synchronization and Adaptive-Impulsive Synchronization of a Novel Financial Hyperchaotic System

    Directory of Open Access Journals (Sweden)

    Xiuli Chai

    2013-01-01

    Full Text Available The impulsive synchronization and adaptive-impulsive synchronization of a novel financial hyperchaotic system are investigated. Based on comparing principle for impulsive functional differential equations, several sufficient conditions for impulsive synchronization are derived, and the upper bounds of impulsive interval for stable synchronization are estimated. Furthermore, a nonlinear adaptive-impulsive control scheme is designed to synchronize the financial system using invariant principle of impulsive dynamical systems. Moreover, corresponding numerical simulations are presented to illustrate the effectiveness and feasibility of the proposed methods.

  4. "Impulsive" youth suicide attempters are not necessarily all that impulsive.

    Science.gov (United States)

    Witte, Tracy K; Merrill, Katherine A; Stellrecht, Nadia E; Bernert, Rebecca A; Hollar, Daniel L; Schatschneider, Christopher; Joiner, Thomas E

    2008-04-01

    The relationship between impulsivity and suicide has been conceptualized in the literature as a direct one. In contrast, Joiner's [Joiner, T.E., 2005. Why people die by suicide. Harvard University Press, Cambridge, MA.] theory posits that this relationship is indirect in that impulsive individuals are more likely to engage in suicidal behavior because impulsivity makes one more likely to be exposed to painful and provocative stimuli. Adolescents were selected from the Youth Risk Behavior Survey (YRBS) sample between the years of 1993-2003 who had planned for a suicide attempt but did not actually attempt (n=5685), who did not plan but did attempt ("impulsive attempters;" n=1172), and who both planned and attempted (n=4807). Items were selected from the YRBS to assess demographic variables, suicidal behaviors, and impulsive behaviors. Participants who had planned suicide without attempting were significantly less impulsive than those who had attempted without planning and than those who had both planned and attempted. Crucially, participants who had made a suicide attempt without prior planning were less impulsive than those who had planned and attempted. We were unable to conduct a multi-method assessment (i.e., measures were self-report); the measure of impulsivity consisted of items pulled from the YRBS rather than a previously validated impulsivity measure. The notion that the most impulsive individuals are more likely to plan for suicide attempts is an important one for many reasons both theoretical and clinical, including that it may refine risk assessment and attendant clinical decision-making.

  5. Training impulsive choices for healthy and sustainable food.

    Science.gov (United States)

    Veling, Harm; Chen, Zhang; Tombrock, Merel C; Verpaalen, Iris A M; Schmitz, Laura I; Dijksterhuis, Ap; Holland, Rob W

    2017-06-01

    Many people find it hard to change their dietary choices. Food choice often occurs impulsively, without deliberation, and it has been unclear whether impulsive food choice can be experimentally created. Across 3 exploratory and 2 confirmatory preregistered experiments we examined whether impulsive food choice can be trained. Participants were cued to make motor responses upon the presentation of, among others, healthy and sustainable food items. They subsequently selected these food items more often for actual consumption when they needed to make their choices impulsively as a result of time pressure. This effect disappeared when participants were asked to think about their choices, merely received more time to make their choices, or when choosing required attention to alternatives. Participants preferred high to low valued food items under time pressure and without time pressure, suggesting that the impulsive choices reflect valid preferences. These findings demonstrate that it is possible to train impulsive choices for food items while leaving deliberative choices for these items unaffected, and connect research on attention training to dual-process theories of decision making. The present research suggests that attention training may lead to behavioral change only when people behave impulsively. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  6. Impulsivity, aggression and suicidal behavior in unipolar and bipolar disorders.

    Science.gov (United States)

    Perroud, Nader; Baud, Patrick; Mouthon, Dominique; Courtet, Philippe; Malafosse, Alain

    2011-11-01

    Predictors of suicidal behaviors (SB) in bipolar (BD) and major depressive disorder (MDD) patients are poorly understood. It has been recognized that behavioral dysregulation characterizes SB with traits of impulsivity and aggression being particularly salient. However, little is known about how these traits are segregated among mood disorder patients with and without a history of suicide attempt (SA). This article aims to compare impulsivity and aggression between 143 controls, 138 BD and 186 MDD subjects with or without a history of SA. BD and MDD patients showed higher impulsivity scores (BIS-10 = 57.9 vs. 44.7, p impulsivity helped to distinguish MDD subjects without a history of SA from those with such a history, this was not the case in BD subjects where no difference in impulsive traits was observed between BD without and with history of SA (57.2 vs. 63.2 for BIS-10; p = 0.259). Impulsive and aggressive traits were strongly correlated in suicide attempters (independently of the diagnosis) but not in non-suicide attempters. Dimensional traits were not characterized at different stages of illness. Impulsivity, as a single trait, may be a reliable suicide risk marker in MDD but not in BD patients, and its strong correlation with aggressive traits seems specifically related to SB. Our study therefore suggests that the specific dimension of impulsive aggression should be systematically assessed in mood disorder patients to address properly their suicidal risk. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Impulsive control of time-delay systems using delayed impulse and its application to impulsive master-slave synchronization

    International Nuclear Information System (INIS)

    Sun Jitao; Han Qinglong; Jiang Xiefu

    2008-01-01

    This Letter is concerned with impulsive control of a class of nonlinear time-delay systems. Some uniform stability criteria for the closed-loop time-delay system under delayed impulsive control are derived by using piecewise Lyapunov functions. Then the criteria are applied to impulsive master-slave synchronization of some secure communication systems with transmission delays and sample delays under delayed impulsive control. Two numerical examples are given to illustrate the effectiveness of the derived results

  8. Impulse generation by detonation tubes

    Science.gov (United States)

    Cooper, Marcia Ann

    Impulse generation with gaseous detonation requires conversion of chemical energy into mechanical energy. This conversion process is well understood in rocket engines where the high pressure combustion products expand through a nozzle generating high velocity exhaust gases. The propulsion community is now focusing on advanced concepts that utilize non-traditional forms of combustion like detonation. Such a device is called a pulse detonation engine in which laboratory tests have proven that thrust can be achieved through continuous cyclic operation. Because of poor performance of straight detonation tubes compared to conventional propulsion systems and the success of using nozzles on rocket engines, the effect of nozzles on detonation tubes is being investigated. Although previous studies of detonation tube nozzles have suggested substantial benefits, up to now there has been no systematic investigations over a range of operating conditions and nozzle configurations. As a result, no models predicting the impulse when nozzles are used exist. This lack of data has severely limited the development and evaluation of models and simulations of nozzles on pulse detonation engines. The first experimental investigation measuring impulse by gaseous detonation in plain tubes and tubes with nozzles operating in varying environment pressures is presented. Converging, diverging, and converging-diverging nozzles were tested to determine the effect of divergence angle, nozzle length, and volumetric fill fraction on impulse. The largest increases in specific impulse, 72% at an environment pressure of 100 kPa and 43% at an environment pressure of 1.4 kPa, were measured with the largest diverging nozzle tested that had a 12° half angle and was 0.6 m long. Two regimes of nozzle operation that depend on the environment pressure are responsible for these increases and were first observed from these data. To augment this experimental investigation, all data in the literature regarding

  9. Effects of cannabis on impulsivity: a systematic review of neuroimaging findings.

    Science.gov (United States)

    Wrege, Johannes; Schmidt, Andre; Walter, Anna; Smieskova, Renata; Bendfeldt, Kerstin; Radue, Ernst-Wilhelm; Lang, Undine E; Borgwardt, Stefan

    2014-01-01

    We conducted a systematic review to assess the evidence for specific effects of cannabis on impulsivity, disinhibition and motor control. The review had a specific focus on neuroimaging findings associated with acute and chronic use of the drug and covers literature published up until May 2012. Seventeen studies were identified, of which 13 met the inclusion criteria; three studies investigated acute effects of cannabis (1 fMRI, 2 PET), while six studies investigated non-acute functional effects (4 fMRI, 2 PET), and four studies investigated structural alterations. Functional imaging studies of impulsivity studies suggest that prefrontal blood flow is lower in chronic cannabis users than in controls. Studies of acute administration of THC or marijuana report increased brain metabolism in several brain regions during impulsivity tasks. Structural imaging studies of cannabis users found differences in reduced prefrontal volumes and white matter integrity that might mediate the abnormal impulsivity and mood observed in marijuana users. To address the question whether impulsivity as a trait precedes cannabis consumption or whether cannabis aggravates impulsivity and discontinuation of usage more longitudinal study designs are warranted.

  10. The relationship between impulsive choice and impulsive action: a cross-species translational study.

    Directory of Open Access Journals (Sweden)

    Nienke Broos

    Full Text Available Maladaptive impulsivity is a core symptom in various psychiatric disorders. However, there is only limited evidence available on whether different measures of impulsivity represent largely unrelated aspects or a unitary construct. In a cross-species translational study, thirty rats were trained in impulsive choice (delayed reward task and impulsive action (five-choice serial reaction time task paradigms. The correlation between those measures was assessed during baseline performance and after pharmacological manipulations with the psychostimulant amphetamine and the norepinephrine reuptake inhibitor atomoxetine. In parallel, to validate the animal data, 101 human subjects performed analogous measures of impulsive choice (delay discounting task, DDT and impulsive action (immediate and delayed memory task, IMT/DMT. Moreover, all subjects completed the Stop Signal Task (SST, as an additional measure of impulsive action and filled out the Barratt impulsiveness scale (BIS-11. Correlations between DDT and IMT/DMT were determined and a principal component analysis was performed on all human measures of impulsivity. In both rats and humans measures of impulsive choice and impulsive action did not correlate. In rats the within-subject pharmacological effects of amphetamine and atomoxetine did not correlate between tasks, suggesting distinct underlying neural correlates. Furthermore, in humans, principal component analysis identified three independent factors: (1 self-reported impulsivity (BIS-11; (2 impulsive action (IMT/DMT and SST; (3 impulsive choice (DDT. This is the first study directly comparing aspects of impulsivity using a cross-species translational approach. The present data reveal the non-unitary nature of impulsivity on a behavioral and pharmacological level. Collectively, this warrants a stronger focus on the relative contribution of distinct forms of impulsivity in psychopathology.

  11. IMPULSE---an advanced, high performance nuclear thermal propulsion system

    International Nuclear Information System (INIS)

    Petrosky, L.J.; Disney, R.K.; Mangus, J.D.; Gunn, S.A.; Zweig, H.R.

    1993-01-01

    IMPULSE is an advanced nuclear propulsion engine for future space missions based on a novel conical fuel. Fuel assemblies are formed by stacking a series of truncated (U, Zr)C cones with non-fueled lips. Hydrogen flows radially inward between the cones to a central plenum connected to a high performance bell nozzle. The reference IMPULSE engine rated at 75,000 lb thrust and 1800 MWt weighs 1360 kg and is 3.65 meters in height and 81 cm in diameter. Specific impulse is estimated to be 1000 for a 15 minute life at full power. If longer life times are required, the operating temperature can be reduced with a concomitant decrease in specific impulse. Advantages of this concept include: well defined coolant paths without outlet flow restrictions; redundant orificing; very low thermal gradients and hence, thermal stresses, across the fuel elements; and reduced thermal stresses because of the truncated conical shape of the fuel elements

  12. Buying Impulses: A Study on Impulsive Consumption

    NARCIS (Netherlands)

    Herabadi, A.G.

    2003-01-01

    This dissertation's objectives were to validate impulse buying tendency as a genuinely distinctive construct related to impulse purchase behavior and attached to fundamental personality traits, and its relationships to a number of relevant factors. Studies reported were steps to a better

  13. Impulsivity, Working Memory, and Impaired Control over Alcohol: A Latent Variable Analysis

    Science.gov (United States)

    Wardell, Jeffrey D.; Quilty, Lena C.; Hendershot, Christian S.

    2017-01-01

    Impaired control over alcohol is an important risk factor for heavy drinking among young adults and may mediate, in part, the association between personality risk and alcohol problems. Research suggests that trait impulsivity is associated with impaired control over alcohol; however, few studies of this association have included a range of impulsivity facets. The purpose of this study was to examine specific pathways from higher-order impulsivity factors to alcohol problems mediated via impaired control over alcohol. We also examined the moderating role of working memory in these associations. Young heavy drinkers (N=300) completed two multidimensional impulsivity measures (UPPS-P and BIS-11) along with self-report measures of impaired control over alcohol, alcohol use, and alcohol problems. Working memory was assessed using a computerized digit span task. Results showed that the impulsivity facets loaded onto two higher-order factors that were labeled response and reflection impulsivity. Response impulsivity predicted unique variance in self-reported impaired control and alcohol problems, whereas reflection impulsivity predicted unique variance in heavy drinking frequency only. Further, significant indirect associations were observed from response and reflection impulsivity to alcohol problems mediated via impaired control and heavy drinking frequency, respectively. Working memory and sensation seeking were not uniquely associated with the alcohol variables, and no support was found for the moderating role of working memory. The results help to clarify associations among impulsivity, impaired control, and alcohol problems, suggesting that impaired control may play a specific role in the pathway to alcohol problems from response impulsivity but not from reflection impulsivity. PMID:27269291

  14. Impulsive and non-impulsive suicide attempts in patients treated for alcohol dependence.

    Science.gov (United States)

    Wojnar, Marcin; Ilgen, Mark A; Czyz, Ewa; Strobbe, Stephen; Klimkiewicz, Anna; Jakubczyk, Andrzej; Glass, Jennifer; Brower, Kirk J

    2009-05-01

    Suicidal behavior has been recognized as an increasing problem among alcohol-dependent subjects. The aim of the study was to identify correlates of impulsive and non-impulsive suicide attempts among a treated population of alcohol-dependent patients. A total of 154 patients with alcohol dependence consecutively admitted for addiction treatment participated in the study. Suicidal behavior was assessed together with severity of alcohol dependence, childhood abuse, impulsivity, and family history. A stop-signal procedure was used as a behavioral measure of impulsivity. Lifetime suicide attempts were reported by 43% of patients in alcohol treatment; of which 62% were impulsive. Compared to patients without a suicide attempt, those with a non-impulsive attempt were more likely to have a history of sexual abuse (OR=7.17), a family history of suicide (OR=4.09), and higher scores on a personality measure of impulsiveness (OR=2.27). The only significant factor that distinguished patients with impulsive suicide attempts from patients without a suicide attempt and from patients with a non-impulsive suicide attempt was a higher level of behavioral impulsivity (OR=1.84-2.42). Retrospective self-report of suicide attempts and family history. Lack of diagnostic measure.

  15. Laser impulse coupling at 130 fs

    International Nuclear Information System (INIS)

    Phipps, C.; Luke, J.; Funk, D.; Moore, D.; Glownia, J.; Lippert, T.

    2006-01-01

    We measured the momentum coupling coefficient C m and laser-generated ion drift velocity and temperature in the femtosecond (fs) region, over a laser intensity range from ablation threshold to about one hundred times threshold. Targets were several pure metals and three organic compounds. The organic compounds were exothermic polymers specifically developed for the micro-laser plasma thruster, and two of these used 'tuned absorbers' rather than carbon particles for laser absorption. The metals ranged from Li to W in atomic weight. We measured time of flight (TOF) profiles for ions. Specific impulse reached record values for this type of measurement and ablation efficiency was near 100%. These measurements extend the laser pulsewidth three orders of magnitude downward in pulsewidth relative to previous reports. Over this range, we found C m to be essentially constant. Ion velocity ranged from 60 to 180 km/s

  16. Individual differences in impulsivity predict anticipatory eye movements.

    Directory of Open Access Journals (Sweden)

    Laetitia Cirilli

    Full Text Available Impulsivity is the tendency to act without forethought. It is a personality trait commonly used in the diagnosis of many psychiatric diseases. In clinical practice, impulsivity is estimated using written questionnaires. However, answers to questions might be subject to personal biases and misinterpretations. In order to alleviate this problem, eye movements could be used to study differences in decision processes related to impulsivity. Therefore, we investigated correlations between impulsivity scores obtained with a questionnaire in healthy subjects and characteristics of their anticipatory eye movements in a simple smooth pursuit task. Healthy subjects were asked to answer the UPPS questionnaire (Urgency Premeditation Perseverance and Sensation seeking Impulsive Behavior scale, which distinguishes four independent dimensions of impulsivity: Urgency, lack of Premeditation, lack of Perseverance, and Sensation seeking. The same subjects took part in an oculomotor task that consisted of pursuing a target that moved in a predictable direction. This task reliably evoked anticipatory saccades and smooth eye movements. We found that eye movement characteristics such as latency and velocity were significantly correlated with UPPS scores. The specific correlations between distinct UPPS factors and oculomotor anticipation parameters support the validity of the UPPS construct and corroborate neurobiological explanations for impulsivity. We suggest that the oculomotor approach of impulsivity put forth in the present study could help bridge the gap between psychiatry and physiology.

  17. Linking Y‐chromosomal short tandem repeat loci to human male impulsive aggression

    OpenAIRE

    Yang, Chun; Ba, Huajie; Cao, Yin; Dong, Guoying; Zhang, Shuyou; Gao, Zhiqin; Zhao, Hanqing; Zhou, Xianju

    2017-01-01

    Abstract Introduction Men are more susceptible to impulsive behavior than women. Epidemiological studies revealed that the impulsive aggressive behavior is affected by genetic factors, and the male‐specific Y chromosome plays an important role in this behavior. In this study, we investigated the association between the impulsive aggressive behavior and Y‐chromosomal short tandem repeats (Y‐STRs) loci. Methods The collected biologic samples from 271 offenders with impulsive aggressive behavior...

  18. Effects of Cannabis on Impulsivity: A Systematic Review of Neuroimaging Findings

    Science.gov (United States)

    Wrege, Johannes; Schmidt, André; Walter, Anna; Smieskova, Renata; Bendfeldt, Kerstin; Radue, Ernst-Wilhelm; Lang, Undine E.; Borgwardt, Stefan

    2014-01-01

    We conducted a systematic review to assess the evidence for specific effects of cannabis on impulsivity, disinhibition and motor control. The review had a specific focus on neuroimaging findings associated with acute and chronic use of the drug and covers literature published up until May 2012. Seventeen studies were identified, of which 13 met the inclusion criteria; three studies investigated acute effects of cannabis (1 fMRI, 2 PET), while six studies investigated non-acute functional effects (4 fMRI, 2 PET), and four studies investigated structural alterations. Functional imaging studies of impulsivity studies suggest that prefrontal blood flow is lower in chronic cannabis users than in controls. Studies of acute administration of THC or marijuana report increased brain metabolism in several brain regions during impulsivity tasks. Structural imaging studies of cannabis users found differences in reduced prefrontal volumes and white matter integrity that might mediate the abnormal impulsivity and mood observed in marijuana users. To address the question whether impulsivity as a trait precedes cannabis consumption or whether cannabis aggravates impulsivity and discontinuation of usage more longitudinal study designs are warranted. PMID:23829358

  19. Effects of Acute Tryptophan Depletion on Three Different Types of Behavioral Impulsivity

    Directory of Open Access Journals (Sweden)

    Donald M. Dougherty

    2010-01-01

    Full Text Available Introduction While central nervous system serotonin has been implicated in a variety of problematic impulsive behaviors, biological manipulation of brain serotonin using acute tryptophan depletion for studying changes in impulsive behavior has received little attention. Methods Using identical treatment conditions, we examined the effects of reduced serotonin synthesis for each of three matched groups using acute tryptophan depletion. Thirty healthy men and women (ages 18–45 were assigned to perform one of three tasks assessing different types of behavioral impulsivity: response initiation, response inhibition, and consequence sensitivity ( N = 90. Participants completed two experimental days during which each consumed either a tryptophan-depletion or balanced-placebo amino-acid formulation and completed 5 sessions of their respective tasks at 0.25 h before and 1.5, 4.0, 5.0, and 6.0 h after beverage consumption. Results During peak effectiveness (5.0 h to 6.0 h following amino-acid consumption, depletion produced selective differences dependent on the type of impulsivity being tested. Specifically, relative to baseline testing (pre-depletion, response initiation impulsivity was significantly increased during the peak effects of depletion. And, when compared to placebo control, both response initiation and consequence sensitivity impulsivity were increased during the peak effects of depletion. Conclusion Though response initiation and consequence sensitivity impulsivity were affected by tryptophan depletion, response inhibition impulsivity was not, suggesting that other biological processes may underlie this specific component of impulsivity. Future research in other populations or using different pharmacological agents is warranted to further examine the biological processes underlying these components of impulsivity.

  20. Effects of Acute Tryptophan Depletion on Three Different Types of Behavioral Impulsivity

    Directory of Open Access Journals (Sweden)

    Donald M. Dougherty

    2010-06-01

    Full Text Available Introduction: While central nervous system serotonin has been implicated in a variety of problematic impulsive behaviors, biological manipulation of brain serotonin using acute tryptophan depletion for studying changes in impulsive behavior has received little attention. Methods: Using identical treatment conditions, we examined the effects of reduced serotonin synthesis for each of three matched groups using acute tryptophan depletion. Thirty healthy men and women (ages 18–45 were assigned to perform one of three tasks assessing different types of behavioral impulsivity: response initiation, response inhibition, and consequence sensitivity (N = 90. Participants completed two experimental days during which each consumed either a tryptophan-depletion or balanced-placebo amino-acid formulation and completed 5 sessions of their respective tasks at 0.25 h before and 1.5, 4.0, 5.0, and 6.0 h after beverage consumption. Results: During peak effectiveness (5.0 h to 6.0 h following amino-acid consumption, depletion produced selective differences dependent on the type of impulsivity being tested. Specifically, relative to baseline testing (pre-depletion, response initiation impulsivity was significantly increased during the peak effects of depletion. And, when compared to placebo control, both response initiation and consequence sensitivity impulsivity were increased during the peak effects of depletion. Conclusion: Though response initiation and consequence sensitivity impulsivity were affected by tryptophan depletion, response inhibition impulsivity was not, suggesting that other biological processes may underlie this specific component of impulsivity. Future research in other populations or using different pharmacological agents is warranted to further examine the biological processes underlying these components of impulsivity.

  1. Materialism moderates the impact of mortality salience on impulsive tendencies toward luxury brands.

    Science.gov (United States)

    Audrin, Catherine; Cheval, Boris; Chanal, Julien

    2018-02-01

    Luxury goods have been shown to help individuals coping with death-related anxiety. However, the extent to which the symbolic value allocated to possessions (i.e., materialism) moderates this effect is still unclear. Here, we investigated the impact of materialism on impulsive approach tendencies toward luxury clothing brands in a context of mortality salience. Results showed that the impact of mortality salience was moderated by materialism with lower impulsive approach tendencies toward luxury clothing brands observed in non-materialistic participants. These findings highlight how materialism values may impact luxury consumption through impulsive pathways in a situation of death-related anxiety.

  2. Campground marketing - the impulse camper

    Science.gov (United States)

    Wilbur F. LaPage; Dale P. Ragain

    1972-01-01

    Impulse or unplanned campground visits may account for one-fourth to one-half of all camping activity. The concepts of impulse travel and impulse camping appear to be potentially useful extensions of the broader concept of impulse purchasing, which has become an important influence in retail marketing. Impulse campers may also be impulse buyers; they were found to...

  3. Impulse-Excited Energy Harvester based on Potassium-Ion- Electret

    Science.gov (United States)

    Ashizawa, H.; Mitsuya, H.; Ishibashi, K.; Ishikawa, T.; Fujita, H.; Hashiguchi, G.; Toshiyoshi, H.

    2015-12-01

    We have developed an energy harvester that is specifically desired for impulse acceleration of infrastructure vibrations such as sudden motion at railway bridges. The energy harvester based on potassium-ion-electret on the sidewalls of 1.8- μm-gap comb electrodes generated a 64 μAp-p current during low impulse acceleration, which was large enough to light a green LED.

  4. Trait impulsivity and impaired prefrontal impulse inhibition function in adolescents with internet gaming addiction revealed by a Go/No-Go fMRI study.

    Science.gov (United States)

    Ding, Wei-na; Sun, Jin-hua; Sun, Ya-Wen; Chen, Xue; Zhou, Yan; Zhuang, Zhi-guo; Li, Lei; Zhang, Yong; Xu, Jian-rong; Du, Ya-song

    2014-05-30

    Recent studies suggest that Internet gaming addiction (IGA) is an impulse disorder, or is at least related to impulse control disorders. In the present study, we hypothesized that different facets of trait impulsivity may be specifically linked to the brain regions with impaired impulse inhibition function in IGA adolescents. Seventeen adolescents with IGA and seventeen healthy controls were scanned during performance of a response-inhibition Go/No-Go task using a 3.0 T MRI scanner. The Barratt Impulsiveness Scale (BIS)-11 was used to assess impulsivity. There were no differences in the behavioral performance on the Go/No-Go task between the groups. However, the IGA group was significantly hyperactive during No-Go trials in the left superior medial frontal gyrus, right anterior cingulate cortex, right superior/middle frontal gyrus, left inferior parietal lobule, left precentral gyrus, and left precuneus and cuneus. Further, the bilateral middle temporal gyrus, bilateral inferior temporal gyrus, and right superior parietal lobule were significantly hypoactive during No-Go trials. Activation of the left superior medial frontal gyrus was positively associated with BIS-11 and Chen Internet Addiction Scale (CIAS) total score across IGA participants. Our data suggest that the prefrontal cortex may be involved in the circuit modulating impulsivity, while its impaired function may relate to high impulsivity in adolescents with IGA, which may contribute directly to the Internet addiction process.

  5. Recreational drug use and impulsivity in a population of Canadian undergraduate drinkers

    Directory of Open Access Journals (Sweden)

    Iris M Balodis

    2010-10-01

    Full Text Available The consumption of drugs during young adulthood may be particularly detrimental given important neurodevelopmental changes occurring during this period. As impulsivity may lead to substance use and substance use to the commission of seemingly impulsive acts, an improved understanding of the relationship between alcohol use, other substance use and impulsivity in young adults is important. We gathered information on self-reported impulsivity, recreational drug use, and drinking habits of 205 (105 female undergraduate students. Results showed that 64% of the students reported using marijuana at least once and these individuals were more likely to report binge drinking. Polydrug use, defined as using marijuana and at least one other illicit substance, was reported by 20% of students. These individuals reported more drinking occasions per month and had higher levels of trait impulsivity. Rates of recreational drug use were similar to those reported in recent national surveys, suggesting an increase in experimentation with specific illicit drugs. Given that a majority of undergraduate drinkers reported marijuana use and its association with binge drinking, future research should clarify the relationship between marijuana use and binge consumption of alcohol and prevention efforts should consider the conjoint targeting of marijuana and binge drinking. The associations between polydrug use, binge-level alcohol consumption and elevated self-reported impulsivity suggests that perceived trait impulsivity across multiple domains may predispose to excessive use of multiple substances. Longitudinal studies should examine the contribution of impulsivity to the initiation and experimentation with illicit drugs and the influence of specific substances on impulsivity.

  6. On Impulsive Boundary Value Problems of Fractional Differential Equations with Irregular Boundary Conditions

    Directory of Open Access Journals (Sweden)

    Guotao Wang

    2012-01-01

    Full Text Available We study nonlinear impulsive differential equations of fractional order with irregular boundary conditions. Some existence and uniqueness results are obtained by applying standard fixed-point theorems. For illustration of the results, some examples are discussed.

  7. Impulsivity and self-harm in adolescence: a systematic review.

    Science.gov (United States)

    Lockwood, Joanna; Daley, David; Townsend, Ellen; Sayal, Kapil

    2017-04-01

    Research supports an association between impulsivity and self-harm, yet inconsistencies in methodology across studies have complicated understanding of this relationship. This systematic review examines the association between impulsivity and self-harm in community-based adolescents aged 11-25 years and aims to integrate findings according to differing concepts and methods. Electronic searches of EMBASE, MEDLINE, PsychINFO, CINAHL, PubMed and The Cochrane Library, and manual searches of reference lists of relevant reviews identified 4496 articles published up to July 2015, of which 28 met inclusion criteria. Twenty-four of the studies reported an association between broadly specified impulsivity and self-harm. However, findings varied according to the conception and measurement of impulsivity and the precision with which self-harm behaviours were specified. Specifically, lifetime non-suicidal self-injury was most consistently associated with mood-based impulsivity-related traits. However, cognitive facets of impulsivity (relating to difficulties maintaining focus or acting without forethought) differentiated current self-harm from past self-harm. These facets also distinguished those with thoughts of self-harm (ideation) from those who acted on thoughts (enaction). The findings suggested that mood-based impulsivity is related to the initiation of self-harm, while cognitive facets of impulsivity are associated with the maintenance of self-harm. In addition, behavioural impulsivity is most relevant to self-harm under conditions of negative affect. Collectively, the findings indicate that distinct impulsivity facets confer unique risks across the life-course of self-harm. From a clinical perspective, the review suggests that interventions focusing on reducing rash reactivity to emotions or improving self-regulation and decision making may offer most benefit in supporting those who self-harm.

  8. Temperament and impulsivity predictors of smoking cessation outcomes.

    Directory of Open Access Journals (Sweden)

    Francisca López-Torrecillas

    respectively. CONCLUSION: Temperament measures, and specifically novelty seeking and reward dependence, predict smoking cessation treatment retention, whereas persistence, non-planning impulsivity and poor decision-making predict smoking relapse.

  9. Sensation-seeking and impulsivity as predictors of reactive and proactive aggression

    Directory of Open Access Journals (Sweden)

    María Del Carmen Pérez Fuentes

    2016-09-01

    Full Text Available In adolescence, such matters as substance use and impulsiveness may give rise to problematic behavior repertoires. This study was therefore done to analyze the predictive value of sensation-seeking and impulsiveness dimensions related to the functions of aggression (reactive/proactive and types of expression (physical/relational. A total of 822 high school students in Almeria (Spain aged 13 to 18, were administered the Sensation-Seeking Scale, the State Impulsiveness Scale and Peer Conflict Scale. The results show the existence of a positive correlation of the majority of factors analyzed, both in impulsiveness and sensation-seeking, with respect to the different types of aggression. Furthermore, aggressive behavior is explained by the combination of a sensation-seeking factor (Disinhibition and two impulsiveness factors (Gratification and Automatism. This study shows the need to analyze aggression as a multidimensional construct.

  10. Dynamic complexities of a Holling II two-prey one-predator system with impulsive effect

    International Nuclear Information System (INIS)

    Song Xinyu; Li Yongfeng

    2007-01-01

    In this paper, we investigate the dynamic behaviors of a Holling II two-prey one-predator system with impulsive effect concerning biological control and chemical control strategies-periodic releasing natural enemies and spraying pesticide (or harvesting pests) at fixed time. By using the Floquet theory of linear periodic impulsive equation and small-amplitude perturbation we show that there exists a globally asymptotically stable two-prey eradication periodic solution when the impulsive period is less than some critical value. Further, we prove that the system is permanent if the impulsive period is larger than some critical value, and meanwhile the conditions for the extinction of one of the two prey and permanence of the remaining two species are given. Finally, numerical simulation shows that there exists a stable positive periodic solution with a maximum value no larger than a given level. Thus, we can use the stability of the positive periodic solution and its period to control insect pests at acceptably low levels

  11. Determination of poles and zeroes using SAVOSIM for digital impulse-shaping

    International Nuclear Information System (INIS)

    Mohamad Idris Taib; Abu Bakar Ghazali; Salina Abdul Samad; Azah Mohamed

    2002-01-01

    Digital impulse pulse-shaping can be used to correct the pile-up for pulse-height (Energy) analyzer because of its fast processing speed. In this initial work on digital impulse pulse-shaping, a study is made on the input signals obtained from combination of preamplifier and prefilter of nuclear instrumentation with specific and general transfer function. Three types of pulses that are commonly produced by a nuclear detection preamplifier and prefilter are used for this application. For the determination of zeros and poles in z-transform, the summation of absolute value of output signal is minimum (SAVOSIM) method is used. Simulations for this type of signal are carried out using the MATLAB software and the TMS320C6701 evaluation module and the results are presented in this paper. Initial results show that the method can be expanded to design and develop for a nuclear spectroscopy based on digital signal processor. (Author)

  12. Pathological gambling: an impulse control disorder? Measurement of impulsivity using neurocognitive tests.

    Science.gov (United States)

    Dannon, Pinhas N; Shoenfeld, Netta; Rosenberg, Oded; Kertzman, Semion; Kotler, Moshe

    2010-04-01

    Pathological gambling is classified in the DSM-IV-TR (Diagnostic and Statistical Manual of Mental Disorders) and in the ICD-10 (International Classification of Disease) as an impulse control disorder. The association between impulsivity and pathological gambling remains a matter of debate: some researchers find high levels of impulsivity within pathological gamblers, others report no difference compared to controls, and yet others even suggest that it is lower. In this review we examine the relationship between pathological gambling and impulsivity assessed by various neurocognitive tests. These tests--the Stroop task, the Stop Signal Task, the Matching Familiar Figures Task, the Iowa Gambling Task, the Wisconsin Card Sorting Test, the Tower of London test, and the Continuous Performance Test--demonstrated less impulsivity in gambling behavior. The differences in performance between pathological gamblers and healthy controls on the neurocognitive tasks could be due to addictive behavior features rather than impulsive behavior.

  13. Impulse noise estimation and removal for OFDM systems

    KAUST Repository

    Al-Naffouri, Tareq Y.

    2014-03-01

    Orthogonal Frequency Division Multiplexing (OFDM) is a modulation scheme that is widely used in wired and wireless communication systems. While OFDM is ideally suited to deal with frequency selective channels and AWGN, its performance may be dramatically impacted by the presence of impulse noise. In fact, very strong noise impulses in the time domain might result in the erasure of whole OFDM blocks of symbols at the receiver. Impulse noise can be mitigated by considering it as a sparse signal in time, and using recently developed algorithms for sparse signal reconstruction. We propose an algorithm that utilizes the guard band subcarriers for the impulse noise estimation and cancellation. Instead of relying on ℓ1 minimization as done in some popular general-purpose compressive sensing schemes, the proposed method jointly exploits the specific structure of this problem and the available a priori information for sparse signal recovery. The computational complexity of the proposed algorithm is very competitive with respect to sparse signal reconstruction schemes based on ℓ1 minimization. The proposed method is compared with respect to other state-of-the-art methods in terms of achievable rates for an OFDM system with impulse noise and AWGN. © 2014 IEEE.

  14. Impulse noise estimation and removal for OFDM systems

    KAUST Repository

    Al-Naffouri, Tareq Y.; Quadeer, Ahmed Abdul; Caire, Giuseppe

    2014-01-01

    Orthogonal Frequency Division Multiplexing (OFDM) is a modulation scheme that is widely used in wired and wireless communication systems. While OFDM is ideally suited to deal with frequency selective channels and AWGN, its performance may be dramatically impacted by the presence of impulse noise. In fact, very strong noise impulses in the time domain might result in the erasure of whole OFDM blocks of symbols at the receiver. Impulse noise can be mitigated by considering it as a sparse signal in time, and using recently developed algorithms for sparse signal reconstruction. We propose an algorithm that utilizes the guard band subcarriers for the impulse noise estimation and cancellation. Instead of relying on ℓ1 minimization as done in some popular general-purpose compressive sensing schemes, the proposed method jointly exploits the specific structure of this problem and the available a priori information for sparse signal recovery. The computational complexity of the proposed algorithm is very competitive with respect to sparse signal reconstruction schemes based on ℓ1 minimization. The proposed method is compared with respect to other state-of-the-art methods in terms of achievable rates for an OFDM system with impulse noise and AWGN. © 2014 IEEE.

  15. On the Impulsive Synchronization Control for a Class of Chaotic Systems

    Directory of Open Access Journals (Sweden)

    Bo Wang

    2014-01-01

    Full Text Available The problem on chaos synchronization for a class of chaotic system is addressed. Based on impulsive control theory and by constructing a novel Lyapunov functional, new impulsive synchronization strategies are presented and possess more practical application value. Finally some typical numerical simulation examples are included to demonstrate the effectiveness of the theoretical results.

  16. Triple positive  solutions of nth order impulsive integro-differential equations

    Directory of Open Access Journals (Sweden)

    Zeyong Qiu

    2011-07-01

    Full Text Available In this paper, we prove the existence of at least three positive solutions of boundary value problems for nth order nonlinear impulsive integro-differential equations of mixed type on infinite interval with infinite number of impulsive times. Our results are obtained by applying a new fixed point theorem introduced by Avery and Peterson.

  17. Imaging impulse control disorders in Parkinson's disease and their relationship to addiction.

    Science.gov (United States)

    Ray, Nicola J; Strafella, Antonio P

    2013-04-01

    Established substance addictions and impulse control disorders (ICDs) such as pathological gambling share similar underlying neurobiology, and recent data extends these commonalities to the risk factors that increase an individuals' susceptibility to develop such behaviours. In Parkinson's disease (PD), impulse control disorders (ICDs) are increasingly recognised to develop after patients begin dopamine (DA) restoration therapy, in particular DA agonists. In both the PD and non-PD population, more impulsive individuals are at increased risk for impulse control disorders. Here, we review the neuroimaging data confirming the connection between addiction and ICDs, and revealing how DA agonists might cause specific alterations of basal ganglia and cortical function that vary as a function of an individuals' propensity for impulsivity.

  18. Fusion impulse containment

    International Nuclear Information System (INIS)

    Bohachevsky, I.O.

    1979-01-01

    The characteristics of impact fusion energy releases are not known sufficiently well to examine in detail specific containment vessel concepts or designs. Therefore it appears appropriate to formulate the impulse containment problem in general and to derive results in the form of explicit expressions from which magnitude estimates and parametric dependencies (trends) can be inferred conveniently and rapidly. In the following presentation we carry out this task using assumptions and approximations that are required to perform the analysis

  19. Improving Inhibitory Control Abilities (ImpulsE)-A Promising Approach to Treat Impulsive Eating?

    Science.gov (United States)

    Preuss, Hanna; Pinnow, Marlies; Schnicker, Katja; Legenbauer, Tanja

    2017-11-01

    Although there is preliminary evidence that inhibitory control training improves impulsive eating, less is known about the effects on eating behaviour and weight loss in clinical samples. Sixty-nine treatment-seeking adults with obesity (binge-eating disorder 33.3%; other specific feeding and eating disorders 40.6%) were randomly blockwise allocated to ImpulsE, an intervention to improve inhibitory control and emotion regulation abilities or a guideline-appropriate cognitive behavioural therapy (CBT)-based treatment as usual. Self-reported and performance-based impulsivity, eating disorder pathology and BMI were compared at baseline (T1), post-treatment (T2) and 1- or 3-month follow-up. ImpulsE led to better food-specific inhibition performance (p = .004), but groups did not differ regarding improvements in global Eating Disorder Examination Questionnaire (EDE-Q) score at T2. At 3-month follow-up, binge eaters benefited most from ImpulsE (p = .028) and completers of ImpulsE demonstrated a significantly greater weight reduction (p = .030). The current findings propose ImpulsE as a promising approach to treat obesity, illustrating acceptability and additional benefits for course of weight. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.

  20. [Association of loneliness, impulsivity and alcohol use with suicidal behavior in adolescents].

    Science.gov (United States)

    Salvo G, Lilian; Castro S, Andrea

    2013-04-01

    Suicide and suicide attempts are public health problems. Their prevention requives the detection of predictor factors. To determine the predictive valué of loneliness, impulsivity and alcohol use on suicidal behavior in adolescents. Suicidal behavior, Loneliness (UCLA), Impulsivity (Barratt) scales and the Alcohol Use Disorders Identification Test (AUDIT), were applied to 763 high school students aged 14 to 19 years (49% males), living in Chillan, Chile. Nineteen percent of participants had attempted suicide and 34.3% had suicidal ideation. Loneliness, impulsivity and alcohol use were directly related to suicidal behavior. These predictors explained 31 % of the suicidal behavior. The most important risk factor was loneliness, followed by femóle gender, impulsivity and alcohol use. Loneliness, impulsivity and alcohol use are risk factors for suicide among adolescents. Women are at higher risk than men.

  1. Integrative Understanding of Familial Impulsivity, Early Adversity and Suicide Risk

    Directory of Open Access Journals (Sweden)

    Isabela M. M. Lima

    2017-12-01

    Full Text Available Introduction: Impulsivity is a core characteristic of bipolar disorder and it was observed as elevated in individuals with the disorder and in their relatives. Both impulsivity and history of maltreatment are risk factors for suicide attempts, however, these two key variables may not be independent, given the fact that parental impulsivity and associated social context could increase the risk of child maltreatment. In this study it was examined the association between the impulsivity of relatives and child maltreatment taking into consideration the conjoint and unique effects of these two variables on the risk of suicide attempts among the patients.Materials and Methods: Participants of the study consisted of 117 patients diagnosed with bipolar disorder and 25 first-degree relatives. Linear regression model was conducted to describe associations between facets of impulsivity of relatives and levels of child maltreatment reported by patients. The independent associations of suicide attempt history with the dimensions of impulsivity of the patient and maltreatment were tested by multinomial logistic regression.Results: Impulsivity of relatives and, more specifically, inhibitory control can predict the maltreatment of the patient. Inhibitory control and emotional abuse were related, conjointly, to a greater likelihood of having a history of more than one suicide attempt.Discussion: Considering that the impulsivity of relatives predicts child maltreatment, it is possible that a genetically shared impulsivity is an underlying feature associated with the history of multiple suicide attempts. These findings highlight the importance of considering child maltreatment, impulsivity and suicide attempt history in integrative models.

  2. Integrative Understanding of Familial Impulsivity, Early Adversity and Suicide Risk.

    Science.gov (United States)

    Lima, Isabela M M; Malloy-Diniz, Leandro F; de Miranda, Débora M; Da Silva, Antônio G; Neves, Fernando S; Johnson, Sheri L

    2017-01-01

    Introduction: Impulsivity is a core characteristic of bipolar disorder and it was observed as elevated in individuals with the disorder and in their relatives. Both impulsivity and history of maltreatment are risk factors for suicide attempts, however, these two key variables may not be independent, given the fact that parental impulsivity and associated social context could increase the risk of child maltreatment. In this study it was examined the association between the impulsivity of relatives and child maltreatment taking into consideration the conjoint and unique effects of these two variables on the risk of suicide attempts among the patients. Materials and Methods: Participants of the study consisted of 117 patients diagnosed with bipolar disorder and 25 first-degree relatives. Linear regression model was conducted to describe associations between facets of impulsivity of relatives and levels of child maltreatment reported by patients. The independent associations of suicide attempt history with the dimensions of impulsivity of the patient and maltreatment were tested by multinomial logistic regression. Results: Impulsivity of relatives and, more specifically, inhibitory control can predict the maltreatment of the patient. Inhibitory control and emotional abuse were related, conjointly, to a greater likelihood of having a history of more than one suicide attempt. Discussion: Considering that the impulsivity of relatives predicts child maltreatment, it is possible that a genetically shared impulsivity is an underlying feature associated with the history of multiple suicide attempts. These findings highlight the importance of considering child maltreatment, impulsivity and suicide attempt history in integrative models.

  3. Impulsivity in borderline personality disorder: a matter of disturbed impulse control or a facet of emotional dysregulation?

    Science.gov (United States)

    Sebastian, Alexandra; Jacob, Gitta; Lieb, Klaus; Tüscher, Oliver

    2013-02-01

    Impulsivity is regarded as a clinical, diagnostic and pathophysiological hallmark of borderline personality disorder (BPD). Self-report measures of impulsivity consistently support the notion of higher impulsive traits in BPD patients as compared to healthy control subjects. Laboratory tests of impulsivity, i.e. neuropsychological tests of impulse control render weak and inconsistent results both across different cognitive components of impulse control and within the same cognitive component of impulse control. One important factor worsening impulsive behaviors and impulse control deficits in BPD is comorbid attention-deficit/hyperactivity disorder (ADHD). In addition, emotional dysregulation interacts with impulse control especially for BPD salient emotions. In sum, although basic mechanisms of impulse control seem not to be disturbed in BPD, clinically well observed impulsive behaviors may be explained by comorbid ADHD or may be the consequence of dysregulation of BPD salient emotions.

  4. Impulsive suicide attempts: a systematic literature review of definitions, characteristics and risk factors.

    Science.gov (United States)

    Rimkeviciene, Jurgita; O'Gorman, John; De Leo, Diego

    2015-01-15

    Extensive research on impulsive suicide attempts, but lack of agreement on the use of this term indicates the need for a systematic literature review of the area. The aim of this review was to examine definitions and likely correlates of impulsive attempts. A search of Medline, Psychinfo, Scopus, Proquest and Web of Knowledge databases was conducted. Additional articles were identified using the cross-referencing function of Google Scholar. 179 relevant papers were identified. Four different groups of research criteria used to assess suicide attempt impulsivity emerged: (a) time-related criteria, (b) absence of proximal planning/preparations, (c) presence of suicide plan in lifetime/previous year, and (d) other. Subsequent analysis used these criteria to compare results from different studies on 20 most researched hypotheses. Conclusions regarding the characteristics of impulsive attempts are more consistent than those on the risk factors specific to such attempts. No risk factors were identified that uniformly related to suicide attempt impulsivity across all criteria groups, but relationships emerged between separate criteria and specific characteristics of suicide attempters. Only published articles were included. Large inconsistencies in methods of the studies included in this review prevented comparison of effect sizes. The vast disparities in findings on risk factors for impulsive suicide attempts among different criteria groups suggest the need to address the methodological issues in defining suicide attempt impulsivity before further research into correlates of such attempts can effectively progress. Specific recommendations are offered for necessary research. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Impulsivity and Gambling Type Among Treatment-Seeking Disordered Gamblers: An Explorative Study.

    Science.gov (United States)

    Lutri, Vittorio; Soldini, Emiliano; Ronzitti, Silvia; Smith, Neil; Clerici, Massimo; Blaszczynski, Alex; Bowden-Jones, Henrietta

    2018-03-03

    Several studies have found that certain traits of impulsivity are associated with gambling disorder, and influence its severity. Furthermore, it has been suggested that some forms of gambling, particularly electronic gambling machines, are particularly widespread among pathological gamblers. In the present, exploratory study, we aim to clarify the role played by impulsivity in influencing the choice of specific gambling activities, by examining the relation between individual dimensions of impulsivity, and the choice of specific gambling activities in a clinical population. 100 consecutively admitted pathological gamblers at the National Problem Gambling Clinic in London (UK) in 2014 were administered the UPPS-P and BIS-11 impulsivity questionnaires, the Problem Gambling Severity Index, and underwent a structured interview concerning their gambling activities in the month and year prior to assessment. The correlation between individual gambling activities and impulsivity dimensions was analyzed both at a bivariate level, and using logistic regression. We found a significant correlation between Negative Urgency, Motor impulsivity and low-stakes machine gambling on multivariate analysis. Negative urgency (i.e. the tendency to act impulsively in response to negative affect), and Motor impulsivity (a tendency to rash action and restlessness) might be mediating factors in the choice of electronic gambling machines, particularly among patients whose gambling is escape-oriented. Structural and situational characteristics of gambling machines, particularly the widespread availability of low-stakes-rather than high-stakes-gaming machines, might concur to the choice of this form of gambling among individuals who present higher negative urgency and restlessness.

  6. Sex differences in impulsivity and brain morphometry in methamphetamine users.

    Science.gov (United States)

    Kogachi, Shannon; Chang, Linda; Alicata, Daniel; Cunningham, Eric; Ernst, Thomas

    2017-01-01

    Methamphetamine (METH) is an addictive stimulant, and METH users have abnormal brain structures and function. The aims of this study were to investigate the relationships between impulsivity, brain structures, and possible sex-specific differences between METH users and non-drug using Controls. Structural MRI and the Barratt Impulsiveness Scale (BIS) questionnaire were completed in 124 subjects: 62 METH (ages 41.2 ± 1.4 years, 34 males) and 62 Controls (ages 43.3 ± 2.3 years, 36 males). Independent and interactive effects of METH use status and sex were evaluated. Relationships between METH usage characteristics, brain morphometry, and impulsivity scores were examined. METH users had higher impulsivity scores, on both the Cognitive and Behavioral Factors from the BIS (p impulsivity (interaction-p ≤ 0.05). Only female METH users showed relatively larger nucleus accumbens (interaction-p = 0.03). Greater impulsivity and thinner frontal cortices in METH users are validated. Larger superior frontal cortex in male METH users with greater cognitive impulsivity suggest decreased dendritic pruning during adolescence might have contributed to their impulsive and drug use behaviors. In the female METH users, smaller frontal cortices and the associated greater impulsivity suggest greater neurotoxicity to these brain regions, while their relatively larger nucleus accumbens suggest an estrogen-mediated neuroprotective glial response. Men and women may be affected differently by METH use.

  7. Linking Y-chromosomal short tandem repeat loci to human male impulsive aggression.

    Science.gov (United States)

    Yang, Chun; Ba, Huajie; Cao, Yin; Dong, Guoying; Zhang, Shuyou; Gao, Zhiqin; Zhao, Hanqing; Zhou, Xianju

    2017-11-01

    Men are more susceptible to impulsive behavior than women. Epidemiological studies revealed that the impulsive aggressive behavior is affected by genetic factors, and the male-specific Y chromosome plays an important role in this behavior. In this study, we investigated the association between the impulsive aggressive behavior and Y-chromosomal short tandem repeats (Y-STRs) loci. The collected biologic samples from 271 offenders with impulsive aggressive behavior and 492 healthy individuals without impulsive aggressive behavior were amplified by PowerPlex R Y23 PCR System and the resultant products were separated by electrophoresis and further genotyped. Then, comparisons in allele and haplotype frequencies of the selected 22 Y-STRs were made in the two groups. Our results showed that there were significant differences in allele frequencies at DYS448 and DYS456 between offenders and controls ( p  impulsive aggression. However, the DYS448-DYS456-22-15 is less related to impulsive aggression. Our results suggest a link between Y-chromosomal allele types and male impulsive aggression.

  8. Relationship between anhedonia and impulsivity in schizophrenia, major depression and schizoaffective disorder.

    Science.gov (United States)

    Amr, Mostafa; Volpe, Fernando Madalena

    2013-12-01

    Anhedonia and impulsivity are prominent symptoms of many psychiatric disorders and may indicate worse prognosis, notably in schizophrenia and major depression. Despite the convergence of negative outcomes from both dimensions, the relationship between anhedonia and impulsivity in psychiatric disorders has been seldom directly assessed. The objective of the present study is to examine the correlations between anhedonia and impulsivity in three diagnostic groups: major depression, schizophrenia and schizoaffective disorder. 121 outpatients (Mansoura University Hospital, Egypt) with major depressive disorder (N=29), schizophrenia (N=59), and schizoaffective disorder (N=33), were assessed and responded to the Beck Depression Inventory, Barrat's Impulsivity Scale-11, and Chapman's Social and Physical Anhedonia Scales. Physical and social anhedonia scores were negatively correlated to impulsivity scores in major depression patients. Conversely, higher scores in physical and social anhedonia predicted higher impulsivity scores in schizophrenia. No correlations between impulsivity and anhedonia were evidenced among schizoaffectives. The relationship between self-reported physical and social anhedonia and impulsivity is diagnosis-specific. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. [The relationship of attachment features and multi-impulsive symptoms in eating disorders].

    Science.gov (United States)

    Szalai, Tamás Dömötör

    2017-07-01

    Attachment dysfunctions determine borderline personality disorder, which is a frequent background factor of multi-impulsivity; however, the relationship between attachment and multi-impulsive eating disorders is almost unexplored. To compare attachment features of multi-impulsive and classical eating disorder patients with individuals without eating disorders, and to test attachment as a predictor of multi-impulsivity. A cross-sectional survey (148 females, mean age: 30.9 years) investigated maternal, paternal and adult attachment, depression, anxiety, eating disorder and multi-impulsive symptoms in these groups. Altogether 41.3% of the individuals without eating disorders, 17.6% of classical and 11.8% of multi-impulsive eating disorder patients had secure attachment. Multi-impulsive patients had the most severe eating disorder symptoms (F (2) = 17.733) and the lowest paternal care (F (2) = 3.443). Preoccupied and fearful attachment explained 14.5% of multi-impulsive symptoms; however, with adjustment for depression only latter one remained the predictor of multi-impulsivity (t = 5.166, peating disorder patients from the aspects of both symptoms and attachment. Handling their negative moods may hold therapeutic potentials. Longitudinal studies are required to investigate the therapeutic value of paternal care, attachment preoccupation and fearfulness. Orv Hetil. 2017; 158(27): 1058-1066.

  10. Nucleus accumbens and impulsivity

    NARCIS (Netherlands)

    Basar, K.; Sesia, T.; Groenewegen, H.J.; Steinbusch, H.W.; Visser-vandewalle, V.; Temel, Y.

    2010-01-01

    The multifaceted concept of impulsivity implies that different impulsivity aspects, mediated by different neural processes, influence behavior at different levels. The nucleus accumbens (NAc) is a key component of the neural processes regulating impulsivity. In this review, we discuss the findings

  11. Dopamine agonists and risk: impulse control disorders in Parkinson's; disease

    OpenAIRE

    Voon, Valerie; Gao, Jennifer; Brezing, Christina; Symmonds, Mkael; Ekanayake, Vindhya; Fernandez, Hubert; Dolan, Raymond J.; Hallett, Mark

    2011-01-01

    Impulse control disorders are common in Parkinson's; disease, occurring in 13.6% of patients. Using a pharmacological manipulation and a novel risk taking task while performing functional magnetic resonance imaging, we investigated the relationship between dopamine agonists and risk taking in patients with Parkinson's; disease with and without impulse control disorders. During functional magnetic resonance imaging, subjects chose between two choices of equal expected value: a ‘Sure’ choice an...

  12. A method of measuring micro-impulse with torsion pendulum based on multi-beam laser heterodyne

    Science.gov (United States)

    Li, Yan-Chao; Wang, Chun-Hui

    2012-02-01

    In this paper, we propose a novel method of multi-beam laser heterodyne measurement for micro-impulse. The measurement of the micro-impulse, which is converted into the measurement of the small tuning angle of the torsion pendulum, is realized by considering the interaction between pulse laser and working medium. Based on Doppler effect and heterodyne technology, the information regarding the small tuning angle is loaded to the frequency difference of the multi-beam laser heterodyne signal by the frequency modulation of the oscillating mirror, thereby obtaining many values of the small tuning angle after the multi-beam laser heterodyne signal demodulation simultaneously. Processing these values by weighted-average, the small tuning angle can be obtained accurately and the value of the micro-impulse can eventually be calculated. Using Polyvinylchlorid+2%C as a working medium, this novel method is used to simulate the value of the micro-impulse by MATLAB which is generated by considering the interaction between the pulse laser and the working medium, the obtained result shows that the relative error of this method is just 0.5%.

  13. A method of measuring micro-impulse with torsion pendulum based on multi-beam laser heterodyne

    International Nuclear Information System (INIS)

    Li Yan-Chao; Wang Chun-Hui

    2012-01-01

    In this paper, we propose a novel method of multi-beam laser heterodyne measurement for micro-impulse. The measurement of the micro-impulse, which is converted into the measurement of the small tuning angle of the torsion pendulum, is realized by considering the interaction between pulse laser and working medium. Based on Doppler effect and heterodyne technology, the information regarding the small tuning angle is loaded to the frequency difference of the multi-beam laser heterodyne signal by the frequency modulation of the oscillating mirror, thereby obtaining many values of the small tuning angle after the multi-beam laser heterodyne signal demodulation simultaneously. Processing these values by weighted-average, the small tuning angle can be obtained accurately and the value of the micro-impulse can eventually be calculated. Using Polyvinylchlorid+2%C as a working medium, this novel method is used to simulate the value of the micro-impulse by MATLAB which is generated by considering the interaction between the pulse laser and the working medium, the obtained result shows that the relative error of this method is just 0.5%. (general)

  14. Integral Boundary Value Problems for Fractional Impulsive Integro Differential Equations in Banach Spaces

    Directory of Open Access Journals (Sweden)

    A. Anguraj

    2014-02-01

    Full Text Available We study in this paper,the existence of solutions for fractional integro differential equations with impulsive and integral conditions by using fixed point method. We establish the Sufficient conditions and unique solution for given problem. An Example is also explained to the main results.

  15. Impulsivity-like traits and risky driving behaviors among college students.

    Science.gov (United States)

    Pearson, Matthew R; Murphy, Elaine M; Doane, Ashley N

    2013-04-01

    The present study examined the predictive effects of five impulsivity-like traits (Premeditation, Perseverance, Sensation Seeking, Negative Urgency, and Positive Urgency) on driving outcomes (driving errors, driving lapses, driving violations, cell phone driving, traffic citations, and traffic collisions). With a convenience sample of 266 college student drivers, we found that each of the impulsivity-like traits was related to multiple risky driving outcomes. Positive Urgency (tendency to act impulsively when experiencing negative affect) was the most robust predictor of risky driving outcomes. Positive Urgency is a relatively newly conceptualized impulsivity-like trait that was not examined in the driving literature previously, suggesting a strong need to further examine its role as a personality trait related to risky driving. These findings generally support the multidimensional assessment of impulsivity-like traits, and they specifically support the addition of Positive Urgency to a list of risk factors for risky driving behaviors. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Simulation Analysis of DC and Switching Impulse Superposition Circuit

    Science.gov (United States)

    Zhang, Chenmeng; Xie, Shijun; Zhang, Yu; Mao, Yuxiang

    2018-03-01

    Surge capacitors running between the natural bus and the ground are affected by DC and impulse superposition voltage during operation in the converter station. This paper analyses the simulation aging circuit of surge capacitors by PSCAD electromagnetic transient simulation software. This paper also analyses the effect of the DC voltage to the waveform of the impulse voltage generation. The effect of coupling capacitor to the test voltage waveform is also studied. Testing results prove that the DC voltage has little effect on the waveform of the output of the surge voltage generator, and the value of the coupling capacitor has little effect on the voltage waveform of the sample. Simulation results show that surge capacitor DC and impulse superimposed aging test is feasible.

  17. Gender and Impulsivity: Effects on Cue-Induced Alcohol Craving.

    Science.gov (United States)

    Yarmush, Devorah E; Manchery, Linda; Luehring-Jones, Peter; Erblich, Joel

    2016-05-01

    Numerous studies have demonstrated that trait impulsivity is linked to increased risk of developing alcohol-use disorders and other substance abuse. Impulsivity has also been shown in some studies to potentiate cue-induced drug cravings. Despite considerable evidence of gender differences in impulsivity and drug craving among individuals suffering from alcohol dependence and other drug use, little research has focused on these processes in healthy young men and women who may be at risk for developing alcohol-use disorders. The objective of this study was to investigate the relationship between impulsivity and cue-induced craving, as well as possible gender differences in these effects among healthy young adults. To that end, female (n = 22) and male (n = 14) social drinkers aged 18 to 25, recruited from an urban university campus, completed the Barratt Impulsiveness Scale and reported their alcohol cravings immediately before and after laboratory exposure to alcohol cues. Findings indicated that exposure to cues elicited increased alcohol cravings, but these effects did not differ by gender. Interestingly, a significant interaction of impulsivity and gender revealed that impulsivity predicted significantly higher cue-induced cravings in women, but not men. Findings underscore the importance of better understanding the interaction of situational factors (e.g., exposure to alcohol cues) and dispositional factors (e.g., impulsivity) as potential contributors to drinking motivation. Future prospective research is needed to identify gender-specific risk factors for the development of problem drinking. Copyright © 2016 by the Research Society on Alcoholism.

  18. Impulsivity makes more susceptible to overeating after contextual appetitive conditioning.

    Science.gov (United States)

    van den Akker, Karolien; Jansen, Anita; Frentz, Florentine; Havermans, Remco C

    2013-11-01

    Animals can learn that specific contexts are associated with important biological events such as food intake through classical conditioning. Very few studies suggest this is also possible in humans and contextual appetitive conditioning might even be a main determinant of habitual overeating in vulnerable humans. A Virtual Reality laboratory was used to test whether humans show conditioned responding (increased food desires and expectations, increased salivation and increased food intake) to a specific context after repeated pairings of this context with intake. It was also examined whether the personality trait impulsivity strengthens this contextual appetitive conditioning. Conditioned context-induced reactivity was indeed demonstrated and impulsivity predicted increased intake in only the intake-associated context. It is concluded that humans easily learn desires to eat in intake-related environments. The data also suggest that in particular more impulsive people are vulnerable for conditioned context-induced overeating. This relatively easy learning of associations between specific contexts and intake might stimulate habitual overeating and contribute to increased obesity prevalence. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. On the Spur of the Moment: Intrinsic Predictors of Impulse Sports Betting.

    Science.gov (United States)

    Hing, Nerilee; Li, En; Vitartas, Peter; Russell, Alex M T

    2018-06-01

    Betting on impulse, without thoughtful consideration, research or informed decision-making, may cause financial and other harms and lead to the development of gambling problems. Impulse betting undermines responsible consumption of gambling because it reflects self-regulatory failure, impaired control, unreflective decision-making and betting more than planned. In this paper we define impulse gambling and report on a study that aimed to understand more about the intrinsic characteristics of sports bettors who have a greater tendency to bet on impulse. Specifically, the study aimed to identify behavioural, psychological and socio-demographic predictors of impulse sports betting. A sample of 1816 Australian sports bettors completed an online survey that measured the proportion of their bets placed on impulse both before and during sporting events, as well as bets that were researched and planned in advance. Impulse betting was common, accounting for nearly one-half of all past-year sports bets by respondents. Over three-quarters of respondents had placed one or more impulse bets in the last year and one in seven respondents had made all of their sports bets on impulse. More impulsive sports bettors were characterised as having higher trait impulsiveness, higher problem gambling severity, more frequent sports betting and a shorter history of sports betting. They favoured betting on in-match contingencies instead of overall match outcomes. While health promotion strategies are needed to discourage impulse betting, research into contextual factors that arouse urges to bet would also provide direction for harm minimisation measures that help consumers to resist impulsive betting decisions.

  20. Impulsivity, gender, and the platelet serotonin transporter in healthy subjects

    Directory of Open Access Journals (Sweden)

    Donatella Marazziti

    2009-12-01

    Full Text Available Donatella Marazziti, Stefano Baroni, Irene Masala, Francesca Golia, Giorgio Consoli, Gabriele Massimetti, Michela Picchetti, Mario Catena Dell’Osso, Gino Giannaccini, Laura Betti, Antonio Lucacchini, Antonio CiapparelliDipartimento di Psichiatria, Neurobiologia, Farmacologia e Biotecnologie, University of Pisa, Pisa, ItalyAbstract: The present study explored the possible relationships between impulsivity, gender, and a peripheral serotonergic marker, the platelet serotonin (5-HT transporter (SERT, in a group of 32 healthy subjects. The impulsivity was measured by means of the Barratt Impulsivity Scale, version 11 (BIS-11, a widely used self-report questionnaire, and the platelet SERT was evaluated by means of the specific binding of 3H-paroxetine (3H-Par to platelet membranes, according to standardized protocols. The results showed that women had a higher BIS-11 total score than men, and also higher scores of two factors of the same scale: the motor impulsivity and the cognitive complexity. The analysis of the correlations revealed that the density of the SERT proteins, as measured by the maximum binding capacity (Bmax of 3H-Par, was significantly and positively related to the cognitive complexity factor, but only in men. Men showed also a significant and negative correlation with the dissociation constant, Kd, of (3H-Par binding, and the motor impulsivity factor. These findings suggest that women are generally more impulsive than men, but that the 5-HT system is more involved in the impulsivity of men than in that of women.Keywords: impulsivity, gender, serotonin transporter, Barratt Impulsivity Scale, platelets, 3H-paroxetine

  1. Sex differences in impulsivity and brain morphometry in methamphetamine users

    Science.gov (United States)

    Kogachi, Shannon; Chang, Linda; Alicata, Daniel; Cunningham, Eric; Ernst, Thomas

    2016-01-01

    Methamphetamine (METH) is an addictive stimulant, and METH users have abnormal brain structures and function. The aims of this study were to investigate the relationships between impulsivity, brain structures, and possible sex-specific differences between METH users and non-drug using Controls. Structural MRI and the Barratt Impulsiveness Scale (BIS) questionnaire were completed in 124 subjects: 62 METH (ages 41.2 ± 1.4 years, 34 males) and 62 Controls (ages 43.3 ± 2.3 years, 36 males). Independent and interactive effects of METH use status and sex were evaluated. Relationships between METH usage characteristics, brain morphometry, and impulsivity scores were examined. METH users had higher impulsivity scores, on both the Cognitive and Behavioral Factors from the BIS (p users had larger, while female METH users had smaller, right superior frontal cortex (interaction-p = 0.0005). The male METH users with larger frontal volumes and female METH users with smaller or thinner frontal cortices had greater Cognitive impulsivity (interaction-p ≤ 0.05). Only female METH users showed relatively larger nucleus accumbens (interaction-p = 0.03). Greater impulsivity and thinner frontal cortices in METH users are validated. Larger superior frontal cortex in male METH users with greater cognitive impulsivity suggest decreased dendritic pruning during adolescence might have contributed to their impulsive and drug use behaviors. In the female METH users, smaller frontal cortices and the associated greater impulsivity suggest greater neurotoxicity to these brain regions, while their relatively larger nucleus accumbens suggest an estrogen-mediated neuroprotective glial response. Men and women may be affected differently by METH use. PMID:27095357

  2. The Effect of Visual Merchandising on Impulsive Buying with Impulsive Buying Tendency As Moderating Variable

    Directory of Open Access Journals (Sweden)

    Jessica Novia

    2015-03-01

    Full Text Available This research aims to classify the female consumer demographic segments linked by impulsive buying, to determine the effect of visual merchandising on impulsive buying, and to determine the effect of visual merchandising on impulsive buying with impulsive buying tendency as moderating variable on customers of Gaudi in Taman Anggrek Mall. This research is quantitative research with a total sample of 100 people. Data were obtained by distributing questionnaires to the respondents by cross sectional. Research used Cluster Analysis and Moderated Regression Analysis. Data processing was performed using SPSS software for Windows version 20. Research found that customers of Gaudi were divided into three groups: the way of the world, sufficient money, and promotions. Then, research found that visual merchandising affected impulsive buying. In addition, there visual merchandising had also an effect on impulsive buying with impulsive buying tendency as moderating variable. As a conclusion, moderating variable strengthens the effect of visual merchandising on impulse buying.

  3. Impulsive social influence increases impulsive choices on a temporal discounting task in young adults.

    Directory of Open Access Journals (Sweden)

    Jodi M Gilman

    Full Text Available Adolescents and young adults who affiliate with friends who engage in impulsive behavior are more likely to engage in impulsive behaviors themselves, and those who associate with prosocial (i.e. more prudent, future oriented peers are more likely to engage in prosocial behavior. However, it is difficult to disentangle the contribution of peer influence vs. peer selection (i.e., whether individuals choose friends with similar traits when interpreting social behaviors. In this study, we combined a novel social manipulation with a well-validated delay discounting task assessing impulsive behavior to create a social influence delay discounting task, in which participants were exposed to both impulsive (smaller, sooner or SS payment and non-impulsive (larger, later or LL payment choices from their peers. Young adults in this sample, n = 51, aged 18-25 had a higher rate of SS choices after exposure to impulsive peer influence than after exposure to non-impulsive peer influence. Interestingly, in highly susceptible individuals, the rate of non-impulsive choices did not increase after exposure to non-impulsive influence. There was a positive correlation between self-reported suggestibility and degree of peer influence on SS choices. These results suggest that, in young adults, SS choices appear to be influenced by the choices of same-aged peers, especially for individuals who are highly susceptible to influence.

  4. Impulsive Social Influence Increases Impulsive Choices on a Temporal Discounting Task in Young Adults

    Science.gov (United States)

    Gilman, Jodi M.; Curran, Max T.; Calderon, Vanessa; Stoeckel, Luke E.; Evins, A. Eden

    2014-01-01

    Adolescents and young adults who affiliate with friends who engage in impulsive behavior are more likely to engage in impulsive behaviors themselves, and those who associate with prosocial (i.e. more prudent, future oriented) peers are more likely to engage in prosocial behavior. However, it is difficult to disentangle the contribution of peer influence vs. peer selection (i.e., whether individuals choose friends with similar traits) when interpreting social behaviors. In this study, we combined a novel social manipulation with a well-validated delay discounting task assessing impulsive behavior to create a social influence delay discounting task, in which participants were exposed to both impulsive (smaller, sooner or SS payment) and non-impulsive (larger, later or LL payment) choices from their peers. Young adults in this sample, n = 51, aged 18–25 had a higher rate of SS choices after exposure to impulsive peer influence than after exposure to non-impulsive peer influence. Interestingly, in highly susceptible individuals, the rate of non-impulsive choices did not increase after exposure to non-impulsive influence. There was a positive correlation between self-reported suggestibility and degree of peer influence on SS choices. These results suggest that, in young adults, SS choices appear to be influenced by the choices of same-aged peers, especially for individuals who are highly susceptible to influence. PMID:24988440

  5. THE INFLUENCE OF HEDONIC SHOPPING MOTIVATION TO THE IMPULSE BUYING OF ONLINE-SHOPPING CONSUMER ON INSTAGRAM

    Directory of Open Access Journals (Sweden)

    Asnawati

    2018-02-01

    Full Text Available This research aims to know the influence of Adventure Shopping, Relaxation Shopping, Value Shopping, Social Shopping and Idea Shopping variables to the variable of Impulse Buying of Online-Shopping Consumer on Instagram. The type of the research is explanatory research. The result of F-test showed that Fcount (12.829 > Ftable (2.669 which meant that research variables had influences to the Impulse Buying. With partial correlation value of 0.548, Idea Shopping variable became the dominant factor influencing Impulse Buying on the online-shopping purchase on Instagram.

  6. Single-photon emission tomography imaging of monoamine transporters in impulsive violent behaviour

    International Nuclear Information System (INIS)

    Tiihonen, J.; Hallikainen, T.; Hakola, P.; Kuikka, J.T.; Bergstroem, K.A.; Yang, J.; Karhu, J.; Viinamaeki, H.; Lehtonen, J.

    1997-01-01

    Several studies have shown that impulsive violent and suicidal behaviour is associated with a central serotonin deficit, but until now it has not been possible to use laboratory tests with high sensitivity and specificity to study this kind of deficit or to localize the sites of serotonergic abnormalities in the living human brain. The aim of this study was to test the hypothesis that monoamine transporter density in brain is decreased in subjects with impulsive violent behaviour. We studied serotonin (5-HT) and dopamine (DA) transporter specific binding in 52 subjects (21 impulsive violent offenders, 21 age- and sex-matched healthy controls, and ten non-violent alcoholic controls) with single-photon emission tomography (SPET) using iodine-123-labelled 2β-carbomethoxy-3β(4-iodophenyl)tropane ([ 123 I]β-CIT) as the tracer. The blind quantitative analysis revealed that the 5-HT specific binding of [ 123 I]β-CIT in the midbrain of violent offenders was lower than that in the healthy control subjects (P<0.005; t test) or the non-violent alcoholics (P<0.05). The results imply that habitual impulsive aggressive behaviour in man is associated with a decrease in the 5-HT transporter density. (orig.)

  7. Diagnosis and treatment of impulse control disorders in patients with movement disorders.

    Science.gov (United States)

    Mestre, Tiago A; Strafella, Antonio P; Thomsen, Teri; Voon, Valerie; Miyasaki, Janis

    2013-05-01

    Impulse control disorders are a psychiatric condition characterized by the failure to resist an impulsive act or behavior that may be harmful to self or others. In movement disorders, impulse control disorders are associated with dopaminergic treatment, notably dopamine agonists (DAs). Impulse control disorders have been studied extensively in Parkinson's disease, but are also recognized in restless leg syndrome and atypical Parkinsonian syndromes. Epidemiological studies suggest younger age, male sex, greater novelty seeking, impulsivity, depression and premorbid impulse control disorders as the most consistent risk factors. Such patients may warrant special monitoring after starting treatment with a DA. Various individual screening tools are available for people without Parkinson's disease. The Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease has been developed specifically for Parkinson's disease. The best treatment for impulse control disorders is prevention. However, after the development of impulse control disorders, the mainstay intervention is to reduce or discontinue the offending anti-Parkinsonian medication. In refractory cases, other pharmacological interventions are available, including neuroleptics, antiepileptics, amantadine, antiandrogens, lithium and opioid antagonists. Unfortunately, their use is only supported by case reports, small case series or open-label clinical studies. Prospective, controlled studies are warranted. Ongoing investigations include naltrexone and nicotine.

  8. Tumour chemotherapy strategy based on impulse control theory.

    Science.gov (United States)

    Ren, Hai-Peng; Yang, Yan; Baptista, Murilo S; Grebogi, Celso

    2017-03-06

    Chemotherapy is a widely accepted method for tumour treatment. A medical doctor usually treats patients periodically with an amount of drug according to empirical medicine guides. From the point of view of cybernetics, this procedure is an impulse control system, where the amount and frequency of drug used can be determined analytically using the impulse control theory. In this paper, the stability of a chemotherapy treatment of a tumour is analysed applying the impulse control theory. The globally stable condition for prescription of a periodic oscillatory chemotherapeutic agent is derived. The permanence of the solution of the treatment process is verified using the Lyapunov function and the comparison theorem. Finally, we provide the values for the strength and the time interval that the chemotherapeutic agent needs to be applied such that the proposed impulse chemotherapy can eliminate the tumour cells and preserve the immune cells. The results given in the paper provide an analytical formula to guide medical doctors to choose the theoretical minimum amount of drug to treat the cancer and prevent harming the patients because of over-treating.This article is part of the themed issue 'Horizons of cybernetical physics'. © 2017 The Author(s).

  9. Acoustic Radiation Force Impulse Quantification in the Evaluation of Thyroid Elasticity in Pediatric Patients With Hashimoto Thyroiditis.

    Science.gov (United States)

    Yucel, Serap; Ceyhan Bilgici, Meltem; Kara, Cengiz; Can Yilmaz, Gulay; Aydin, H Murat; Elmali, Muzaffer; Tomak, Leman; Saglam, Dilek

    2018-05-01

    To evaluate the parenchymal elasticity of the thyroid gland with acoustic radiation force impulse imaging in pediatric patients with Hashimoto thyroiditis and to compare it with healthy volunteers. Twenty-six patients with Hashimoto thyroiditis and 26 healthy volunteers between 6 and 17 years were included. The shear wave velocity (SWV) values of both thyroid lobes in both groups were evaluated. The age and sex characteristics of the controls and patients with Hashimoto thyroiditis were similar. The SWV of the thyroid gland in patients with Hashimoto thyroiditis (mean ± SD, 1.67 ± 0.63 m/s) was significantly higher than that in the control group (1.30 ± 0.13 m/s; P thyroid lobes in both groups. A receiver operating characteristic curve analyses showed an optimal cutoff value of 1.41 m/s, with 73.1% sensitivity, 80.8% specificity, a 79.2 % positive predictive value, and a 75.0% negative predictive value (area under the curve, 0.806; P Hashimoto thyroiditis, there was a positive correlation between the SWV values versus anti-thyroperoxidase (Pearson r = 0.46; P = .038). There were no correlations between age, body mass index, thyroid function test results, and anti-thyroglobulin values and versus SWV values. Also, no significant differences were seen between the groups for gland size, gland vascularity, and l-thyroxine treatment. Acoustic radiation force impulse elastography showed a significant difference in the stiffness of the thyroid gland between children with Hashimoto thyroiditis and the healthy group. Using acoustic radiation force impulse elastography immediately after a standard ultrasound evaluation may predict chronic autoimmune thyroiditis. © 2017 by the American Institute of Ultrasound in Medicine.

  10. Measurement of glomerular filtration rate by impulse synthesis: Clinical validation and optimization

    International Nuclear Information System (INIS)

    Palagi, B.; Verga, P.; Broggi, A.; Picozzi, R.; Villa, F.; Guzzini, F.; Cozzi, C.; Tomasi, A.

    1988-01-01

    Impulse synthesis is a technique which relies upon the logic of continuous infusion but extracts the clearance value from single-injection data by shifting and adding them until an asymptotic value is attained. This study has been aimed at validating and optimizing clinically the measurement of glomerular filtration rate by impulse synthesis. A single intravenous injection of 51 Cr-EDTA has been made in 32 patients and plasma activity monitored over the next 6 h. Glomerular filtration rate computed by a single-exponential fit method (GFR-SEF) has been shown to be significantly (p [de

  11. A Plasma Diagnostic Set for the Study of a Variable Specific Impulse Magnetoplasma Rocket

    Science.gov (United States)

    Squire, J. P.; Chang-Diaz, F. R.; Bengtson Bussell, R., Jr.; Jacobson, V. T.; Wootton, A. J.; Bering, E. A.; Jack, T.; Rabeau, A.

    1997-11-01

    The Advanced Space Propulsion Laboratory (ASPL) is developing a Variable Specific Impulse Magnetoplasma Rocket (VASIMR) using an RF heated magnetic mirror operated asymmetrically. We will describe the initial set of plasma diagnostics and data acquisition system being developed and installed on the VASIMR experiment. A U.T. Austin team is installing two fast reciprocating probes: a quadruple Langmuir and a Mach probe. These measure electron density and temperature profiles, electrostatic plasma fluctuations, and plasma flow profiles. The University of Houston is developing an array of 20 highly directional Retarding Potential Analyzers (RPA) for measuring ion energy distribution function profiles in the rocket plume, giving a measurement of total thrust. We have also developed a CAMAC based data acquisition system using LabView running on a Power Macintosh communicating through a 2 MB/s serial highway. We will present data from initial plasma operations and discuss future diagnostic development.

  12. Dynamics of cholera epidemics with impulsive vaccination and disinfection.

    Science.gov (United States)

    Sisodiya, Omprakash Singh; Misra, O P; Dhar, Joydip

    2018-04-01

    Waterborne diseases have a tremendous influence on human life. The contaminated drinking water causes water-borne disease like cholera. Pulse vaccination is an important and effective strategy for the elimination of infectious diseases. A waterborne disease like cholera can also be controlled by using impulse technique. In this paper, we have proposed a delayed SEIRB epidemic model with impulsive vaccination and disinfection. We have studied the pulse vaccination strategy and sanitation to control the cholera disease. The existence and stability of the disease-free and endemic periodic solution are investigated both analytically and numerically. It is shown that there exists an infection-free periodic solution, using the impulsive dynamical system defined by the stroboscopic map. It is observed that the infection-free periodic solution is globally attractive when the impulse period is less than some critical value. From the analysis of the model, we have obtained a sufficient condition for the permanence of the epidemic with pulse vaccination. The main highlight of this paper is to introduce impulse technique along with latent period into the SEIRB epidemic model to investigate the role of pulse vaccination and disinfection on the dynamics of the cholera epidemics. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. Impulsivity in adolescents with major depressive disorder: A comparative tunisian study.

    Science.gov (United States)

    Khemakhem, Khaoula; Boudabous, Jaweher; Cherif, Leila; Ayadi, Hela; Walha, Adel; Moalla, Yousr; Hadjkacem, Imen; Ghribi, Farhat

    2017-08-01

    The association between impulsivity and depressive disorders in adolescence has been little studied at the literature and in our country, yet impulsivity is a major risk factor for suicide. Thus we aimed on this study to evaluate impulsivity in 25 adolescents with Major Depressive Disorder MDD compared to a control sample and to analyze the correlations between impulsivity and clinical features of MDD. Employing a matched case-control design, participants included 25 adolescents with MDD and 75 controls. We have administered the Barratt Impulsivity Scale BIS-11 for the two groups to evaluate impulsivity. Semi structured interviews according DSM 5 criteria were conducted for adolescents with MDD. The Child Depressive Inventory CDI was used to measure depressive symptoms in the control sample. Adolescents with MDD were more impulsive compared to controls according to the BIS-11 in its three domains: motor (24.96±6.26 against 20.6±4.84; p=0.000), attentional (20.88±5.03 against 16.64±3.2; p=0.000) and non planning (28.2±7.26 against 24.44±4.32; p=0.02). Impulsivity was not correlated with clinical features of MDD (suicide attempts, psychiatric comorbidities, antidepressant medication …). Adolescents with MDD seem to be more impulsive than control subjects regardless their clinical features. Whether it is a specific characteristic or a symptom among others of MDD, impulsivity predicts health-related behaviors and associated damage that need to be detected and prevented in time. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Trait Impulsivity and Anhedonia: Two Gateways for the Development of Impulse Control Disorders in Parkinson's Disease?

    Science.gov (United States)

    Houeto, Jean-Luc; Magnard, Robin; Dalley, Jeffrey W; Belin, David; Carnicella, Sebastien

    2016-01-01

    Apathy and impulsivity are two major comorbid syndromes of Parkinson's disease (PD) that may represent two extremes of a behavioral spectrum modulated by dopamine-dependent processes. PD is characterized by a progressive loss of dopaminergic neurons in the substantia nigra pars compacta to which are attributed the cardinal motor symptoms of the disorder. Dopamine replacement therapy (DRT), used widely to treat these motor symptoms, is often associated with deficits in hedonic processing and motivation, including apathy and depression, as well as impulse control disorders (ICDs). ICDs comprise pathological gambling, hypersexuality, compulsive shopping, binge eating, compulsive overuse of dopaminergic medication, and punding. More frequently observed in males with early onset PD, ICDs are associated not only with comorbid affective symptoms, such as depression and anxiety, but also with behavioral traits, such as novelty seeking and impulsivity, as well as with personal or familial history of alcohol use. This constellation of associated risk factors highlights the importance of inter-individual differences in the vulnerability to develop comorbid psychiatric disorders in PD patients. Additionally, withdrawal from DRT in patients with ICDs frequently unmasks a severe apathetic state, suggesting that apathy and ICDs may be caused by overlapping neurobiological mechanisms within the cortico-striato-thalamo-cortical networks. We suggest that altered hedonic and impulse control processes represent distinct prodromal substrates for the development of these psychiatric symptoms, the etiopathogenic mechanisms of which remain unknown. Specifically, we argue that deficits in hedonic and motivational states and impulse control are mediated by overlapping, yet dissociable, neural mechanisms that differentially interact with DRT to promote the emergence of ICDs in vulnerable individuals. Thus, we provide a novel heuristic framework for basic and clinical research to better

  15. Trait impulsivity and anhedonia: two gateways for the development of impulse control disorders in Parkinson's disease?

    Directory of Open Access Journals (Sweden)

    Jean-Luc eHoueto

    2016-05-01

    Full Text Available Apathy and impulsivity are two major comorbid syndromes of Parkinson’s disease (PD that may represent two extremes of a behavioral spectrum modulated by dopamine-dependent processes. PD is characterized by a progressive loss of dopaminergic neurons in the substantia nigra pars compacta to which are attributed the cardinal motor symptoms of the disorder. Dopamine replacement therapy (DRT, used widely to treat these motor symptoms, is often associated with deficits in hedonic processing and motivation, including apathy and depression, as well as impulse control disorders (ICDs. ICDs comprise pathological gambling, hypersexuality, compulsive shopping, binge eating, compulsive overuse of dopaminergic medication, and punding. More frequently observed in males with early onset PD, ICDs are associated not only with co-morbid affective symptoms such as depression and anxiety, but also with behavioral traits such as novelty seeking and impulsivity, as well as with personal or familial history of alcohol use. This constellation of associated risk factors highlights the importance of inter-individual differences in the vulnerability to develop comorbid psychiatric disorders in PD patients. Additionally, withdrawal from DRT in patients with ICDs frequently unmasks a severe apathetic state, suggesting that apathy and ICDs may be caused by overlapping neurobiological mechanisms within the cortico-striato-thalamo-cortical networks. We suggest that altered hedonic and impulse control processes represent distinct prodromal substrates for the development of these psychiatric symptoms, the etiopathogenic mechanisms of which remain unknown. Specifically, we argue that deficits in hedonic and motivational states and impulse control are mediated by overlapping, yet dissociable, neural mechanisms that differentially interact with DRT to promote the emergence of ICDs in vulnerable individuals. We thus provide a novel heuristic framework for basic and clinical

  16. Impulse pumping modelling and simulation

    International Nuclear Information System (INIS)

    Pierre, B; Gudmundsson, J S

    2010-01-01

    Impulse pumping is a new pumping method based on propagation of pressure waves. Of particular interest is the application of impulse pumping to artificial lift situations, where fluid is transported from wellbore to wellhead using pressure waves generated at wellhead. The motor driven element of an impulse pumping apparatus is therefore located at wellhead and can be separated from the flowline. Thus operation and maintenance of an impulse pump are facilitated. The paper describes the different elements of an impulse pumping apparatus, reviews the physical principles and details the modelling of the novel pumping method. Results from numerical simulations of propagation of pressure waves in water-filled pipelines are then presented for illustrating impulse pumping physical principles, and validating the described modelling with experimental data.

  17. Complex Dynamical Behaviors in a Predator-Prey System with Generalized Group Defense and Impulsive Control Strategy

    Directory of Open Access Journals (Sweden)

    Shunyi Li

    2013-01-01

    Full Text Available A predator-prey system with generalized group defense and impulsive control strategy is investigated. By using Floquet theorem and small amplitude perturbation skills, a local asymptotically stable prey-eradication periodic solution is obtained when the impulsive period is less than some critical value. Otherwise, the system is permanent if the impulsive period is larger than the critical value. By using bifurcation theory, we show the existence and stability of positive periodic solution when the pest eradication lost its stability. Numerical examples show that the system considered has more complicated dynamics, including (1 high-order quasiperiodic and periodic oscillation, (2 period-doubling and halving bifurcation, (3 nonunique dynamics (meaning that several attractors coexist, and (4 chaos and attractor crisis. Further, the importance of the impulsive period, the released amount of mature predators and the degree of group defense effect are discussed. Finally, the biological implications of the results and the impulsive control strategy are discussed.

  18. Full-waveform detection of non-impulsive seismic events based on time-reversal methods

    Science.gov (United States)

    Solano, Ericka Alinne; Hjörleifsdóttir, Vala; Liu, Qinya

    2017-12-01

    We present a full-waveform detection method for non-impulsive seismic events, based on time-reversal principles. We use the strain Green's tensor as a matched filter, correlating it with continuous observed seismograms, to detect non-impulsive seismic events. We show that this is mathematically equivalent to an adjoint method for detecting earthquakes. We define the detection function, a scalar valued function, which depends on the stacked correlations for a group of stations. Event detections are given by the times at which the amplitude of the detection function exceeds a given value relative to the noise level. The method can make use of the whole seismic waveform or any combination of time-windows with different filters. It is expected to have an advantage compared to traditional detection methods for events that do not produce energetic and impulsive P waves, for example glacial events, landslides, volcanic events and transform-fault earthquakes for events which velocity structure along the path is relatively well known. Furthermore, the method has advantages over empirical Greens functions template matching methods, as it does not depend on records from previously detected events, and therefore is not limited to events occurring in similar regions and with similar focal mechanisms as these events. The method is not specific to any particular way of calculating the synthetic seismograms, and therefore complicated structural models can be used. This is particularly beneficial for intermediate size events that are registered on regional networks, for which the effect of lateral structure on the waveforms can be significant. To demonstrate the feasibility of the method, we apply it to two different areas located along the mid-oceanic ridge system west of Mexico where non-impulsive events have been reported. The first study area is between Clipperton and Siqueiros transform faults (9°N), during the time of two earthquake swarms, occurring in March 2012 and May

  19. An approach to remove impulse noise from a corrupted image

    International Nuclear Information System (INIS)

    Jin, Cong; Yan, Meng; Jin, Shu-Wei

    2013-01-01

    In this paper, we propose an efficient approach for detecting the impulse noise from corrupted images. This method is based on the principle that the feature of the digital image is usually local correlation and the feature of the impulse noise is usually located near one of the two ends of the image’s maximum and minimum gray values. After the noisy pixel has been detected by the proposed detector, a modified version of the mean filter is proposed to remove the detected impulse noise. Experimental results show that the implementation of the proposed method is simple, and it has better performance than comparison filters with regard to effective noise suppression and preservation of detail, especially when the noise ratio is very high. (paper)

  20. Differences between Impulsive and Non-Impulsive Suicide Attempts among Individuals Treated in Emergency Rooms of South Korea

    Science.gov (United States)

    Lim, Meerae; Lee, Soojung

    2016-01-01

    Objective A considerable proportion of suicide attempts are the result of sudden desires. Understanding such impulsive suicide attempts is necessary for effective interventions. We evaluated the impulsivity of suicide attempters treated in emergency rooms. The aim of the study was to identify the characteristics of impulsive suicide attempts by comparing these individuals to those who attempted to commit suicide in a non-impulsive manner. Methods This study analyzed suicide attempters who visited the emergency departments of seven selected university hospitals. A total of 269 medical records in which impulsivity of suicide attempt were confirmed were subject to be analyzed. The impulsivity of the suicide attempt was examined using a summative score of items 6 and 15 on the Suicide Intent Scale. Results A total of 48.0% of the participants were impelled by sudden inclinations to attempt suicide. Impulsive attempters were younger, unmarried and less physical illness than non-impulsive attempters, whereas no significant differences were found on psychiatric history and previous suicide history. Impulsive suicide attempters had suicide ideations that were not as severe (χ2=55.33, pimpulsive suicide attempts were better than non-impulsive suicide attempts (t=-3.77, psuicide attempts were the result of sudden inclinations. Impulsive attempts were made in relatively earlier stages of suicide ideation; consequently, they have less intent than non-impulsive attempts. PMID:27482239

  1. Sensation-Seeking and Impulsivity as Predictors of Reactive and Proactive Aggression in Adolescents

    Science.gov (United States)

    Pérez Fuentes, María Del Carmen; Molero Jurado, Maria del Mar; Carrión Martínez, José J.; Mercader Rubio, Isabel; Gázquez, José J.

    2016-01-01

    In adolescence, such matters as substance use and impulsiveness may give rise to problematic behavior repertoires. This study was therefore done to analyze the predictive value of sensation-seeking and impulsiveness dimensions related to the functions of aggression (reactive/proactive) and types of expression (physical/relational). A total of 822 high school students in Almeria (Spain) aged 13–18, were administered the Sensation-Seeking Scale, the State Impulsiveness Scale and Peer Conflict Scale. The results show the existence of a positive correlation of the majority of factors analyzed, both in impulsiveness and sensation-seeking, with respect to the different types of aggression. Furthermore, aggressive behavior is explained by the combination of a sensation-seeking factor (Disinhibition) and two impulsiveness factors (Gratification and Automatism). This study shows the need to analyze aggression as a multidimensional construct. PMID:27729883

  2. Impulse control disorders in Parkinson's disease are associated with dysfunction in stimulus valuation but not action valuation.

    Science.gov (United States)

    Piray, Payam; Zeighami, Yashar; Bahrami, Fariba; Eissa, Abeer M; Hewedi, Doaa H; Moustafa, Ahmed A

    2014-06-04

    A substantial subset of Parkinson's disease (PD) patients suffers from impulse control disorders (ICDs), which are side effects of dopaminergic medication. Dopamine plays a key role in reinforcement learning processes. One class of reinforcement learning models, known as the actor-critic model, suggests that two components are involved in these reinforcement learning processes: a critic, which estimates values of stimuli and calculates prediction errors, and an actor, which estimates values of potential actions. To understand the information processing mechanism underlying impulsive behavior, we investigated stimulus and action value learning from reward and punishment in four groups of participants: on-medication PD patients with ICD, on-medication PD patients without ICD, off-medication PD patients without ICD, and healthy controls. Analysis of responses suggested that participants used an actor-critic learning strategy and computed prediction errors based on stimulus values rather than action values. Quantitative model fits also revealed that an actor-critic model of the basal ganglia with different learning rates for positive and negative prediction errors best matched the choice data. Moreover, whereas ICDs were associated with model parameters related to stimulus valuation (critic), PD was associated with parameters related to action valuation (actor). Specifically, PD patients with ICD exhibited lower learning from negative prediction errors in the critic, resulting in an underestimation of adverse consequences associated with stimuli. These findings offer a specific neurocomputational account of the nature of compulsive behaviors induced by dopaminergic drugs. Copyright © 2014 the authors 0270-6474/14/347814-11$15.00/0.

  3. Single-photon emission tomography imaging of monoamine transporters in impulsive violent behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Tiihonen, J.; Hallikainen, T.; Hakola, P. [Department of Forensic Psychiatry, University of Kuopio and Niuvanniemi Hospital, FIN-70240 Kuopio (Finland); Kuikka, J.T.; Bergstroem, K.A.; Yang, J. [Department of Clinical Physiology, Kuopio University Hospital, FIN-70210 Kuopio (Finland); Karhu, J. [Department of Clinical Neurophysiology, Kuopio University Hospital, FIN-70210 Kuopio (Finland); Viinamaeki, H.; Lehtonen, J. [Department of Psychiatry, Kuopio University Hospital, FIN-70210 Kuopio (Finland)

    1997-10-01

    Several studies have shown that impulsive violent and suicidal behaviour is associated with a central serotonin deficit, but until now it has not been possible to use laboratory tests with high sensitivity and specificity to study this kind of deficit or to localize the sites of serotonergic abnormalities in the living human brain. The aim of this study was to test the hypothesis that monoamine transporter density in brain is decreased in subjects with impulsive violent behaviour. We studied serotonin (5-HT) and dopamine (DA) transporter specific binding in 52 subjects (21 impulsive violent offenders, 21 age- and sex-matched healthy controls, and ten non-violent alcoholic controls) with single-photon emission tomography (SPET) using iodine-123-labelled 2{beta}-carbomethoxy-3{beta}(4-iodophenyl)tropane ([{sup 123}I]{beta}-CIT) as the tracer. The blind quantitative analysis revealed that the 5-HT specific binding of [{sup 123}I]{beta}-CIT in the midbrain of violent offenders was lower than that in the healthy control subjects (P<0.005; t test) or the non-violent alcoholics (P<0.05). The results imply that habitual impulsive aggressive behaviour in man is associated with a decrease in the 5-HT transporter density. (orig.) With 4 figs., 2 tabs., 55 refs.

  4. Existence results for impulsive semilinear damped differential inclusions

    Directory of Open Access Journals (Sweden)

    Mouffak Benchohra

    2003-06-01

    Full Text Available In this paper we investigate the existence of mild solutions for first and second order impulsive semilinear evolution inclusions in separable Banach spaces. By using suitable fixed point theorems, we study the case when the multivalued map has convex and nonconvex values.

  5. About positivity of green's functions for nonlocal boundary value problems with impulsive delay equations.

    Science.gov (United States)

    Domoshnitsky, Alexander; Volinsky, Irina

    2014-01-01

    The impulsive delay differential equation is considered (Lx)(t) = x'(t) + ∑(i=1)(m) p(i)(t)x(t - τ(i) (t)) = f(t), t ∈ [a, b], x(t j) = β(j)x(t(j - 0)), j = 1,…, k, a = t0 equation are obtained.

  6. Chemically ignited thermonuclear reactions: A near-term means for a high specific impulse - High thrust propulsion system

    International Nuclear Information System (INIS)

    Winterberg, F.

    1982-01-01

    A proposal for the fissionless ignition of small thermonuclear reactions is made which involves the combination of the magnetic booster target inertial fusion concept with the chemical implosion of metallic shells. The magnetic booster employs a very dense and magnetically confined low yield thermonuclear plasma to trigger an inertially confined high yield plasma. Fissionless ignition permits smaller yields than with fission- or fusion-induced fusion bombs, yields that are appropriate for use in a spacecraft propulsion system. Each bomb would release about 10 to the 18th erg or 100 tons of TNT, and with one explosion per second, an average thrust of 10 to the third tons and a specific impulse of about 3000 seconds can be expected

  7. Reward processing and intertemporal decision making in adults and adolescents: the role of impulsivity and decision consistency.

    Science.gov (United States)

    Ripke, Stephan; Hübner, Thomas; Mennigen, Eva; Müller, Kathrin U; Rodehacke, Sarah; Schmidt, Dirk; Jacob, Mark J; Smolka, Michael N

    2012-10-10

    Several studies report differences between adults and adolescents in reward processing and impulsivity. Consistently, adolescents are more impulsive in their decision making, as measured by intertemporal choice tasks. Since impulsivity affects an individual's perception and neural processing of rewards, it is unclear whether previously reported differences in brain activation between adults and adolescents are primarily due to maturation of the brain reward system or differences in impulsivity (i.e. discounting behaviour). To disentangle this, we analysed data from 235 adolescents and 29 adults who performed an intertemporal choice task in which monetary rewards were adapted to individual impulsivity. Using functional magnetic resonance imaging (fMRI), we measured brain activity and assessed impulsivity and consistency of choices at the behavioural level. Although adolescents discounted delayed rewards more steeply than adults, when controlling for impulsivity, neural processing of reward value did not differ between groups. However, more impulsive subjects showed a lower brain response to delayed rewards, independent of age. Concerning decision making, adolescents exhibited a lower consistency of choices and less brain activity in the parietal network than adults. We conclude that processing of the value of prospective delayed rewards is more sensitive to discounting behaviour than to chronological age. Lower consistency of intertemporal choices might indicate ongoing maturation of parietal brain areas in adolescents. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Trait and state impulsivity in males with tendency towards Internet-pornography-use disorder.

    Science.gov (United States)

    Antons, Stephanie; Brand, Matthias

    2018-04-01

    Impulsivity has been identified to be involved in the development and maintenance of specific Internet-use disorders (IUD). It can be differentiated between relatively stable trait impulsivity and state impulsivity which is dependent on environmental and affective factors such as craving. Following the I-PACE (Interaction of Person-Affect-Cognition-Execution) model, both trait and state impulsivity may play an interactive role in IUD. The present study aimed to investigate the relationship between trait and state impulsivity and symptom severity of Internet-pornography-use disorder (IPD) as one form of IUD. Fifty heterosexual males participated in this study. State impulsivity was measured with reaction times in a modified stop-signal task. Each participant conducted two blocks of this task which included neutral and pornographic pictures. Moreover, current subjective craving, trait impulsivity, and symptom severity of IPD were assessed using several questionnaires. Results indicate that trait impulsivity was associated with higher symptom severity of IPD. Especially those males with higher trait impulsivity and state impulsivity in the pornographic condition of the stop-signal task as well as those with high craving reactions showed severe symptoms of IPD. The results indicate that both trait and state impulsivity play a crucial role in the development of IPD. In accordance with dual-process models of addiction, the results may be indicative of an imbalance between the impulsive and reflective systems which might be triggered by pornographic material. This may result in loss of control over the Internet-pornography use albeit experiencing negative consequences. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Attentional bias toward high-calorie food-cues and trait motor impulsivity interactively predict weight gain

    Directory of Open Access Journals (Sweden)

    Adrian Meule

    2016-05-01

    Full Text Available Strong bottom-up impulses and weak top-down control may interactively lead to overeating and, consequently, weight gain. In the present study, female university freshmen were tested at the start of the first semester and again at the start of the second semester. Attentional bias toward high- or low-calorie food-cues was assessed using a dot-probe paradigm and participants completed the Barratt Impulsiveness Scale . Attentional bias and motor impulsivity interactively predicted change in body mass index: motor impulsivity positively predicted weight gain only when participants showed an attentional bias toward high-calorie food-cues. Attentional and non-planning impulsivity were unrelated to weight change. Results support findings showing that weight gain is prospectively predicted by a combination of weak top-down control (i.e. high impulsivity and strong bottom-up impulses (i.e. high automatic motivational drive toward high-calorie food stimuli. They also highlight the fact that only specific aspects of impulsivity are relevant in eating and weight regulation.

  10. Spectrogram Image Analysis of Error Signals for Minimizing Impulse Noise

    Directory of Open Access Journals (Sweden)

    Jeakwan Kim

    2016-01-01

    Full Text Available This paper presents the theoretical and experimental study on the spectrogram image analysis of error signals for minimizing the impulse input noises in the active suppression of noise. Impulse inputs of some specific wave patterns as primary noises to a one-dimensional duct with the length of 1800 mm are shown. The convergence speed of the adaptive feedforward algorithm based on the least mean square approach was controlled by a normalized step size which was incorporated into the algorithm. The variations of the step size govern the stability as well as the convergence speed. Because of this reason, a normalized step size is introduced as a new method for the control of impulse noise. The spectrogram images which indicate the degree of the attenuation of the impulse input noises are considered to represent the attenuation with the new method. The algorithm is extensively investigated in both simulation and real-time control experiment. It is demonstrated that the suggested algorithm worked with a nice stability and performance against impulse noises. The results in this study can be used for practical active noise control systems.

  11. The Effect of Visual Merchandising on Impulsive Buying with Impulsive Buying Tendency As Moderating Variable

    OpenAIRE

    Jessica Novia

    2015-01-01

    This research aims to classify the female consumer demographic segments linked by impulsive buying, to determine the effect of visual merchandising on impulsive buying, and to determine the effect of visual merchandising on impulsive buying with impulsive buying tendency as moderating variable on customers of Gaudi in Taman Anggrek Mall. This research is quantitative research with a total sample of 100 people. Data were obtained by distributing questionnaires to the respondents by cross secti...

  12. Are Adolescents Gambling With Cannabis Use? A Longitudinal Study of Impulsivity Measures and Adolescent Substance Use : The TRAILS Study

    NARCIS (Netherlands)

    van Leeuwen, Andrea Prince; Creemers, Hanneke E.; Verhulst, Frank C.; Ormel, Johan; Huizink, Anja C.

    Objective: This study examined (a) the predictive value of observed versus reported measures of impulsivity on the onset of cannabis use and determined if lifetime tobacco and cannabis users can be differentiated by their level of impulsivity and (b) the predictive value of observed versus reported

  13. Impulsive behavior in adults with attention deficit/ hyperactivity disorder: characterization of attentional, motor and cognitive impulsiveness.

    Science.gov (United States)

    Malloy-Diniz, L; Fuentes, D; Leite, W Borges; Correa, H; Bechara, A

    2007-07-01

    Attention-deficit/hyperactivity disorder (ADHD) is characterized by inattention and/or hyperactivity/impulsivity. Impulsivity persists in adults with ADHD and might be the basis of much of the impairment observed in the daily lives of such individuals. The objective of this study was to address the presence, and more importantly, the three dimensions of impulsivity: attentional, non-planning and motor, in how they may relate to neuropsychological mechanisms of impulse control. We studied a sample of 50 adults with ADHD and 51 healthy comparison controls using the Barratt Impulsivity Scale Version 11 (BIS), and neuropsychological tasks, namely the Continuous Performance Task (CPT-II) and the Iowa Gambling Task (IGT). The ADHD group showed more signs of impulsivity on the three dimensions of BIS, committed more errors of omission and commission on the CPT-II, and made more disadvantageous choices on the IGT. These results support the existence of deficits related to three components of impulsivity: motor, cognitive, and attentional among adults with ADHD. Most importantly, this study also highlights the complementary nature of self-report questionnaires and neuropsychological tasks in the assessment of impulsivity in ADHD adults.

  14. Food-Related Impulsivity in Obesity and Binge Eating Disorder—A Systematic Update of the Evidence

    Directory of Open Access Journals (Sweden)

    Katrin E. Giel

    2017-10-01

    Full Text Available The specific eating pattern of Binge Eating Disorder (BED patients has provoked the assumption that BED might represent a phenotype within the obesity spectrum that is characterized by increased impulsivity. Following the guidelines of the PRISMA statement (preferred reporting items for systematic reviews and meta-analyses, we here provide a systematic update on the evidence on food-related impulsivity in obese individuals, with and without BED, as well as normal-weight individuals. We separately analyzed potential group differences in the impulsivity components of reward sensitivity and rash-spontaneous behavior. Our search resulted in twenty experimental studies with high methodological quality. The synthesis of the latest evidence consolidates conclusions drawn in our initial systematic review that BED represents a distinct phenotype within the obesity spectrum that is characterized by increased impulsivity. Rash-spontaneous behavior in general, and specifically towards food, is increased in BED, while food-specific reward sensitivity is also increased in obese individuals without BED, but potentially to a lesser degree. A major next step for research entails the investigation of sub-domains and temporal components of inhibitory control in BED and obesity. Based on the evidence of impaired inhibitory control in BED, affected patients might profit from interventions that address impulsive behavior.

  15. Impulse oscillometry: a measure for airway obstruction.

    Science.gov (United States)

    Vink, Geraldine R; Arets, Hubertus G M; van der Laag, Johan; van der Ent, Cornelis K

    2003-03-01

    The impulse oscillometry system (IOS) was introduced as a new technique to assess airflow obstruction in patients who are not able to perform forced breathing maneuvers, e.g., subjects with cerebral palsy or severe mental retardation, and young children. This study evaluates the sensitivity and specificity of IOS parameters to quantify changes in airflow obstruction in comparison with forced expiratory volume in the first second (FEV(1)) and peak expiratory flow (PEF) measurements. Measurements of FEV(1), PEF, and resistance (R) and reactance (X) at frequencies of 5-35 Hz were performed in 19 children with asthma before, during, and after methacholine challenge and subsequent bronchodilatation. All parameters changed significantly during tests. Values of R5 and R10 correlated with FEV(1) (r = -0.71 and -0.73, respectively, P operating characteristic (ROC) curve to predict a 15% fall in FEV(1) showed better sensitivity and specificity for R5 (area under the curve, 0.85) compared to PEF (0.79) or R10 (0.73). We conclude that IOS parameters can be easily used as an indirect measure of airflow obstruction. This might be helpful in patients who are not able to perform forced breathing maneuvers. In individual subjects, R values measured at 5 Hz showed to be superior to PEF measurements in the detection of a 15% fall in FEV(1). Copyright 2003 Wiley-Liss, Inc.

  16. NORMATIVE MODERATORS OF IMPULSE BUYING BEHAVIOR

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    Danes Jaya Negara

    2003-01-01

    Full Text Available Prior research has presented the moderating role of normative evaluations in the relationship between the impulsive buying trait and consumers’ buying behaviors. In this article the authors show that consumer tendency to buy something spontaneous, unreflectively and immediately can be perceived as a factor which describes buying impulsiveness. This article also shows conceptual and empirical evidence that there is some support for the moderating role of normative evaluations in the relationship between buying impulsiveness and impulse buying behaviors. Significance occurs when consumers believe that act on impulse is suitable. The result suggests that consumers’ normative evaluation can moderate the link between the trait and behavioral aspects of impulse buying.

  17. Dopamine agonists and risk: impulse control disorders in Parkinson's disease.

    Science.gov (United States)

    Voon, Valerie; Gao, Jennifer; Brezing, Christina; Symmonds, Mkael; Ekanayake, Vindhya; Fernandez, Hubert; Dolan, Raymond J; Hallett, Mark

    2011-05-01

    Impulse control disorders are common in Parkinson's disease, occurring in 13.6% of patients. Using a pharmacological manipulation and a novel risk taking task while performing functional magnetic resonance imaging, we investigated the relationship between dopamine agonists and risk taking in patients with Parkinson's disease with and without impulse control disorders. During functional magnetic resonance imaging, subjects chose between two choices of equal expected value: a 'Sure' choice and a 'Gamble' choice of moderate risk. To commence each trial, in the 'Gain' condition, individuals started at $0 and in the 'Loss' condition individuals started at -$50 below the 'Sure' amount. The difference between the maximum and minimum outcomes from each gamble (i.e. range) was used as an index of risk ('Gamble Risk'). Sixteen healthy volunteers were behaviourally tested. Fourteen impulse control disorder (problem gambling or compulsive shopping) and 14 matched Parkinson's disease controls were tested ON and OFF dopamine agonists. Patients with impulse control disorder made more risky choices in the 'Gain' relative to the 'Loss' condition along with decreased orbitofrontal cortex and anterior cingulate activity, with the opposite observed in Parkinson's disease controls. In patients with impulse control disorder, dopamine agonists were associated with enhanced sensitivity to risk along with decreased ventral striatal activity again with the opposite in Parkinson's disease controls. Patients with impulse control disorder appear to have a bias towards risky choices independent of the effect of loss aversion. Dopamine agonists enhance sensitivity to risk in patients with impulse control disorder possibly by impairing risk evaluation in the striatum. Our results provide a potential explanation of why dopamine agonists may lead to an unconscious bias towards risk in susceptible individuals.

  18. Impulsivity and test meal intake among women with bulimia nervosa.

    Science.gov (United States)

    Sysko, Robyn; Ojserkis, Rachel; Schebendach, Janet; Evans, Suzette M; Hildebrandt, Tom; Walsh, B Timothy

    2017-05-01

    Many patients with bulimia nervosa (BN) also meet criteria for a lifetime alcohol use disorder (AUD). In order to understand possible mechanisms contributing to the co-occurrence and perpetuation of these disorders, this study investigated the importance of impulsivity and test meal intake among patients with BN by comparing women with BN only (n = 18), BN and current/past AUDs (n = 13), and healthy controls (n = 12). All participants completed assessments of eating disorder symptoms, frequency of alcohol use, binge eating, and purging via questionnaires and semi-structured interviews over two sessions. Measures of impulsivity consisted of computerized and self-report measures, and laboratory test meals. Significant differences between individuals with BN with/without comorbid AUDs were not found for test meal intake, impulsivity measures, or self-reported psychological symptoms. As hypothesized, compared to healthy controls, individuals with BN had significantly higher scores on two subscales and the total score of the Barratt Impulsiveness Scale, a trait measure of impulsivity, and consumed significantly more calories in the binge instruction meal. Total Barratt Impulsiveness Scale scores were also significantly related to kcal consumed during the laboratory test meal when individuals were instructed to binge eat (BN groups). Data from this study add to the existing literature implicating impulsivity in the psychopathology of disorders of binge eating, including BN, and also support the use of laboratory meals as a symptom-specific measure of this trait in eating disorder populations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Factors Affecting Online Impulse Buying: Evidence from Chinese Social Commerce Environment

    Directory of Open Access Journals (Sweden)

    Umair Akram

    2018-01-01

    Full Text Available First, the purpose of this study is to examine the impact of situational variables, scarcity and serendipity, on online impulse buying (OIB in Chinese social commerce (SC environment. Second, the study further assesses the moderating role of five dimensions of hedonic shopping value. Data were gathered from 671 online shoppers who come from two metropolitan cities of China, Beijing, and Shanghai. Structure equation modeling utilized was generated by AMOS 23 version to test the study hypotheses. The results confirm that situational factors positively influence the online impulse buying among Chinese online shoppers in SC environment. Four dimensions of hedonic shopping value (social shopping, relaxation shopping, adventure shopping and idea shopping positively moderate the relationship between serendipity and OIB; value shopping is insignificant with moderation effect. The finding is helpful to the online retailers and SC web developers by recommending them to take the scarcity and serendipity in their consideration. These factors have the potential to motivate the consumers to initiate the hedonic shopping aptitude to urge to buy impulsively. Unlike the previous work which remained unsuccessful in incorporating all factors into one study, this study has incorporated irrational and unplanned consumption along with rational and planned one in the same research.

  20. Dopamine Gene Profiling to Predict Impulse Control and Effects of Dopamine Agonist Ropinirole.

    Science.gov (United States)

    MacDonald, Hayley J; Stinear, Cathy M; Ren, April; Coxon, James P; Kao, Justin; Macdonald, Lorraine; Snow, Barry; Cramer, Steven C; Byblow, Winston D

    2016-07-01

    Dopamine agonists can impair inhibitory control and cause impulse control disorders for those with Parkinson disease (PD), although mechanistically this is not well understood. In this study, we hypothesized that the extent of such drug effects on impulse control is related to specific dopamine gene polymorphisms. This double-blind, placebo-controlled study aimed to examine the effect of single doses of 0.5 and 1.0 mg of the dopamine agonist ropinirole on impulse control in healthy adults of typical age for PD onset. Impulse control was measured by stop signal RT on a response inhibition task and by an index of impulsive decision-making on the Balloon Analogue Risk Task. A dopamine genetic risk score quantified basal dopamine neurotransmission from the influence of five genes: catechol-O-methyltransferase, dopamine transporter, and those encoding receptors D1, D2, and D3. With placebo, impulse control was better for the high versus low genetic risk score groups. Ropinirole modulated impulse control in a manner dependent on genetic risk score. For the lower score group, both doses improved response inhibition (decreased stop signal RT) whereas the lower dose reduced impulsiveness in decision-making. Conversely, the higher score group showed a trend for worsened response inhibition on the lower dose whereas both doses increased impulsiveness in decision-making. The implications of the present findings are that genotyping can be used to predict impulse control and whether it will improve or worsen with the administration of dopamine agonists.

  1. Impulse Oscillometry and Spirometry Small-Airway Parameters in Mild to Moderate Bronchiectasis.

    Science.gov (United States)

    Guan, Wei-Jie; Yuan, Jing-Jing; Gao, Yong-Hua; Li, Hui-Min; Zheng, Jin-Ping; Chen, Rong-Chang; Zhong, Nan-Shan

    2016-11-01

    Both impulse oscillometry and spirometry can reflect small-airway disorders. The objective of this work was to investigate the diagnostic value of impulse oscillometry and spirometry small-airway parameters and their correlation with radiology, disease severity, and sputum bacteriology in mild to moderate bronchiectasis (bronchiectasis severity index spirometry, and sputum culture were performed. Correlation between small-airway parameters and clinical indices was determined, adjusting for age, sex, body mass index, and smoking history. Sensitivity analyses were repeated when excluding subjects with bronchiectasis severity index ≥9 or HRCT score ≥13. Impulse oscillometry and spirometry small-airway parameters could discriminate mild to moderate bronchiectasis from healthy subjects and correlated significantly with HRCT score and the number of bronchiectatic lobes and the bronchiectasis severity index (all P Spirometry, but not impulse oscillometry, small-airway parameters differed statistically between subjects with isolated peripheral-airway bronchiectasis and those with peripheral plus central-airway bronchiectasis (all P spirometry small-airway parameters have similar diagnostic value in reflecting peripheral-airway disorders and correlate with the HRCT scores, the bronchiectasis severity index, and the number of bronchiectatic lobes in mild to moderate bronchiectasis. Assessment of small-airway parameters should be incorporated in future lung function investigations in bronchiectasis. Copyright © 2016 by Daedalus Enterprises.

  2. IMPULSIVE BUYING PADA DEWASA AWAL DI YOGYAKARTA

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    Paulus Henrietta

    2012-10-01

    Full Text Available T his research aimed to know the impulsive buying tendency of early adult in Yogyakarta. Impulsive buying was a buying activity without cosideration, and accompanied by strong emotional response. High impulsive buying tendency occured between age 18 to 39 years old. This research was a quantitative descriptive research with 395 subjects. Generally, the impulsive buying tendency in this research was low. Based on comparation between man and woman, it was found that woman was more impulsive than man. The result also showed that married person was more impulsive than unmarried person. Based on the types of job, there was several different among those types. But there was no different of impulsive buying tendency based on the education background level. Keywords: impulsive buying, early adult

  3. Impulsive action and impulsive choice across substance and behavioral addictions: cause or consequence?

    Science.gov (United States)

    Grant, Jon E; Chamberlain, Samuel R

    2014-11-01

    Substance use disorders are prevalent and debilitating. Certain behavioral syndromes ('behavioral addictions') characterized by repetitive habits, such as gambling disorder, stealing, shopping, and compulsive internet use, may share clinical, co-morbid, and neurobiological parallels with substance addictions. This review considers overlap between substance and behavioral addictions with a particular focus on impulsive action (inability to inhibit motor responses), and impulsive choice (preference for immediate smaller rewards to the detriment of long-term outcomes). We find that acute consumption of drugs with abuse potential is capable of modulating impulsive choice and action, although magnitude and direction of effect appear contingent on baseline function. Many lines of evidence, including findings from meta-analyses, show an association between chronic drug use and elevated impulsive choice and action. In some instances, elevated impulsive choice and action have been found to predate the development of substance use disorders, perhaps signifying their candidacy as objective vulnerability markers. Research in behavioral addictions is preliminary, and has mostly focused on impulsive action, finding this to be elevated versus controls, similar to that seen in chronic substance use disorders. Only a handful of imaging studies has explored the neural correlates of impulsive action and choice across these disorders. Key areas for future research are highlighted along with potential implications in terms of neurobiological models and treatment. In particular, future work should further explore whether the cognitive deficits identified are state or trait in nature: i.e. are evident before addiction perhaps signaling risk; or are a consequence of repetitive engagement in habitual behavior; and effects of novel agents known to modulate these cognitive abilities on various addictive disorders. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Impulsivity and the Sexes: Measurement and Structural Invariance of the UPPS-P Impulsive Behavior Scale

    Science.gov (United States)

    Cyders, Melissa A.

    2013-01-01

    Before it is possible to test whether men and women differ in impulsivity, it is necessary to evaluate whether impulsivity measures are invariant across sex. The UPPS-P Impulsive Behavior Scale (negative urgency, lack of premeditation, lack of perseverance, and sensation seeking, with added subscale of positive urgency) is one measure of five…

  5. Quantum calculus new concepts, impulsive IVPs and BVPs, inequalities

    CERN Document Server

    Ahmad, Bashir; Tariboon, Jessada

    2016-01-01

    The main objective of this book is to extend the scope of the q-calculus based on the definition of q-derivative [Jackson (1910)] to make it applicable to dense domains. As a matter of fact, Jackson's definition of q-derivative fails to work for impulse points while this situation does not arise for impulsive equations on q-time scales as the domains consist of isolated points covering the case of consecutive points. In precise terms, we study quantum calculus on finite intervals.In the first part, we discuss the concepts of qk-derivative and qk-integral, and establish their basic properties. As applications, we study initial and boundary value problems of impulsive qk-difference equations and inclusions equipped with different kinds of boundary conditions. We also transform some classical integral inequalities and develop some new integral inequalities for convex functions in the context of qk-calculus. In the second part, we develop fractional quantum calculus in relation to a new qk-shifting operator and e...

  6. Design of a High Temperature Radiator for the Variable Specific Impulse Magnetoplasma Rocket

    Science.gov (United States)

    Sheth, Rubik B.; Ungar, Eugene K.; Chambliss, Joe P.

    2012-01-01

    The Variable Specific Impulse Magnetoplasma Rocket (VASIMR), currently under development by Ad Astra Rocket Company (Webster, TX), is a unique propulsion system that could change the way space propulsion is performed. VASIMR's efficiency, when compared to that of a conventional chemical rocket, reduces the propellant needed for exploration missions by a factor of 10. Currently plans include flight tests of a 200 kW VASIMR system, titled VF-200, on the International Space Station (ISS). The VF-200 will consist of two 100 kW thruster units packaged together in one engine bus. Each thruster core generates 27 kW of waste heat during its 15 minute firing time. The rocket core will be maintained between 283 and 573 K by a pumped thermal control loop. The design of a high temperature radiator is a unique challenge for the vehicle design. This paper will discuss the path taken to develop a steady state and transient-based radiator design. The paper will describe the radiator design option selected for the VASIMR thermal control system for use on ISS, and how the system relates to future exploration vehicles.

  7. Epidemiologic and clinical updates on impulse control disorders: a critical review

    Science.gov (United States)

    Altamura, A. Carlo; Allen, Andrea; Marazziti, Donatella; Hollander, Eric

    2006-01-01

    The article reviews the current knowledge about the impulse control disorders (ICDs) with specific emphasis on epidemiological and pharmacological advances. In addition to the traditional ICDs present in the DSM-IV—pathological gambling, trichotillomania, kleptomania, pyromania and intermittent explosive disorder—a brief description of the new proposed ICDs—compulsive–impulsive (C–I) Internet usage disorder, C–I sexual behaviors, C–I skin picking and C–I shopping—is provided. Specifically, the article summarizes the phenomenology, epidemiology and comorbidity of the ICDs. Particular attention is paid to the relationship between ICDs and obsessive–compulsive disorder (OCD). Finally, current pharmacological options for treating ICDs are presented and discussed. PMID:16960655

  8. Impulsiveness and venturesomeness in German smokers.

    Science.gov (United States)

    Bernow, Nina; Kruck, Bernadette; Pfeifer, Philippe; Lieb, Klaus; Tüscher, Oliver; Fehr, Christoph

    2011-08-01

    Cigarette smoking is a behavior, which is influenced by genetic, demographic, and psychological factors. A large body of research has examined the association of cigarette smoking variables with individual differences in personality traits. The aim of the current study was to replicate the findings of higher self-reported impulsivity in smokers compared with never-smokers in a German sample using Eysenck´s construct of impulsivity. Furthermore, it was intended to further the knowledge about associations between different self-reported impulsivity components and different smoking variables. We used the Impulsiveness-Venturesomeness-Empathy questionnaire (I7) to measure self-reported impulsiveness and venturesomeness and the Temperament and Character Inventory (TCI) to measure novelty seeking (NS) in a sample of 82 nicotine-dependent smokers and 119 never-smokers. Smokers scored higher on impulsiveness, venturesomeness, and NS than never-smokers independent of age, gender, and years of education. We found a significant association between venturesomeness, impulsiveness and smoking status in daily smokers. In summary, this study provides evidence that impulsiveness and venturesomeness as well as the novelty-seeking subscale extravagance are significantly associated with smoking status in a German sample of female and male smokers compared with never-smokers.

  9. Impaired decisional impulsivity in pathological videogamers.

    Directory of Open Access Journals (Sweden)

    Michael A Irvine

    Full Text Available Pathological gaming is an emerging and poorly understood problem. Impulsivity is commonly impaired in disorders of behavioural and substance addiction, hence we sought to systematically investigate the different subtypes of decisional and motor impulsivity in a well-defined pathological gaming cohort.Fifty-two pathological gaming subjects and age-, gender- and IQ-matched healthy volunteers were tested on decisional impulsivity (Information Sampling Task testing reflection impulsivity and delay discounting questionnaire testing impulsive choice, and motor impulsivity (Stop Signal Task testing motor response inhibition, and the premature responding task. We used stringent diagnostic criteria highlighting functional impairment.In the Information Sampling Task, pathological gaming participants sampled less evidence prior to making a decision and scored fewer points compared with healthy volunteers. Gaming severity was also negatively correlated with evidence gathered and positively correlated with sampling error and points acquired. In the delay discounting task, pathological gamers made more impulsive choices, preferring smaller immediate over larger delayed rewards. Pathological gamers made more premature responses related to comorbid nicotine use. Greater number of hours played also correlated with a Motivational Index. Greater frequency of role playing games was associated with impaired motor response inhibition and strategy games with faster Go reaction time.We show that pathological gaming is associated with impaired decisional impulsivity with negative consequences in task performance. Decisional impulsivity may be a potential target in therapeutic management.

  10. Narcissism predicts impulsive buying: phenotypic and genetic evidence

    Directory of Open Access Journals (Sweden)

    Huajian eCai

    2015-07-01

    Full Text Available Impulsive buying makes billions of dollars for retail businesses every year, particularly in an era of thriving e-commerce. Narcissism, characterized by impulsivity and materialism, may serve as a potential antecedent to impulsive buying. To test this hypothesis, two studies examined the relationship between narcissism and impulsive buying. In study 1, we surveyed narcissism and the impulsive buying tendency among an online sample and found that while adaptive narcissism was not correlated with impulsive buying, maladaptive narcissism was significantly predictive of the impulsive buying tendency. By investigating narcissism and the impulsive buying tendency in 304 twin pairs, study 2 showed that global narcissism and its two components, adaptive and maladaptive narcissism, as well as the impulsive buying tendency were heritable. The study found, moreover, that the connections between global narcissism and impulsive buying, and between maladaptive narcissism and impulsive buying were genetically based. These findings not only establish a link between narcissism and impulsive buying but also help to identify the origins of the link. The present studies deepen our understanding of narcissism, impulsive buying, and their interrelationship.

  11. Effects of goal clarification on impulsivity and academic procrastination of college students

    OpenAIRE

    Juan F. Muñoz-Olano; Camilo Hurtado-Parrado

    2017-01-01

    Nearly 50% of the college population struggles with academic procrastination, which is an impulsivity problem that often leads to emotional difficulties and college dropout. This study aimed to assess whether an online intervention on clarification of academic goals could reduce impulsivity and academic procrastination in college students. Forty-eight participants were assigned to three different types of interventions: (a) SMART-type goal clarification treatment (setting specific, measurable...

  12. Impulsivity in Parkinson’s Disease Is Associated With Alterations in Affective and Sensorimotor Striatal Networks

    Directory of Open Access Journals (Sweden)

    Marit F. L. Ruitenberg

    2018-04-01

    Full Text Available A subset of patients with Parkinson’s disease (PD experiences problems with impulse control, characterized by a loss of voluntary control over impulses, drives, or temptations regarding excessive hedonic behavior. The present study aimed to better understand the neural basis of such impulse control disorders (ICDs in PD. We collected resting-state functional connectivity and structural MRI data from 21 PD patients with ICDs and 30 patients without such disorders. To assess impulsivity, all patients completed the Barratt Impulsiveness Scale and performed an information-gathering task. MRI results demonstrated substantial differences in neural characteristics between PD patients with and without ICDs. Results showed that impulsivity was linked to alterations in affective basal ganglia circuitries. Specifically, reduced frontal–striatal connectivity and GPe volume were associated with more impulsivity. We suggest that these changes affect decision making and result in a preference for risky or inappropriate actions. Results further showed that impulsivity was linked to alterations in sensorimotor striatal networks. Enhanced connectivity within this network and larger putamen volume were associated with more impulsivity. We propose that these changes affect sensorimotor processing such that patients have a greater propensity to act. Our findings suggest that the two mechanisms jointly contribute to impulsive behaviors in PD.

  13. ACOUSTIC RADIATION FORCE IMPULSE IS EQUIVALENT TO LIVER BIOPSY TO EVALUATE LIVER FIBROSIS IN PATIENTS WITH CHRONIC HEPATITIS C AND NONALCOHOLIC FATTY LIVER DISEASE

    Directory of Open Access Journals (Sweden)

    Juliana Ayres de Alencar Arrais GUERRA

    2015-09-01

    Full Text Available BackgroundLiver biopsy is recommended as the gold standard method for assessing the stage of liver fibrosis in patients with chronic liver disease. However, it is invasive, with potential risks and complications. Elastography is an ultrasound technique that provides information of changes in the liver tissue, evaluating tissue elasticity and acoustic radiation force impulse is one of the available techniques.ObjectiveThe main objective of this study was to evaluate the sensitivity and specificity of acoustic radiation force impulse comparing to liver biopsy to evaluate fibrosis in patients with chronic hepatitis C virus and nonalcoholic fatty liver disease.MethodsTwenty four patients were included, everyone underwent liver biopsy and acoustic radiation force impulse, and the results were compared with values described in the literature by several authors.ResultsIn the population of patients with chronic hepatitis C, our data were better correlated with data published by Carmen Fierbinteanu-Braticevici et al., with an accuracy of 82.4%, sensitivity of 71.4% and specificity of 90%. For nonalcoholic fatty liver disease, our data were better correlated with data published by Masato Yoneda et al., with an accuracy of 85.7%, sensitivity 80% and specificity of 100%.ConclusionAcoustic radiation force impulse is a method with good accuracy to distinguish initial fibrosis from advanced fibrosis in hepatitis C virus and nonalcoholic fatty liver disease and can replace biopsy in most cases.

  14. Impulsivity: A deficiency of inhibitory control?

    NARCIS (Netherlands)

    Lansbergen, M.M.

    2007-01-01

    Impulsivity has been defined as acting without thinking. Impulsivity can be quantified by impulsivity questionnaires, but also by behavioral paradigms which tax inhibitory control. Previous research has repeatedly demonstrated deficient inhibitory control in psychopathological samples characterized

  15. Relativistic impulse dynamics.

    Science.gov (United States)

    Swanson, Stanley M

    2011-08-01

    Classical electrodynamics has some annoying rough edges. The self-energy of charges is infinite without a cutoff. The calculation of relativistic trajectories is difficult because of retardation and an average radiation reaction term. By reconceptuallizing electrodynamics in terms of exchanges of impulses rather than describing it by forces and potentials, we eliminate these problems. A fully relativistic theory using photonlike null impulses is developed. Numerical calculations for a two-body, one-impulse-in-transit model are discussed. A simple relationship between center-of-mass scattering angle and angular momentum was found. It reproduces the Rutherford cross section at low velocities and agrees with the leading term of relativistic distinguishable-particle quantum cross sections (Møller, Mott) when the distance of closest approach is larger than the Compton wavelength of the particle. Magnetism emerges as a consequence of viewing retarded and advanced interactions from the vantage point of an instantaneous radius vector. Radiation reaction becomes the local conservation of energy-momentum between the radiating particle and the emitted impulse. A net action is defined that could be used in developing quantum dynamics without potentials. A reinterpretation of Newton's laws extends them to relativistic motion.

  16. Predicting impulsive self-injurious behavior in a sample of adult women.

    Science.gov (United States)

    Black, Emma B; Mildred, Helen

    2013-01-01

    Different types of self-injury have been classified as reflecting impulsive and compulsive characteristics (article by Simeon and Favazza [Self-injurious Behaviors: Assessment and Treatment {pp 1-28}. Washington, DC: American Psychiatric Publishing, Inc, 2001]). The current research used a prospective design to evaluate whether there is a progression between these different types of self-injurious behaviors (SIB) over time. Support was found for a progression from compulsive SIB (including hair pulling, nail-biting, skin picking, scratching, and preventing wounds from healing) to impulsive SIB (including cutting, burning, carving, pin sticking, and punching) in a group of adult women (N = 106). Other factors hypothesized to be linked to this outcome were disordered eating, age, and personality facets of impulsivity (specifically, urgency and lack of perseverance). Of these variables, only urgency positively predicted impulsive SIB at the study's conclusion. These findings are discussed, limitations of the study are noted, and directions for future research are outlined.

  17. Parental monitoring may protect impulsive children from overeating.

    Science.gov (United States)

    Bennett, C; Blissett, J

    2017-10-01

    Research has highlighted links between impulsivity and weight in children and adults. Nevertheless, little is known about the nature of this link in very young children or about the underlying mechanism by which impulsivity leads to greater adiposity. The present study aimed to explore relationships between impulsivity, weight and eating behaviour in a sample of 95 2 to 4-year-olds. Parent-child dyads visited the laboratory and consumed a meal after which parents completed measures of child impulsivity, eating behaviour and parental feeding, whilst children completed impulsivity tasks measuring the impulsivity facet delay of gratification (Snack Delay task), motor impulsivity (Line Walking task) and inhibitory control (Tower task). Pearson's correlations showed that girls with greater motor impulsivity were heavier. Additionally, monitoring moderated the relationship between impulsivity and food approach behaviour, indicating that monitoring may protect more impulsive children from displaying problematic eating behaviours. The motor impulsivity facet appears particularly relevant to child weight; parents can modulate the impact of impulsivity on child eating behaviour through their feeding style. © 2016 World Obesity Federation.

  18. Impulsive behavior and nicotinic acetylcholine receptors.

    Science.gov (United States)

    Ohmura, Yu; Tsutsui-Kimura, Iku; Yoshioka, Mitsuhiro

    2012-01-01

    Higher impulsivity is thought to be a risk factor for drug addiction, criminal involvement, and suicide. Excessive levels of impulsivity are often observed in several psychiatric disorders including attention-deficit/hyperactivity disorder and schizophrenia. Previous studies have demonstrated that nicotinic acetylcholine receptors (nAChRs) are involved in impulsive behavior. Here, we introduce recent advances in this field and describe the role of the following nAChR-related brain mechanisms in modulating impulsive behavior: dopamine release in the ventral striatum; α4β2 nAChRs in the infralimbic cortex, which is a ventral part of the medial prefrontal cortex (mPFC); and dopamine release in the mPFC. We also suggest several potential therapeutic drugs to address these mechanisms in impulsivity-related disorders and explore future directions to further elucidate the roles of central nAChRs in impulsive behavior.

  19. Narcissism predicts impulsive buying: phenotypic and genetic evidence

    Science.gov (United States)

    Cai, Huajian; Shi, Yuanyuan; Fang, Xiang; Luo, Yu L. L.

    2015-01-01

    Impulsive buying makes billions of dollars for retail businesses every year, particularly in an era of thriving e-commerce. Narcissism, characterized by impulsivity and materialism, may serve as a potential antecedent to impulsive buying. To test this hypothesis, two studies examined the relationship between narcissism and impulsive buying. In Study 1, we surveyed an online sample and found that while adaptive narcissism was not correlated with impulsive buying, maladaptive narcissism was significantly predictive of the impulsive buying tendency. By investigating 304 twin pairs, Study 2 showed that global narcissism and its two components, adaptive and maladaptive narcissism, as well as the impulsive buying tendency were heritable. The study found, moreover, that the connections between global narcissism and impulsive buying, and between maladaptive narcissism and impulsive buying were genetically based. These findings not only establish a link between narcissism and impulsive buying but also help to identify the origins of the link. The present studies deepen our understanding of narcissism, impulsive buying, and their interrelationship. PMID:26217251

  20. Narcissism predicts impulsive buying: phenotypic and genetic evidence.

    Science.gov (United States)

    Cai, Huajian; Shi, Yuanyuan; Fang, Xiang; Luo, Yu L L

    2015-01-01

    Impulsive buying makes billions of dollars for retail businesses every year, particularly in an era of thriving e-commerce. Narcissism, characterized by impulsivity and materialism, may serve as a potential antecedent to impulsive buying. To test this hypothesis, two studies examined the relationship between narcissism and impulsive buying. In Study 1, we surveyed an online sample and found that while adaptive narcissism was not correlated with impulsive buying, maladaptive narcissism was significantly predictive of the impulsive buying tendency. By investigating 304 twin pairs, Study 2 showed that global narcissism and its two components, adaptive and maladaptive narcissism, as well as the impulsive buying tendency were heritable. The study found, moreover, that the connections between global narcissism and impulsive buying, and between maladaptive narcissism and impulsive buying were genetically based. These findings not only establish a link between narcissism and impulsive buying but also help to identify the origins of the link. The present studies deepen our understanding of narcissism, impulsive buying, and their interrelationship.

  1. A compressed sensing based method with support refinement for impulse noise cancelation in DSL

    KAUST Repository

    Quadeer, Ahmed Abdul

    2013-06-01

    This paper presents a compressed sensing based method to suppress impulse noise in digital subscriber line (DSL). The proposed algorithm exploits the sparse nature of the impulse noise and utilizes the carriers, already available in all practical DSL systems, for its estimation and cancelation. Specifically, compressed sensing is used for a coarse estimate of the impulse position, an a priori information based maximum aposteriori probability (MAP) metric for its refinement, followed by least squares (LS) or minimum mean square error (MMSE) estimation for estimating the impulse amplitudes. Simulation results show that the proposed scheme achieves higher rate as compared to other known sparse estimation algorithms in literature. The paper also demonstrates the superior performance of the proposed scheme compared to the ITU-T G992.3 standard that utilizes RS-coding for impulse noise refinement in DSL signals. © 2013 IEEE.

  2. The role of impulsivity, inattention and comorbid ADHD in patients with bulimia nervosa.

    Directory of Open Access Journals (Sweden)

    Jochen Seitz

    Full Text Available INTRODUCTION: Little is known about the contribution of impulsivity, inattention and comorbid attention deficit/hyperactivity disorder (ADHD in the development and maintenance of bulimia nervosa (BN. In particular, their specific contribution to disordered eating symptoms and whether they have additive effects to the general psychopathological burden remains unclear. METHODS: Fifty-seven female patients seeking treatment for BN and 40 healthy controls completed diagnostic questionnaires and interviews that investigated: a ADHD, b impulsivity, c eating disorders and d general psychopathology. Attentional processes and impulsivity were assessed by a comprehensive computer-based neuropsychological battery. RESULTS: Twenty-one percent of patients with BN met the clinical cut-off for previous childhood ADHD compared to 2.5% of healthy controls. Adult ADHD according to DSM IV was also more prevalent in patients with BN, with an odds ratio of 4.2. Patients with BN and previous childhood ADHD were more impulsive and inattentive than patients with BN alone. These patients also displayed more severely disordered eating patterns and more general psychopathological symptoms compared with those without ADHD. Severity of eating disorder symptoms was better explained by inattentiveness than by either impulsivity or hyperactivity. DISCUSSION: Our data suggest an elevated rate of former childhood and current ADHD-symptoms in treatment-seeking patients with BN. Stronger impulsivity and inattention associated with more severe neuropsychological deficits and eating disorder symptoms indicate an additive risk that is clinically relevant for these patients. Thus, clinicians should identify comorbid patients who might profit from additional ADHD-specific treatments.

  3. Trait impulsivity in suicide attempters: preliminary study.

    Science.gov (United States)

    Doihara, Chiho; Kawanishi, Chiaki; Ohyama, Nene; Yamada, Tomoki; Nakagawa, Makiko; Iwamoto, Yohko; Odawara, Toshinari; Hirayasu, Yoshio

    2012-10-01

    Suicide attempt is a risk factor for suicide. To investigate trait impulsivity among suicide attempters, 93 attempters admitted to an emergency department and 113 healthy controls were evaluated using the Japanese version of the Barratt Impulsiveness Scale (BIS-11J). Impulsivity was analyzed in relation to clinical data in the attempters. Total BIS-11J, attention impulsiveness, and motor impulsiveness scores were significantly higher in the attempters than in the controls. Both total BIS-11J and non-planning impulsiveness scores were significantly higher in attempters with schizophrenia and other psychotic disorders among the diagnostic groups. Control of impulsivity should be considered as one of the targets for suicide prevention. © 2012 The Authors. Psychiatry and Clinical Neurosciences © 2012 Japanese Society of Psychiatry and Neurology.

  4. Female impulsive aggression: a sleep research perspective.

    Science.gov (United States)

    Lindberg, Nina; Tani, Pekka; Putkonen, Hanna; Sailas, Eila; Takala, Pirjo; Eronen, Markku; Virkkunen, Matti

    2009-01-01

    The rate of violent crimes among girls and women appears to be increasing. One in every five female prisoners has been reported to have antisocial personality disorder. However, it has been quite unclear whether the impulsive, aggressive behaviour among women is affected by the same biological mechanisms as among men. Psychiatric sleep research has attempted to identify diagnostically sensitive and specific sleep patterns associated with particular disorders. Most psychiatric disorders are typically characterized by a severe sleep disturbance associated with decreased amounts of slow wave sleep (SWS), the physiologically significant, refreshing part of sleep. Among men with antisocial behaviour with severe aggression, on the contrary, increased SWS has been reported, reflecting either specific brain pathology or a delay in the normal development of human sleep patterns. In our preliminary study among medication-free, detoxified female homicidal offenders with antisocial personality disorder, the same profound abnormality in sleep architecture was found. From the perspective of sleep research, the biological correlates of severe impulsive aggression seem to share similar features in both sexes.

  5. THE INFLUENCE OF HEDONIC SHOPPING MOTIVATION TO THE IMPULSE BUYING OF ONLINE-SHOPPING CONSUMER ON INSTAGRAM

    OpenAIRE

    Asnawati; Wahyuni S.

    2018-01-01

    This research aims to know the influence of Adventure Shopping, Relaxation Shopping, Value Shopping, Social Shopping and Idea Shopping variables to the variable of Impulse Buying of Online-Shopping Consumer on Instagram. The type of the research is explanatory research. The result of F-test showed that Fcount (12.829) > Ftable (2.669) which meant that research variables had influences to the Impulse Buying. With partial correlation value of 0.548, Idea Shopping variable became the dominant fa...

  6. Impulsivity, self-regulation,and pathological video gaming among youth: testing a mediation model.

    Science.gov (United States)

    Liau, Albert K; Neo, Eng Chuan; Gentile, Douglas A; Choo, Hyekyung; Sim, Timothy; Li, Dongdong; Khoo, Angeline

    2015-03-01

    Given the potential negative mental health consequences of pathological video gaming, understanding its etiology may lead to useful treatment developments. The purpose of the study was to examine the influence of impulsive and regulatory processes on pathological video gaming. Study 1 involved 2154 students from 6 primary and 4 secondary schools in Singapore. Study 2 involved 191 students from 2 secondary schools. The results of study 1 and study 2 supported the hypothesis that self-regulation is a mediator between impulsivity and pathological video gaming. Specifically, higher levels of impulsivity was related to lower levels of self-regulation, which in turn was related to higher levels of pathological video gaming. The use of impulsivity and self-regulation in predicting pathological video gaming supports the dual-system model of incorporating both impulsive and reflective systems in the prediction of self-control outcomes. The study highlights the development of self-regulatory resources as a possible avenue for future prevention and treatment research. © 2011 APJPH.

  7. Guidance Preconditioning by an Impulse Sequence for Robust Residual Vibration Suppression

    Directory of Open Access Journals (Sweden)

    I. Antoniadis

    1999-01-01

    Full Text Available In order to suppress residual vibrations, a general method is presented for preconditioning any guidance function prior to its application to a dynamic system, by convolving it with a sequence of impulses. The approach includes first the development of the necessary design specifications for the impulse sequence, so that the robustness properties cover the widest possible variation of the system natural frequencies. Three solution methods are proposed then, with special emphasis in the achievement of the minimum possible duration time of the impulse sequence. Numerical experiments verify the effectiveness of the robustness, not only with respect to variations of the natural frequency, but also with respect to variations of a range of other linear and non-linear variables.

  8. N-th order impulsive integro-differential equations in Banach spaces

    Directory of Open Access Journals (Sweden)

    Manfeng Hu

    2004-03-01

    Full Text Available We investigate the maximal and minimal solutions of initial value problem for N-th order nonlinear impulsive integro-differential equation in Banach space by establishing a comparison result and using the upper and lower solutions methods.

  9. "Impulsive" suicide attempts: What do we really mean?

    Science.gov (United States)

    May, Alexis M; Klonsky, E David

    2016-07-01

    Suicide attempts are often regarded as impulsive acts. However, there is little consensus regarding the definition or clinical characteristics of an "impulsive" attempt. To clarify this issue, we examined 3 indicators of the impulsivity of an attempt: (a) preparation, (b) time contemplating the attempt, and (c) self-report that impulsivity motivated the attempt. We examined relationships among the indicators and their relationship to trait impulsivity and characteristics of the suicide attempt. Adult participants (N = 205) with a history of suicide attempts were administered validated interviews and questionnaires. In general, the 3 attempt impulsivity indicators correlated only moderately with each other and not at all with trait impulsivity or with important characteristics of the attempt (e.g., lethality, preattempt communication, motivations). However, there were 2 exceptions. First, intent to die was inversely related to the 3 attempt impulsivity indicators (rs ranged from -.17 to .45) such that more impulsive attempts were associated with lower intent. Second, self-report that the attempt was motivated by impulsivity was related to 3 facets of trait impulsivity (rs ranged from .16 to .41). These findings suggest that individuals endorsing trait impulsivity are likely to describe their attempts as motivated by impulsivity, regardless of the presence of preparation or prolonged contemplation. Overall, study results suggest that the common conception of a unidimensional impulsive attempt may be inaccurate and that the emphasis on general impulsivity in prevention guidelines should be tempered. Implications for suicide risk assessment and prevention are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  10. Impulse control disorders and levodopa-induced dyskinesias in Parkinson's disease: an update.

    Science.gov (United States)

    Voon, Valerie; Napier, T Celeste; Frank, Michael J; Sgambato-Faure, Veronique; Grace, Anthony A; Rodriguez-Oroz, Maria; Obeso, Jose; Bezard, Erwan; Fernagut, Pierre-Olivier

    2017-03-01

    Dopaminergic medications used in the treatment of patients with Parkinson's disease are associated with motor and non-motor behavioural side-effects, such as dyskinesias and impulse control disorders also known as behavioural addictions. Levodopa-induced dyskinesias occur in up to 80% of patients with Parkinson's after a few years of chronic treatment. Impulse control disorders, including gambling disorder, binge eating disorder, compulsive sexual behaviour, and compulsive shopping occur in about 17% of patients with Parkinson's disease on dopamine agonists. These behaviours reflect the interactions of the dopaminergic medications with the individual's susceptibility, and the underlying neurobiology of Parkinson's disease. Parkinsonian rodent models show enhanced reinforcing effects of chronic dopaminergic medication, and a potential role for individual susceptibility. In patients with Parkinson's disease and impulse control disorders, impairments are observed across subtypes of decisional impulsivity, possibly reflecting uncertainty and the relative balance of rewards and losses. Impairments appear to be more specific to decisional than motor impulsivity, which might reflect differences in ventral and dorsal striatal engagement. Emerging evidence suggests impulse control disorder subtypes have dissociable correlates, which indicate that individual susceptibility predisposes towards the expression of different behavioural subtypes and neurobiological substrates. Therapeutic interventions to treat patients with Parkinson's disease and impulse control disorders have shown efficacy in randomised controlled trials. Large-scale studies are warranted to identify individual risk factors and novel therapeutic targets for these diseases. Mechanisms underlying impulse control disorders and dyskinesias could provide crucial insights into other behavioural symptoms in Parkinson's disease and addictions in the general population. Copyright © 2017 Elsevier Ltd. All rights

  11. Impulsive Buying Pada Dewasa Awal Di YOGYAKARTA

    OpenAIRE

    Henrietta, Paulus

    2012-01-01

    This research aimed to know the impulsive buying tendency of early adult in Yogyakarta. Impulsive buying was a buying activity without cosideration, and accompanied by strong emotional response. High impulsive buying tendency occured between age 18 to 39 years old. This research was a quantitative descriptive research with 395 subjects. Generally, the impulsive buying tendency in this research was low. Based on comparation between man and woman, it was found that woman was more impulsive than...

  12. IMPULSIVE BUYING PADA DEWASA AWAL DI YOGYAKARTA

    OpenAIRE

    Paulus Henrietta

    2012-01-01

    T his research aimed to know the impulsive buying tendency of early adult in Yogyakarta. Impulsive buying was a buying activity without cosideration, and accompanied by strong emotional response. High impulsive buying tendency occured between age 18 to 39 years old. This research was a quantitative descriptive research with 395 subjects. Generally, the impulsive buying tendency in this research was low. Based on comparation between man and woman, it was found that woman was more impulsive...

  13. Proficient motor impulse control in Parkinson disease patients with impulsive and compulsive behaviors

    NARCIS (Netherlands)

    Claassen, D.O.; van den Wildenberg, W.P.; Harrison, M.B.; van Wouwe, N.C.; Kanoff, K.; Neimat, J.S.; Wylie, S.A.

    2015-01-01

    BACKGROUND: Parkinson disease (PD) patients treated with dopamine agonist therapy can develop maladaptive reward-driven behaviors, known as impulse control disorder (ICD). In this study, we assessed if ICD patients have evidence of motor-impulsivity. METHODS: We used the stop-signal task in a cohort

  14. Impulsivity, self-control, and hypnotic suggestibility.

    Science.gov (United States)

    Ludwig, V U; Stelzel, C; Krutiak, H; Prunkl, C E; Steimke, R; Paschke, L M; Kathmann, N; Walter, H

    2013-06-01

    Hypnotic responding might be due to attenuated frontal lobe functioning after the hypnotic induction. Little is known about whether personality traits linked with frontal functioning are associated with responsiveness to hypnotic suggestions. We assessed whether hypnotic suggestibility is related to the traits of self-control and impulsivity in 154 participants who completed the Brief Self-Control Scale, the Self-Regulation Scale, the Barratt Impulsiveness Scale (BIS-11), and the Harvard Group Scale of Hypnotic Susceptibility (HGSHS:A). BIS-11 non-planning impulsivity correlated positively with HGSHS:A (Bonferroni-corrected). Furthermore, in the best model emerging from a stepwise multiple regression, both non-planning impulsivity and self-control positively predicted hypnotic suggestibility, and there was an interaction of BIS-11 motor impulsivity with gender. For men only, motor impulsivity tended to predict hypnotic suggestibility. Hypnotic suggestibility is associated with personality traits linked with frontal functioning, and hypnotic responding in men and women might differ. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Rethinking Impulsivity in Suicide

    Science.gov (United States)

    Klonsky, E. David; May, Alexis

    2010-01-01

    Elevated impulsivity is thought to facilitate the transition from suicidal thoughts to suicidal behavior. Therefore, impulsivity should distinguish those who have attempted suicide (attempters) from those who have only considered suicide (ideators-only). This hypothesis was examined in three large nonclinical samples: (1) 2,011 military recruits,…

  16. The dynamical behaviors of a food chain model with impulsive effect and Ivlev functional response

    International Nuclear Information System (INIS)

    Xiang Zhongyi; Song Xinyu

    2009-01-01

    In this paper, a food chain model with Ivlev functional response and impulsive effect of top predator is investigated. Conditions for extinction of mid-level predator are given. By using the Floquet theory of linear τ-period impulsive differential equation and small amplitude perturbation skills, we show that the lowest-level prey and the mid-level predator extinction periodic solution is unstable, while the mid-level predator eradication periodic solution is stable, and meanwhile, we prove that the system is permanent if the impulsive period is larger than some critical value. Furthermore, influences of the impulsive perturbation on the inherent oscillation are studied numerically, which displays complicated behavior including a sequence of direct and inverse cascade of period doubling, period halfing as well as chaos.

  17. General and Food-Specific Inhibitory Control As Moderators of the Effects of the Impulsive Systems on Food Choices

    Directory of Open Access Journals (Sweden)

    Xuemeng Zhang

    2017-05-01

    Full Text Available The present study aimed to extend the application of the reflective-impulsive model to restrained eating and explore the effect of automatic attention (impulsive system on food choices. Furthermore, we examined the moderating effects of general inhibitory control (G-IC and food-specific inhibitory control (F-IC on successful and unsuccessful restrained eaters (US-REs. Automatic attention was measured using “the EyeLink 1000,” which tracked eye movements during the process of making food choices, and G-IC and F-IC were measured using the Stop-Signal Task. The results showed that food choices were related to automatic attention and that G-IC and F-IC moderated the predictive relationship between automatic attention and food choices. Furthermore, among successful restrained eaters (S-REs, automatic attention to high caloric foods did not predict food choices, regardless of whether G-IC or F-IC was high or low. Whereas food choice was positively correlated with automatic attention among US-REs with poor F-IC, this pattern was not observed in those with poor G-IC. In conclusion, the S-REs had more effective self-management skills and their food choices were affected less by automatic attention and inhibitory control. Unsuccessful restrained eating was associated with poor F-IC (not G-IC and greater automatic attention to high caloric foods. Thus, clinical interventions should focus on enhancing F-IC, not G-IC, and on reducing automatic attention to high caloric foods.

  18. Multiple modes of impulsivity in Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Cristina Nombela

    Full Text Available Cognitive problems are a major factor determining quality of life of patients with Parkinson's disease. These include deficits in inhibitory control, ranging from subclinical alterations in decision-making to severe impulse control disorders. Based on preclinical studies, we proposed that Parkinson's disease does not cause a unified disorder of inhibitory control, but rather a set of impulsivity factors with distinct psychological profiles, anatomy and pharmacology. We assessed a broad set of measures of the cognitive, behavioural and temperamental/trait aspects of impulsivity. Sixty adults, including 30 idiopathic Parkinson's disease patients (Hoehn and Yahr stage I-III and 30 healthy controls, completed a neuropsychological battery, objective behavioural measures and self-report questionnaires. Univariate analyses of variance confirmed group differences in nine out of eleven metrics. We then used factor analysis (principal components method to identify the structure of impulsivity in Parkinson's disease. Four principal factors were identified, consistent with four different mechanisms of impulsivity, explaining 60% of variance. The factors were related to (1 tests of response conflict, interference and self assessment of impulsive behaviours on the Barrett Impulsivity Scale, (2 tests of motor inhibitory control, and the self-report behavioural approach system, (3 time estimation and delay aversion, and (4 reflection in hypothetical scenarios including temporal discounting. The different test profiles of these four factors were consistent with human and comparative studies of the pharmacology and functional anatomy of impulsivity. Relationships between each factor and clinical and demographic features were examined by regression against factor loadings. Levodopa dose equivalent was associated only with factors (2 and (3. The results confirm that impulsivity is common in Parkinson's disease, even in the absence of impulse control disorders, and

  19. Dynamic Properties of Impulse Measuring Systems

    DEFF Research Database (Denmark)

    Pedersen, A.; Lausen, P.

    1971-01-01

    After some basic considerations the dynamic properties of the measuring system are subjected to a general examination based on a number of responses, characteristic of the system. It is demonstrated that an impulse circuit has an internal impedance different from zero, for which reason...... the interaction between the generator and the measuring circuit is of paramount importance to the voltage across the test object. Based on the measured values the determination of the applied voltage is considered....

  20. Mediators of the association between narcissism and compulsive buying: the roles of materialism and impulse control.

    Science.gov (United States)

    Rose, Paul

    2007-12-01

    Building upon past research about the guiding values and self-regulation difficulties of people with narcissistic personalities, this study tested a model of the association between narcissism and compulsive consumption. In data obtained from a sample of undergraduate consumers (N=238) with varying degrees of spending problems, positive associations emerged between narcissism, materialism, and compulsive buying. Impulse control was negatively correlated with each of these variables. Mediation tests revealed that both impulse control and materialism accounted for significant portions of the shared variance between narcissism and compulsive consumption. These findings highlight the importance of both personal values and impulse control as correlates of addictive buying. They also add to growing evidence that people who are relatively narcissistic are poor self-regulators who may be at risk of developing a variety of addictive behaviors.

  1. Numerical Algorithms for Deterministic Impulse Control Models with Applications

    NARCIS (Netherlands)

    Grass, D.; Chahim, M.

    2012-01-01

    Abstract: In this paper we describe three different algorithms, from which two (as far as we know) are new in the literature. We take both the size of the jump as the jump times as decision variables. The first (new) algorithm considers an Impulse Control problem as a (multipoint) Boundary Value

  2. Evaluation of factors that affect hip moment impulse during gait: A systematic review.

    Science.gov (United States)

    Inai, Takuma; Takabayashi, Tomoya; Edama, Mutsuaki; Kubo, Masayoshi

    2018-03-01

    Decreasing the daily cumulative hip moments in the frontal and sagittal planes may lower the risk of hip osteoarthritis. Therefore, it may be important to evaluate factors that affect hip moment impulse during gait. It is unclear what factors affect hip moment impulse during gait. This systematic review aimed to evaluate different factors that affect hip moment impulse during gait in healthy adults and patients with hip osteoarthritis. Four databases (Scopus, ScienceDirect, PubMed, and PEDro) were searched up to August 2017 to identify studies that examined hip moment impulse during gait. Data extracted for analysis included the sample size, age, height, body mass, type of intervention, and main findings. After screening, 10 of the 975 studies identified were included in our analysis. Several factors, including a rocker bottom shoe, FitFlop™ sandals, ankle push-off, posture, stride length, body-weight unloading, a rollator, walking poles, and a knee brace, were reviewed. The main findings were as follows: increasing ankle push-off decreased both the hip flexion and extension moment impulses; body-weight unloading decreased both the hip extension and adduction moment impulses; the FitFlop™ sandal increased the sum of the hip flexion and extension moment impulses; long strides increased the hip extension moment impulse; and the use of a knee brace increased hip flexion moment impulse. Of note, none of the eligible studies included patients with hip osteoarthritis. The hip moment impulses can be modified by person-specific factors (ankle push-off and long strides) and external factors (body-weight unloading and use of the FitFlop™ sandals and a knee brace). Effects on the progression of hip osteoarthritis remain to be evaluated. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Ethanol induces impulsive-like responding in a delay-of-reward operant choice procedure: impulsivity predicts autoshaping.

    Science.gov (United States)

    Tomie, A; Aguado, A S; Pohorecky, L A; Benjamin, D

    1998-10-01

    Autoshaping conditioned responses (CRs) are reflexive and targeted motor responses expressed as a result of experience with reward. To evaluate the hypothesis that autoshaping may be a form of impulsive responding, within-subjects correlations between performance on autoshaping and impulsivity tasks were assessed in 15 Long-Evans hooded rats. Autoshaping procedures [insertion of retractable lever conditioned stimulus (CS) followed by the response-independent delivery of food (US)] were followed by testing for impulsive-like responding in a two-choice lever-press operant delay-of-reward procedure (immediate small food reward versus delayed large food reward). Delay-of-reward functions revealed two distinct subject populations. Subjects in the Sensitive group (n=7) were more impulsive-like, increasing immediate reward choices at longer delays for large reward, while those in the Insensitive group (n=8) responded predominantly on only one lever. During the prior autoshaping phase, the Sensitive group had performed more autoshaping CRs, and correlations revealed that impulsive subjects acquired the autoshaping CR in fewer trials. In the Sensitive group, acute injections of ethanol (0, 0.25, 0.50, 1.00, 1.50 g/kg) given immediately before delay-of-reward sessions yielded an inverted U-shaped dose-response curve with increased impulsivity induced by the 0.25, 0.50, and 1.00 g/kg doses of ethanol, while choice strategy of the Insensitive group was not influenced by ethanol dose. Ethanol induced impulsive-like responding only in rats that were flexible in their response strategy (Sensitive group), and this group also performed more autoshaping CRs. Data support the hypothesis that autoshaping and impulsivity are linked.

  4. Associations among types of impulsivity, substance use problems and neurexin-3 polymorphisms.

    Science.gov (United States)

    Stoltenberg, Scott F; Lehmann, Melissa K; Christ, Christa C; Hersrud, Samantha L; Davies, Gareth E

    2011-12-15

    Some of the genetic vulnerability for addiction may be mediated by impulsivity. This study investigated relationships among impulsivity, substance use problems and six neurexin-3 (NRXN3) polymorphisms. Neurexins (NRXNs) are presynaptic transmembrane proteins that play a role in the development and function of synapses. Impulsivity was assessed with the Barratt Impulsiveness Scale Version 11 (BIS-11), the Boredom Proneness Scale (BPS) and the TIME paradigm; alcohol problems with the Michigan Alcoholism Screening Test (MAST); drug problems with the Drug Abuse Screening Test (DAST-20); and regular tobacco use with a single question. Participants (n=439 Caucasians, 64.7% female) donated buccal cells for genotyping. Six NRXN3 polymorphisms were genotyped: rs983795, rs11624704, rs917906, rs1004212, rs10146997 and rs8019381. A dual luciferase assay was conducted to determine whether allelic variation at rs917906 regulated gene expression. In general, impulsivity was significantly higher in those who regularly used tobacco and/or had alcohol or drug problems. In men, there were modest associations between rs11624704 and attentional impulsivity (p=0.005) and between rs1004212 and alcohol problems (p=0.009). In women, there were weak associations between rs10146997 and TIME estimation (p=0.03); and between rs1004212 and drug problems (p=0.03). The dual luciferase assay indicated that C and T alleles of rs917906 did not differentially regulate gene expression in vitro. Associations between impulsivity, substance use problems and polymorphisms in NRXN3 may be gender specific. Impulsivity is associated with substance use problems and may provide a useful intermediate phenotype for addiction. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  5. Work experience effect on idolatry and the impulsive buying tendencies of adolescents.

    Science.gov (United States)

    Niu, Han-Jen; Wang, Yau-De

    2009-01-01

    The interrelationships of three issues relevant to adolescents are the focus of this study, namely, work experience, idolatry, and impulsive buying. Many young people work at some time during their years at high school, which is part of the process of socialization in terms of both thinking and behavior. Idolatry is a common phenomenon among adolescents, and is the way adolescents develop their own values and ideals. Marketers have long recognized the significance of impulse buying, but most studies focus on adult consumers. The purpose of this study was to examine the part-time job effect on idolatry and impulsive buying tendencies of 13- to 20-year-old Taiwanese adolescents. A survey of 337 high school and college students was conducted and results indicate that it has a moderating effect.

  6. Nonlinear impulsive system of fed-batch culture in fermentative production and its properties

    International Nuclear Information System (INIS)

    Gao Caixia; Li Kezan; Feng Enmin; Xiu Zhilong

    2006-01-01

    In this study, the nonlinear dynamical system of fed-batch fermentation is investigated in the process of bio-dissimilation of glycerol to 1,3-propanediol by Klebsiella pneumoniae. Considering the abrupt increase of glycerol in fed-batch culture, this paper proposes a nonlinear impulsive system of the culture process, which is fit for formulating the factual fermentation better than the continuous models in being. We study the questions of existence and properties of mild solutions for the system and the continuous dependence of solutions on initial values and the controllable variable. Finally, the numerical simulations show that the errors between experimental and computational values using the impulsive system are less than those using the previous continuous system

  7. Random Fuzzy Differential Equations with Impulses

    Directory of Open Access Journals (Sweden)

    Ho Vu

    2017-01-01

    Full Text Available We consider the random fuzzy differential equations (RFDEs with impulses. Using Picard method of successive approximations, we shall prove the existence and uniqueness of solutions to RFDEs with impulses under suitable conditions. Some of the properties of solution of RFDEs with impulses are studied. Finally, an example is presented to illustrate the results.

  8. Impulsive and reflective processes related to alcohol use in young adolescents

    Directory of Open Access Journals (Sweden)

    Sara ePieters

    2014-05-01

    Full Text Available Background: Dual process models suggest that the development of addictive behaviors is the result of interplay between impulsive and reflective processes, modulated by boundary conditions such as individual or situational factors. Empirical support for this model has been repeatedly demonstrated in adult samples (for a meta-analysis see Rooke, Hine, & Thorsteinsson, 2008. The purpose of this study was to test these processes as they relate to emerging alcohol use in adolescents. Specifically, the interactive effects of several measures of impulsive and reflective processes and working memory capacity are examined as predictors of changes in alcohol use among adolescents. It was expected that measures of reflective processes would better predict changes in alcohol use than measures of impulsive processes. Moreover, it was anticipated that working memory capacity would moderate the relation between alcohol-specific impulsive and reflective processes and changes in adolescent alcohol use. Methods: The sample consisted of 427 adolescents (47.7% male between 12 and 16 years of age (M = 13.96, SD = .78 who reported drinking alcohol at least once. Four measures of impulsive processes were included. Attentional bias for alcohol was assessed with a Visual Probe Test; approach bias toward alcohol was assessed with a Stimulus Response Compatibility Test (SRC; and memory associations with alcohol were assessed with an Implicit Association Test (IAT and a Word Association Test (WAT. Two measures of reflective measures were included: positive and negative expectancies. Working memory capacity was measured using a Self-Ordered Pointing Task (SOPT.Results: Results showed that positive expectancies predicted changes in alcohol use, but this effect was qualified by an interaction with IAT scores. Moreover, SRC scores predicted changes in alcohol use only when negative expectancies were low. Attentional bias and word association scores did not predict changes in

  9. Anger and Impulsivity Among Japanese Adolescents: A Nationwide Representative Survey.

    Science.gov (United States)

    Itani, Osamu; Kaneita, Yoshitaka; Munezawa, Takeshi; Ikeda, Maki; Osaki, Yoneatsu; Higuchi, Susumu; Kanda, Hideyuki; Nakagome, Sachi; Suzuki, Kenji; Ohida, Takashi

    2016-07-01

    This study aimed to clarify the prevalence of anger and impulsivity and its associated factors through a nationwide survey of junior and senior high school adolescent students in Japan. A self-administered questionnaire covering (1) personal data, (2) lifestyle, (3) mental health status, and (4) feelings of anger and impulsivity was distributed to junior and senior high school students in Japan. Among the total of 10,955 junior high schools and 5,115 senior high schools nationwide, 130 and 110 were randomly selected, respectively. Of those, 92 junior and 80 senior high schools participated in the survey. The survey period was from December 2008 to the end of January 2009. A total of 95,680 questionnaires were collected. After excluding invalid responses, the remaining 94,777 responses (response rate: 62.3%) were analyzed. From the questions regarding anger and impulsivity, 8.7% (95% CI, 8.5%-8.9%) and 7.5% (95% CI, 7.3%-7.7%) of the participants were considered to have experienced intense anger and impulsivity, respectively. Logistic regression analysis indicated that the odds ratios for experiencing intense feelings of anger were significantly higher (all P values breakfast, did not wish to go to university, had short sleep duration, had decreased positive feelings, had increased depressive feelings, or used mobile phones for longer hours. The odds ratios for experiencing intense impulsivity were significantly higher among students who smoked, consumed alcohol, skipped breakfast, did not participate in club activities, had short sleep duration, had decreased positive feelings, had increased depressive feelings, or used mobile phones for longer hours. The results suggest that healthy lifestyle habits, good sleep habits, and improved mental health are important for preventing intense feelings of anger and impulsivity among adolescents. © Copyright 2016 Physicians Postgraduate Press, Inc.

  10. Non-instantaneous impulses in differential equations

    CERN Document Server

    Agarwal, Ravi; O'Regan, Donal

    2017-01-01

    This monograph is the first published book devoted to the theory of differential equations with non-instantaneous impulses. It aims to equip the reader with mathematical models and theory behind real life processes in physics, biology, population dynamics, ecology and pharmacokinetics. The authors examine a wide scope of differential equations with non-instantaneous impulses through three comprehensive chapters, providing an all-rounded and unique presentation on the topic, including: - Ordinary differential equations with non-instantaneous impulses (scalar and n-dimensional case) - Fractional differential equa tions with non-instantaneous impulses (with Caputo fractional derivatives of order q ϵ (0, 1)) - Ordinary differential equations with non-instantaneous impulses occurring at random moments (with exponential, Erlang, or Gamma distribution) Each chapter focuses on theory, proofs and examples, and contains numerous graphs to enrich the reader’s understanding. Additionally, a carefully selected bibliogr...

  11. Chaotic behavior of a Watt-type predator-prey system with impulsive control strategy

    International Nuclear Information System (INIS)

    Wang, Xiaoqin; Wang Weiming; Lin Xiaolin

    2008-01-01

    In this paper, by using theories and methods of ecology and ODE, a predator-prey system with Watt-type functional response and impulsive perturbations on the predator is established. It proves that there exists a locally asymptotically stable prey-eradication periodic solution when the impulse period is less than some critical value, otherwise, the system can be permanent. Further, by using the method of computer simulation, the influences of the impulsive perturbations on the inherent oscillation are investigated, which shows the more complex dynamics of the system we considered, such as quasi-periodic oscillation, narrow periodic window, wide periodic window, chaotic bands, period doubling bifurcation, symmetry-breaking pitchfork bifurcation, period-halving bifurcation and crisis, etc. It will be useful for studying the dynamical complexity of ecosystems

  12. Students’ Relational Thinking of Impulsive and Reflective in Solving Mathematical Problem

    Science.gov (United States)

    Satriawan, M. A.; Budiarto, M. T.; Siswono, T. Y. E.

    2018-01-01

    This is a descriptive research which qualitatively investigates students’ relational thinking of impulsive and reflective cognitive style in solving mathematical problem. The method used in this research are test and interview. The data analyzed by reducing, presenting and concluding the data. The results of research show that the students’ reflective cognitive style can possibly help to find out important elements in understanding a problem. Reading more than one is useful to identify what is being questioned and write the information which is known, building relation in every element and connecting information with arithmetic operation, connecting between what is being questioned with known information, making equation model to find out the value by using substitution, and building a connection on re-checking, re-reading, and re-counting. The impulsive students’ cognitive style supports important elements in understanding problems, building a connection in every element, connecting information with arithmetic operation, building a relation about a problem comprehensively by connecting between what is being questioned with known information, finding out the unknown value by using arithmetic operation without making any equation model. The result of re-checking problem solving, impulsive student was only reading at glance without re-counting the result of problem solving.

  13. Overlapping and disease specific trait, response, and reflection impulsivity in adolescents with first-episode schizophrenia spectrum disorders or attention-deficit/hyperactivity disorder

    NARCIS (Netherlands)

    Jepsen, Jens Richardt M.; Rydkjaer, J.; Fagerlund, B.; Pagsberg, A. K.; Jespersen, R. Av F.; Glenthøj, Birte Y.; Oranje, B.

    BACKGROUND: Schizophrenia and attention-deficit/hyperactivity disorder (ADHD) are developmental disorders with shared clinical characteristics such as cognitive impairments and impulsivity. Impulsivity is a core feature of ADHD and an important factor in aggression, violence, and substance use in

  14. Performance Improvement of a Micro Impulse Water Turbine Based on Orthogonal Array

    OpenAIRE

    Tang, Lingdi; Yuan, Shouqi; Tang, Yue

    2017-01-01

    The study on structural design and efficiency improvement of the micro impulse water turbine with the super-low specific speed has rarely been reported in literature. In this paper, a micro impulse water turbine was optimized on the base of the orthogonal array of L18(37) with six factors. The range analysis and variance analysis were conducted to present the significance ranking of factors and the optimal combinations of factors, aiming to improve the water turbine efficiency taken as the ex...

  15. Impulsivity and compulsive buying are associated in a non-clinical sample: an evidence for the compulsivity-impulsivity continuum?

    Science.gov (United States)

    Paula, Jonas J de; Costa, Danielle de S; Oliveira, Flavianne; Alves, Joana O; Passos, Lídia R; Malloy-Diniz, Leandro F

    2015-01-01

    Compulsive buying is controversial in clinical psychiatry. Although it is defined as an obsessive-compulsive disorder, other personality aspects besides compulsivity are related to compulsive buying. Recent studies suggest that compulsivity and impulsivity might represent a continuum, with several psychiatric disorders lying between these two extremes. In this sense, and following the perspective of dimensional psychiatry, symptoms of impulsivity and compulsivity should correlate even in a non-clinical sample. The present study aims to investigate whether these two traits are associated in a healthy adult sample. We evaluated 100 adults, with no self-reported psychiatric disorders, using the Barratt Impulsiveness Scale-11 and two scales of compulsive buying. Using multiple linear regressions, we found that impulsivity accounted for about 15% of variance in the compulsive-buying measure. Our results suggest that an association between impulsivity and compulsive buying occurs even in non-clinical samples, evidence that compulsivity and impulsivity might form a continuum and that compulsive buying might be an intermediate condition between these two personality traits.

  16. Narcissism predicts impulsive buying: phenotypic and genetic evidence

    OpenAIRE

    Cai, Huajian; Shi, Yuanyuan; Fang, Xiang; Luo, Yu L. L.

    2015-01-01

    Impulsive buying makes billions of dollars for retail businesses every year, particularly in an era of thriving e-commerce. Narcissism, characterized by impulsivity and materialism, may serve as a potential antecedent to impulsive buying. To test this hypothesis, two studies examined the relationship between narcissism and impulsive buying. In study 1, we surveyed narcissism and the impulsive buying tendency among an online sample and found that while adaptive narcissism was not correlated wi...

  17. Differences and similarities between impulse buying and variety seeking: A personality-based perspective

    DEFF Research Database (Denmark)

    Olsen, Svein Ottar; Tudoran, Ana Alina; Honkanen, Pirjo

    2016-01-01

    Although personality is a key determinant of consumer purchasing decision making, the role of personality traits on impulse buying and variety seeking is not conclusive. This research uses a personality perspective to determine the unique associations between impulse buying tendency (IBT), variety......: Neuroticism and Openness to Experience. Specifically, the present study indicates that Neuroticism predicted IBT positively and VST negatively, while Openness was a strong predictor of VST and unrelated to IBT....

  18. Impulsivity and eating behaviour: an examination of subtypes of impulsive behaviour and overeating in healthy females

    OpenAIRE

    Leitch, Margaret

    2011-01-01

    A wealth of support has shown higher levels of state and trait impulsivity can be found among those individuals prone to developing problematic eating behaviors and obesity. Thus, upon commencing the investigations in this thesis, it was hypothesized that impulsivity is an individual difference implicated in overeating behaviour.\\ud \\ud Increasing information indicates that there are divisions within impulsivity subtypes. Prior to this thesis, studies in the field of eating behaviour had not ...

  19. Clinical aspects of impulsive compulsive behaviours in Parkinson's disease.

    Science.gov (United States)

    Djamshidian, Atbin; Averbeck, Bruno B; Lees, Andrew J; O'Sullivan, Sean S

    2011-11-15

    Impulsive-compulsive behaviours (ICBs) are an increasingly well-recognised adverse-effect of dopaminergic medications used to treat Parkinson's disease. ICBs include pathological gambling, compulsive sexual behaviour, compulsive buying, and binge eating, together with punding and the addiction-like compulsive use of dopamine replacement therapy, or dopamine dysregulation syndrome. The prevalence of ICBs was approximately 14% in a large study undertaken in specialist movement disorder clinics. Dopamine dysregulation syndrome is more associated with compulsive l-dopa use, whereas other ICBs are more linked with oral dopamine agonist use. Other mechanisms implicated in the development and perpetuation of ICBs in PD include aberrant learning from reward-related situations, including decreased learning from negative feedback, increased measures of impulsivity or sensation seeking, and strong preference for immediate over future rewards. Treatment options for impulsive-compulsive behaviours include pharmacological, surgical and psychological interventions. The early recognition and prevention of ICBs, coupled with awareness of clinical risk factors for the development of these behaviours is of paramount importance, given the lack of specific treatments for these sometimes debilitating behaviours. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Barratt Impulsivity and Neural Regulation of Physiological Arousal.

    Directory of Open Access Journals (Sweden)

    Sheng Zhang

    Full Text Available Theories of personality have posited an increased arousal response to external stimulation in impulsive individuals. However, there is a dearth of studies addressing the neural basis of this association.We recorded skin conductance in 26 individuals who were assessed with Barratt Impulsivity Scale (BIS-11 and performed a stop signal task during functional magnetic resonance imaging. Imaging data were processed and modeled with Statistical Parametric Mapping. We used linear regressions to examine correlations between impulsivity and skin conductance response (SCR to salient events, identify the neural substrates of arousal regulation, and examine the relationship between the regulatory mechanism and impulsivity.Across subjects, higher impulsivity is associated with greater SCR to stop trials. Activity of the ventromedial prefrontal cortex (vmPFC negatively correlated to and Granger caused skin conductance time course. Furthermore, higher impulsivity is associated with a lesser strength of Granger causality of vmPFC activity on skin conductance, consistent with diminished control of physiological arousal to external stimulation. When men (n = 14 and women (n = 12 were examined separately, however, there was evidence suggesting association between impulsivity and vmPFC regulation of arousal only in women.Together, these findings confirmed the link between Barratt impulsivity and heightened arousal to salient stimuli in both genders and suggested the neural bases of altered regulation of arousal in impulsive women. More research is needed to explore the neural processes of arousal regulation in impulsive individuals and in clinical conditions that implicate poor impulse control.

  1. Barratt Impulsivity and Neural Regulation of Physiological Arousal.

    Science.gov (United States)

    Zhang, Sheng; Hu, Sien; Hu, Jianping; Wu, Po-Lun; Chao, Herta H; Li, Chiang-shan R

    2015-01-01

    Theories of personality have posited an increased arousal response to external stimulation in impulsive individuals. However, there is a dearth of studies addressing the neural basis of this association. We recorded skin conductance in 26 individuals who were assessed with Barratt Impulsivity Scale (BIS-11) and performed a stop signal task during functional magnetic resonance imaging. Imaging data were processed and modeled with Statistical Parametric Mapping. We used linear regressions to examine correlations between impulsivity and skin conductance response (SCR) to salient events, identify the neural substrates of arousal regulation, and examine the relationship between the regulatory mechanism and impulsivity. Across subjects, higher impulsivity is associated with greater SCR to stop trials. Activity of the ventromedial prefrontal cortex (vmPFC) negatively correlated to and Granger caused skin conductance time course. Furthermore, higher impulsivity is associated with a lesser strength of Granger causality of vmPFC activity on skin conductance, consistent with diminished control of physiological arousal to external stimulation. When men (n = 14) and women (n = 12) were examined separately, however, there was evidence suggesting association between impulsivity and vmPFC regulation of arousal only in women. Together, these findings confirmed the link between Barratt impulsivity and heightened arousal to salient stimuli in both genders and suggested the neural bases of altered regulation of arousal in impulsive women. More research is needed to explore the neural processes of arousal regulation in impulsive individuals and in clinical conditions that implicate poor impulse control.

  2. Relationships between impulsivity, anxiety, and risk-taking and neural correlates of attention in adolescents

    Science.gov (United States)

    Elsey, James W. B.; Crowley, Michael J.; Mencl, W. Einar; Lacadie, Cheryl M.; Mayes, Linda C.; Potenza, Marc N.

    2016-01-01

    Although impulsivity, anxiety, and risk-taking may relate to attentional processes, little research has directly investigated how each may be associated with specific facets of attentional processes and their underlying neural correlates. Nineteen adolescents performed an fMRI task involving simple, selective and divided attention. Out-of-scanner-assessed impulsivity, anxiety and risk-taking scores were not correlated with each other and showed task-phase-specific patterns of association. Results are discussed in light of research and theory suggesting a relationship between these domains and attention and may serve to focus future research aiming to understand these relationships. PMID:27135550

  3. Mechanoluminescence by impulsive deformation of γ-irradiated Er-doped CaF2 crystals

    International Nuclear Information System (INIS)

    Brahme, Nameeta; Shukla, Manju; Bisen, D.P.; Kurrey, U.; Choubey, Anil; Kher, R.S.; Singh, Manisha

    2011-01-01

    An impulsive technique has been used for mechanoluminescence (ML) measurements in γ-irradiated Er doped CaF 2 crystals. When the ML is excited impulsively by the impact of moving piston on to γ-irradiated CaF 2 :Er crystals, two peaks are observed in ML intensity with time and it is seen that the peak intensities of first and second peaks (I m1 and I m2 ) increase with increasing impact velocity. However the time corresponding to first and second peaks (t m1 and t m2 ) shifts towards shorter time values with increasing impact velocity. It is also seen that the total ML intensity I Total initially increases with the impact velocity and then it attains a saturation value for higher values of the impact velocity. We have presented a theoretical explanation for the observed results. - Research highlights: → Impulsive technique has been used for mechanoluminescence (ML) studies in γ-irradiated Er doped CaF 2 crystals. → ML intensity exhibited two peaks with time (I m1 and I m2 ), where the intensity of both the peaks increased with increasing impact velocity. → The time of occurrence of the peaks (t m1 and t m2 ) reduced with increasing the impact velocity. → Total ML intensity (I Total ) first increases and then attains a saturation value with an increment in the impact velocity. → A theoretical explanation is presented to the observed results.

  4. Predicting inpatient aggression by self-reported impulsivity in forensic psychiatric patients

    NARCIS (Netherlands)

    Bousardt, A.M.C.; Hoogendoorn, A.W.; Noorthoorn, E.O.; Hummelen, J.W.; Nijman, H.L.I.

    2016-01-01

    Background: Empirical knowledge of 'predictors' of physical inpatient aggression may provide staff with tools to prevent aggression or minimise its consequences. Aim: To test the value of a self-reported measure of impulsivity for predicting inpatient aggression. Methods: Self-report measures of

  5. Facets of impulsivity in the relationship between antisocial personality and abstinence.

    Science.gov (United States)

    Sargeant, Marsha N; Bornovalova, Marina A; Trotman, Adria J-M; Fishman, Shira; Lejuez, Carl W

    2012-03-01

    Most individuals who enter drug treatment programs are unable to maintain long-term abstinence. This problem is especially relevant for those presenting with Antisocial Personality Disorder (ASPD). In examining potential mechanisms underlying the relationship between ASPD and abstinence, one factor that may be especially useful is the personality variable of impulsivity. Thus, the current study examined ASPD status in relation to longest abstinence attempt among 117 substance use treatment-seeking individuals, considering the mediating role of five facets of impulsivity: urgency, perseverance, premeditation, control, and delay discounting. Results indicated that individuals with ASPD evidenced shorter previous abstinence attempts and lower levels of perseverance and control than those without ASPD. Further, lower levels of control were associated with shorter abstinence attempts. Finally, control mediated the relationship between ASPD and longest quit attempt. These results suggest the potential value of multiple facets of impulsivity in efforts to understand relapse and subsequent treatment development efforts. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Impulsivity, "advergames," and food intake.

    Science.gov (United States)

    Folkvord, Frans; Anschütz, Doeschka J; Nederkoorn, Chantal; Westerik, Henk; Buijzen, Moniek

    2014-06-01

    Previous studies have focused on the effect of food advertisements on the caloric intake of children. However, the role of individual susceptibility in this effect is unclear. The aim of this study was to examine the role of impulsivity in the effect of advergames that promote energy-dense snacks on children's snack intake. First, impulsivity scores were assessed with a computer task. Then a randomized between-subject design was conducted with 261 children aged 7 to 10 years who played an advergame promoting either energy-dense snacks or nonfood products. As an extra manipulation, half of the children in each condition were rewarded for refraining from eating, the other half were not. Children could eat freely while playing the game. Food intake was measured. The children then completed questionnaire measures, and were weighed and measured. Overall, playing an advergame containing food cues increased general caloric intake. Furthermore, rewarding children to refrain from eating decreased their caloric intake. Finally, rewarding impulsive children to refrain from eating had no influence when they were playing an advergame promoting energy-dense snacks, whereas it did lead to reduced intake among low impulsive children and children who played nonfood advergames. Playing an advergame promoting energy-dense snacks contributes to increased caloric intake in children. The advergame promoting energy-dense snacks overruled the inhibition task to refrain from eating among impulsive children, making it more difficult for them to refrain from eating. The findings suggest that impulsivity plays an important role in susceptibility to food advertisements. Copyright © 2014 by the American Academy of Pediatrics.

  7. Suicidality in temporal lobe epilepsy: measuring the weight of impulsivity and depression.

    Science.gov (United States)

    de Oliveira, Guilherme Nogueira M; Kummer, Arthur; Salgado, João Vinícius; Filho, Gerardo Maria de Araújo; David, Anthony S; Teixeira, Antônio Lúcio

    2011-12-01

    The aim of the work described here was to measure the role of psychopathological features, specifically impulsivity and depression, in suicidality in patients with temporal lobe epilepsy (TLE). Neuropsychiatric evaluation of 66 outpatients with TLE was performed with the following instruments: a structured clinical interview (Mini International Neuropsychiatric Interview Plus), the Barratt Impulsiveness Scale, the Hamilton Anxiety Scale, the Beck Depression Inventory, and the Brief Psychiatric Rating Scale. A current Axis I psychiatric diagnosis, mainly mood and anxiety disorders, was assigned to 37 subjects (56.1%) Presence of suicide risk was identified in 19 patients (28.8%), and 14 (21.2%) had attempted suicide. Frequency of seizures (P=0.012), current major depression (P=0.001), and motor impulsivity (P=0.005) were associated with suicide risk on univariate analysis. Logistic regression stressed the main relevance of major depression (OR=12.82, 95% CI=2.58-63.76, P=0.002) and motor impulsivity (OR=1.21, 95% CI=1.06-1.38, P=0.005) to suicide risk. Depression has a major influence on suicidality in epilepsy. Motor impulsivity is also relevant and may be an important component of depression in TLE associated with suicide risk. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Life Event Stress and Binge Eating Among Adolescents: The Roles of Early Maladaptive Schemas and Impulsivity.

    Science.gov (United States)

    Zhu, Hong; Luo, Xingwei; Cai, Taisheng; He, Jinbo; Lu, Yao; Wu, Siyao

    2016-10-01

    This study examined the relationships between life event stress, early maladaptive schemas, impulsivity and binge eating among adolescents and investigated the effects of early maladaptive schemas and impulsivity on the relationship between life event stress and binge eating. Specifically, we examined a moderated mediation model in which early maladaptive schemas mediated this relationship and impulsivity moderated the mediation effect. Life event stress, early maladaptive schemas, impulsivity and binge eating were investigated in a sample of 2172 seventh-, eighth- and tenth-grade middle and high school students (mean age = 14.55 years, standard deviation = 1.29). The results indicated that adolescents with greater life event stress, more early maladaptive schemas and higher levels of impulsivity displayed more severe binge eating. In addition, early maladaptive schemas mediated the relationship between life event stress and binge eating, while impulsivity moderated this relationship. Furthermore, impulsivity also moderated the mediation effect of early maladaptive schemas; as impulsivity levels increased, the strength of the association between life event stress and early maladaptive schemas increased. This study illustrates the importance of understanding individual differences and their effects on the relationship between life event stress and binge eating. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  9. Impulsivity and compulsive buying are associated in a non-clinical sample: an evidence for the compulsivity-impulsivity continuum?

    Directory of Open Access Journals (Sweden)

    Jonas J. de Paula

    2015-09-01

    Full Text Available Objective:Compulsive buying is controversial in clinical psychiatry. Although it is defined as an obsessive-compulsive disorder, other personality aspects besides compulsivity are related to compulsive buying. Recent studies suggest that compulsivity and impulsivity might represent a continuum, with several psychiatric disorders lying between these two extremes. In this sense, and following the perspective of dimensional psychiatry, symptoms of impulsivity and compulsivity should correlate even in a non-clinical sample. The present study aims to investigate whether these two traits are associated in a healthy adult sample.Methods:We evaluated 100 adults, with no self-reported psychiatric disorders, using the Barratt Impulsiveness Scale-11 and two scales of compulsive buying.Results:Using multiple linear regressions, we found that impulsivity accounted for about 15% of variance in the compulsive-buying measure.Conclusions:Our results suggest that an association between impulsivity and compulsive buying occurs even in non-clinical samples, evidence that compulsivity and impulsivity might form a continuum and that compulsive buying might be an intermediate condition between these two personality traits.

  10. Impulsivity and Reasons for Living Among African American Youth: A Risk-Protection Framework of Suicidal Ideation

    Directory of Open Access Journals (Sweden)

    Temilola K. Salami

    2015-05-01

    Full Text Available This study aims to explore the impact of specific facets of impulsivity as measured by the UPPS Impulsive Behavior Scale (UPPS, as well as reasons for living in predicting suicidal ideation among African American college-aged students. The incremental validity of each facet of the UPPS interacting with reasons for living, a construct meant to buffer against risk for suicide, was explored in a sample of African American students (N = 130; ages 18–24. Results revealed significant interactions between reasons for living and two factors of impulsivity, (lack of premeditation and sensation seeking. Higher levels of sensation seeking and lack of premeditation in conjunction with lower reasons for living was associated with increased suicidal ideation. Neither urgency nor (lack of perseverance significantly interacted with reasons for living in association with suicidal ideation. These results suggest including elements of impulsivity, specifically sensation seeking and (lack of premeditation, when screening for suicidal ideation among African American youth. Future investigations should continue to integrate factors of both risk and protection when determining risk for suicide.

  11. Impulsivity and reasons for living among African American youth: a risk-protection framework of suicidal ideation.

    Science.gov (United States)

    Salami, Temilola K; Brooks, Bianca A; Lamis, Dorian A

    2015-05-15

    This study aims to explore the impact of specific facets of impulsivity as measured by the UPPS Impulsive Behavior Scale (UPPS), as well as reasons for living in predicting suicidal ideation among African American college-aged students. The incremental validity of each facet of the UPPS interacting with reasons for living, a construct meant to buffer against risk for suicide, was explored in a sample of African American students (N = 130; ages 18-24). Results revealed significant interactions between reasons for living and two factors of impulsivity, (lack of) premeditation and sensation seeking. Higher levels of sensation seeking and lack of premeditation in conjunction with lower reasons for living was associated with increased suicidal ideation. Neither urgency nor (lack of) perseverance significantly interacted with reasons for living in association with suicidal ideation. These results suggest including elements of impulsivity, specifically sensation seeking and (lack of) premeditation, when screening for suicidal ideation among African American youth. Future investigations should continue to integrate factors of both risk and protection when determining risk for suicide.

  12. Impulse position control algorithms for nonlinear systems

    Energy Technology Data Exchange (ETDEWEB)

    Sesekin, A. N., E-mail: sesekin@list.ru [Ural Federal University, 19 S. Mira, Ekaterinburg, 620002 (Russian Federation); Institute of Mathematics and Mechanics, Ural Division of Russian Academy of Sciences, 16 S. Kovalevskaya, Ekaterinburg, 620990 (Russian Federation); Nepp, A. N., E-mail: anepp@urfu.ru [Ural Federal University, 19 S. Mira, Ekaterinburg, 620002 (Russian Federation)

    2015-11-30

    The article is devoted to the formalization and description of impulse-sliding regime in nonlinear dynamical systems that arise in the application of impulse position controls of a special kind. The concept of trajectory impulse-sliding regime formalized as some limiting network element Euler polygons generated by a discrete approximation of the impulse position control This paper differs from the previously published papers in that it uses a definition of solutions of systems with impulse controls, it based on the closure of the set of smooth solutions in the space of functions of bounded variation. The need for the study of such regimes is the fact that they often arise when parry disturbances acting on technical or economic control system.

  13. Impulse position control algorithms for nonlinear systems

    Science.gov (United States)

    Sesekin, A. N.; Nepp, A. N.

    2015-11-01

    The article is devoted to the formalization and description of impulse-sliding regime in nonlinear dynamical systems that arise in the application of impulse position controls of a special kind. The concept of trajectory impulse-sliding regime formalized as some limiting network element Euler polygons generated by a discrete approximation of the impulse position control This paper differs from the previously published papers in that it uses a definition of solutions of systems with impulse controls, it based on the closure of the set of smooth solutions in the space of functions of bounded variation. The need for the study of such regimes is the fact that they often arise when parry disturbances acting on technical or economic control system.

  14. Impulsivity and Fast-Food Consumption: A Cross-Sectional Study among Working Adults.

    Science.gov (United States)

    Garza, Kimberly B; Ding, Meng; Owensby, Justin K; Zizza, Claire A

    2016-01-01

    Little is known about the decision-making process of adults who choose to eat at fast-food restaurants. Impulsivity is the concept that individuals value immediate rewards and disregard future costs. To determine the association between impulsivity and consumption of fast food among employed adults and to explore their reasons for eating fast food. A cross-sectional, online survey was conducted; participants were recruited using a mass electronic mailing. Four hundred seventy-eight adults employed in a university setting completed the survey. The association between frequency of fast-food consumption and impulsivity was assessed. Impulsivity is assessed by the area under the delay discounting curve (AUC). The AUC is estimated by using a binary choice delay discounting task incorporating hypothetical monetary rewards. Greater AUC reflects lower impulsivity. Analysis of variance, Student's t tests, and Pearson correlation coefficients were used to measure unadjusted associations among demographic variables, fast-food consumption, and AUC. Linear regression was used to assess whether AUC was a significant predictor of having consumed fast food in the past 7 days, controlling for age, total household income, and education. The majority (67%) of the participants reported eating one or more meals from a fast-food restaurant or pizza place in the past 7 days. The mean number of meals was 2.8±2.5 per week among those who reported eating at a fast-food restaurant or pizza place. Both fast-food consumption and body mass index (BMI) were correlated with greater impulsivity. Controlling for age, total household income, and education level, fast-food consumption was negatively related to AUC (P=0.017). The most commonly reported reasons for consuming fast food were convenience and to socialize. These findings indicate that greater impulsivity was associated with greater fast-food consumption. Successful efforts to encourage healthful dietary behaviors might emphasize methods

  15. Age-specific growth, reproductive values, and intrinsic r

    Directory of Open Access Journals (Sweden)

    Robert Schoen

    2011-06-01

    Full Text Available The age-specific growth function of an observed population and the reproductive value function based on the population's current vital rates determine the intrinsic rate of growth implied by those vital rates through the simple relationship given in equation (1. That equation establishes the analytical significance of age-specific growth, and leads to relationships that quantify a population's approach to stability and that specify the extraordinarily close connection between reproductive values and population momentum.

  16. Destabilizing Effects of Impulse in Delayed Bam Neural Networks

    Science.gov (United States)

    Li, Chuandong; Li, Chaojie; Liu, Chao

    This paper further studies the global exponential stability of the equilibrium point of the delayed bidirectional associative memory (DBAM) neural networks with impulse effects. Several results characterizing the aggregated effects of impulse and dynamical property of the impulse-free DBAM on the exponential stability of the considered DBAM have been established. It is shown that the impulsive DBAM will preserve the global exponential stability of the impulse-free DBAM even if the impulses have enlarging effects on the states of neurons.

  17. How do impulsivity and education relate to smoking initiation and cessation among young adults?

    Science.gov (United States)

    Kvaavik, Elisabeth; Rise, Jostein

    2012-09-01

    This study examined the predictive value of impulsivity for starting and quitting smoking and whether education had an independent effect on smoking careers or moderated the impulsivity-smoking association. Two waves of the cohort study Young in Norway were used in the present study (third wave: 1999, age range: 19-32 years; fourth wave: 2005, age range: 25-38 years). Postal questionnaires were used for data collection. Subjects participating in 1999 and 2005 were eligible (N = 2,562). Stable smokers (daily smokers in 1999 and 2005) and nonsmokers (never smokers in 1999 and 2005), quitters (daily smokers in 1999, nonsmokers in 2005), and starters (never smokers in 1999, daily smokers in 2005) constituted the analytical sample (1,776 men and women). The associations between self-reported impulsivity and education and smoking were investigated using logistic regression analyses. The odds ratio (OR) for a 1-unit increase in the impulsivity score was 2.16 (95% CI [1.09, 4.30]) for smoking initiation, whereas the OR [95% CI] for low compared with high education was 2.55 (95% CI [1.36, 4.77]). Education, but not impulsivity, emerged as a significant determinant for smoking cessation compared with continued smoking. The OR for quitting smoking by low compared with high education was 0.61 (95% CI [0.42, 0.90]). Mutual adjustment for education and impulsivity did not change any of the results. The interaction term between impulsivity and education was not significantly related to smoking. Because impulsivity emerged as important for smoking initiation regardless of educational level, it should be considered when planning and implementing smoking prevention programs for both low and high socioeconomic groups.

  18. Impulse control disorders and related behaviours (ICD-RBs) in Parkinson's disease patients: Assessment using "Questionnaire for impulsive-compulsive disorders in Parkinson's disease" (QUIP).

    Science.gov (United States)

    Sharma, Ashish; Goyal, Vinay; Behari, Madhuri; Srivastva, Achal; Shukla, Garima; Vibha, Deepti

    2015-01-01

    There is limited data on the prevalence of impulse control disorder and related behaviors (ICD-RBs) in Indian patients with Parkinson's Disease (PD). In the context of potential genetic and environmental factors affecting the expression of ICD-RBs, studying other multiethnic populations may bring in-sights into the mechanisms of these disorders. To ascertain point prevalence estimate of ICD-RBs in Indian PD patients, using the validated "Questionnaire for Impulsive-Compulsive Disorders in Parkinson's disease (QUIP)" and to examine their association with Dopamine replacement therapy (DRT). This was a hospital based observational cross-sectional study. After taking informed consent, patients and their informants (spouse, or primary caregiver) were made to complete the QUIP, and were instructed to answer questions based on behaviors that occurred anytime during PD that lasted at least four consecutive weeks. Total of 299 patients participated in the study. At least one ICD-RB was present in 128 (42.8%), at least one Impulse control disorder (ICD) was present in 74 (24.75%) and at least one Impulse control related compulsive behaviour (ICRB) was present in 93 (31.1%) patients. Punding was the most frequent (12.4%) followed by hyper sexuality (11.04%), compulsive hobbyism (9.4%), compulsive shopping (8.4%), compulsive medication use (7.7%), compulsive eating (5.35%), walkabout (4%) and pathological gambling (3.3%). ≥ 2 ICD-RBs were observed in 15.7% of patients. After multivariate analysis, younger age of onset, being unmarried were specifically associated with presence of ICD. Longer disease duration was specifically associated with presence of ICRB. Whereas smoking and higher dopamine levodopa equivalent daily doses (DA LEDD) were associated with both presence of ICD and ICRB. Higher LD LEDD was specifically associated with presence of ICD-RB. Our study revealed a relatively higher frequency of ICD-RBs, probably because of the use of screening instrument and because

  19. The role of impulsivity in the association between childhood trauma and dissociative psychopathology: mediation versus moderation.

    Science.gov (United States)

    Somer, Eli; Ginzburg, Karni; Kramer, Lilach

    2012-03-30

    Previous studies on survivors of childhood trauma documented associations between psychological dysregulation, impulsivity, and both behavioral and emotional manifestations of distress. Yet, the mechanism that links these variables remains unclear. The current study aims to examine the pattern of relations between a history of child abuse, impulsivity and dissociation. More specifically, it examines whether impulsivity serves as a moderator or mediator in the association between childhood trauma and dissociation. Eighty-one inpatients from the acute wards of two psychiatric hospitals participated in this study. Data were collected by clinician-administered questionnaires. A highly significant linear hierarchical regression analysis revealed that both psychiatric comorbidity and childhood trauma made unique contributions to the variance of dissociation. Yet, the significant association between childhood trauma and dissociation decreased when impulsivity was entered into the regression model. Our findings suggest that impulsivity mediates the association between childhood trauma and dissociative psychopathology and imply that the identification and treatment of impulsivity could be a potentially valuable clinical target in individuals with dissociative disorders. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. The dynamical complexity of a Ivlev-type prey-predator system with impulsive effect

    International Nuclear Information System (INIS)

    Wang Hailing; Wang Weiming

    2008-01-01

    Based on the classical predator-prey system with Ivlev-type functional response, an impulsive differential equations to model the process of periodic perturbations on the predator at different fixed time is established. It proves that there exists a locally asymptotically stable prey-eradication periodic solution when the impulse period is less than some critical value, and otherwise, the system can be permanent. Numerical results show that the system considered has more complicated dynamics. such as quasi-periodic oscillation, narrow periodic window, wide periodic window, chaotic bands, symmetry-breaking pitchfork bifurcation and crises, etc

  1. Impulsive suicide attempts predict post-treatment relapse in alcohol-dependent patients.

    Science.gov (United States)

    Wojnar, Marcin; Ilgen, Mark A; Jakubczyk, Andrzej; Wnorowska, Anna; Klimkiewicz, Anna; Brower, Kirk J

    2008-10-01

    The present study was designed to examine the influence of suicidality on relapse in alcohol-dependent patients. Specifically, a lifetime suicide attempt at baseline was used to predict relapse in the year after treatment. Also, the unique contribution of impulsive suicide attempts was examined. A total of 154 patients with alcohol dependence, consecutively admitted to four addiction treatment facilities in Warsaw, Poland participated in the study. Of the 154 eligible patients, 118 (76.6%) completed a standardized follow-up assessment at 12 months. Previous suicide attempts were common in adults treated for alcohol dependence with 43% patients in the present sample reporting an attempt at some point during their lifetime. Additionally, more than 62% of those with a lifetime suicide attempt reported making an impulsive attempt. Lifetime suicide attempts were not associated with post-treatment relapse (chi-square=2.37, d.f.=1, p=0.124). However, impulsive suicide attempts strongly predicted relapse (OR=2.81, 95% CI=1.13-6.95, p=0.026) and time to relapse (OR=2.10, 95% CI=1.18-3.74, p=0.012) even after adjusting for other measures of baseline psychopathology, depression, impulsivity, hopelessness and alcohol use severity. This study is the first to document the relationship between pre-treatment impulsive suicide attempts and higher likelihood of post-treatment relapse in alcohol-dependent patents. Clinicians should routinely conduct an assessment for previous suicide attempts in patients with alcohol use disorders, and when impulsive suicidality is reported, they should recognize the increased risk for relapse and formulate their patients' treatment plans accordingly with the goals of reducing both alcoholic relapse and suicide rates.

  2. Effect of management of patients with Anorexia and Bulimia nervosa on symptoms and impulsive behavior.

    Science.gov (United States)

    Sernec, Karin; Tomori, Martina; Zalar, Bojan

    2010-12-01

    The aim of the study was to provide further and up to date information on the evaluation of the management of Anorexia and Bulimia nervosa at the Eating Disorders Unit (EDU) of the Ljubljana Psychiatric Clinic, based upon detailed assessment of the eating disorders specific and non specific symptoms of impulsive behaviors, highly correlated with these entities. 34 female patients with anorexia (restrictive or purgative type) and 38 female patients with Bulimia nervosa (purgative or non-purgative type) undergoing hospital treatment at the EDU were evaluated upon admission, as well as upon discharge and three and six months after discharge, using the Eating Disorder Questionnaire. Upon discharge a marked decrease in the overall symptoms was noted. The differences in symptoms incidences between the two groups were significantly specific for the individual form of eating disorder, especially upon admission, and were more pronounced in anorexia group. In later measurements, performed during the period of three and six months after discharge, a mild trend of increase in the disorder specific symptoms was detected in both groups, but was not statistically significant. In addition to binging on food, striking, quarreling and spending sprees are characteristics of patients with eating disorders, which in particular apply to the Bulimia nervosa group. Apart from the disorder specific symptoms, impulsive behavior was also reduced during study period, while the difference in its occurrence between the two groups gradually became non-significant. The management of patients with eating disorders at the EDU was successful in both groups, confirmed by an intense reduction of the disorder specific symptoms, impulsive behavior and increased stability recorded three and six months after discharge. The study strongly suggests that the effect of treatment regime for eating disorders can be predicted by careful assessment of the relevant symptoms and impulsive behavioral patterns.

  3. Impulsive synchronization of Chen's hyperchaotic system

    International Nuclear Information System (INIS)

    Haeri, Mohammad; Dehghani, Mahsa

    2006-01-01

    In this Letter the impulsive synchronization of the Chen's hyperchaotic systems is discussed. Some new and sufficient conditions on varying impulsive distance are established in order to guarantee the synchronizabillity of the systems using the synchronization method. In particular, some simple conditions are derived in synchronizing the systems by equal impulsive distances. Two illustrative examples are provided to show the feasibility and the effectiveness of the proposed method. The boundaries of the stable regions are also estimated

  4. Ballistic impulse gauge

    Science.gov (United States)

    Ault, Stanley K.

    1993-01-01

    A gauge for detecting the impulse generated in sample materials by X-rays or other impulse producing mechanisms utilizes a pair of flat annular springs to support a plunger relative to a housing which may itself be supported by a pair of flat annular springs in a second housing. The plunger has a mounting plate mounted on one end and at the other, a position or velocity transducer is mounted. The annular springs consist of an outer ring and an inner ring with at least three arcuate members connecting the outer ring with the inner ring.

  5. Impulsive action and motivation.

    Science.gov (United States)

    Frijda, Nico H

    2010-07-01

    This paper explores the way in which emotions are causal determinants of action. It argues that emotional events, as appraised by the individual, elicit changes in motive states (called states of action readiness), which in turn may (or may not) cause action. Actions can be elicited automatically, without prior intention (called impulsive actions), or intentionally. Impulsive actions reflect the simplest and biologically most general form in which emotions can cause action, since they require no reflection, no foresight, and no planning. Impulsive actions are determined conjointly by the nature of action readiness, the affordances perceived in the eliciting event as appraised, and the individual's action repertoire. Those actions from one's repertoire are performed that both match the perceived affordances and the aim of the state of action readiness. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Interactions between risky decisions, impulsiveness and smoking in young tattooed women

    Science.gov (United States)

    2013-01-01

    Background According to previous studies, one of the common problems of everyday life of persons with tattoos is risky behavior. However, direct examination of the decision making process, as well as factors which determine women’s risk-taking decisions to get tattoos, have not been conducted. This study investigates whether risk taking decision-making is associated with the self-assessment impulsiveness in tattooed women. Methods Young women (aged 18–35 years) with (N = 60) and without (N = 60) tattoos, performed the Iowa Gambling Task (IGT), as a measure of decision-making processes, as well as completing the Barratt Impulsivity Scale (BIS-11). Results Tattooed women showed significantly higher scores in the BIS-11 and preference for disadvantageous decks on the IGT compared to non-tattooed women. There was no significant correlation between risky decision-making in the IGT and BIS-11 impulsivity measures. A significantly higher rate of smoking was observed in the tattooed women. However, the analysis did not reveal a group effect after adjustment for smoking in the IGT and the BIS-11 measures. Conclusions The present study was specifically designed to resolve questions regarding associations between impulsiveness and risky decision-making in tattooed women. It shows that in tattooed women, risky decisions are not a direct result of their self-reported impulsiveness. Smoking does not explain the psychometric differences between tattooed women and controls. PMID:24180254

  7. Behind impulsive suicide attempts: indications from a community study.

    Science.gov (United States)

    Wyder, Marianne; De Leo, Diego

    2007-12-01

    A considerable proportion of suicide attempts are made on impulse. However, knowledge of characteristics of impulsive attempters is still limited. The present study investigated some of these characteristics and aimed to identify the pattern (if any) of suicidal ideation before an impulsive attempt. Data from a randomized and stratified population of 5130 individuals from Brisbane, Australia, were analysed. Computer-assisted telephone interviews (CATI) were adopted to recruit subjects. Those reporting previous suicidal behaviour were sent a questionnaire by mail. One hundred and twelve subjects reported a suicide attempt. One quarter of these described a pattern consistent with an impulsive attempt. Most impulsive attempters experienced suicidal thoughts before their attempt. They were less likely to believe that their attempt would cause death, and less likely to experience depression. Impulsive attempters did not differ significantly from non-impulsive attempters in regards to age, gender, and motivations for the attempt. Surprisingly, no differences in mean scores of trait impulsivity between impulsive and non-impulsive attempters were found. In addition, the majority of suicide attempters (whether impulsive or not) experienced the suicidal process as fluctuating and not as developing along a continuum. The number of attempters who validly entered the study limited our ability to identify potential confounders. Due to the retrospective nature of the survey, the reliability of the information collected may have been affected by recall biases. In addition, as the surveys were administered by mail, it is possible that some questions may have been misinterpreted. The presence of suicidal feelings prior to an attempt constitutes an opportunity for intervention also in impulsive attempters. However, the identification of impulsiveness requires more research efforts.

  8. Design Analysis of a High Temperature Radiator for the Variable Specific Impulse Magnetoplasma Rocket (VASIMR)

    Science.gov (United States)

    Sheth, Rubik B.; Ungar, Eugene K.; Chambliss, Joe P.; Cassady, Leonard D.

    2011-01-01

    The Variable Specific Impulse Magnetoplasma Rocket (VASIMR), currently under development by Ad Astra Rocket Company, is a unique propulsion system that can potentially change the way space propulsion is performed. VASIMR's efficiency, when compared to that of a conventional chemical rocket, reduce propellant needed for exploration missions by a factor of 10. Currently plans include flight tests of a 200 kW VASIMR system, titled VF-200, on the International Space Station. The VF-200 will consist of two 100 kW thruster units packaged together in one engine bus. Each thruster unit has a unique heat rejection requirement of about 27 kW over a firing time of 15 minutes. In order to control rocket core temperatures, peak operating temperatures of about 300 C are expected within the thermal control loop. Design of a high temperature radiator is a unique challenge for the vehicle design. This paper will discuss the path taken to develop a steady state and transient based radiator design. The paper will describe radiator design options for the VASIMR thermal control system for use on ISS as well as future exploration vehicles.

  9. Effects of dopamine agonist dose and gender on the prognosis of impulse control disorders in Parkinson's disease.

    Science.gov (United States)

    Joutsa, Juho; Martikainen, Kirsti; Vahlberg, Tero; Kaasinen, Valtteri

    2012-12-01

    Cross-sectional studies have demonstrated that Parkinson's disease patients have an increased risk of impulse control disorders, and that the disorders frequently co-exist with depressive symptoms. There have been no previous large-scale prospective studies investigating predictive and prognostic factors of these disorders. A population of 290 Parkinson's disease patients was studied at baseline and approximately 15 months later. The same screening methodology was used at both time-points (demographic and medication data together with the Questionnaire for Impulsive-compulsive Disorders in Parkinson's disease and the Beck Depression Inventory). The data was analyzed separating patients with and without impulse control disorders at baseline to obtain clinically useful prognostic factors. In patients who had impulse control disorders at baseline (n = 119), high dopamine agonist dose was associated with the presence of disorders at follow-up. Dopamine agonist levodopa equivalent daily dose over 160 mg was significantly associated with impulse control disorders with a positive predictive value of 92.5% (95% confidence interval 79.6%-98.4%). In addition, females had a better prognosis of impulse control disorders compared to males. The development of novel impulse control disorders (no disorder at baseline, disorder at follow-up) was associated with a concurrent increase in depression scores. The results suggest that dopamine agonist dose and gender are associated with the prognosis of impulse control disorders. Symptoms of depression emerge together with novel impulse control disorders in Parkinson's disease. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Methylphenidate alleviates manganese-induced impulsivity but not distractibility

    Science.gov (United States)

    Beaudin, Stephane A.; Strupp, Barbara J.; Uribe, Walter; Ysais, Lauren; Strawderman, Myla; Smith, Donald R.

    2017-01-01

    Recent studies from our lab have demonstrated that postnatal manganese (Mn) exposure in a rodent model can cause lasting impairments in fine motor control and attention, and that oral methylphenidate (MPH) treatment can effectively treat the dysfunction in fine motor control. However, it is unknown whether MPH treatment can alleviate the impairments in attention produced by Mn exposure. Here we used a rodent model of postnatal Mn exposure to determine whether (1) oral MPH alleviates attention and impulse control deficits caused by postnatal Mn exposure, using attention tasks that are variants of the 5-choice serial reaction time task, and (2) whether these treatments affected neuronal dendritic spine density in the medial prefrontal cortex (mPFC) and dorsal striatum. Male Long-Evans rats were exposed orally to 0 or 50 mg Mn/kg/d throughout life starting on PND 1, and tested as young adults (PND 107 – 115) on an attention task that specifically tapped selective attention and impulse control. Animals were treated with oral MPH (2.5 mg/kg/d) throughout testing on the attention task. Our findings show that lifelong postnatal Mn exposure impaired impulse control and selective attention in young adulthood, and that a therapeutically relevant oral MPH regimen alleviated the Mn-induced dysfunction in impulse control, but not selective attention, and actually impaired focused attention in the Mn group. In addition, the effect of MPH was qualitatively different for the Mn-exposed versus control animals across a range of behavioral measures of inhibitory control and attention, as well as dendritic spine density in the mPFC, suggesting that postnatal Mn exposure alters catecholaminergic systems modulating these behaviors. Collectively these findings suggest that MPH may hold promise for treating the behavioral dysfunction caused by developmental Mn exposure, although further research is needed with multiple MPH doses to determine whether a dose can be identified that

  11. Methylphenidate alleviates manganese-induced impulsivity but not distractibility.

    Science.gov (United States)

    Beaudin, Stephane A; Strupp, Barbara J; Uribe, Walter; Ysais, Lauren; Strawderman, Myla; Smith, Donald R

    2017-05-01

    Recent studies from our lab have demonstrated that postnatal manganese (Mn) exposure in a rodent model can cause lasting impairments in fine motor control and attention, and that oral methylphenidate (MPH) treatment can effectively treat the dysfunction in fine motor control. However, it is unknown whether MPH treatment can alleviate the impairments in attention produced by Mn exposure. Here we used a rodent model of postnatal Mn exposure to determine whether (1) oral MPH alleviates attention and impulse control deficits caused by postnatal Mn exposure, using attention tasks that are variants of the 5-choice serial reaction time task, and (2) whether these treatments affected neuronal dendritic spine density in the medial prefrontal cortex (mPFC) and dorsal striatum. Male Long-Evans rats were exposed orally to 0 or 50Mn/kg/d throughout life starting on PND 1, and tested as young adults (PND 107-115) on an attention task that specifically tapped selective attention and impulse control. Animals were treated with oral MPH (2.5mg/kg/d) throughout testing on the attention task. Our findings show that lifelong postnatal Mn exposure impaired impulse control and selective attention in young adulthood, and that a therapeutically relevant oral MPH regimen alleviated the Mn-induced dysfunction in impulse control, but not selective attention, and actually impaired focused attention in the Mn group. In addition, the effect of MPH was qualitatively different for the Mn-exposed versus control animals across a range of behavioral measures of inhibitory control and attention, as well as dendritic spine density in the mPFC, suggesting that postnatal Mn exposure alters catecholaminergic systems modulating these behaviors. Collectively these findings suggest that MPH may hold promise for treating the behavioral dysfunction caused by developmental Mn exposure, although further research is needed with multiple MPH doses to determine whether a dose can be identified that ameliorates the

  12. The error-related negativity (ERN is an electrophysiological marker of motor impulsiveness on the Barratt Impulsiveness Scale (BIS-11 during adolescence

    Directory of Open Access Journals (Sweden)

    Jasmine B. Taylor

    2018-04-01

    Full Text Available Objectives: Previous studies have postulated that the error-related negativity (ERN may reflect individual differences in impulsivity; however, none have used a longitudinal framework or evaluated impulsivity as a multidimensional construct. The current study evaluated whether ERN amplitude, measured in childhood and adolescence, is predictive of impulsiveness during adolescence. Methods: Seventy-five children participated in this study, initially at ages 7–9 years and again at 12–18 years. The interval between testing sessions ranged from 5 to 9 years. The ERN was extracted in response to behavioural errors produced during a modified visual flanker task at both time points (i.e. childhood and adolescence. Participants also completed the Barratt Impulsiveness Scale − a measure that considers impulsiveness to comprise three core sub-traits − during adolescence. Results: At adolescence, the ERN amplitude was significantly larger than during childhood. Additionally, ERN amplitude during adolescence significantly predicted motor impulsiveness at that time point, after controlling for age, gender, and the number of trials included in the ERN. In contrast, ERN amplitude during childhood did not uniquely predict impulsiveness during adolescence. Conclusions: These findings provide preliminary evidence that ERN amplitude is an electrophysiological marker of self-reported motor impulsiveness (i.e. acting without thinking during adolescence. Keywords: Error-related negativity, ERN, Impulsivity, BIS, Development, Adolescence

  13. Ground vibration test results of a JetStar airplane using impulsive sine excitation

    Science.gov (United States)

    Kehoe, Michael W.; Voracek, David F.

    1989-01-01

    Structural excitation is important for both ground vibration and flight flutter testing. The structural responses caused by this excitation are analyzed to determine frequency, damping, and mode shape information. Many excitation waveforms have been used throughout the years. The use of impulsive sine (sin omega t)/omega t as an excitation waveform for ground vibration testing and the advantages of using this waveform for flight flutter testing are discussed. The ground vibration test results of a modified JetStar airplane using impulsive sine as an excitation waveform are compared with the test results of the same airplane using multiple-input random excitation. The results indicated that the structure was sufficiently excited using the impulsive sine waveform. Comparisons of input force spectrums, mode shape plots, and frequency and damping values for the two methods of excitation are presented.

  14. A Model-based Analysis of Impulsivity Using a Slot-Machine Gambling Paradigm

    Directory of Open Access Journals (Sweden)

    Saee ePaliwal

    2014-07-01

    Full Text Available Impulsivity plays a key role in decision-making under uncertainty. It is a significant contributor to problem and pathological gambling. Standard assessments of impulsivity by questionnaires, however, have various limitations, partly because impulsivity is a broad, multi-faceted concept. What remains unclear is which of these facets contribute to shaping gambling behavior. In the present study, we investigated impulsivity as expressed in a gambling setting by applying computational modeling to data from 47 healthy male volunteers who played a realistic, virtual slot-machine gambling task. Behaviorally, we found that impulsivity, as measured independently by the 11th revision of the Barratt Impulsiveness Scale (BIS-11, correlated significantly with an aggregate read-out of the following gambling responses: bet increases, machines switches, casino switches and double-ups. Using model comparison, we compared a set of hierarchical Bayesian belief-updating models, i.e. the Hierarchical Gaussian Filter (HGF and Rescorla-Wagner reinforcement learning models, with regard to how well they explained different aspects of the behavioral data. We then examined the construct validity of our winning models with multiple regression, relating subject-specific model parameter estimates to the individual BIS-11 total scores. In the most predictive model (a three-level HGF, the two free parameters encoded uncertainty-dependent mechanisms of belief updates and significantly explained BIS-11 variance across subjects. Furthermore, in this model, decision noise was a function of trial-wise uncertainty about winning probability. Collectively, our results provide a proof of concept that hierarchical Bayesian models can characterize the decision-making mechanisms linked to impulsivity. These novel indices of gambling mechanisms unmasked during actual play may be useful for online prevention measures for at-risk players and future assessments of pathological gambling.

  15. Generalized synchronization via impulsive control

    International Nuclear Information System (INIS)

    Zhang Rong; Xu Zhenyuan; Yang, Simon X.; He Xueming

    2008-01-01

    This paper demonstrates theoretically that two completely different systems can implement GS via impulsive control, moreover by using impulsive control, for a given manifold y = H(x) we construct a response system to achieve GS with drive system and the synchronization manifold is y = H(x). Our theoretical results are supported by numerical examples

  16. Cognitive control training for emotion-related impulsivity.

    Science.gov (United States)

    Peckham, Andrew D; Johnson, Sheri L

    2018-06-01

    Many forms of psychopathology are tied to a heightened tendency to respond impulsively to strong emotions, and this tendency, in turn, is closely tied to problems with cognitive control. The goal of the present study was to test whether a two-week, six-session cognitive control training program is efficacious in reducing emotion-related impulsivity. Participants (N = 52) reporting elevated scores on an emotion-related impulsivity measure completed cognitive control training targeting working memory and response inhibition. A subset of participants were randomized to a waitlist control group. Impulsivity, emotion regulation, and performance on near and far-transfer cognitive tasks were assessed at baseline and after completion of training. Emotion-related impulsivity declined significantly from pre-training to post-training and at two-week follow-up; improvements were not observed in the waitlist control group. A decrease in brooding rumination and an increase in reappraisal were also observed. Participants showed significant improvements on trained versions of the working memory and inhibition tasks as well as improvements on an inhibition transfer task. In sum, these preliminary findings show that cognitive training appears to be well-tolerated for people with significant emotion-driven impulsivity. Results provide preliminary support for the efficacy of cognitive training interventions as a way to reduce emotion-related impulsivity. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Impulsivity in bipolar disorders in a Tunisian sample.

    Science.gov (United States)

    Feki, Ines; Moalla, Mariem; Baati, Imen; Trigui, Dorsaf; Sellami, Rim; Masmoudi, Jaweher

    2016-08-01

    Impulsivity as a trait characteristic is increased in bipolar disorder and may be a core factor of the illness. The objectives of our work are to evaluate the level of impulsivity among patients with bipolar disorder and to study its relation with mood state, alcohol misuse, suicide attempts and other socio-demographic and clinical factors. We measured impulsivity in 60 subjects with bipolar disorder in relationship to socio-demographic and clinical variables. The subjects completed Data included socio-demographic details and clinical variables, the Barratt Impulsiveness Scale (BIS-11) in an Arabic version to assess impulsivity, The Mini International Neuropsychiatric Interview "MINI" version 05 to screen for alcohol abuse or dependence and mood graphic rate scale (MGRS) to evaluate mood state. Our results show that the mean score of BIS-11 was 71.5. Fifty-five per cent of the patients had a high level of impulsiveness. No differences were found relating to mood state. Impulsivity was related to Male gender, lower educational level, early age of onset, smoking, alcohol and drug misuse and prior suicide attempts. The treatment of patients with BD should consider to reduce impulsivity to improve morbidity. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Impulsivity in remitted depression: a meta-analytical review.

    Science.gov (United States)

    Saddichha, Sahoo; Schuetz, Christian

    2014-06-01

    Depressive disorder and suicide have been associated with impulsivity in several studies. This paper aimed to review measures of trait impulsivity in remitted depressive disorder. We used keywords "impulsivity and depression"; "impulsivity and depressive disorder" to narrow down our search on Medline, EMBASE and Psychinfo to include those studies that had reported impulsivity scores using validated and reliable assessment measures in remitted depressive disorder. We searched all English language studies from 1990 to December 2012 with 9 reports meeting the inclusion criteria for depression, which were then reviewed by the two reviewers independently. We generated weighted mean differences (WMDs) for depression from the pooled data using RevManager 5.1 from Cochrane analysis. The Barratt Impulsivity Scale (BIS) 11 was the instrument commonly used in depression. 9 studies met inclusion criteria in depression, which yielded a WMD of 10.12 on BIS 11 total scores. There is a strong association of impulsivity and depression, which persists even in remission. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Comparison among various methods of assessment of impulsiveness.

    Science.gov (United States)

    Carrillo-de-la-Peña, M T; Otero, J M; Romero, E

    1993-10-01

    The current confused status of the research on impulsivity may be attributed to the lack of precise definitions, the reliance of most operationalizations on a single index, and inconsistency among different measures of the construct. Empirical measurements of impulsivity by self-reports, rating scales, or performance tasks suggest that the instruments employed measure aspects that have very little in common, a finding that throws serious doubts on the validity of the construct and implies a need for further research. To clarify this topic, we applied four different measures of impulsivity to 46 7th-grade (12 to 13 years old) schoolchildren. The children were rated by their teachers on an impulsivity behavior scale and were administered Kagan's Matching Familiar Figures Test, Version MFF-20, and two self-report forms, the Eysenck Impulsiveness Questionnaire, and the Barratt Impulsiveness Scale. Although the results confirmed the lack of convergence among these measures, high latencies on matching were associated with the cognitive aspect of the self-report scales. Treating impulsivity as a multidimensional construct is discussed.

  20. A high temperature superconducting impulse generator

    International Nuclear Information System (INIS)

    Locker, J.R.; Geers, S.

    1992-01-01

    A mechanism based upon the Superconducting Vector Switch (SVS) effect displays the property of impulse generation. In this paper the principle of operation of this impulse generator is discussed. Experimental results and analytical predictions are presented

  1. Nonlinear Dynamic in an Ecological System with Impulsive Effect and Optimal Foraging

    Directory of Open Access Journals (Sweden)

    Min Zhao

    2014-01-01

    Full Text Available The population dynamics of a three-species ecological system with impulsive effect are investigated. Using the theories of impulsive equations and small-amplitude perturbation scales, the conditions for the system to be permanent when the number of predators released is less than some critical value can be obtained. Furthermore, because the predator in the system follows the predictions of optimal foraging theory, it follows that optimal foraging promotes species coexistence. In particular, the less beneficial prey can support the predator alone when the more beneficial prey goes extinct. Moreover, the influences of the impulsive effect and optimal foraging on inherent oscillations are studied using simulation, which reveals rich dynamic behaviors such as period-halving bifurcations, a chaotic band, a periodic window, and chaotic crises. In addition, the largest Lyapunov exponent and the power spectra of the strange attractor, which can help analyze the chaotic dynamic behavior of the model, are investigated. This information will be useful for studying the dynamic complexity of ecosystems.

  2. BMI predicts emotion-driven impulsivity and cognitive inflexibility in adolescents with excess weight.

    Science.gov (United States)

    Delgado-Rico, Elena; Río-Valle, Jacqueline S; González-Jiménez, Emilio; Campoy, Cristina; Verdejo-García, Antonio

    2012-08-01

    Adolescent obesity is increasingly viewed as a brain-related dysfunction, whereby reward-driven urges for pleasurable foods "hijack" response selection systems, such that behavioral control progressively shifts from impulsivity to compulsivity. In this study, we aimed to examine the link between personality factors (sensitivity to reward (SR) and punishment (SP), BMI, and outcome measures of impulsivity vs. flexibility in--otherwise healthy--excessive weight adolescents. Sixty-three adolescents (aged 12-17) classified as obese (n = 26), overweight (n = 16), or normal weight (n = 21) participated in the study. We used psychometric assessments of the SR and SP motivational systems, impulsivity (using the UPPS-P scale), and neurocognitive measures with discriminant validity to dissociate inhibition vs. flexibility deficits (using the process-approach version of the Stroop test). We tested the relative contribution of age, SR/SP, and BMI on estimates of impulsivity and inhibition vs. switching performance using multistep hierarchical regression models. BMI significantly predicted elevations in emotion-driven impulsivity (positive and negative urgency) and inferior flexibility performance in adolescents with excess weight--exceeding the predictive capacity of SR and SP. SR was the main predictor of elevations in sensation seeking and lack of premeditation. These findings demonstrate that increases in BMI are specifically associated with elevations in emotion-driven impulsivity and cognitive inflexibility, supporting a dimensional path in which adolescents with excess weight increase their proneness to overindulge when under strong affective states, and their difficulties to switch or reverse habitual behavioral patterns.

  3. State impulsive control strategies for a two-languages competitive model with bilingualism and interlinguistic similarity

    Science.gov (United States)

    Nie, Lin-Fei; Teng, Zhi-Dong; Nieto, Juan J.; Jung, Il Hyo

    2015-07-01

    For reasons of preserving endangered languages, we propose, in this paper, a novel two-languages competitive model with bilingualism and interlinguistic similarity, where state-dependent impulsive control strategies are introduced. The novel control model includes two control threshold values, which are different from the previous state-dependent impulsive differential equations. By using qualitative analysis method, we obtain that the control model exhibits two stable positive order-1 periodic solutions under some general conditions. Moreover, numerical simulations clearly illustrate the main theoretical results and feasibility of state-dependent impulsive control strategies. Meanwhile numerical simulations also show that state-dependent impulsive control strategy can be applied to other general two-languages competitive model and obtain the desired result. The results indicate that the fractions of two competitive languages can be kept within a reasonable level under almost any circumstances. Theoretical basis for finding a new control measure to protect the endangered language is offered.

  4. Assessing the role of impulsivity in smoking & non-smoking disordered gamblers.

    Science.gov (United States)

    Boothby, Célina A; Kim, Hyoun S; Romanow, Nicole K; Hodgins, David C; McGrath, Daniel S

    2017-07-01

    Co-morbidity with other addictive behaviors is common in disordered gambling (DG). In particular, tobacco dependence has been found to be among the most prevalent disorders co-morbid with DG. While the extant literature has firmly established the co-occurrence of DG and smoking, there is a paucity of research examining factors that differentiate DGs who smoke from those who do not. To address this empirical gap, the current study tested whether dimensions of trait impulsivity as measured by the UPPS-P Impulsive Behavior Scale (positive urgency, negative urgency, lack of premeditation, lack of perseverance, and sensation seeking), discriminated between non-DGs and DGs based on their present smoking status: non-smoker, occasional smoker, and daily smoker. To this end, 564 community gamblers were recruited through a crowdsourcing platform (Amazon's Mechanical Turk) and completed an online survey, assessing problem gambling severity, tobacco use, and trait impulsivity. MANOVA analyses revealed significant main effects for both gambling severity and smoking status groups. Importantly, a significant gambling by smoking interaction was also found. Pairwise comparisons revealed that DGs who were daily smokers scored higher on negative urgency than those who smoked occasionally or not all. Furthermore, among non-DGs, smoking status failed to discriminate between mean scores on negative urgency. No other significant interaction effects were found for the remaining UPPS-P impulsivity facets. Results suggest that individual components of trait impulsivity, and more specifically negative urgency, successfully differentiate DGs who do not smoke, or just smoke occasionally, from DGs who smoke daily. These findings suggest that the degree of trait impulsivity may potentially distinguish between DGs and DGs who are dually addicted to other substances such as tobacco. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Isolating the delay component of impulsive choice in adolescent rats

    Directory of Open Access Journals (Sweden)

    Jesse eMcClure

    2014-01-01

    Full Text Available Impulsive choice — the preference for small immediate rewards over larger delayed rewards — has been linked to various psychological conditions ranging from behavioral disorders to addiction. These links highlight the critical need to dissect the various components of this multifaceted behavioral trait. Delay discounting tasks allow researchers to study an important factor of this behavior: how the subjective value of a rewards changes over a delay period. However, existing methods of delay discounting include a confound of modifying reward sizes during the procedure. Here we present a new approach of using a single constant reward size to assess delay discounting. A complementary approach could hold delay constant and assess the utility of changing quantities of a reward. Isolating these behavioral components can advance our ability to explore the behavioral complexity of impulsive choice. We present the methods for isolating delay in detail, and further capitalize on this method by pairing it with a standard peak interval task to test whether individual variation in delay discounting can be explained by differences in perception of time in male and female adolescent rats. We find that rats that were more precise in discriminating time intervals were also less impulsive in their choice. Our data suggest that differences in timing and delay discounting are not causally related, but instead are more likely influenced by a common factor. Further, the mean-level change in our measure between postnatal day 28 and 42 suggests this test may be capturing a developmental change in this factor. In summary, this new method of isolating individual components of impulsive choice (delay or quantity can be efficiently applied in either adolescent or adult animal models and may help elucidate the mechanisms underlying impulsivity and its links to psychological disorders.

  6. Training impulsive choices for healthy and sustainable food

    NARCIS (Netherlands)

    Veling, H.P.; Chen, Z.; Tombrock, M.C.; Verpaalen, I.A.M.; Schmitz, L.I.; Dijksterhuis, A.J.; Holland, R.W.

    2017-01-01

    Many people find it hard to change their dietary choices. Food choice often occurs impulsively, without deliberation, and it has been unclear whether impulsive food choice can be experimentally created. Across 3 exploratory and 2 confirmatory preregistered experiments we examined whether impulsive

  7. Impulsive phase of solar flares: theory

    International Nuclear Information System (INIS)

    Mackinnon, A.L.

    1986-01-01

    The paper reviews the theoretical interpretation of impulsive phase phenomena in solar flares. The impulsive phase is defined to be that period of approx. 10 - 100s duration, during which the flare radiative output undergoes its most rapid, dramatic increase and decrease. The interpretation of the various impulsive phase radiation signatures are examined, including the i) hard x-ray emission, ii) radio emission, iii) UV, Hα and white light emissions and iv) gamma-ray emission. The acceleration mechanisms are discussed with respect to candidate acceleration mechanisms, and the synthesis of the theory and observations. (UK)

  8. Firm-specific information, analysts’ superiority and investment value

    Institute of Scientific and Technical Information of China (English)

    Lu; Li; Erjia; Yang; Tusheng; Xiao

    2014-01-01

    Using a sample of Chinese security analysts’recommendations from 2005 to2010,we examine the source of analysts’superiority and the investment value of their recommendations.Using a calendar-time portfolio approach,we find that,on average,analysts’recommendations are valuable and that analysts are better at analyzing and transferring firm-specific information than market-wide or industry-level information.In addition,we show that the investment value of recommendations increases as firm-specific information becomes more important in stock pricing.Our empirical results are useful in guiding investors and helping brokerage houses to evaluate the output of research departments.

  9. Silicon oxynitride films deposited by reactive high power impulse magnetron sputtering using nitrous oxide as a single-source precursor

    Energy Technology Data Exchange (ETDEWEB)

    Hänninen, Tuomas, E-mail: tuoha@ifm.liu.se; Schmidt, Susann; Jensen, Jens; Hultman, Lars; Högberg, Hans [Thin Film Physics Division, Department of Physics, Chemistry, and Biology (IFM), Linköping University, Linköping SE-581 83 (Sweden)

    2015-09-15

    Silicon oxynitride thin films were synthesized by reactive high power impulse magnetron sputtering of silicon in argon/nitrous oxide plasmas. Nitrous oxide was employed as a single-source precursor supplying oxygen and nitrogen for the film growth. The films were characterized by elastic recoil detection analysis, x-ray photoelectron spectroscopy, x-ray diffraction, x-ray reflectivity, scanning electron microscopy, and spectroscopic ellipsometry. Results show that the films are silicon rich, amorphous, and exhibit a random chemical bonding structure. The optical properties with the refractive index and the extinction coefficient correlate with the film elemental composition, showing decreasing values with increasing film oxygen and nitrogen content. The total percentage of oxygen and nitrogen in the films is controlled by adjusting the gas flow ratio in the deposition processes. Furthermore, it is shown that the film oxygen-to-nitrogen ratio can be tailored by the high power impulse magnetron sputtering-specific parameters pulse frequency and energy per pulse.

  10. High impulsivity predicting vulnerability to cocaine addiction in rats

    DEFF Research Database (Denmark)

    Molander, Anna C; Mar, Adam; Norbury, Agnes

    2011-01-01

    RATIONALE: Impulsivity is a vulnerability marker for drug addiction in which other behavioural traits such as anxiety and novelty seeking ('sensation seeking') are also widely present. However, inter-relationships between impulsivity, novelty seeking and anxiety traits are poorly understood...... increasing or decreasing impulsivity in SHI and SLI rats, did reduce the contrast in impulsivity between these two groups of animals. CONCLUSIONS: This investigation indicates that behavioural impulsivity in rats on the 5-CSRTT, which predicts vulnerability for cocaine addiction, is distinct from anxiety...

  11. Differential associations between impulsivity and risk-taking and brain activations underlying working memory in adolescents.

    Science.gov (United States)

    Panwar, Karni; Rutherford, Helena J V; Mencl, W Einar; Lacadie, Cheryl M; Potenza, Marc N; Mayes, Linda C

    2014-11-01

    Increased impulsivity and risk-taking are common during adolescence and relate importantly to addictive behaviors. However, the extent to which impulsivity and risk-taking relate to brain activations that mediate cognitive processing is not well understood. Here we examined the relationships between impulsivity and risk-taking and the neural correlates of working memory. Neural activity was measured in 18 adolescents (13-18 years) while they engaged in a working memory task that included verbal and visuospatial components that each involved encoding, rehearsal and recognition stages. Risk-taking and impulsivity were assessed using the Balloon Analogue Risk Task (BART) and the adolescent version of the Barratt Impulsiveness Scale-11 (BIS-11A), respectively. We found overlapping as well as distinct regions subserving the different stages of verbal and visuospatial working memory. In terms of risk-taking, we found a positive correlation between BART scores and activity in subcortical regions (e.g., thalamus, dorsal striatum) recruited during verbal rehearsal, and an inverse correlation between BART scores and cortical regions (e.g., parietal and temporal regions) recruited during visuospatial rehearsal. The BIS-11A evidenced that motor impulsivity was associated with activity in regions recruited during all stages of working memory, while attention and non-planning impulsivity was only associated with activity in regions recruited during recognition. In considering working memory, impulsivity and risk-taking together, both impulsivity and risk-taking were associated with activity in regions recruited during rehearsal; however, during verbal rehearsal, differential correlations were found. Specifically, positive correlations were found between: (1) risk-taking and activity in subcortical regions, including the thalamus and dorsal striatum; and, (2) motor impulsivity and activity in the left inferior frontal gyrus, insula, and dorsolateral prefrontal cortex. Therefore

  12. Impulsivity and Concussion in Juvenile Rats: Examining Molecular and Structural Aspects of the Frontostriatal Pathway.

    Directory of Open Access Journals (Sweden)

    Harleen Hehar

    Full Text Available Impulsivity and poor executive control have been implicated in the pathogenesis of many developmental and neuropsychiatric disorders. Similarly, concussions/mild traumatic brain injuries (mTBI have been associated with increased risk for neuropsychiatric disorders and the development of impulsivity and inattention. Researchers and epidemiologists have therefore considered whether or not concussions induce symptoms of attention-deficit/hyperactivity disorder (ADHD, or merely unmask impulsive tendencies that were already present. The purpose of this study was to determine if a single concussion in adolescence could induce ADHD-like impulsivity and impaired response inhibition, and subsequently determine if inherent impulsivity prior to a pediatric mTBI would exacerbate post-concussion symptomology with a specific emphasis on impulsive and inattentive behaviours. As these behaviours are believed to be associated with the frontostriatal circuit involving the nucleus accumbens (NAc and the prefrontal cortex (PFC, the expression patterns of 8 genes (Comt, Drd2, Drd3, Drd4, Maoa, Sert, Tph1, and Tph2 from these two regions were examined. In addition, Golgi-Cox staining of medium spiny neurons in the NAc provided a neuroanatomical examination of mTBI-induced structural changes. The study found that a single early brain injury could induce impulsivity and impairments in response inhibition that were more pronounced in males. Interestingly, when animals with inherent impulsivity experienced mTBI, injury-related deficits were exacerbated in female animals. The single concussion increased dendritic branching, but reduced synaptic density in the NAc, and these changes were likely associated with the increase in impulsivity. Finally, mTBI-induced impulsivity was associated with modifications to gene expression that differed dramatically from the gene expression pattern associated with inherent impulsivity, despite very similar behavioural phenotypes. Our

  13. Differential associations between impulsivity and risk-taking and brain activations underlying working memory in adolescents

    Science.gov (United States)

    Panwar, Karni; Rutherford, Helena J.V.; Mencl, W. Einar; Lacadie, Cheryl M.; Potenza, Marc N.; Mayes, Linda C.

    2014-01-01

    Increased impulsivity and risk-taking are common during adolescence and relate importantly to addictive behaviors. However, the extent to which impulsivity and risk-taking relate to brain activations that mediate cognitive processing is not well understood. Here we examined the relationships between impulsivity and risk-taking and the neural correlates of working memory. Neural activity was measured in 18 adolescents (13–18 years) while they engaged in a working memory task that included verbal and visuospatial components that each involved encoding, rehearsal and recognition stages. Risk-taking and impulsivity were assessed using the Balloon Analogue Risk Task (BART) and the adolescent version of the Barratt Impulsiveness Scale -11 (BIS-11A), respectively. We found overlapping as well as distinct regions subserving the different stages of verbal and visuospatial working memory. In terms of risk-taking, we found a positive correlation between BART scores and activity in subcortical regions (e.g., thalamus, dorsal striatum) recruited during verbal rehearsal, and an inverse correlation between BART scores and cortical regions (e.g., parietal and temporal regions) recruited during visuospatial rehearsal. The BIS-11A evidenced that motor impulsivity was associated with activity in regions recruited during all stages of working memory, while attention and non-planning impulsivity was only associated with activity in regions recruited during recognition. In considering working memory, impulsivity and risk-taking together, both impulsivity and risk-taking were associated with activity in regions recruited during rehearsal; however, during verbal rehearsal, differential correlations were found. Specifically, positive correlations were found between: (1) risk-taking and activity in subcortical regions, including the thalamus and dorsal striatum; and, (2) motor impulsivity and activity in the left inferior frontal gyrus, insula, dorsolateral and ventrolateral prefrontal

  14. Characteristics of individuals who make impulsive suicide attempts.

    Science.gov (United States)

    Spokas, Megan; Wenzel, Amy; Brown, Gregory K; Beck, Aaron T

    2012-02-01

    Previous research has identified only a few variables that have been associated with making an impulsive suicide attempt. The aim of the current study was to compare individuals who made an impulsive suicide attempt with those who made a premeditated attempt on both previously examined and novel characteristics. Participants were classified as making an impulsive or premeditated attempt based on the Suicide Intent Scale (Beck et al., 1974a) and were compared on a number of characteristics relevant to suicidality, psychiatric history, and demographics. Individuals who made an impulsive attempt expected that their attempts would be less lethal; yet the actual lethality of both groups' attempts was similar. Those who made an impulsive attempt were less depressed and hopeless than those who made a premeditated attempt. Participants who made an impulsive attempt were less likely to report a history of childhood sexual abuse and more likely to be diagnosed with an alcohol use disorder than those who made a premeditated attempt. Although the sample size was adequate for bivariate statistics, future studies using larger sample sizes will allow for multivariate analyses of characteristics that differentiate individuals who make impulsive and premeditated attempts. Clinicians should not minimize the significance of impulsive attempts, as they are associated with a similar level of lethality as premeditated attempts. Focusing mainly on depression and hopelessness as indicators of suicide risk has the potential to under-identify those who are at risk for making impulsive attempts. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. I want it and I want it now: using a temporal discounting paradigm to examine predictors of consumer impulsivity.

    Science.gov (United States)

    Dittmar, Helga; Bond, Rod

    2010-11-01

    This paper proposes a new model of consumer impulsivity, using type of good, a person's endorsement of materialistic values, and identity deficits as predictors. Traditional decision making and psychological accounts see impulsive behaviour as a general overweighing of short-term gratification (I want that dress now) relative to longer-term concerns, irrespective of consumer good. Our proposal is that consumers' impulsivity (a) differs according to type of good and (b) is linked systematically to a combination of materialistic values and high identity deficits. Beginning with Study 1, three experiments, using a temporal discounting paradigm, show consistently that discount rates are higher for goods that are seen as highly expressive of identity (e.g., clothes) than goods not expressive of identity (e.g., basic body care products). For materialistic consumers, identity deficits predict discount rates for identity-expressive goods (Study 2), and discount rates change for materialistic individuals when their identity deficits are made salient (Study 3). These findings support a conceptualization of consumer impulsivity as identity-seeking behaviour.

  16. Global existence for Volterra-Fredholm type neutral impulsive functional integrodifferential equations

    Directory of Open Access Journals (Sweden)

    V. Vijayakumar

    2012-09-01

    Full Text Available n this paper, we study the global existence of solutions for the initial value problems for Volterra-Fredholm type neutral impulsive functional integrodifferential equations. Using the Leray-Schauder's Alternative theorem, we derive conditions under which a solution exists globally. An application is provided to illustrate the theory.

  17. Comprehensive evaluation of the acoustic impulse-response of apples as a measure of fruit quality

    OpenAIRE

    Landahl, Sandra

    2007-01-01

    The acoustic impulse-response technique is a means to evaluate apple quality. In this work the effect of physiological changes in the fruit on the physical measurements of fruit quality are examined. In the acoustic impulse-response technique the fruit is mechanically excited by an impact force and starts to vibrate at its own natural frequency. The resulting sound waves are then recorded and analysed. It is a fast method and yields a produce-averaged value: the stiffness factor. Experimen...

  18. Impulse approximation in solid helium

    International Nuclear Information System (INIS)

    Glyde, H.R.

    1985-01-01

    The incoherent dynamic form factor S/sub i/(Q, ω) is evaluated in solid helium for comparison with the impulse approximation (IA). The purpose is to determine the Q values for which the IA is valid for systems such a helium where the atoms interact via a potential having a steeply repulsive but not infinite hard core. For 3 He, S/sub i/(Q, ω) is evaluated from first principles, beginning with the pair potential. The density of states g(ω) is evaluated using the self-consistent phonon theory and S/sub i/(Q,ω) is expressed in terms of g(ω). For solid 4 He resonable models of g(ω) using observed input parameters are used to evaluate S/sub i/(Q,ω). In both cases S/sub i/(Q, ω) is found to approach the impulse approximation S/sub IA/(Q, ω) closely for wave vector transfers Q> or approx. =20 A -1 . The difference between S/sub i/ and S/sub IA/, which is due to final state interactions of the scattering atom with the remainder of the atoms in the solid, is also predominantly antisymmetric in (ω-ω/sub R/), where ω/sub R/ is the recoil frequency. This suggests that the symmetrization procedure proposed by Sears to eliminate final state contributions should work well in solid helium

  19. Impulsivity in self-mutilative behavior: psychometric and biological findings.

    Science.gov (United States)

    Herpertz, S; Sass, H; Favazza, A

    1997-01-01

    This paper examines impulsivity as a central factor in moderate/superficial self-mutilation such as skin-cutting and burning. A sample of 165 subjects were divided into four groups, namely self-mutilators, patients with any modes of impulsive behavior other than self-mutilation, patients without any impulsive behavior, and normal probands. All were administered the 10th version of the Barratt Impulsiveness Scale, the State-Trait Anger Expression Inventory, and the Inventory for the Assessment of Factors of Aggressiveness. They also were interviewed carefully in regards to both impulsive and self-mutilative behavior. A d-fenfluramine challenge test was administered to 36 females and prolactin levels were measured. On the whole results implicate impulsive personality functioning as a major factor in subjects with moderate/superficial self-mutilative behavior whose trait pathology is similar to personality disordered patients with other modes of self-harming impulsive behavior.

  20. Substance Use in Undergraduate Students With Histories of Attention-Deficit/Hyperactivity Disorder (ADHD): The Role of Impulsivity.

    Science.gov (United States)

    Egan, Theresa E; Dawson, Anne E; Wymbs, Brian T

    2017-08-24

    Emerging adulthood (18-25 years old) is regarded as a time of identity exploration that includes a peak in risky behaviors, such as substance use and misuse. Attention-deficit/hyperactivity disorder (ADHD) is also associated with greater levels of risky behaviors, including substance use and misuse; however, there is a lack of research on substance use by emerging adults with ADHD, in particular the potential mechanisms that may facilitate this risk. The present study builds on the existing research regarding the association between ADHD and substance use by examining roles of multiple facets of impulsivity in facilitating this association during emerging adulthood. In a sample of 197 undergraduate students (24 students with an ADHD diagnostic history), we assessed for components of impulsivity (e.g., urgency, sensation-seeking) and rates of alcohol abuse, tobacco use, cannabis use, illicit drug use, and stimulant medication misuse within the past year. Findings indicate that facets of impulsivity, as a whole, explained the association between an ADHD diagnostic history and both illicit drug use and alcohol abuse such that students with ADHD histories tended to report higher levels of impulsivity, which increased risk of alcohol abuse and illicit drug use. Higher levels of specific facets of impulsivity, particularly negative urgency, also facilitated associations between having ADHD and engaging in most forms of substance use tested herein. Conclusions/Importance: Specific facets of impulsivity appear to be important mediators of the association between ADHD and substance use, and should be considered as potential targets of substance use interventions for this population.

  1. [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.

  2. An Exploration of Taiwanese Adolescents' Impulsive Buying Tendency

    Science.gov (United States)

    Lin, Chien-Huang; Lin, Hung-Ming

    2005-01-01

    The purpose of this study was to examine via a questionnaire the personal characteristics and impulsive buying tendencies of 15- to 19-year-old Taiwanese adolescents. Results indicated that the impulsive buying was significantly associated with gender, age, and amount of pocket money available. Females indicated more impulsive buying than did…

  3. Projectile Aerodynamic Jump Due to Lateral Impulsives

    National Research Council Canada - National Science Library

    Cooper, Gene

    2003-01-01

    .... The formulation shows for sufficiently long-range target interception; lateral impulse trajectory response for a guided projectile is independent of when the impulse is activated during the yaw cycle...

  4. Is impulsivity a common trait in bipolar and unipolar disorders?

    Science.gov (United States)

    Henna, Elaine; Hatch, John P; Nicoletti, Mark; Swann, Alan C; Zunta-Soares, Giovana; Soares, Jair C

    2013-03-01

    Impulsivity is increased in bipolar and unipolar disorders during episodes and is associated with substance abuse disorders and suicide risk. Impulsivity between episodes predisposes to relapses and poor therapeutic compliance. However, there is little information about impulsivity during euthymia in mood disorders. We sought to investigate trait impulsivity in euthymic bipolar and unipolar disorder patients, comparing them to healthy individuals and unaffected relatives of bipolar disorder patients.   Impulsivity was evaluated by the Barratt Impulsiveness Scale (BIS-11A) in 54 bipolar disorder patients, 25 unipolar disorder patients, 136 healthy volunteers, and 14 unaffected relatives. The BIS-11A mean scores for all four groups were compared through the Games-Howell test for all possible pairwise combinations. Additionally, we compared impulsivity in bipolar and unipolar disorder patients with and without a history of suicide attempt and substance abuse disorder.   Bipolar and unipolar disorder patients scored significantly higher than the healthy controls and unaffected relatives on all measures of the BIS-11A except for attentional impulsivity. On the attentional impulsivity measures there were no differences among the unaffected relatives and the bipolar and unipolar disorder groups, but all three of these groups scored higher than the healthy participant group. There was no difference in impulsivity between bipolar and unipolar disorder subjects with and without suicide attempt. However, impulsivity was higher among bipolar and unipolar disorder subjects with past substance use disorder compared to patients without such a history.   Questionnaire-measured impulsivity appears to be relatively independent of mood state in bipolar and unipolar disorder patients; it remains elevated in euthymia and is higher in individuals with past substance abuse. Elevated attentional and lower non-planning impulsivity in unaffected relatives of bipolar disorder

  5. Impulsivity, aggression and suicide risk among male schizophrenia patients.

    Science.gov (United States)

    Iancu, Iulian; Bodner, Ehud; Roitman, Suzana; Piccone Sapir, Anna; Poreh, Amir; Kotler, Moshe

    2010-01-01

    Impulsivity has been shown to be a major variable in the etiology of suicide and aggression, but has not been researched as much in the schizophrenic population, which is characterized by serious suicide and aggression risks. 68 male schizophrenia patients responded to a battery of measures including the Positive and Negative Syndrome Scale (PANSS), the impulsivity control scale (IS), the Suicide Risk Scale (SRS) and the Overt Aggression Scale. We divided our subjects into those who received scores above and below the median on the IS. The high-impulsivity group had higher present and past rates of suicidal ideation and showed a trend for more lifetime suicidal attempts than the low-impulsivity group. The impulsivity score correlated positively with the SRS score and with some of the scores of the PANSS (the positive symptoms score, the general psychopathology score and the total score). A multiple regression analysis revealed that an older age, higher levels of aggression, high impulsivity and an elevated score on the general psychopathology subscale of the PANSS contributed positively and significantly to the explained variance of the SRS. Our study supports the contention that high impulsivity in schizophrenia patients is significant in the etiology of suicide in schizophrenia. However, the relationship between impulsivity and aggression in schizophrenia patients, and also the amelioration of impulsivity by pharmacological interventions, require further study. Copyright (c) 2010 S. Karger AG, Basel.

  6. Stability analysis of impulsive parabolic complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jinliang, E-mail: wangjinliang1984@yahoo.com.cn [Science and Technology on Aircraft Control Laboratory, School of Automation Science and Electrical Engineering, Beihang University, XueYuan Road, No. 37, HaiDian District, Beijing 100191 (China); Wu Huaining [Science and Technology on Aircraft Control Laboratory, School of Automation Science and Electrical Engineering, Beihang University, XueYuan Road, No. 37, HaiDian District, Beijing 100191 (China)

    2011-11-15

    Highlights: > Two impulsive parabolic complex network models are proposed. > The global exponential stability of impulsive parabolic complex networks are considered. > The robust global exponential stability of impulsive parabolic complex networks are considered. - Abstract: In the present paper, two kinds of impulsive parabolic complex networks (IPCNs) are considered. In the first one, all nodes have the same time-varying delay. In the second one, different nodes have different time-varying delays. Using the Lyapunov functional method combined with the inequality techniques, some global exponential stability criteria are derived for the IPCNs. Furthermore, several robust global exponential stability conditions are proposed to take uncertainties in the parameters of the IPCNs into account. Finally, numerical simulations are presented to illustrate the effectiveness of the results obtained here.

  7. Stability analysis of impulsive parabolic complex networks

    International Nuclear Information System (INIS)

    Wang Jinliang; Wu Huaining

    2011-01-01

    Highlights: → Two impulsive parabolic complex network models are proposed. → The global exponential stability of impulsive parabolic complex networks are considered. → The robust global exponential stability of impulsive parabolic complex networks are considered. - Abstract: In the present paper, two kinds of impulsive parabolic complex networks (IPCNs) are considered. In the first one, all nodes have the same time-varying delay. In the second one, different nodes have different time-varying delays. Using the Lyapunov functional method combined with the inequality techniques, some global exponential stability criteria are derived for the IPCNs. Furthermore, several robust global exponential stability conditions are proposed to take uncertainties in the parameters of the IPCNs into account. Finally, numerical simulations are presented to illustrate the effectiveness of the results obtained here.

  8. Chaotification of complex networks with impulsive control.

    Science.gov (United States)

    Guan, Zhi-Hong; Liu, Feng; Li, Juan; Wang, Yan-Wu

    2012-06-01

    This paper investigates the chaotification problem of complex dynamical networks (CDN) with impulsive control. Both the discrete and continuous cases are studied. The method is presented to drive all states of every node in CDN to chaos. The proposed impulsive control strategy is effective for both the originally stable and unstable CDN. The upper bound of the impulse intervals for originally stable networks is derived. Finally, the effectiveness of the theoretical results is verified by numerical examples.

  9. A Triadic Reflective-Impulsive-Interoceptive Awareness Model of General and Impulsive Information System Use: Behavioral Tests of Neuro-Cognitive Theory.

    Science.gov (United States)

    Turel, Ofir; Bechara, Antoine

    2016-01-01

    This study examines a behavioral tripartite model developed in the field of addiction, and applies it here to understanding general and impulsive information technology use. It suggests that technology use is driven by two information-processing brain systems: reflective and impulsive, and that their effects on use are modulated by interoceptive awareness processes. The resultant reflective-impulsive-interoceptive awareness model is tested in two behavioral studies. Both studies employ SEM techniques to time-lagged self-report data from n 1 = 300 and n 2 = 369 social networking site users. Study 1 demonstrated that temptations augment the effect of habit on technology use, and reduce the effect of satisfaction on use. Study 2 showed that temptations strengthen the effect of habit on impulsive technology use, and weaken the effect of behavioral expectations on impulsive technology use. Hence, the results consistently support the notion that information technology users' behaviors are influenced by reflective and impulsive information processing systems; and that the equilibrium of these systems is determined, at least in part, by one's temptations. These results can serve as a basis for understanding the etiology of modern day addictions.

  10. Using Dual Process Models to Examine Impulsivity Throughout Neural Maturation.

    Science.gov (United States)

    Leshem, Rotem

    2016-01-01

    The multivariate construct of impulsivity is examined through neural systems and connections that comprise the executive functioning system. It is proposed that cognitive and behavioral components of impulsivity can be divided into two distinct groups, mediated by (1) the cognitive control system: deficits in top-down cognitive control processes referred to as action/cognitive impulsivity and (2) the socioemotional system: related to bottom-up affective/motivational processes referred to as affective impulsivity. Examination of impulsivity from a developmental viewpoint can guide future research, potentially enabling the selection of more effective interventions for impulsive individuals, based on the cognitive components requiring improvement.

  11. Total Variation Based Parameter-Free Model for Impulse Noise Removal

    DEFF Research Database (Denmark)

    Sciacchitano, Federica; Dong, Yiqiu; Andersen, Martin Skovgaard

    2017-01-01

    We propose a new two-phase method for reconstruction of blurred images corrupted by impulse noise. In the first phase, we use a noise detector to identify the pixels that are contaminated by noise, and then, in the second phase, we reconstruct the noisy pixels by solving an equality constrained...... total variation minimization problem that preserves the exact values of the noise-free pixels. For images that are only corrupted by impulse noise (i. e., not blurred) we apply the semismooth Newton's method to a reduced problem, and if the images are also blurred, we solve the equality constrained...... reconstruction problem using a first-order primal-dual algorithm. The proposed model improves the computational efficiency (in the denoising case) and has the advantage of being regularization parameter-free. Our numerical results suggest that the method is competitive in terms of its restoration capabilities...

  12. Personality differences in the susceptibility to stress-eating: The influence of emotional control and impulsivity.

    Science.gov (United States)

    Van Blyderveen, Sherry; Lafrance, Adele; Emond, Michael; Kosmerly, Stacey; O'Connor, Megan; Chang, Felicia

    2016-12-01

    Stress has been associated with deviations from typical eating patterns, with respect to both food choice and overall caloric intake. Both increases and decreases in dietary intake have been previously noted in response to stress. The purpose of the present study was to determine whether the affect regulation strategies of emotional control and impulsivity predict susceptibility to eating in response to stress. Specifically, it was anticipated that emotional suppression would predict decreases in caloric intake, whereas impulsivity would predict increases in caloric intake, in response to a stressor. Participants were randomly assigned to view either a video designed to elicit stress or a control video. Food was provided during the video and the amount and type of food consumed was measured. Participants' nutritional intake was greater in the stress condition than in the control condition. One aspect of affect regulation, impulsivity, moderated this relationship, with a tendency for greater impulsivity to be associated with greater caloric intake in the stress condition. The degree of negative affect that participants experienced in the stress condition predicted food choice and overall caloric intake. Both emotional control and impulsivity moderated the relationship between negative affect and both food choice and caloric intake in the stress condition. The present study highlights the importance of considering the personality attributes of both impulsivity and emotional suppression in understanding stress eating. Copyright © 2016. Published by Elsevier Ltd.

  13. Impulse control disorders and related behaviours (ICD-RBs in Parkinson′s disease patients: Assessment using “Questionnaire for impulsive-compulsive disorders in Parkinson′s disease” (QUIP

    Directory of Open Access Journals (Sweden)

    Ashish Sharma

    2015-01-01

    Full Text Available Background: There is limited data on the prevalence of impulse control disorder and related behaviors (ICD-RBs in Indian patients with Parkinson′s Disease (PD. In the context of potential genetic and environmental factors affecting the expression of ICD-RBs, studying other multiethnic populations may bring in-sights into the mechanisms of these disorders. Objectives: To ascertain point prevalence estimate of ICD-RBs in Indian PD patients, using the validated “Questionnaire for Impulsive-Compulsive Disorders in Parkinson′s disease (QUIP” and to examine their association with Dopamine replacement therapy (DRT. Materials and Methods: This was a hospital based observational cross-sectional study. After taking informed consent, patients and their informants (spouse, or primary caregiver were made to complete the QUIP, and were instructed to answer questions based on behaviors that occurred anytime during PD that lasted at least four consecutive weeks. Results: Total of 299 patients participated in the study. At least one ICD-RB was present in 128 (42.8%, at least one Impulse control disorder (ICD was present in 74 (24.75% and at least one Impulse control related compulsive behaviour (ICRB was present in 93 (31.1% patients. Punding was the most frequent (12.4% followed by hyper sexuality (11.04%, compulsive hobbyism (9.4%, compulsive shopping (8.4%, compulsive medication use (7.7%, compulsive eating (5.35%, walkabout (4% and pathological gambling (3.3%. ≥ 2 ICD-RBs were observed in 15.7% of patients. After multivariate analysis, younger age of onset, being unmarried were specifically associated with presence of ICD. Longer disease duration was specifically associated with presence of ICRB. Whereas smoking and higher dopamine levodopa equivalent daily doses (DA LEDD were associated with both presence of ICD and ICRB. Higher LD LEDD was specifically associated with presence of ICD-RB. Conclusions: Our study revealed a relatively higher

  14. College drinking behaviors: mediational links between parenting styles, impulse control, and alcohol-related outcomes.

    Science.gov (United States)

    Patock-Peckham, Julie A; Morgan-Lopez, Antonio A

    2006-06-01

    Mediational links between parenting styles (authoritative, authoritarian, permissive), impulsiveness (general control), drinking control (specific control), and alcohol use and abuse were tested. A pattern-mixture approach (for modeling non-ignorable missing data) with multiple-group structural equation models with 421 (206 female, 215 male) college students was used. Gender was examined as a potential moderator of parenting styles on control processes related to drinking. Specifically, the parent-child gender match was found to have implications for increased levels of impulsiveness (a significant mediator of parenting effects on drinking control). These findings suggest that a parent with a permissive parenting style who is the same gender as the respondent can directly influence control processes and indirectly influence alcohol use and abuse.

  15. Impulsive-compulsive buying disorder: clinical overview.

    Science.gov (United States)

    Dell'Osso, Bernardo; Allen, Andrea; Altamura, A Carlo; Buoli, Massimiliano; Hollander, Eric

    2008-04-01

    Impulsive-compulsive buying disorder (ICBD) is an impulse control disorder not otherwise specified (ICD-NOS) characterized by impulsive drives and compulsive behaviours (buying unneeded things), personal distress, impaired social and vocational functioning and financial problems. Despite being described in the 19th century, serious attention to ICBD began only in the last decade with the first epidemiological and pharmacological investigation. Biological, social and psychological factors contribute to the aetiology of ICBD. Cognitive-behavioural therapy and selective serotonin re-uptake inhibitors are currently considered the more effective interventions in the treatment of ICBD. The present review aims to provide a broad overview of the epidemiology, aetiology, phenomenology and treatment options of ICBD.

  16. Proficient motor impulse control in Parkinson disease patients with impulsive and compulsive behaviors.

    Science.gov (United States)

    Claassen, Daniel O; van den Wildenberg, Wery P M; Harrison, Madaline B; van Wouwe, Nelleke C; Kanoff, Kristen; Neimat, Joseph S; Wylie, Scott A

    2015-02-01

    Parkinson disease (PD) patients treated with dopamine agonist therapy can develop maladaptive reward-driven behaviors, known as impulse control disorder (ICD). In this study, we assessed if ICD patients have evidence of motor-impulsivity. We used the stop-signal task in a cohort of patients with and without active symptoms of ICD to evaluate motor-impulsivity. Of those with PD, 12 were diagnosed with ICD symptoms (PD-ICD) and were assessed before clinical reduction of dopamine agonist medication; 12 were without symptoms of ICD [PD-control] and taking equivalent dosages of dopamine agonist. Levodopa, if present, was maintained in both settings. Groups were similar in age, duration, and severity of motor symptoms, levodopa co-therapy, and total levodopa daily dose. All were tested in the dopamine agonist medicated and acutely withdrawn (24 h) state, in a counterbalanced manner. Primary outcome measures were mean reaction time to correct go trials (go reaction time), and mean stop-signal reaction time (SSRT). ICD patients produce faster SSRT than both Healthy Controls, and PD-Controls. Faster SSRT in ICD patients is apparent in both dopamine agonist medication states. Also, we show unique dopamine medication effects on Go Reaction time (GoRT). In dopamine agonist monotherapy patients, dopamine agonist administration speeds GoRT. Conversely, in those with levodopa co-therapy, dopamine agonist administration slows. PD patients with active ICD symptoms are significantly faster at stopping initiated motor actions, and this is not altered by acute dopamine agonist withdrawal. In addition, the effect of dopamine agonist on GoRT is strongly influenced by the presence or absence of levodopa, even though levodopa co-therapy does not appear to influence SSRT. We discuss these findings as they pertain to the multifaceted definition of 'impulsivity,' the lack of evidence for motor-impulsivity in PD-ICD, and dopamine effects on motor-control in PD. Copyright © 2014 Elsevier Inc

  17. Value-based decision-making battery: A Bayesian adaptive approach to assess impulsive and risky behavior.

    Science.gov (United States)

    Pooseh, Shakoor; Bernhardt, Nadine; Guevara, Alvaro; Huys, Quentin J M; Smolka, Michael N

    2018-02-01

    Using simple mathematical models of choice behavior, we present a Bayesian adaptive algorithm to assess measures of impulsive and risky decision making. Practically, these measures are characterized by discounting rates and are used to classify individuals or population groups, to distinguish unhealthy behavior, and to predict developmental courses. However, a constant demand for improved tools to assess these constructs remains unanswered. The algorithm is based on trial-by-trial observations. At each step, a choice is made between immediate (certain) and delayed (risky) options. Then the current parameter estimates are updated by the likelihood of observing the choice, and the next offers are provided from the indifference point, so that they will acquire the most informative data based on the current parameter estimates. The procedure continues for a certain number of trials in order to reach a stable estimation. The algorithm is discussed in detail for the delay discounting case, and results from decision making under risk for gains, losses, and mixed prospects are also provided. Simulated experiments using prescribed parameter values were performed to justify the algorithm in terms of the reproducibility of its parameters for individual assessments, and to test the reliability of the estimation procedure in a group-level analysis. The algorithm was implemented as an experimental battery to measure temporal and probability discounting rates together with loss aversion, and was tested on a healthy participant sample.

  18. Impulsivity, Mental Disorder, and Suicide in Rural China.

    Science.gov (United States)

    Lin, Lin; Zhang, Jie

    2017-01-02

    The purpose of this study was to investigate the relationship among impulsivity, mental disorder, and suicide with a sample of rural young Chinese. Subjects were 392 consecutively recruited male and female suicides aged 15-34 years and 416 community male and female controls of the same age range sampled in rural China. The case-control data were obtained using psychological autopsy with structured and semi-structured instruments. Dysfunctional impulsivity was a significant risk factor regardless of mental disorder in rural China. Dysfunctional impulsivity is a potential area for further study of suicidal behavior. The suicide prevention efforts in rural China may address impulsivity.

  19. Impulsive control of a financial model [rapid communication

    Science.gov (United States)

    Sun, Jitao; Qiao, Fei; Wu, Qidi

    2005-02-01

    In this Letter, several new theorems on the stability of impulsive control systems are presented. These theorem are then used to find the conditions under which an advertising strategy can be asymptotically control to the equilibrium point by using impulsive control. Given the parameters of the financial model and the impulsive control law, an estimation of the upper bound of the impulse interval is given, i.e., number of advert can been decreased (i.e., can decrease cost) for to obtain the equivalent advertising effect.The result is illustrated to be efficient through a numerical example.

  20. About Positivity of Green's Functions for Nonlocal Boundary Value Problems with Impulsive Delay Equations

    Directory of Open Access Journals (Sweden)

    Alexander Domoshnitsky

    2014-01-01

    Full Text Available The impulsive delay differential equation is considered (Lx(t=x′(t+∑i=1mpi(tx(t-τi(t=f(t, t∈[a,b],  x(tj=βjx(tj-0, j=1,…,k, a=t0

  1. Periodicity and stability for variable-time impulsive neural networks.

    Science.gov (United States)

    Li, Hongfei; Li, Chuandong; Huang, Tingwen

    2017-10-01

    The paper considers a general neural networks model with variable-time impulses. It is shown that each solution of the system intersects with every discontinuous surface exactly once via several new well-proposed assumptions. Moreover, based on the comparison principle, this paper shows that neural networks with variable-time impulse can be reduced to the corresponding neural network with fixed-time impulses under well-selected conditions. Meanwhile, the fixed-time impulsive systems can be regarded as the comparison system of the variable-time impulsive neural networks. Furthermore, a series of sufficient criteria are derived to ensure the existence and global exponential stability of periodic solution of variable-time impulsive neural networks, and to illustrate the same stability properties between variable-time impulsive neural networks and the fixed-time ones. The new criteria are established by applying Schaefer's fixed point theorem combined with the use of inequality technique. Finally, a numerical example is presented to show the effectiveness of the proposed results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Normative data of the Barratt Impulsiveness Scale 11 (BIS-11 for Brazilian adults

    Directory of Open Access Journals (Sweden)

    Leandro F. Malloy-Diniz

    2015-09-01

    Full Text Available Objective:The Barratt Impulsiveness Scale (BIS-11 is a valid and reliable instrument, and one of the most often used tools to assess impulsivity. This study assesses the performance of a large sample of adults by using a version of BIS-11 adapted to Brazilian Portuguese.Methods:We assessed 3,053 adults from eight Brazilian states. Internal consistencies and performance data were presented for two correction criteria of BIS-11: original and the two-factor score.Results:The associations between age, sex, region, and education and the BIS-11 scores present very small effect sizes. Therefore, we provided a percentile rank parameter for the different BIS-11 subscores considering the whole sample. Given the internal consistency of the two correction systems, we found that only the two-factor system fulfills the psychometric criteria of Cronbach’s alpha (cutoff value of at least 0.6.Conclusion:Our results support the use of the Brazilian adaptation of BIS-11 in different regions of the country as a measure of impulsivity. Since high impulsiveness is a characteristic of several dysfunctional behaviors, the establishment of normative parameters is of utmost relevance and should be extended to other age ranges and populations in future studies.

  3. Applied impulsive mathematical models

    CERN Document Server

    Stamova, Ivanka

    2016-01-01

    Using the theory of impulsive differential equations, this book focuses on mathematical models which reflect current research in biology, population dynamics, neural networks and economics. The authors provide the basic background from the fundamental theory and give a systematic exposition of recent results related to the qualitative analysis of impulsive mathematical models. Consisting of six chapters, the book presents many applicable techniques, making them available in a single source easily accessible to researchers interested in mathematical models and their applications. Serving as a valuable reference, this text is addressed to a wide audience of professionals, including mathematicians, applied researchers and practitioners.

  4. The influence of impulsiveness on binge eating and problem gambling: A prospective study of gender differences in Canadian adults.

    Science.gov (United States)

    Farstad, Sarah M; von Ranson, Kristin M; Hodgins, David C; El-Guebaly, Nady; Casey, David M; Schopflocher, Don P

    2015-09-01

    This study investigated the degree to which facets of impulsiveness predicted future binge eating and problem gambling, 2 theorized forms of behavioral addiction. Participants were 596 women and 406 men from 4 age cohorts randomly recruited from a Canadian province. Participants completed self-report measures of 3 facets of impulsiveness (negative urgency, sensation seeking, lack of persistence), binge-eating frequency, and problem-gambling symptoms. Impulsiveness was assessed at baseline, and assessments of binge eating and problem gambling were followed up after 3 years. Weighted data were analyzed using zero-inflated negative binomial and Poisson regression models. We found evidence of transdiagnostic and disorder-specific predictors of binge eating and problem gambling. Negative urgency emerged as a common predictor of binge eating and problem gambling among women and men. There were disorder-specific personality traits identified among men only: High lack-of-persistence scores predicted binge eating and high sensation-seeking scores predicted problem gambling. Among women, younger age predicted binge eating and older age predicted problem gambling. Thus, there are gender differences in facets of impulsiveness that longitudinally predict binge eating and problem gambling, suggesting that treatments for these behaviors should consider gender-specific personality and demographic traits in addition to the common personality trait of negative urgency. (c) 2015 APA, all rights reserved).

  5. Impulsivity moderates promotive environmental influences on adolescent delinquency: A comparison across family, school, and neighborhood contexts

    Science.gov (United States)

    Chen, Pan; Jacobson, Kristen C.

    2013-01-01

    The present study examined moderating effects of impulsivity on the relationships between promotive factors from family (family warmth, parental knowledge), school (school connectedness), and neighborhood (neighborhood cohesion) contexts with delinquency using data collected from N = 2,978 sixth to eighth graders from 16 schools surrounding a major city in the Midwestern United States. More than half of the respondents were non-Caucasian (Mage = 12.48; 41.0% male). Multilevel modeling analyses were conducted to take into account the clustering of the participants within schools. Impulsivity was positively associated with adolescent delinquency. Additionally, family warmth, parental knowledge, and school connectedness, but not neighborhood cohesion, were independently and inversely related to adolescent delinquency. Finally, impulsivity moderated relationships between family warmth and parental knowledge with delinquency but not relationships between school attachment and neighborhood cohesion with delinquency. Specifically, the negative relationship between family warmth and delinquency was significant for adolescents with high levels of, but not for those with below-average levels of, impulsivity. In addition, parental knowledge had a stronger association with decreased levels of delinquency for adolescents reporting higher levels of impulsivity. The moderating effects of impulsivity did not differ for males and females or for minority and non-minority participants. Findings indicate that impulsivity may have greater impact on adolescents’ susceptibility to positive family influences than on their susceptibility to promotive factors from school or neighborhood contexts. Implications for future research and practice are discussed. PMID:23673971

  6. How impulsivity relates to compulsive buying and the burden perceived by caregivers after moderate-to-severe traumatic brain injury.

    Science.gov (United States)

    Rochat, Lucien; Beni, Catia; Billieux, Joël; Annoni, Jean-Marie; Van der Linden, Martial

    2011-01-01

    Impulsivity is a core feature in patients with traumatic brain injury (TBI). The aim of the study is to investigate how a specific dimension of impulsivity, namely urgency (the tendency to act rashly when distressed), might shed new light on the aetiology of compulsive buying proneness in patients with TBI and to explore how urgency and compulsive buying relate to the burden perceived by the caregivers. Caregivers of 74 patients with TBI were given 3 questionnaires in order to assess their subjective burden as well as patients' impulsivity and compulsive buying proneness. Both urgency and compulsive buying tendencies significantly increased after TBI. Furthermore, path analyses revealed that current urgency was both directly and indirectly related to the subjective burden perceived by the caregivers, and this indirect pathway was mediated by compulsive buying. Urgency plays a central role in understanding specific problematic behaviours after TBI and their impact on caregivers. These findings are discussed in light of the cognitive processes underlying the urgency component of impulsivity in relation to the occurrence of compulsive buying behaviours after TBI. Copyright © 2011 S. Karger AG, Basel.

  7. Distribution of energy of impulses of the modernized IBR-2 REACTOR

    International Nuclear Information System (INIS)

    Tayibov, L.A; Mehtiyeva, R.N.; )

    2011-01-01

    Full text: For the modernized IBR-2 reactor there are two main reasons causing fluctuations of energy of impulses [1,3] on low power of stochastic fluctuations, on the nominal - giving rise to fluctuations of external reactance. The fluctuations of pulse energy is quite significant (20%). They affect the dynamics of the reactor, the process of regulation, starting, as well as the work of the experimental apparatus, etc. It is clear that research of fluctuation of energy of impulses has special value for the IBR-2 type reactor. Sufficient information about the statistical properties of the reactor noise gives the density distribution of the energy pulse power. We used the usual procedure of statistical analysis of time series. Calculated pulse energy of density and the parameters of this distribution.

  8. Stability analysis of impulsive functional differential equations

    CERN Document Server

    Stamova, Ivanka

    2009-01-01

    This book is devoted to impulsive functional differential equations which are a natural generalization of impulsive ordinary differential equations (without delay) and of functional differential equations (without impulses). At the present time the qualitative theory of such equationsis under rapid development. After a presentation of the fundamental theory of existence, uniqueness and continuability of solutions, a systematic development of stability theory for that class of problems is given which makes the book unique. It addresses to a wide audience such as mathematicians, applied research

  9. Impulsivity and alcohol demand in relation to combined alcohol and caffeine use.

    Science.gov (United States)

    Amlung, Michael; Few, Lauren R; Howland, Jonathan; Rohsenow, Damaris J; Metrik, Jane; MacKillop, James

    2013-12-01

    Problematic alcohol use among college students continues to be a prominent concern in the United States, including the growing trend of consuming caffeinated alcoholic beverages (CABs). Epidemiologically, CAB use is associated with incremental risks from drinking, although these relationships could be due to common predisposing factors rather than specifically due to CABs. This study investigated the relationship between CAB use, alcohol misuse, and person-level characteristics, including impulsive personality traits, delayed reward discounting, and behavioral economic demand for alcohol use. Participants were 273 regularly drinking undergraduate students. Frequency of CAB use was assessed over the past month. A multidimensional assessment of impulsivity included the UPPS-P questionnaire, which measures positive and negative urgency, premeditation (lack thereof), perseverance (lack thereof), and sensation seeking (Lynam, Smith, Whiteside, & Cyders, 2007), and a validated questionnaire-based measure of delayed reward discounting. Demand was assessed via a hypothetical alcohol purchase task. Frequency of CAB consumption was significantly higher in men than in women and was also associated with higher impulsivity on the majority of the UPPS-P subscales, steeper delayed reward discounting, and greater demand for alcohol. Significant correlations between CAB use and both alcohol demand and lack of premeditation remained present after including level of alcohol misuse in partial correlations. In a hierarchical linear regression incorporating demographic, demand, and impulsivity variables, CAB frequency continued to be a significant predictor of hazardous alcohol use. These results suggest that although there are significant associations between CAB consumption and gender, impulsivity, and alcohol demand, CAB use continues to be associated with alcohol misuse after controlling for these variables.

  10. The Relationship between Impulsivity and Internet Gaming Disorder in Young Adults: Mediating Effects of Interpersonal Relationships and Depression

    Science.gov (United States)

    Ryu, Hyera; Lee, Ji-Yoon; Choi, Aruem; Park, Sunyoung; Kim, Dai-Jin

    2018-01-01

    Background: This study aimed to explore relationships between impulsivity, interpersonal relationships, depression, and Internet Gaming Disorder (IGD) symptoms. Methods: A total of 118 young adults participated in this study: 67 IGD patients who met five or more of the DSM-5 diagnostic criteria for IGD and 56 healthy controls. We administered questionnaires to assess IGD symptoms (Young’s Internet Addiction Test; Y-IAT), impulsivity (Barratt Impulsiveness Scale; BIS-11), interpersonal relationship (Relationship Change Scale; RCS), and depression (Beck Depression Inventory; BDI). We used PROCESS macro in SPSS to perform mediation analysis. Results: IGD symptom was positively related to depression and impulsivity, and negatively related to the quality of interpersonal relationships. Mediation analysis revealed full mediation effects of interpersonal relationships and depression on the association between impulsivity and IGD symptoms in the IGD group. Specifically, even after adjusting for gender as a covariate, high impulsivity was associated with greater difficulty with interpersonal relationships; which further affected depression and increased the risk of IGD. Conclusions: These results demonstrate the importance of early intervention in IGD patients, particularly in young adults with high impulsivity. When intervening in adults’ IGD, we should consider not only individual factors (e.g., depression) but also socioenvironmental factors (e.g., interpersonal relationships). PMID:29509708

  11. The Relationship between Impulsivity and Internet Gaming Disorder in Young Adults: Mediating Effects of Interpersonal Relationships and Depression.

    Science.gov (United States)

    Ryu, Hyera; Lee, Ji-Yoon; Choi, Aruem; Park, Sunyoung; Kim, Dai-Jin; Choi, Jung-Seok

    2018-03-06

    Background: This study aimed to explore relationships between impulsivity, interpersonal relationships, depression, and Internet Gaming Disorder (IGD) symptoms. Methods: A total of 118 young adults participated in this study: 67 IGD patients who met five or more of the DSM-5 diagnostic criteria for IGD and 56 healthy controls. We administered questionnaires to assess IGD symptoms (Young's Internet Addiction Test; Y-IAT), impulsivity (Barratt Impulsiveness Scale; BIS-11), interpersonal relationship (Relationship Change Scale; RCS), and depression (Beck Depression Inventory; BDI). We used PROCESS macro in SPSS to perform mediation analysis. Results: IGD symptom was positively related to depression and impulsivity, and negatively related to the quality of interpersonal relationships. Mediation analysis revealed full mediation effects of interpersonal relationships and depression on the association between impulsivity and IGD symptoms in the IGD group. Specifically, even after adjusting for gender as a covariate, high impulsivity was associated with greater difficulty with interpersonal relationships; which further affected depression and increased the risk of IGD. Conclusions: These results demonstrate the importance of early intervention in IGD patients, particularly in young adults with high impulsivity. When intervening in adults' IGD, we should consider not only individual factors (e.g., depression) but also socioenvironmental factors (e.g., interpersonal relationships).

  12. The Relationship between Impulsivity and Internet Gaming Disorder in Young Adults: Mediating Effects of Interpersonal Relationships and Depression

    Directory of Open Access Journals (Sweden)

    Hyera Ryu

    2018-03-01

    Full Text Available Background: This study aimed to explore relationships between impulsivity, interpersonal relationships, depression, and Internet Gaming Disorder (IGD symptoms. Methods: A total of 118 young adults participated in this study: 67 IGD patients who met five or more of the DSM-5 diagnostic criteria for IGD and 56 healthy controls. We administered questionnaires to assess IGD symptoms (Young’s Internet Addiction Test; Y-IAT, impulsivity (Barratt Impulsiveness Scale; BIS-11, interpersonal relationship (Relationship Change Scale; RCS, and depression (Beck Depression Inventory; BDI. We used PROCESS macro in SPSS to perform mediation analysis. Results: IGD symptom was positively related to depression and impulsivity, and negatively related to the quality of interpersonal relationships. Mediation analysis revealed full mediation effects of interpersonal relationships and depression on the association between impulsivity and IGD symptoms in the IGD group. Specifically, even after adjusting for gender as a covariate, high impulsivity was associated with greater difficulty with interpersonal relationships; which further affected depression and increased the risk of IGD. Conclusions: These results demonstrate the importance of early intervention in IGD patients, particularly in young adults with high impulsivity. When intervening in adults’ IGD, we should consider not only individual factors (e.g., depression but also socioenvironmental factors (e.g., interpersonal relationships.

  13. The comparition of Personality Patterns, irrational beliefs and impulsivity in males with with drug abuse disorder under Treatment

    Directory of Open Access Journals (Sweden)

    samere asadi

    2015-03-01

    Full Text Available Objective: the aim of this research was to determine the difference between personality Patterns, irrational beliefs and impulsivity in men with drug abuse disorder under Treatment. Method: in this casual- comparative research, 80 men ( 40 males with drug abuse under Treatment and 40 of normal males that were selected with available sampling .Groups were matched in terms of demoghraphy characteristics ( age, sexuality, education level and marital status and were valued with means of Eysenk Perceived Stress Inventory, Jonze Irrational Beliefs Scale and Baret Impulsivity Inventory. Results: The result of variance analysis showed that addicts compared to normal people, get more scores on extraversion, neuroticism and psychosis. Addicts group had Higher men scores in irrational beliefs compare of other group. There was significant difference between groups in impulsivity and impulsivity in addicts persons is the most. Conclussion: The traits of Personality, irrational beliefs and Unrealistic and high level impulsivity are factors that propel individuals toward more drug abuse and finally addict and aiming this factors in individuals with abuse disorder under Treatment can lead to prevent of Substance Abuse Relapse.

  14. Chronotype differences in suicidal behavior and impulsivity among suicide attempters.

    Science.gov (United States)

    Selvi, Yavuz; Aydin, Adem; Atli, Abdullah; Boysan, Murat; Selvi, Fatih; Besiroglu, Lutfullah

    2011-03-01

    Morning- and evening-type individuals differ on a number of psychological and biological variables. There has been increasing interest in the relationship between chronotype and personality traits. The aim of this study was to investigate the relationship between impulsivity and chronotype in suicide attempters. Eighty-nine suicide attempters were included in the study, and systematic information on suicide attempts was recorded. The Morningness-Eveningness Questionnaire was applied to determine chronotype, and attempter impulsivity was measured by the total score of the Barratt Impulsiveness Scale. Significant differences between chronotype and impulsivity scores were found. Evening-type subjects reported significantly higher impulsivity scores than both neither- and morning-types. A significant association between chronotype and type of suicide attempt was detected. The largest proportion of violent suicide attempters were evening-type subjects. Violent suicide attempters also reported significantly higher impulsivity scores than nonviolent attempters. Previous studies have pointed out possible relations between eveningness and impulsivity. Current findings suggest that eveningness may be a risk factor for violent suicide attempts by increasing impulsivity.

  15. Why are you happy with impulse buying? Evidence from Indonesia

    Directory of Open Access Journals (Sweden)

    Wiwik Handayani

    2018-05-01

    Full Text Available Happiness is an ideal condition needed by everyone. In the real life, happiness comes not only from the harmony in the home but also from the exciting environment or atmosphere outside the home, such as impulse buying. When someone makes impulse buying, she could feel the happiness be-cause she gets something she wants. This means that when someone makes a purchase, she will experience happiness. This study aimed to examine the variables that affect impulse buying which may also affect the happiness. It is assumed that the experience and the pleasant shopping atmosphere affect the impulse buying and, as a result, the impulse buying affects happiness. The samples in this study were 150 women making purchases of fashion products at malls in Surabaya. The hypothesis testing was conducted by using Structural Equation Modelling. The test results indicated the hypothesis 1 stating that the experiential marketing influenced the impulse buying and hypothesis 2 stating that the shopping enjoyment affected the impulse buying were accepted. Further, hypothesis 3 were also accepted, stating that the impulse buying influenced happiness.

  16. Ecstasy use and self-reported depression, impulsivity, and sensation seeking: a prospective cohort study

    NARCIS (Netherlands)

    de Win, Maartje M. L.; Schilt, Thelma; Reneman, Liesbeth; Vervaeke, Hylke; Jager, Gerry; Dijkink, Sarah; Booij, Jan; van den Brink, Wim

    2006-01-01

    Although there are indications that ecstasy users have higher levels of depression, impulsivity, and sensation seeking, it is unknown whether these are consequences of ecstasy use or predisposing factors for starting ecstasy use. We prospectively assessed the predictive value of depression,

  17. Paralimbic and lateral prefrontal encoding of reward value during intertemporal choice in attempted suicide.

    Science.gov (United States)

    Vanyukov, P M; Szanto, K; Hallquist, M N; Siegle, G J; Reynolds, C F; Forman, S D; Aizenstein, H J; Dombrovski, A Y

    2016-01-01

    Alongside impulsive suicide attempts, clinicians encounter highly premeditated suicidal acts, particularly in older adults. We have previously found that in contrast to the more impulsive suicide attempters' inability to delay gratification, serious and highly planned suicide attempts were associated with greater willingness to wait for larger rewards. This study examined neural underpinnings of intertemporal preference in suicide attempters. We expected that impulsivity and suicide attempts, particularly poorly planned ones, would predict altered paralimbic subjective value representations. We also examined lateral prefrontal and paralimbic correlates of premeditation in suicidal behavior. A total of 48 participants aged 46-90 years underwent extensive clinical and cognitive characterization and completed the delay discounting task in the scanner: 26 individuals with major depression (13 with and 13 without history of suicide attempts) and 22 healthy controls. More impulsive individuals displayed greater activation in the precuneus/posterior cingulate cortex (PCC) to value difference favoring the delayed option. Suicide attempts, particularly better-planned ones, were associated with deactivation of the lateral prefrontal cortex (lPFC) in response to value difference favoring the immediate option. Findings were robust to medication exposure, depression severity and possible brain damage from suicide attempts, among other confounders. Finally, in suicide attempters longer reward delays were associated with diminished parahippocampal responses. Impulsivity was associated with an altered paralimbic (precuneus/PCC) encoding of value difference during intertemporal choice. By contrast, better-planned suicidal acts were associated with altered lPFC representations of value difference. The study provides preliminary evidence of impaired decision processes in both impulsive and premeditated suicidal behavior.

  18. Relationship between impulsivity, snack consumption and children's weight

    OpenAIRE

    Scholten, Eline W. M.; Schrijvers, Carola; Nederkoorn, Chantal; Kremers, Stef; Rodenburg, Gerda

    2014-01-01

    textabstractBackground: Childhood overweight is a public health problem associated with psychosocial and physical problems. Personality traits, such as impulsivity, may contribute to the development of overweight. Objective: This study examines 1) the association between general impulsivity traits (reward sensitivity and disinhibition) and children's weight, 2) the association between impulsivity traits and unhealthy snack consumption, and 3) the potential mediating role of unhealthy snack co...

  19. Razumikhin-Type Stability Criteria for Differential Equations with Delayed Impulses.

    Science.gov (United States)

    Wang, Qing; Zhu, Quanxin

    2013-01-01

    This paper studies stability problems of general impulsive differential equations where time delays occur in both differential and difference equations. Based on the method of Lyapunov functions, Razumikhin technique and mathematical induction, several stability criteria are obtained for differential equations with delayed impulses. Our results show that some systems with delayed impulses may be exponentially stabilized by impulses even if the system matrices are unstable. Some less restrictive sufficient conditions are also given to keep the good stability property of systems subject to certain type of impulsive perturbations. Examples with numerical simulations are discussed to illustrate the theorems. Our results may be applied to complex problems where impulses depend on both current and past states.

  20. Razumikhin-type stability criteria for differential equations with delayed impulses

    Directory of Open Access Journals (Sweden)

    Qing Wang

    2013-01-01

    Full Text Available This paper studies stability problems of general impulsive differential equations where time delays occur in both differential and difference equations. Based on the method of Lyapunov functions, Razumikhin technique and mathematical induction, several stability criteria are obtained for differential equations with delayed impulses. Our results show that some systems with delayed impulses may be exponentially stabilized by impulses even if the system matrices are unstable. Some less restrictive sufficient conditions are also given to keep the good stability property of systems subject to certain type of impulsive perturbations. Examples with numerical simulations are discussed to illustrate the theorems. Our results may be applied to complex problems where impulses depend on both current and past states.

  1. Resonant Impulsive Stimulated Raman Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtari, A; Chesnoy, J

    1988-03-15

    Using a femtosecond dye laser, we observe in real-time vibrational oscillations excited by impulsive stimulated Raman scattering (ISRS) close to an electronic resonance. We perform single-beam Raman excitation and probe the driven coherence by a polarization-sensitive detection. We demonstrate for the first time impulsively Raman-induced dichroism, birefringence as well as frequency and time delay shifts. We analyse the characteristics of resonant ISRS on a vibrational mode of a dye molecule (malachite green) in solution.

  2. Resonant Impulsive Stimulated Raman Scattering

    International Nuclear Information System (INIS)

    Mokhtari, A.; Chesnoy, J.

    1988-01-01

    Using a femtosecond dye laser, we observe in real-time vibrational oscillations excited by impulsive stimulated Raman scattering (ISRS) close to an electronic resonance. We perform single-beam Raman excitation and probe the driven coherence by a polarization-sensitive detection. We demonstrate for the first time impulsively Raman-induced dichroism, birefringence as well as frequency and time delay shifts. We analyse the characteristics of resonant ISRS on a vibrational mode of a dye molecule (malachite green) in solution

  3. Are old people so gentle? Functional and dysfunctional impulsivity in the elderly.

    Science.gov (United States)

    Morales-Vives, Fabia; Vigil-Colet, Andreu

    2012-03-01

    Although old people may seem less impulsive than adults, numerous experimental studies report that they have inhibitory deficits. Bearing in mind that there is a relationship between inhibition processes and impulsivity, age-related inhibition deficits suggest that older people could be more impulsive than adults. The aim of the current study was to compare the functional and dysfunctional impulsivity scores obtained in a sample of elderly people (65 years old and above) with those obtained in previous studies on samples of adolescents and adults. Dickman's Impulsivity Inventory was administered to 190 individuals aged between 65 and 94 years without dementia or cognitive impairment. Results indicated that the elderly sample showed higher dysfunctional impulsivity levels than the adult samples, which is consistent with the inhibition deficits mentioned above. There were no significant differences in functional impulsivity. Furthermore, old women had higher scores than old men on dysfunctional impulsivity. This study provides evidence of age-related changes in dysfunctional impulsivity. Functional impulsivity did not show the same pattern as dysfunctional impulsivity, being quite stable across the age span. it seems, then, that impulsivity cannot be considered to decrease with age and dysfunctional impulsivity may even increase.

  4. The Effectiveness of Cognitive Behavior Therapy of Impulse Control on Reduction of Impulsiveness, Crave of Usage and Addiction Severity among Crack Users

    Directory of Open Access Journals (Sweden)

    Rohollah Hadadi

    2009-08-01

    Full Text Available Introduction: The present study was done in order to study of the effectiveness of CBT of impulse control on the reduction of impulsiveness, crave of usage and addiction severity of Crack users. Method: In a quasi experimental design 30 Crack addict users who were treating with Methadone in a clinic selected by interview method and consideration of entrance criterions. Then they allocated to two groups (15 subjects for each group as a witness and experimental groups. The experimental group was under Methadone drug therapy and CBT of impulse control for 8 sessions, and 60 min for each session. But witness group was under Methadone drug therapy and there was not any other intervention. All participants in research were examined before and after treatment by three scales namely: Bart's Impulsiveness Scale, Tifani's Crave Usage, and Addiction Severity Index. MANCOVA was run for analyzing of data. Results: The results showed that significant difference between two groups on impulsiveness subscales crave usage, and addiction severity (except of medical status, job status, law status, and family status. Conclusion: It can say CBT of impulse control can be effective on the reduction of impulsiveness, crave usage and addiction severity in Crack users.

  5. Association between Impulsivity and Weight Status in a General Population

    Directory of Open Access Journals (Sweden)

    Marc Bénard

    2017-03-01

    Full Text Available The objective of this study is to examine the association between impulsivity and weight status in a large sample of the adult general population in France, and the influence of gender on this relationship. A total of 11,929 men and 39,114 women participating in the NutriNet-Santé cohort were selected in this cross-sectional analysis. The Barratt Impulsiveness Scale (BIS-11 was used to assess impulsivity. Weight and height were self-reported. The association between impulsivity and BMI was estimated using logistic regressions adjusted for socio-demographic and lifestyle factors. Individuals with high impulsivity levels (BIS-11 total score >71 were more likely to be obese (Odds Ratio (OR = 1.80, 95% Confidence Interval (CI: 1.39, 2.33 in men; OR = 1.30, 95% CI: 1.15, 1.48 in women compared to individuals in the average range of impulsivity. The strongest associations between impulsivity and obesity were observed in men, where highly impulsive participants were more likely to be class III obese (BMI > 40 kg/m2 (OR = 3.57, 95% CI: 1.86, 6.85. This large sample analysis supports the existence of a relationship between impulsivity and weight status and the importance of psychological factors in the prevention of obesity.

  6. Association between Impulsivity and Weight Status in a General Population.

    Science.gov (United States)

    Bénard, Marc; Camilleri, Géraldine M; Etilé, Fabrice; Méjean, Caroline; Bellisle, France; Reach, Gérard; Hercberg, Serge; Péneau, Sandrine

    2017-03-01

    The objective of this study is to examine the association between impulsivity and weight status in a large sample of the adult general population in France, and the influence of gender on this relationship. A total of 11,929 men and 39,114 women participating in the NutriNet-Santé cohort were selected in this cross-sectional analysis. The Barratt Impulsiveness Scale (BIS-11) was used to assess impulsivity. Weight and height were self-reported. The association between impulsivity and BMI was estimated using logistic regressions adjusted for socio-demographic and lifestyle factors. Individuals with high impulsivity levels (BIS-11 total score >71) were more likely to be obese (Odds Ratio (OR) = 1.80, 95% Confidence Interval (CI): 1.39, 2.33 in men; OR = 1.30, 95% CI: 1.15, 1.48 in women) compared to individuals in the average range of impulsivity. The strongest associations between impulsivity and obesity were observed in men, where highly impulsive participants were more likely to be class III obese (BMI > 40 kg/m²) (OR = 3.57, 95% CI: 1.86, 6.85). This large sample analysis supports the existence of a relationship between impulsivity and weight status and the importance of psychological factors in the prevention of obesity.

  7. Study of suicidal ideations, hopelessness and impulsivity in elderly

    Directory of Open Access Journals (Sweden)

    Surbhi C Trivedi

    2014-01-01

    Full Text Available Aims and Objectives: This study aimed to assess the suicidal ideations, hopelessness and impulsivity in depressed and non-depressed elderly and to study the relationship of suicidal ideations with hopelessness and impulsivity in them. Materials and Methods: This cross sectional study was done on 60 elderly patients (30 cases and 30 controls above the age of 60 years. The scales used were Geriatric Suicide Ideation Scale, Beck Hopelessness Scale, Barrat′s Impulsiveness Scale, Geriatric Depression Scale. Results: Mean Geriatric Suicide Ideations Scale scores, mean Beck Hopelessness Scale scores and mean Barrat′s Impulsiveness Scale and scores of depressed elderly were higher than that of elderly who were not depressed and these differences were statistically significant. Hopelessness was a significant predictor of suicidal ideation in the entire sample as well as in the depressed and non-depressed elderly when the two groups were considered separately. Impulsivity when considered alone was a significant predictor of suicidal ideations in the entire sample. Conclusion: Hopelessness and impulsivity both by themselves are significant predictors for suicidal ideations in the elderly and when both are considered together hopelessness is a better predictor of suicidal ideations than impulsivity.

  8. ADHD symptoms in non-treatment seeking young adults: relationship with other forms of impulsivity.

    Science.gov (United States)

    Chamberlain, Samuel R; Ioannidis, Konstantinos; Leppink, Eric W; Niaz, Faiza; Redden, Sarah A; Grant, Jon E

    2017-02-01

    Attention-deficit hyperactivity disorder (ADHD) has been associated with various manifestations of impulsivity in adults, including elevated rates of other impulsive disorders, substance use, questionnaire-based impulsivity scores, and inhibitory dysregulation on neurocognitive tests. The relationship between ADHD and all these other forms of impulsivity has yet to be explored within the context of a single comprehensive study. A total of 423 young adults, who gambled ≥5 times in the preceding year, were recruited using media advertisements and undertook detailed assessment including structured psychiatric interview, questionnaires, and neurocognitive tests. Participants with ADHD symptoms were identified using the Adult ADHD Self-Report Scale Screener (ASRS-V1.1) and were compared to controls using multivariate analysis of variance (MANOVA). ADHD symptoms were found in 20.3% of the sample, but only 7.3% of these subjects had ever received a formal diagnosis. ADHD symptoms were associated with significantly lower quality of life, lower self-esteem, higher emotional dysregulation, higher impulsivity questionnaire scores, more problematic Internet use, greater occurrence of psychiatric disorders, and impaired stop-signal reaction times. Of these variables, stop-signal reaction times and Barratt attentional impulsiveness were the strongest predictors of group classification. ADHD symptoms are common and under-diagnosed in young adults who gamble, and are most strongly linked with certain other types of impulsivity (questionnaire- and cognitive-based measures) and with emotional dysregulation, suggesting that these are each important considerations in understanding the pathophysiology of the disorder, but also potential treatment targets. It is necessary to question whether treatment for adult ADHD could be enhanced by considering self-esteem, emotional reactivity, and impaired inhibitory control as specific treatment targets, in addition to the core diagnostic

  9. Relationship between impulsivity, snack consumption and children's weight.

    Directory of Open Access Journals (Sweden)

    Eline W M Scholten

    Full Text Available Childhood overweight is a public health problem associated with psychosocial and physical problems. Personality traits, such as impulsivity, may contribute to the development of overweight.This study examines 1 the association between general impulsivity traits (reward sensitivity and disinhibition and children's weight, 2 the association between impulsivity traits and unhealthy snack consumption, and 3 the potential mediating role of unhealthy snack consumption in the relationship between impulsivity traits and children's weight.Included were 1,377 parent-child dyads participating in the IVO Nutrition and Physical Activity Child cohorT (INPACT. Children had a mean age of 10 years. Parents completed a questionnaire to measure children's unhealthy snack consumption. Children completed a door-opening task to assess reward sensitivity and completed a questionnaire to measure disinhibition. Children's height and weight were measured to calculate their BMI z-scores. Cross-sectional linear regression analyses were performed to test the associations.Disinhibition was positively associated with unhealthy snack consumption but not with BMI z-scores. Reward sensitivity was not related to unhealthy snack consumption or to BMI z-scores.No evidence was found for a mediating effect of unhealthy snack consumption in the relation between impulsivity traits and children's weight. However, disinhibition appears to have a negative influence on children's unhealthy snack consumption. Future research focusing on food-related impulsivity in addition to general impulsivity will provide additional insight into factors that influence children's unhealthy snack consumption and weight.

  10. Relationship between impulsivity, snack consumption and children's weight.

    Science.gov (United States)

    Scholten, Eline W M; Schrijvers, Carola T M; Nederkoorn, Chantal; Kremers, Stef P J; Rodenburg, Gerda

    2014-01-01

    Childhood overweight is a public health problem associated with psychosocial and physical problems. Personality traits, such as impulsivity, may contribute to the development of overweight. This study examines 1) the association between general impulsivity traits (reward sensitivity and disinhibition) and children's weight, 2) the association between impulsivity traits and unhealthy snack consumption, and 3) the potential mediating role of unhealthy snack consumption in the relationship between impulsivity traits and children's weight. Included were 1,377 parent-child dyads participating in the IVO Nutrition and Physical Activity Child cohorT (INPACT). Children had a mean age of 10 years. Parents completed a questionnaire to measure children's unhealthy snack consumption. Children completed a door-opening task to assess reward sensitivity and completed a questionnaire to measure disinhibition. Children's height and weight were measured to calculate their BMI z-scores. Cross-sectional linear regression analyses were performed to test the associations. Disinhibition was positively associated with unhealthy snack consumption but not with BMI z-scores. Reward sensitivity was not related to unhealthy snack consumption or to BMI z-scores. No evidence was found for a mediating effect of unhealthy snack consumption in the relation between impulsivity traits and children's weight. However, disinhibition appears to have a negative influence on children's unhealthy snack consumption. Future research focusing on food-related impulsivity in addition to general impulsivity will provide additional insight into factors that influence children's unhealthy snack consumption and weight.

  11. The nature of impulsivity: visual exposure to natural environments decreases impulsive decision-making in a delay discounting task.

    Directory of Open Access Journals (Sweden)

    Meredith S Berry

    Full Text Available The benefits of visual exposure to natural environments for human well-being in areas of stress reduction, mood improvement, and attention restoration are well documented, but the effects of natural environments on impulsive decision-making remain unknown. Impulsive decision-making in delay discounting offers generality, predictive validity, and insight into decision-making related to unhealthy behaviors. The present experiment evaluated differences in such decision-making in humans experiencing visual exposure to one of the following conditions: natural (e.g., mountains, built (e.g., buildings, or control (e.g., triangles using a delay discounting task that required participants to choose between immediate and delayed hypothetical monetary outcomes. Participants viewed the images before and during the delay discounting task. Participants were less impulsive in the condition providing visual exposure to natural scenes compared to built and geometric scenes. Results suggest that exposure to natural environments results in decreased impulsive decision-making relative to built environments.

  12. Impact of steep-front short-duration impulse on electric power system insulation

    Energy Technology Data Exchange (ETDEWEB)

    Burrage, L M; Veverka, E F; Shaw, J H [Cooper Industries, Inc., Franksville, WI (USA). Cooper Power Systems; McConnell, B W [Oak Ridge National Lab., TN (USA)

    1991-04-01

    This research effort required the performance evaluation of three specific insulation systems in common usage by electric power transmission and distribution utilities under stresses imposed by: three characteristic impulse waveforms (two waves representative of steep-front short duration (SFSD) impulses and one representative of lightning), the cumulative effect of multiple shots'' of each pulse, 60 Hz voltage, and, where appropriate, and mechanical load. The insulation systems evaluated are the cellulose-paper/oil combination typical of power transformer and condenser bushing usage, the cellulose-paper/enamel/oil combination used in distribution transformer construction, and the porcelain/air combination representing transmission and distribution line structural insulation. 4 refs., 94 figs., 11 tabs.

  13. Impulsivity facets’ predictive relations with DSM-5 PTSD symptom clusters

    Science.gov (United States)

    Roley, Michelle E.; Contractor, Ateka A.; Weiss, Nicole H.; Armour, Cherie; Elhai, Jon D.

    2017-01-01

    Objective Posttraumatic Stress Disorder (PTSD) has a well-established theoretical and empirical relation with impulsivity. Prior research has not used a multidimensional approach for measuring both PTSD and impulsivity constructs when assessing their relationship. Method The current study assessed the unique relationship of impulsivity facets on PTSD symptom clusters among a non-clinical sample of 412 trauma-exposed adults. Results Linear regression analyses revealed that impulsivity facets best accounted for PTSD’s arousal symptoms. The negative urgency facet of impulsivity was most predictive, as it was associated with all of PTSD’s symptom clusters. Sensation seeking did not predict PTSD’s intrusion symptoms, but did predict the other symptom clusters of PTSD. Lack of perseverance only predicted intrusion symptoms, while lack of premeditation only predicted PTSD’s mood/cognition symptoms. Conclusions Results extend theoretical and empirical research on the impulsivity-PTSD relationship, suggesting that impulsivity facets may serve as both risk and protective factors for PTSD symptoms. PMID:27243571

  14. Shock Tube as an Impulsive Application Device

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    Soumya Ranjan Nanda

    2017-01-01

    Full Text Available Current investigations solely focus on application of an impulse facility in diverse area of high-speed aerodynamics and structural mechanics. Shock tube, the fundamental impulse facility, is specially designed and calibrated for present objectives. Force measurement experiments are performed on a hemispherical test model integrated with the stress wave force balance. Similar test model is considered for heat transfer measurements using coaxial thermocouple. Force and heat transfer experiments demonstrated that the strain gauge and thermocouple have lag time of 11.5 and 9 microseconds, respectively. Response time of these sensors in measuring the peak load is also measured successfully using shock tube facility. As an outcome, these sensors are found to be suitable for impulse testing. Lastly, the response of aluminum plates subjected to impulsive loading is analyzed by measuring the in-plane strain produced during deformation. Thus, possibility of forming tests in shock is also confirmed.

  15. Effects of Strategies Marketing of Collective Buying about Impulsive Behavior

    Directory of Open Access Journals (Sweden)

    Suzi Elen Ferreira Dias

    2014-08-01

    Full Text Available Brazil has the second largest e-commerce market in the world. One model used in this sector is "collective buying", a feature of which is impulse sales. Consumer behavior can be influenced by several factors, two of which are addressed in this article: the individual impulsivity of consumers and strategies of mix marketing. Impulsive buying is characterized by an unplanned purchase, i.e. the need to acquire the product arises just before the purchase. Consumers respond differently to mixed strategies depending on their degree of impulsivity. Thus, this article aims to analyze the efficacy of different marketing mix strategies for impulsive and non-impulsive consumer purchasing behavior. 137 participants were given a questionnaire containing the Buying Impulsiveness scale from Rook and Fisher (1995, and statements about the marketing strategies used by collective buying sites. Through a regression analysis, three strategies were found to relate more to impulsivity: search for products from well-known brands, search for deals with big discounts and confidence in receiving the product. For e-commerce and researchers, this study elucidates which strategies, from the consumer's perspective, effectively persuade purchasing behavior.

  16. Nightside High Latitude Magnetic Impulse Events

    Science.gov (United States)

    Engebretson, M. J.; Connors, M. G.; Braun, D.; Posch, J. L.; Kaur, M.; Guillon, S.; Hartinger, M.; Kim, H.; Behlke, R.; Reiter, K.; Jackel, B. J.; Russell, C. T.

    2017-12-01

    High latitude Magnetic Impulse Events (MIEs), isolated pulses with periods 5-10 min, were first noted in ground-based magnetometer data near local noon, and are now understood to be signatures of transient pressure increases in the solar wind (sudden impulses - SIs) and/or in the ion foreshock (traveling convection vortex events - TCVs). However, solitary pulses with considerably larger amplitude (ΔB up to 1500 nT) have often been observed in the night sector at these same latitudes. These events are not directly associated with transient external pressure increases, and are often large enough to produce significant ground induced currents. Although many night sector MIEs occur in association with substorm signatures, others appear to be very isolated. We present here a survey of intense MIE events identified in magnetometer data from the AUTUMNX and MACCS arrays in eastern Arctic Canada at all local times between July 1, 2014 and June 30, 2017. We also show maps of horizontal and vertical perturbations and maximum dB/dt values, as well as sample magnetograms, for several example events using data from these and other arrays in Arctic Canada, as well as in West Greenland and Antarctica, the latter to show the conjugate nature of these events. A basic relation to GIC data in the Hydro-Québec electrical transmission network in eastern Canada has been determined and will be discussed.

  17. Impulsive response of nonuniform density liquid in a laterally excited tank

    International Nuclear Information System (INIS)

    Tang, Y.; Chang, Y.W.

    1994-04-01

    A study on the impulsive component of the dynamic response of a liquid of nonuniform density in a tank undergoing lateral base excitations is presented. The system considered is a circular cylindrical tank containing an incompressible and inviscid liquid whose density increases with the liquid depth. The density distribution along the depth can be of any arbitrary continuous or discontinuous function. In the analysis, the liquid field is divided into n layers. The thickness of the liquid layers can be different, but the density of each liquid layer is considered to be uniform and is equal to the value of the original liquid density at the mid-height of that layer. The problem is solved by the eigenfunction expansion in conjunction with the transfer matrix technique. The effect of the nonuniform liquid density on the impulsive component of the dynamic response is illustrated in a numerical example in which the linear and cosine distributions of the liquid density are assumed. The response quantities examined include the impulsive pressure, base shear and moments. The results are presented in tabular and graphical forms. It is found that the impulsive pressure distribution along the tank wall is not sensitive to the detailed distribution function of the density, and the base shear and moments for the nonuniform liquid can be estimated by assuming an equivalent uniform liquid density that preserves the total liquid weight. The effect of tank flexibility is assessed by a simple approach in which the response quantities for flexible tanks are evaluated by simplified equations

  18. Influence of demographic and individual difference factors on impulse buying

    Directory of Open Access Journals (Sweden)

    Mirela Mihić

    2010-06-01

    Full Text Available The main purpose of the paper is to determine the correlation of consumers’ demographic or socioeconomic characteristics and individual difference factors on the impulse buying behavior with respect to a number of single impulsivity indicators and one collective indicator. The paper consists of theoretical and research aspects. The first part encompasses theoretical insights into the secondary research regarding impulse buying while the practical part presents the methodology and primary research results. With respect to the subject matter, research goals as well as previous findings and primary research results, corresponding hypotheses were set and mainly confirmed. The results showed that demographic factors, such as the age and working status, are related to most impulse buying indicators and to the impulsivity collective indicator. However, household income produced opposite results. Household income proved to have no major influence on the majority of impulse buying indicators but to be related noticeably to the collective impulsivity indicator, indicating that this result should be regarded with caution. Research results also pointed to the fact that the majority of individual indicators (innovativeness, tendency to the fashionable and shopping enjoyment are positively and negatively related to the impulse buying behavior and that individual difference factors have a greater influence on impulse buying than do demographic characteristics. The paper also summarizes research limitations as well as the work contribution and future research guidelines.

  19. Trait impulsivity is associated with the risk of falls in Parkinson's disease.

    Science.gov (United States)

    Smulders, Katrijn; Esselink, Rianne A; Cools, Roshan; Bloem, Bastiaan R

    2014-01-01

    Impulsivity is a "tendency to act prematurely without foresight." Clinical experience suggests that such impulsive behavior can impact on the fall risk in Parkinson's disease (PD), but this has never been tested. We investigated whether trait impulsivity is related to fall risk in a large cohort of PD patients. We also investigated whether trait impulsivity affects the fall risk differently for patients with more or less postural instability and gait disability (PIGD). 388 patients with PD (H&Y ≤ 3) completed the Barratt Impulsiveness Scale (BIS-11, higher scores indicating greater impulsivity) to assess trait impulsivity, including three subscales: motor impulsivity (e.g. "I do things without thinking"), attentional impulsivity (e.g. "I concentrate easily") and non-planning (e.g. "I plan tasks carefully"). Falls were registered prospectively for 6 months. Patients classified as non-fallers (0 falls, n = 237) were compared to recurrent PD fallers (>1 fall, n = 78). Total impulsivity scores were higher for recurrent fallers (59.5) compared to non-fallers (56.8; p = .012). This effect was predominantly driven by higher scores on the subscale for attentional impulsivity (p = .003). The difference in attentional impulsivity was independent of gender, disease severity, dopaminergic medication, and cognitive function. Motor and non-planning impulsivity did not differ between recurrent fallers and non-fallers. There was no evidence that impulsivity modulated the association between PIGD and fall risk. This is the first evidence that impulsivity, in particular in the attentional domain, is related to fall risk in PD.

  20. Cued to Act on Impulse: More Impulsive Choice and Risky Decision Making by Women Susceptible to Overeating after Exposure to Food Stimuli.

    Science.gov (United States)

    Yeomans, Martin R; Brace, Aaron

    2015-01-01

    There is increasing evidence that individual differences in tendency to overeat relate to impulsivity, possibly by increasing reactivity to food-related cues in the environment. This study tested whether acute exposure to food cues enhanced impulsive and risky responses in women classified on tendency to overeat, indexed by scores on the three factor eating questionnaire disinhibition (TFEQ-D), restraint (TFEQ-R) and hunger scales. Ninety six healthy women completed two measures of impulsive responding (delayed discounting, DDT and a Go No-Go, GNG, task) and a measure of risky decision making (the balloon analogue risk task, BART) as well as questionnaire measures of impulsive behaviour either after looking at a series of pictures of food or visually matched controls. Impulsivity (DDT) and risk-taking (BART) were both positively associated with TFEQ-D scores, but in both cases this effect was exacerbated by prior exposure to food cues. No effects of restraint were found. TFEQ-D scores were also related to more commission errors on the GNG, while restrained women were slower on the GNG, but neither effect was modified by cue exposure. Overall these data suggest that exposure to food cues act to enhance general impulsive responding in women at risk of overeating and tentatively suggest an important interaction between tendency for impulsive decision making and food cues that may help explain a key underlying risk factor for overeating.

  1. Impulsive generalized function synchronization of complex dynamical networks

    International Nuclear Information System (INIS)

    Zhang, Qunjiao; Chen, Juan; Wan, Li

    2013-01-01

    This Letter investigates generalized function synchronization of continuous and discrete complex networks by impulsive control. By constructing the reasonable corresponding impulsively controlled response networks, some criteria and corollaries are derived for the generalized function synchronization between the impulsively controlled complex networks, continuous and discrete networks are both included. Furthermore, the generalized linear synchronization and nonlinear synchronization are respectively illustrated by several examples. All the numerical simulations demonstrate the correctness of the theoretical results

  2. Boundary conditions of the exact impulse wave function

    International Nuclear Information System (INIS)

    Gravielle, M.; Miraglia, J.E.

    1997-01-01

    The behavior of the exact impulse wave function is investigated at intermediate and high impact energies. Numerical details of the wave function and its perturbative potential are reported. We conclude that the impulse wave function does not tend to the proper Coulomb asymptotic limit. For electron capture, however, it is shown that the impulse wave function produces reliable probabilities even for intermediate velocities and symmetric collision systems. copyright 1997 The American Physical Society

  3. Another Look at Impulsivity: A Meta- Analytic Review Comparing Specific Dispositions to Rash Action in their Relationship to Bulimic Symptoms

    Science.gov (United States)

    Fischer, Sarah; Smith, Gregory T.; Cyders, Melissa A.

    2008-01-01

    Recent advances in personality theory indicate that there are distinct constructs that dispose individuals to rash action and risky behavior, as opposed to one broad trait of impulsivity. Two are emotion based, two represent deficits in conscientiousness, and one is sensation seeking. Previous studies of impulsivity and its relationship to bulimia nervosa have yielded mixed findings. The authors applied this advance in personality theory to the study of bulimia nervosa (BN) to test the hypothesis that the emotion-based disposition of negative urgency (the tendency to act rashly when distressed) relates most strongly to BN symptoms. A meta analysis of 50 articles indicated the following. Negative urgency had by far the largest effect size (weighted r = .38), followed by sensation seeking (weighted r = .16); lack of planning (weighted r = .16) and lack of persistence (weighted r = .08). Methodological moderators of the effect of distinct traits on BN symptoms were the use of scales that precisely measured one construct as opposed to general impulsivity scales that measured several constructs, clinical vs. non-clinical samples, and whether or not the personality scale was translated from its original language or not. Negative urgency appears especially important for BN; more broadly, researchers should consider the role of emotion-based dispositions to rash acts in their risk theories. PMID:18848741

  4. Correlations between the disintegration of melt and the measured impulses in steam explosions

    Energy Technology Data Exchange (ETDEWEB)

    Froehlich, G.; Linca, A.; Schindler, M. [Univ. of Stuttgart (Germany)

    1995-09-01

    To find our correlations in steam explosions (melt water interactions) between the measured impulses and the disintegration of the melt, experiments were performed in three configurations i.e. stratified, entrapment and jet experiments. Linear correlations were detected between the impulse and the total surface of the fragments. Theoretical considerations point out that a linear correlation assumes superheating of a water layer around the fragments of a constant thickness during the fragmentation process to a constant temperature (here the homogeneous nucleation temperature of water was assumed) and a constant expansion velocity of the steam in the main expansion time. The correlation constant does not depend on melt temperature and trigger pressure, but it depends on the configuration of the experiment or of a scenario of an accident. Further research is required concerning the correlation constant. For analysing steam explosion accidents the explosivity is introduced. The explosivity is a mass specific impulse. The explosivity is linear correlated with the degree of fragmentation. Knowing the degree of fragmentation with proper correlation constant the explosivity can be calculated and from the explosivity combined with the total mass of fragments the impulse is obtained which can be used to an estimation of the maximum force.

  5. Modeling Impulse and Non-Impulse Store Choice Processes in a Multi-Agent Simulation of Pedestrian Activity in Shopping Environments

    NARCIS (Netherlands)

    Dijkstra, J.; Timmermans, H.J.P.; Vries, de B.; Timmermans, H.J.P.

    2009-01-01

    This chapter presents a multi-agent approach for modeling impulse and non-impulse store choice processes of pedestrian activity in shopping environments. The pedestrian simulation context will be discussed as well as the behavioral principles underlying the store choice processes. For these

  6. LMFBR core flowering response to an impulse load

    International Nuclear Information System (INIS)

    Brochard, D.; Petret, J.C.; Queval, J.C.; Gibert, R.J.

    1993-01-01

    Some incidental situations like MFCI (Meeting Fuel Coolant Incident) may induce a core flowering and lead to consider impulse loans applied to LMFBR core. These highly dynamic loads are very different considering their spatial repartition and their frequency content from the seismic loads which have been deeply studied. Recently, tests have been performed on the LMFBR core mock-up RAPSODIE in order to validate the calculation methods for centered impulse load. These tests consist in injecting water quickly in the mock-up through a specific device replacing the core central assembly. The influence of the injection pressure and the influence of the injection axial position have been investigate. During the tests, the top displacements of some assemblies have been measured. The aim of this paper is first to present the experimental device and the test results. Then a non linear numerical model is described; this model includes the impact between subassemblies and is based on an homogenization method allowing to take into account with accuracy the fluid structure interaction.The comparisons between calculation results an test results will finally be presented

  7. Cooperation and stability through periodic impulses.

    Directory of Open Access Journals (Sweden)

    Bo-Yu Zhang

    2010-03-01

    Full Text Available Basic games, where each individual chooses between two strategies, illustrate several issues that immediately emerge from the standard approach that applies strategic reasoning, based on rational decisions, to predict population behavior where no rationality is assumed. These include how mutual cooperation (which corresponds to the best outcome from the population perspective can evolve when the only individually rational choice is to defect, illustrated by the Prisoner's Dilemma (PD game, and how individuals can randomize between two strategies when neither is individually rational, illustrated by the Battle of the Sexes (BS game that models male-female conflict over parental investment in offspring. We examine these questions from an evolutionary perspective where the evolutionary dynamics includes an impulsive effect that models sudden changes in collective population behavior. For the PD game, we show analytically that cooperation can either coexist with defection or completely take over the population, depending on the strength of the impulse. By extending these results for the PD game, we also show that males and females each evolve to a single strategy in the BS game when the impulsive effect is strong and that weak impulses stabilize the randomized strategies of this game.

  8. The role of impulsivity in self-mutilators, suicide ideators and suicide attempters - a study of 1265 male incarcerated individuals.

    Science.gov (United States)

    Carli, Vladimir; Jovanović, Nikolina; Podlesek, Anja; Roy, Alec; Rihmer, Zoltan; Maggi, Stefania; Marusic, Dragan; Cesaro, Caterina; Marusic, Andrej; Sarchiapone, Marco

    2010-06-01

    We explored differences between high and low-impulsive incarcerated individuals in the context of lifetime self-mutilation, suicide ideation and suicide attempt. A total of 1265 males detained in Italian penitentiary institutions were studied between January 2006 and December 2008. The study raters were specifically trained to discriminate between suicide attempters, ideators and self-mutilators. Participants completed the Barratt Impulsivity Scale, Childhood Trauma Questionnaire (CTQ), Eysenck Personality Questionnaire (EPQ), Connor-Davidson Resilience Scale (CD-RISC), Brown-Goodwin Assessment for Lifetime History of Aggression (BGLHA) and Buss and Durkee Hostility Inventory (BDHI). Based on BIS 7 total score distribution, two extreme quarters - high-impulsive group (n=306) and low-impulsive group (n=285) - were compared. Over 42% of participants had lifetime suicide ideation, 13% attempted suicide and 17% were self-mutilators. High-impulsive subjects were younger, more often single and with more prominent psychoticism, extraversion, aggression, hostility and resilience capacity. They were more frequently diagnosed with substance use disorders and engaged in self-mutilating behaviour. There was no difference in the rate of suicide attempts between the two groups. Although high-impulsive subjects were more prone to suicidal behaviour, it was not predicted by higher impulsivity when other psychological variables were accounted for. Copyright 2010 Elsevier B.V. All rights reserved.

  9. Institution-specific value

    OpenAIRE

    Ken Peasnell

    2006-01-01

    The introduction of a new accounting standard for financial instruments, has raised a number of issues related to the application of fair value principles. This paper discusses some of these issues which are generally related to the fact that "fair values" are not always easily defined or readily available. It concludes that the application of fair value for financial liabilities might present fewer complications if it is matched by similar valuation principles for financial assets. The issue...

  10. Self-reported impulsivity and inhibitory control in problem gamblers.

    Science.gov (United States)

    Lorains, Felicity K; Stout, Julie C; Bradshaw, John L; Dowling, Nicki A; Enticott, Peter G

    2014-01-01

    Impulsivity is considered a core feature of problem gambling; however, self-reported impulsivity and inhibitory control may reflect disparate constructs. We examined self-reported impulsivity and inhibitory control in 39 treatment-seeking problem gamblers and 41 matched controls using a range of self-report questionnaires and laboratory inhibitory control tasks. We also investigated differences between treatment-seeking problem gamblers who prefer strategic (e.g., sports betting) and nonstrategic (e.g., electronic gaming machines) gambling activities. Treatment-seeking problem gamblers demonstrated elevated self-reported impulsivity, more go errors on the Stop Signal Task, and a lower gap score on the Random Number Generation task than matched controls. However, overall we did not find strong evidence that treatment-seeking problem gamblers are more impulsive on laboratory inhibitory control measures. Furthermore, strategic and nonstrategic problem gamblers did not differ from their respective controls on either self-reported impulsivity questionnaires or laboratory inhibitory control measures. Contrary to expectations, our results suggest that inhibitory dyscontrol may not be a key component for some treatment-seeking problem gamblers.

  11. Numerical analysis on acoustic impulse response for watermelon

    International Nuclear Information System (INIS)

    Kim, Yong Sul; Yang, Dong Hoon; Choi, Young Jae; Bae, Tas Joo; So, Chul Ho; Lee, Yun Ho

    2002-01-01

    In this study, we conducted both analysis on impact pulse signal and acoustic impulse response method using numerical analysistic finite element method. Considering its velocity, density, Young's Modulus, and Poisson's Ratio, we extracted featured parameters and compared both results of analysis on impact pulse signal and numerical analysis on acoustic impulse response then we found the feature of generated acoustic sound signal by way of numerical analysis varying featured parameters and consequently intended to extract feature indices influenced on its internal maturity through analysis of acoustic impulse response. As we analyzed impact pulse signal and extracted featured parameters concerned with evaluation of its ripeness, we found the plausibility of progress on nondestructive evaluation of ripeness and adoption of numerical analysis on acoustic impulse response.

  12. Explaining suicide attempt with personality traits of aggression and impulsivity in a high risk tribal population of India.

    Science.gov (United States)

    Singh, Piyoosh Kumar; Rao, V R

    2018-01-01

    Suicide is a spectrum of behavior including suicide ideation and suicidal attempt and is undoubtedly the outcome of the interaction of several factors. The role of two main constructs of human nature, aggression and impulsivity, has been discussed broadly in relation to suicide, as endophenotypes or traits of personality, in research and in clinical practice across diagnoses. The objective of our study was to assess impulsive and aggressive behaviors among primitive people of the Idu Mishmi tribe, who are known for high suicide completer and attempter rates. The study group was comprised of 177 unrelated Idu Mishmi participants divided into two sets: 39 suicide attempters and 138 non-attempters. Data on demographic factors and details of suicide attempts were collected. Participants completed a set of instruments for assessment of aggression and impulsivity traits. In the Idu Mishimi population we screened (n = 177), 22.03% of the individuals had attempted suicide, a high percentage. The suicide attempters also showed a significant sex difference: 35.9% were male and 64.10% were female (p = .002*). The suicide attempters (A) scored significantly higher than non-attempters (NA) on aggression (A = 23.93,NA = 18.46) and impulsivity (A = 75.53,NA = 71.59, with p value = 0.05). The trait impulsiveness showed a significantly higher difference (F (1, 117) = 7.274) in comparison to aggression (F (1, 117) = 2.647), suggesting a profound role of impulsiveness in suicide attempts in the Idu Mishmi population. Analysis of sub-traits of aggression and impulsivity revealed significant correlations between them. Using different models, multivariate logistic regression implied roles of gender (OR = 1.079 (0.05)) and impulsiveness (OR = 3.355 (0.013)) in suicide attempts. Results demonstrate that gender and impulsivity are strong risk factors for suicide attempts in the Idu Mishmi population.

  13. Explaining suicide attempt with personality traits of aggression and impulsivity in a high risk tribal population of India.

    Directory of Open Access Journals (Sweden)

    Piyoosh Kumar Singh

    Full Text Available Suicide is a spectrum of behavior including suicide ideation and suicidal attempt and is undoubtedly the outcome of the interaction of several factors. The role of two main constructs of human nature, aggression and impulsivity, has been discussed broadly in relation to suicide, as endophenotypes or traits of personality, in research and in clinical practice across diagnoses. The objective of our study was to assess impulsive and aggressive behaviors among primitive people of the Idu Mishmi tribe, who are known for high suicide completer and attempter rates.The study group was comprised of 177 unrelated Idu Mishmi participants divided into two sets: 39 suicide attempters and 138 non-attempters. Data on demographic factors and details of suicide attempts were collected. Participants completed a set of instruments for assessment of aggression and impulsivity traits.In the Idu Mishimi population we screened (n = 177, 22.03% of the individuals had attempted suicide, a high percentage. The suicide attempters also showed a significant sex difference: 35.9% were male and 64.10% were female (p = .002*. The suicide attempters (A scored significantly higher than non-attempters (NA on aggression (A = 23.93,NA = 18.46 and impulsivity (A = 75.53,NA = 71.59, with p value = 0.05. The trait impulsiveness showed a significantly higher difference (F (1, 117 = 7.274 in comparison to aggression (F (1, 117 = 2.647, suggesting a profound role of impulsiveness in suicide attempts in the Idu Mishmi population. Analysis of sub-traits of aggression and impulsivity revealed significant correlations between them. Using different models, multivariate logistic regression implied roles of gender (OR = 1.079 (0.05 and impulsiveness (OR = 3.355 (0.013 in suicide attempts.Results demonstrate that gender and impulsivity are strong risk factors for suicide attempts in the Idu Mishmi population.

  14. Unified synchronization criteria in an array of coupled neural networks with hybrid impulses.

    Science.gov (United States)

    Wang, Nan; Li, Xuechen; Lu, Jianquan; Alsaadi, Fuad E

    2018-05-01

    This paper investigates the problem of globally exponential synchronization of coupled neural networks with hybrid impulses. Two new concepts on average impulsive interval and average impulsive gain are proposed to deal with the difficulties coming from hybrid impulses. By employing the Lyapunov method combined with some mathematical analysis, some efficient unified criteria are obtained to guarantee the globally exponential synchronization of impulsive networks. Our method and criteria are proved to be effective for impulsively coupled neural networks simultaneously with synchronizing impulses and desynchronizing impulses, and we do not need to discuss these two kinds of impulses separately. Moreover, by using our average impulsive interval method, we can obtain an interesting and valuable result for the case of average impulsive interval T a =∞. For some sparse impulsive sequences with T a =∞, the impulses can happen for infinite number of times, but they do not have essential influence on the synchronization property of networks. Finally, numerical examples including scale-free networks are exploited to illustrate our theoretical results. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Treatment of impulsive aggression in correctional settings.

    Science.gov (United States)

    Shelton, Deborah; Sampl, Susan; Kesten, Karen L; Zhang, Wanli; Trestman, Robert L

    2009-01-01

    This article reports the implementation of Dialectical Behavioral Therapy-Corrections Modified (DBT-CM) for difficult to manage, impulsive and/or aggressive correctional populations. Participants were English-speaking women (n = 18) and men (n = 45) of diverse cultural backgrounds between the ages of 16 and 59 years old retained in state-run prisons in Connecticut. Following consent, and a psychological assessment battery, twice-weekly DBT-CM groups were held over 16 weeks followed by random assignment to DBT coaching or case management condition, with sessions taking place individually for eight weeks. Data analysis. A mixed effects regression model was used to test the hypotheses: participants will show decreased aggression, impulsivity, and psychopathology, as well as improved coping, after completing the DBT-CM groups; and will show greater reduction in targeted behaviors than those receiving case management at the six month and 12 month follow-up assessment periods. Significant reduction in targeted behavior was found from baseline to following the 16 week DBT-CM skills treatment groups. Both case management and DBT coaching were significant at 12 month follow-up. A significant difference was found for adult men and women. The study supports the value of DBT-CM for management of aggressive behaviors in prison settings. (c) 2009 John Wiley & Sons, Ltd.

  16. Obesity and dissociable forms of impulsivity in young adults.

    Science.gov (United States)

    Chamberlain, Samuel R; Derbyshire, Katherine L; Leppink, Eric; Grant, Jon E

    2015-10-01

    Obesity is one of the leading causes of preventable morbidity and mortality, and young people are increasingly affected. The aim of this study was to examine relationships between obesity and dissociable forms of impulsivity in young adults. A group of young adults (511) was recruited from city areas in the United States using media advertisements. These young adults were administered careful and extensive clinical and neurocognitive assessment in order to quantify different aspects of impulsivity (behavioral/phenomenological-, cognitive-, and personality-related measures). Associations between obesity and impulsivity were explored using multivariate analysis of variance and discriminant function analysis. 10.8% of the sample was obese, and 21.5% was overweight. Compared to controls, subjects with obesity showed significantly elevated rates of maladaptive gambling behaviors, monetary amounts lost to gambling, nicotine consumption, impulsive action (prolonged stop-signal reaction times in the Stop-Signal Test), and impulsive decision-making (reduced modulation of behavior as a function of risk in the Cambridge Gamble Test). Even accounting for potential confounding variables, obesity was significantly predicted by female gender, older age, more maladaptive gambling behaviors, and worse inhibitory control (stop-signal reaction times). Obesity is associated with several dissociable forms of impulsivity in young people, especially gambling and impulse dyscontrol. Family doctors should screen for gambling problems in obese young adults. Successful treatment of nicotine dependence in young obese people is likely to require intensive weight management support. Neuropsychological deficits relating to impulsivity occur in obese people in early adulthood, and may represent vulnerability markers rather than being due to chronic untoward metabolic effects on brain function.

  17. Frequency modulation television analysis: Threshold impulse analysis. [with computer program

    Science.gov (United States)

    Hodge, W. H.

    1973-01-01

    A computer program is developed to calculate the FM threshold impulse rates as a function of the carrier-to-noise ratio for a specified FM system. The system parameters and a vector of 1024 integers, representing the probability density of the modulating voltage, are required as input parameters. The computer program is utilized to calculate threshold impulse rates for twenty-four sets of measured probability data supplied by NASA and for sinusoidal and Gaussian modulating waveforms. As a result of the analysis several conclusions are drawn: (1) The use of preemphasis in an FM television system improves the threshold by reducing the impulse rate. (2) Sinusoidal modulation produces a total impulse rate which is a practical upper bound for the impulse rates of TV signals providing the same peak deviations. (3) As the moment of the FM spectrum about the center frequency of the predetection filter increases, the impulse rate tends to increase. (4) A spectrum having an expected frequency above (below) the center frequency of the predetection filter produces a higher negative (positive) than positive (negative) impulse rate.

  18. Study of Influencing Factors on ConsumerOnline Impulse Buying

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    The convenience and anonymity of online shopping have stimulated people's impulse buying tendency. Impulse buying is notonly a competitive method for businesses, but also a crucial factor influencing sales of e-commerce. Based on a systematic reviewof literatures, this paper explores factors affecting the online impulse buying. Moreover, by using the S-O-R model, this paperdescribes the formation mechanism of the online impulse buying behavior. At Last, it points out issues worthy of future studies.For example, this paper suggests to take into consideration of sociocultural impact and to put more emphasis on empirical studies.

  19. Integrative Understanding of Familial Impulsivity, Early Adversity and Suicide Risk

    OpenAIRE

    Lima, Isabela M. M.; Malloy-Diniz, Leandro F.; de Miranda, Débora M.; Da Silva, Antônio G.; Neves, Fernando S.; Johnson, Sheri L.

    2017-01-01

    Introduction: Impulsivity is a core characteristic of bipolar disorder and it was observed as elevated in individuals with the disorder and in their relatives. Both impulsivity and history of maltreatment are risk factors for suicide attempts, however, these two key variables may not be independent, given the fact that parental impulsivity and associated social context could increase the risk of child maltreatment. In this study it was examined the association between the impulsivity of relat...

  20. Cued to Act on Impulse: More Impulsive Choice and Risky Decision Making by Women Susceptible to Overeating after Exposure to Food Stimuli.

    Directory of Open Access Journals (Sweden)

    Martin R Yeomans

    Full Text Available There is increasing evidence that individual differences in tendency to overeat relate to impulsivity, possibly by increasing reactivity to food-related cues in the environment. This study tested whether acute exposure to food cues enhanced impulsive and risky responses in women classified on tendency to overeat, indexed by scores on the three factor eating questionnaire disinhibition (TFEQ-D, restraint (TFEQ-R and hunger scales. Ninety six healthy women completed two measures of impulsive responding (delayed discounting, DDT and a Go No-Go, GNG, task and a measure of risky decision making (the balloon analogue risk task, BART as well as questionnaire measures of impulsive behaviour either after looking at a series of pictures of food or visually matched controls. Impulsivity (DDT and risk-taking (BART were both positively associated with TFEQ-D scores, but in both cases this effect was exacerbated by prior exposure to food cues. No effects of restraint were found. TFEQ-D scores were also related to more commission errors on the GNG, while restrained women were slower on the GNG, but neither effect was modified by cue exposure. Overall these data suggest that exposure to food cues act to enhance general impulsive responding in women at risk of overeating and tentatively suggest an important interaction between tendency for impulsive decision making and food cues that may help explain a key underlying risk factor for overeating.

  1. Externalizing behavior and impulsivity in the children of alcoholics: A case-control study

    Directory of Open Access Journals (Sweden)

    Ayyanar Sugaparaneetharan

    2016-01-01

    Full Text Available Context: Reduced behavioural inhibition, characterized by impulsivity and disruptive behaviour disorders, has been identified as a developmental precursor of alcoholism with a considerable genetic component. Aims: The present study aimed to assess whether children of fathers with alcohol dependence have high impulsivity and externalizing behaviours. Setting and Design: Observational case-control study, done in a tertiary care teaching hospital of Southern India. Materials and Methods: The present case-control study recruited 50 children aged 7 to 14 years of fathers with alcohol dependence and 50 age- and gender-matched children of fathers without alcohol dependence. The two groups were compared using the DSM-IV-TR criteria for ADHD, the Barratt Impulsivity Scale (BIS and the Child Behaviour Checklist (CBCL. Statistical Analysis Used: Descriptive statistics used to summarise the study findings. Cases and controls were compared on BIS and CBCL scores using a general linear model (GLM. All analyses were two tailed and test P value <0.05 was considered significant. Results: The children of fathers with alcohol dependence were more likely to meet criteria for ADHD (30% versus 10%, χ2 = 6.250, P = 0.012. After controlling for age and gender, impulsivity scores on the BIS tended to be higher in the cases (F = 2.410, P = 0.055 than controls, mainly in the non-planning domains (F = 3.650, P = 0.008. Similarly, externalizing behaviours on CBCL were more common in the cases than controls (F = 2.817, P = 0.029. Conclusions: Children of fathers with alcohol dependence had greater impulsivity and externalizing behaviours. This may represent a behavioural phenotype as well as a potential target for early intervention.

  2. Impulse control disorders are associated with multiple psychiatric symptoms in Parkinson's disease.

    Science.gov (United States)

    Jaakkola, Elina; Kaasinen, Valtteri; Siri, Chiara; Martikainen, Kirsti; Cilia, Roberto; Niemelä, Solja; Joutsa, Juho

    2014-01-01

    Impulse control disorders can have serious adverse consequences to the life of a patient with Parkinson's disease. Although impulse control disorders are common, a possible psychiatric comorbidity has not been fully characterized. The aim of this study was to investigate the psychiatric symptoms exhibited by Parkinson's disease patients with impulse control disorders. The study was conducted as a postal survey to patients in the registry of the Finnish Parkinson Association. A total of 290 Parkinson's disease patients were evaluated for impulse control disorders using the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease. Psychiatric symptoms were systematically screened using the Symptom Checklist 90. We found that 108 of the evaluated patients had one or more impulse control disorders. Patients with impulse control disorders had markedly higher scores for symptoms of psychoticism (Bonferroni corrected p disorder (p impulse control disorders. Impulse control disorders were shown to be independently associated with these symptoms. Patients with multiple impulse control disorders had higher scores for depression and obsessive-compulsive symptoms when compared with patients that exhibited only one impulse control disorder. COUNCLUSIONS: Our results confirm the previous observations that impulse control disorders in Parkinson's disease are linked with multiple psychiatric symptoms, including psychoticism, interpersonal sensitivity, obsessive-compulsive symptoms and depression. Clinicians treating these patients should acknowledge the concomitant psychiatric symptoms.

  3. "Latent" infection with Toxoplasma gondii: association with trait aggression and impulsivity in healthy adults.

    Science.gov (United States)

    Cook, Thomas B; Brenner, Lisa A; Cloninger, C Robert; Langenberg, Patricia; Igbide, Ajirioghene; Giegling, Ina; Hartmann, Annette M; Konte, Bettina; Friedl, Marion; Brundin, Lena; Groer, Maureen W; Can, Adem; Rujescu, Dan; Postolache, Teodor T

    2015-01-01

    Latent chronic infection with Toxoplasma gondii (T. gondii), a common neurotropic pathogen, has been previously linked with suicidal self-directed violence (SSDV). We sought to determine if latent infection with T. gondii is associated with trait aggression and impulsivity, intermediate phenotypes for suicidal behavior, in psychiatrically healthy adults. Traits of aggression and impulsivity were analyzed in relationship to IgG antibody seropositivity for T. gondii and two other latent neurotropic infections, herpes simplex virus 1 (HSV1) and cytomegalovirus (CMV). One thousand community-residing adults residing in the Munich metropolitan area with no Axis I or II conditions by SCID for DSM-IV (510 men, 490 women, mean age 53.6 ± 15.8, range 20-74). Plasma samples were tested for IgG antibodies to T. gondii, HSV-1 and CMV by ELISA. Self-reported ratings of trait aggression scores (Questionnaire for Measuring Factors of Aggression [FAF]) and trait impulsivity (Sensation-Seeking Scale-V [SSS-V]) were analyzed using linear multivariate methods. T. gondii IgG seropositivity was significantly associated with higher trait reactive aggression scores among women (p impulsive sensation-seeking (SSS-V Disinhibition) among younger men (p impulsivity, personality traits considered as endophenotypes for SSDV, are associated with latent T. gondii infection in a gender and age-specific manner, and could be further investigated as prognostic and treatment targets in T. gondii-positive individuals at risk for SSDV. Published by Elsevier Ltd.

  4. Losing control: assaultive behavior as a predictor of impulse control disorders in young adults.

    Science.gov (United States)

    Leppink, Eric; Odlaug, Brian L; Lust, Katherine; Christenson, Gary; Derbyshire, Katherine; Grant, Jon E

    2014-11-01

    Assaultive behaviors are common among young people and have been associated with a range of other unhealthy, impulsive behaviors such as substance use and problem gambling. This study sought to determine the predictive ability of single assaultive incidents for impulse control disorders, an association that has yet to be examined, especially in young adults. The authors conducted a university-wide email survey in the spring of 2011 on 6000 university students. The survey examined assaultive behavior and associated mental health variables (using a clinically validated screening instrument, the Minnesota Impulsive Disorders Interview), stress and mood states, and psychosocial functioning. The rate of response was 35.1% (n=2108). 109 (5.9%) participants reported that they had assaulted another person or destroyed property at some time in their lives. Compared with respondents without lifetime assaultive behavior, those with a history of assaultive or destructive behavior reported more depressive symptoms, more stress, and higher rates of a range of impulse control disorders (intermittent explosive disorder, compulsive sexual behavior, compulsive buying, and skin picking disorder). Assaultive behavior appears fairly common among college students and is associated with symptoms of depression and impulse control disorders. Significant distress and diminished behavioral control suggest that assaultive behaviors may often be associated with significant morbidity. Additional research is needed to develop specific prevention and treatment strategies for young adults attending college who report problems with assaultive behaviors. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Mood instability and impulsivity as trait predictors of suicidal thoughts.

    Science.gov (United States)

    Peters, Evyn M; Balbuena, Lloyd; Marwaha, Steven; Baetz, Marilyn; Bowen, Rudy

    2016-12-01

    Impulsivity, the tendency to act quickly without adequate planning or concern for consequences, is a commonly cited risk factor for suicidal thoughts and behaviour. There are many definitions of impulsivity and how it relates to suicidality is not well understood. Mood instability, which describes frequent fluctuations of mood over time, is a concept related to impulsivity that may help explain this relationship. The purpose of this study was to determine whether impulsivity could predict suicidal thoughts after controlling for mood instability. This study utilized longitudinal data from the 2000 Adult Psychiatric Morbidity Survey (N = 2,406). There was a time interval of 18 months between the two waves of the study. Trait impulsivity and mood instability were measured with the Structured Clinical Interview for DSM-IV Axis II Personality Disorders. Logistic regression analyses were used to evaluate baseline impulsivity and mood instability as predictors of future suicidal thoughts. Impulsivity significantly predicted the presence of suicidal thoughts, but this effect became non-significant with mood instability included in the same model. Impulsivity may be a redundant concept when predicting future suicidal thoughts if mood instability is considered. The significance is that research and therapy focusing on mood instability along with impulsivity may be useful in treating the suicidal patient. Mood instability and impulsivity both predict future suicidal thoughts. Impulsivity does not predict suicidal thoughts after controlling for mood instability. Assessing and treating mood instability could be important aspects of suicide prevention and risk management. © 2015 The British Psychological Society.

  6. Multidimensional Assessment of Impulsivity in Relation to Obesity and Food Addiction

    Science.gov (United States)

    VanderBroek-Stice, Lauren; Stojek, Monika K.; Beach, Steven R. H.; vanDellen, Michelle R.; MacKillop, James

    2017-01-01

    Based on similarities between overconsumption of food and addictive drugs, there is increasing interest in “food addiction,” a compulsive eating pattern defined using symptoms parallel to substance use disorders. Impulsivity, a multidimensional construct robustly linked to drug addiction, has been increasingly examined as an obesity determinant, but with mixed findings. This study sought to clarify relations between three major domains of impulsivity (i.e., impulsive personality traits, discounting of delayed rewards, and behavioral inhibition) in both obesity and food addiction. Based on the association between impulsivity and compulsive drug use, the general hypothesis was that the impulsivity-food addiction relation would be stronger than and responsible for the impulsivity-obesity relation. Using a cross-sectional dimensional design, participants (N = 181; 32% obese) completed a biometric assessment, the Yale Food Addiction Scale (YFAS), the UPPS-P Impulsive Behavior Scales, a Go/NoGo task, and measures of monetary delay discounting. Results revealed significantly higher prevalence of food addiction among obese participants and stronger zero-order associations between impulsivity indices and YFAS compared to obesity. Two aspects of impulsivity were independently significantly associated with food addiction: (a) a composite of Positive and Negative Urgency, reflecting proneness to act impulsively during intense mood states, and (b) steep discounting of delayed rewards. Furthermore, the results supported food addiction as a mediator connecting both urgency and delay discounting with obesity. These findings provide further evidence linking impulsivity to food addiction and obesity, and suggest that food addiction may be a candidate etiological pathway to obesity for individuals exhibiting elevations in these domains. PMID:28087369

  7. On some impulsive fractional differential equations in Banach spaces

    Directory of Open Access Journals (Sweden)

    JinRong Wang

    2010-01-01

    Full Text Available This paper deals with some impulsive fractional differential equations in Banach spaces. Utilizing the Leray-Schauder fixed point theorem and the impulsive nonlinear singular version of the Gronwall inequality, the existence of \\(PC\\-mild solutions for some fractional differential equations with impulses are obtained under some easily checked conditions. At last, an example is given for demonstration.

  8. Temperament, insecure attachment, impulsivity, and sexuality in women in jail.

    Science.gov (United States)

    Iliceto, Paolo; Pompili, Maurizio; Candilera, Gabriella; Rosafio, Iole; Erbuto, Denise; Battuello, Michele; Lester, David; Girardi, Paolo

    2012-03-01

    Women constitute only a small proportion of inmates, but several studies have shown that they have higher rates of psychiatric disturbance than incarcerated men and community samples. Mental health treatment is necessary to prevent severe illness and suicide in these women. The convenience sample consisted of 40 female detainees and 40 controls who were administered self-report questionnaires to assess temperament (TEMPS-A), insecure attachment (ECR), impulsivity (BIS-11), and sexual behavior (SESAMO). The incarcerated women had higher levels of affective temperament (except for hyperthymia), avoidance, anxiety, impulsivity, and psychosexual issues than the female community sample. Many interrelated emotional and affective disturbances affect the physical and psychological well-being of women in jail, and it is possible that these problems may lead to suicide. Health professionals need to develop gender-specific therapeutic interventions for women in jail. © 2012 International Association of Forensic Nurses.

  9. Numerical analysis on acoustic impulse response for watermelon

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Sul; Yang, Dong Hoon; Choi, Young Jae; Bae, Tas Joo; So, Chul Ho [Dongshin University, Naju (Korea, Republic of); Lee, Yun Ho [Korea Inspection and Engineering CO.,LTD., Seoul (Korea, Republic of)

    2002-11-15

    In this study, we conducted both analysis on impact pulse signal and acoustic impulse response method using numerical analysistic finite element method. Considering its velocity, density, Young's Modulus, and Poisson's Ratio, we extracted featured parameters and compared both results of analysis on impact pulse signal and numerical analysis on acoustic impulse response then we found the feature of generated acoustic sound signal by way of numerical analysis varying featured parameters and consequently intended to extract feature indices influenced on its internal maturity through analysis of acoustic impulse response. As we analyzed impact pulse signal and extracted featured parameters concerned with evaluation of its ripeness, we found the plausibility of progress on nondestructive evaluation of ripeness and adoption of numerical analysis on acoustic impulse response.

  10. Impulsive synchronisation of a class of fractional-order hyperchaotic systems

    International Nuclear Information System (INIS)

    Wang Xing-Yuan; Zhang Yong-Lei; Lin Da; Zhang Na

    2011-01-01

    In this paper, an impulsive synchronisation scheme for a class of fractional-order hyperchaotic systems is proposed. The sufficient conditions of a class of integral-order hyperchaotic systems' impulsive synchronisation are illustrated. Furthermore, we apply the sufficient conditions to a class of fractional-order hyperchaotic systems and well achieve impulsive synchronisation of these fractional-order hyperchaotic systems, thereby extending the applicable scope of impulsive synchronisation. Numerical simulations further demonstrate the feasibility and effectiveness of the proposed scheme. (general)

  11. Alterations in Brain Structure and Functional Connectivity in Alcohol Dependent Patients and Possible Association with Impulsivity.

    Science.gov (United States)

    Wang, Junkai; Fan, Yunli; Dong, Yue; Ma, Mengying; Ma, Yi; Dong, Yuru; Niu, Yajuan; Jiang, Yin; Wang, Hong; Wang, Zhiyan; Wu, Liuzhen; Sun, Hongqiang; Cui, Cailian

    2016-01-01

    Previous studies have documented that heightened impulsivity likely contributes to the development and maintenance of alcohol use disorders. However, there is still a lack of studies that comprehensively detected the brain changes associated with abnormal impulsivity in alcohol addicts. This study was designed to investigate the alterations in brain structure and functional connectivity associated with abnormal impulsivity in alcohol dependent patients. Brain structural and functional magnetic resonance imaging data as well as impulsive behavior data were collected from 20 alcohol dependent patients and 20 age- and sex-matched healthy controls respectively. Voxel-based morphometry was used to investigate the differences of grey matter volume, and tract-based spatial statistics was used to detect abnormal white matter regions between alcohol dependent patients and healthy controls. The alterations in resting-state functional connectivity in alcohol dependent patients were examined using selected brain areas with gray matter deficits as seed regions. Compared with healthy controls, alcohol dependent patients had significantly reduced gray matter volume in the mesocorticolimbic system including the dorsal posterior cingulate cortex, the dorsal anterior cingulate cortex, the medial prefrontal cortex, the orbitofrontal cortex and the putamen, decreased fractional anisotropy in the regions connecting the damaged grey matter areas driven by higher radial diffusivity value in the same areas and decreased resting-state functional connectivity within the reward network. Moreover, the gray matter volume of the left medial prefrontal cortex exhibited negative correlations with various impulse indices. These findings suggest that chronic alcohol dependence could cause a complex neural changes linked to abnormal impulsivity.

  12. A serious videogame as an additional therapy tool for training emotional regulation and impulsivity control in severe gambling disorder.

    Directory of Open Access Journals (Sweden)

    Salome eTarrega

    2015-11-01

    Full Text Available Background: Gambling disorder (GD is characterized by a significant lack of self-control and is associated with impulsivity-related personality traits. It is also linked to deficits in emotional regulation and frequently co-occurs with anxiety and depression symptoms. There is also evidence that emotional dysregulation may play a mediatory role between GD and psychopathological symptomatology. Few studies have reported the outcomes of psychological interventions that specifically address these underlying processes. Objectives: To assess the utility of the Playmancer platform, a serious video game, as an additional therapy tool in a CBT intervention for GD, and to estimate pre-post changes in measures of impulsivity, anger expression and psychopathological symptomatology. Method: The sample comprised a single group of 16 male treatment-seeking individuals with severe GD diagnosis. Therapy intervention consisted of 16 group weekly CBT sessions and, concurrently, 10 additional weekly sessions of a serious video game. Pre-post treatment scores on South Oaks Gambling Screen (SOGS, Barratt Impulsiveness Scale (BIS-11, I7 Impulsiveness Questionnaire (I7, State-Trait Anger Expression Inventory 2 (STAXI-2, Symptom Checklist-Revised (SCL-90-R, State-Trait Anxiety Inventory (STAI-S-T, and Novelty Seeking from the Temperament and Character Inventory-Revised (TCI-R were compared. Results: After the intervention, significant changes were observed in several measures of impulsivity, anger expression and other psychopathological symptoms. Dropout and relapse rates during treatment were similar to those described in the literature for CBT. Conclusion: Complementing CBT interventions for GD with a specific therapy approach like a serious video game might be helpful in addressing certain underlying factors which are usually difficult to change, including impulsivity and anger expression.

  13. A Serious Videogame as an Additional Therapy Tool for Training Emotional Regulation and Impulsivity Control in Severe Gambling Disorder.

    Science.gov (United States)

    Tárrega, Salomé; Castro-Carreras, Laia; Fernández-Aranda, Fernando; Granero, Roser; Giner-Bartolomé, Cristina; Aymamí, Neus; Gómez-Peña, Mónica; Santamaría, Juan J; Forcano, Laura; Steward, Trevor; Menchón, José M; Jiménez-Murcia, Susana

    2015-01-01

    Gambling disorder (GD) is characterized by a significant lack of self-control and is associated with impulsivity-related personality traits. It is also linked to deficits in emotional regulation and frequently co-occurs with anxiety and depression symptoms. There is also evidence that emotional dysregulation may play a mediatory role between GD and psychopathological symptomatology. Few studies have reported the outcomes of psychological interventions that specifically address these underlying processes. To assess the utility of the Playmancer platform, a serious video game, as an additional therapy tool in a CBT intervention for GD, and to estimate pre-post changes in measures of impulsivity, anger expression and psychopathological symptomatology. The sample comprised a single group of 16 male treatment-seeking individuals with severe GD diagnosis. Therapy intervention consisted of 16 group weekly CBT sessions and, concurrently, 10 additional weekly sessions of a serious video game. Pre-post treatment scores on South Oaks Gambling Screen (SOGS), Barratt Impulsiveness Scale (BIS-11), I7 Impulsiveness Questionnaire (I7), State-Trait Anger Expression Inventory 2 (STAXI-2), Symptom Checklist-Revised (SCL-90-R), State-Trait Anxiety Inventory (STAI-S-T), and Novelty Seeking from the Temperament and Character Inventory-Revised (TCI-R) were compared. After the intervention, significant changes were observed in several measures of impulsivity, anger expression and other psychopathological symptoms. Dropout and relapse rates during treatment were similar to those described in the literature for CBT. Complementing CBT interventions for GD with a specific therapy approach like a serious video game might be helpful in addressing certain underlying factors which are usually difficult to change, including impulsivity and anger expression.

  14. A Serious Videogame as an Additional Therapy Tool for Training Emotional Regulation and Impulsivity Control in Severe Gambling Disorder

    Science.gov (United States)

    Tárrega, Salomé; Castro-Carreras, Laia; Fernández-Aranda, Fernando; Granero, Roser; Giner-Bartolomé, Cristina; Aymamí, Neus; Gómez-Peña, Mónica; Santamaría, Juan J.; Forcano, Laura; Steward, Trevor; Menchón, José M.; Jiménez-Murcia, Susana

    2015-01-01

    Background: Gambling disorder (GD) is characterized by a significant lack of self-control and is associated with impulsivity-related personality traits. It is also linked to deficits in emotional regulation and frequently co-occurs with anxiety and depression symptoms. There is also evidence that emotional dysregulation may play a mediatory role between GD and psychopathological symptomatology. Few studies have reported the outcomes of psychological interventions that specifically address these underlying processes. Objectives: To assess the utility of the Playmancer platform, a serious video game, as an additional therapy tool in a CBT intervention for GD, and to estimate pre-post changes in measures of impulsivity, anger expression and psychopathological symptomatology. Method: The sample comprised a single group of 16 male treatment-seeking individuals with severe GD diagnosis. Therapy intervention consisted of 16 group weekly CBT sessions and, concurrently, 10 additional weekly sessions of a serious video game. Pre-post treatment scores on South Oaks Gambling Screen (SOGS), Barratt Impulsiveness Scale (BIS-11), I7 Impulsiveness Questionnaire (I7), State-Trait Anger Expression Inventory 2 (STAXI-2), Symptom Checklist-Revised (SCL-90-R), State-Trait Anxiety Inventory (STAI-S-T), and Novelty Seeking from the Temperament and Character Inventory-Revised (TCI-R) were compared. Results: After the intervention, significant changes were observed in several measures of impulsivity, anger expression and other psychopathological symptoms. Dropout and relapse rates during treatment were similar to those described in the literature for CBT. Conclusion: Complementing CBT interventions for GD with a specific therapy approach like a serious video game might be helpful in addressing certain underlying factors which are usually difficult to change, including impulsivity and anger expression. PMID:26617550

  15. Impulsivity modulates performance under response uncertainty in a reaching task.

    Science.gov (United States)

    Tzagarakis, C; Pellizzer, G; Rogers, R D

    2013-03-01

    We sought to explore the interaction of the impulsivity trait with response uncertainty. To this end, we used a reaching task (Pellizzer and Hedges in Exp Brain Res 150:276-289, 2003) where a motor response direction was cued at different levels of uncertainty (1 cue, i.e., no uncertainty, 2 cues or 3 cues). Data from 95 healthy adults (54 F, 41 M) were analysed. Impulsivity was measured using the Barratt Impulsiveness Scale version 11 (BIS-11). Behavioral variables recorded were reaction time (RT), errors of commission (referred to as 'early errors') and errors of precision. Data analysis employed generalised linear mixed models and generalised additive mixed models. For the early errors, there was an interaction of impulsivity with uncertainty and gender, with increased errors for high impulsivity in the one-cue condition for women and the three-cue condition for men. There was no effect of impulsivity on precision errors or RT. However, the analysis of the effect of RT and impulsivity on precision errors showed a different pattern for high versus low impulsives in the high uncertainty (3 cue) condition. In addition, there was a significant early error speed-accuracy trade-off for women, primarily in low uncertainty and a 'reverse' speed-accuracy trade-off for men in high uncertainty. These results extend those of past studies of impulsivity which help define it as a behavioural trait that modulates speed versus accuracy response styles depending on environmental constraints and highlight once more the importance of gender in the interplay of personality and behaviour.

  16. Global stability of discrete-time recurrent neural networks with impulse effects

    International Nuclear Information System (INIS)

    Zhou, L; Li, C; Wan, J

    2008-01-01

    This paper formulates and studies a class of discrete-time recurrent neural networks with impulse effects. A stability criterion, which characterizes the effects of impulse and stability property of the corresponding impulse-free networks on the stability of the impulsive networks in an aggregate form, is established. Two simplified and numerically tractable criteria are also provided

  17. Modelling impulsive factors for electronics and restaurant coupons’ e-store display

    Science.gov (United States)

    Ariningsih, P. K.; Nainggolan, M.; Sandy, I. A.

    2018-04-01

    In many times, the increment of e-store visitors does not followed by sales increment. Most purchases through e-commerce are impulsive buying, however only small amount of study is available to understand impulsive factors of e-store display. This paper suggests a preliminary concept on understanding the impulsive factors in Electronics and Restaurant Coupons e-store display, which are two among few popular group products sold through e-commerce. By conducting literature study and survey, 31 attributes were identified as impulsive factors in electronics e-store display and 20 attributes were identified as impulsive factors for restaurant coupon e-store. The attributes were then grouped into comprehensive impulsive factors by factor analysis. Each group of impulsive attributes were generated into 3 factors. Accessibility Factors and Trust Factors appeared for each group products. The other factors are Internal Factors for electronics e-store and Marketing factors for restaurant coupons e-store. Structural Equation Model of the impulsive factors was developed for each type of e-store, which stated the covariance between Trust Factors and Accessibility Factors. Based on preliminary model, Internal Factor and Trust Factor are influencing impulsive buying in electronics store. Special factor for electronics e-store is Internal Factor, while for restaurant coupons e-store is Marketing Factor.

  18. Multidimensional assessment of impulsivity in relation to obesity and food addiction.

    Science.gov (United States)

    VanderBroek-Stice, Lauren; Stojek, Monika K; Beach, Steven R H; vanDellen, Michelle R; MacKillop, James

    2017-05-01

    Based on similarities between overconsumption of food and addictive drugs, there is increasing interest in "food addiction," a compulsive eating pattern defined using symptoms parallel to substance use disorders. Impulsivity, a multidimensional construct robustly linked to drug addiction, has been increasingly examined as an obesity determinant, but with mixed findings. This study sought to clarify relations between three major domains of impulsivity (i.e., impulsive personality traits, discounting of delayed rewards, and behavioral inhibition) in both obesity and food addiction. Based on the association between impulsivity and compulsive drug use, the general hypothesis was that the impulsivity-food addiction relation would be stronger than and responsible for the impulsivity-obesity relation. Using a cross-sectional dimensional design, participants (N = 181; 32% obese) completed a biometric assessment, the Yale Food Addiction Scale (YFAS), the UPPS-P Impulsive Behavior Scales, a Go/NoGo task, and measures of monetary delay discounting. Results revealed significantly higher prevalence of food addiction among obese participants and stronger zero-order associations between impulsivity indices and YFAS compared to obesity. Two aspects of impulsivity were independently significantly associated with food addiction: (a) a composite of Positive and Negative Urgency, reflecting proneness to act impulsively during intense mood states, and (b) steep discounting of delayed rewards. Furthermore, the results supported food addiction as a mediator connecting both urgency and delay discounting with obesity. These findings provide further evidence linking impulsivity to food addiction and obesity, and suggest that food addiction may be a candidate etiological pathway to obesity for individuals exhibiting elevations in these domains. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Attentional and motor impulsivity interactively predict 'food addiction' in obese individuals.

    Science.gov (United States)

    Meule, Adrian; de Zwaan, Martina; Müller, Astrid

    2017-01-01

    Impulsivity is a multifaceted construct and constitutes a common risk factor for a range of behaviors associated with poor self-control (e.g., substance use or binge eating). The short form of the Barratt Impulsiveness Scale (BIS-15) measures impulsive behaviors related to attentional (inability to focus attention or concentrate), motor (acting without thinking), and non-planning (lack of future orientation or forethought) impulsivity. Eating-related measures appear to be particularly related to attentional and motor impulsivity and recent findings suggest that interactive effects between these two facets may play a role in eating- and weight-regulation. One-hundred thirty-three obese individuals presenting for bariatric surgery (77.4% female) completed the BIS-15 and the Yale Food Addiction Scale (YFAS) 2.0, which measures addiction-like eating based on the eleven symptoms of substance use disorder outlined in the fifth version of the Diagnostic and Statistical Manual of Mental Disorders. Sixty-three participants (47.4%) were classified as being 'food addicted'. Scores on attentional and motor impulsivity interactively predicted 'food addiction' status: higher attentional impulsivity was associated with a higher likelihood of receiving a YFAS 2.0 diagnosis only at high (+1 SD), but not at low (-1 SD) levels of motor impulsivity. Results support previous findings showing that non-planning impulsivity does not appear to play a role in eating-related self-regulation. Furthermore, this is the first study that shows interactive effects between different impulsivity facets when predicting 'food addiction' in obese individuals. Self-regulatory failure in eating-regulation (e.g., addiction-like overeating) may particularly emerge when both attentional and motor impulsivity levels are elevated. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Relationship between impulsivity, snack consumption and children's weight

    NARCIS (Netherlands)

    E.W.M. Scholten (Eline W. M.); C.Th.M. Schrijvers (Carola); C. Nederkoorn (Chantal); S.P.J. Kremers (Stef); G. Rodenburg (Gerda)

    2014-01-01

    textabstractBackground: Childhood overweight is a public health problem associated with psychosocial and physical problems. Personality traits, such as impulsivity, may contribute to the development of overweight. Objective: This study examines 1) the association between general impulsivity traits

  1. Impulsive Alfven coupling between the magnetosphere and ionosphere

    International Nuclear Information System (INIS)

    Reddy, R.V.; Watanabe, K.; Sato, T.; Watanabe, T.H.

    1994-04-01

    Basic properties of the impulsive Alfven interaction between the magnetosphere and ionosphere have been studied by means of a three-dimensional self-consistent simulation of the coupled magnetosphere and ionosphere system. It is found that the duration time of an impulsive perturbation at the magnetospheric equator, the latitudinal distribution of the Alfven propagation time along the field lines, and the ratio between the magnetospheric impedance and the ionospheric resistance is the main key factors that determine the propagation dynamics and the ionospheric responses for an impulsive MHD perturbation in the magnetosphere. (author)

  2. The slant of the forehead as a craniofacial feature of impulsiveness

    Directory of Open Access Journals (Sweden)

    J. David Guerrero-Apolo

    2018-03-01

    Full Text Available Objective: Impulsiveness has been the subject of much research, but little is known about the possible relationship between craniofacial anatomy and impulsiveness. The present study was designed to investigate the relationship between one aspect of craniofacial structure (the angle of inclination of the forehead and impulsiveness. Method: Photographs in profile were obtained from 131 volunteers who had been fined for driving at high speed and were undergoing a court-mandated driving license point-recovery course. They completed the Barratt Impulsiveness Scale (BIS-11, the Impulsive Behavior Scale (UPPS-P, and Zuckerman’s Sensation Seeking Scale (V. The angle of the slant of the forehead was measured with a photographic support and a protractor. Results: High positive concordance was found between forehead inclination and 14 out of the 15 impulsiveness factors studied. Conclusions: The angle of inclination of the forehead was significantly associated with self-reported impulsiveness in this sample of traffic violators.

  3. Effect of nicotine on negative affect among more impulsive smokers.

    Science.gov (United States)

    Doran, Neal; McChargue, Dennis; Spring, Bonnie; VanderVeen, Joe; Cook, Jessica Werth; Richmond, Malia

    2006-08-01

    In the present study, the authors tested the hypothesis that nicotine would provide greater relief from negative affect for more impulsive smokers than for less impulsive smokers. Euthymic adult smokers (N=70) participated in 2 laboratory sessions, during which they underwent a negative mood induction (music + autobiographical memory), then smoked either a nicotinized or de-nicotinized cigarette. Mixed-effects regression yielded a significant Impulsivity x Condition (nicotinized vs. de-nicotinized) x Time interaction. Simple effects analyses showed that heightened impulsivity predicted greater negative affect relief after smoking a nicotinized cigarette but not after smoking a de-nicotinized cigarette. These data suggest that nicotine may be a disproportionately powerful negative reinforcer for highly impulsive smokers, promoting higher levels of nicotine dependence and inhibiting smoking cessation.

  4. Partial discharge characteristics and mechanism in voids at impulse voltages

    International Nuclear Information System (INIS)

    Zhao, X F; Guo, Z F; Wang, Y Y; Li, J H; Li, Y M; Yao, X

    2011-01-01

    Partial discharge (PD) characteristics and mechanism in artificial cavities in an epoxy plate have been investigated for different void dimensions and impulse voltage waveforms. A differential measurement system was developed in order to detect PD current pulses effectively. Experimental results showed that the 50% probability PD inception voltage (PDIV 50 ) increases initially as the cavity diameter decreases at constant depth for double exponential impulses as well as oscillating impulses, but after aging, it becomes independent of the cavity diameter. Moreover, some distinctive characteristics of PD (e.g. main discharge and reverse discharge during the rise and fall phases of the applied voltage) were also investigated. The differences of the PD propagation and the mechanism between double exponential impulses and oscillating impulse were discussed

  5. Impulsivity and pathological gambling: Is it a state or a trait problem?

    Directory of Open Access Journals (Sweden)

    Lai Florence DM

    2011-11-01

    Full Text Available Abstract Background This study tested 37 Chinese male pathological gamblers and 40 controls to understand the relationship between pathological gambling and impulsivity as a long-term trait or a short-term state in the cognitive and affective domain. Results Trait impulsivity was measured by the Barratt Impulsiveness Scale-11. State impulsivity in the cognitive and affective domains were measured by the Stroop Color Word Test and the Emotional Conflict Task, respectively. The pathological gamblers scored significantly higher than the controls on the Barratt Impulsiveness Scale-11. However, there were no significant group differences in performance on the Stroop Color Word Test or the Emotional Conflict Task. Conclusions Findings clearly show that pathological gambling is associated with trait but not state impulsivity. In other words, pathological gambling is associated with an impulsivity stemming from enduring personality characteristics that lead gamblers to focus on short-term gains (trait impulsivity rather than momentary cognitive or affective disinhibition (state impulsivity. Interventions should aim to change pathological gamblers' habitual functioning style by cultivating healthy reflection habits and focusing on long-term rewards.

  6. Dopamine and Impulse Control Disorders in Parkinson's Disease

    NARCIS (Netherlands)

    Weintraub, Daniel

    2008-01-01

    There is an increasing awareness that impulse control disorders (ICDs), including compulsive gambling, buying, sexual behavior, and eating, can occur as a complication of Parkinson's disease (PD). In addition, other impulsive or compulsive disorders have been reported to occur, including dopamine

  7. Reduced rank adaptive filtering in impulsive noise environments

    KAUST Repository

    Soury, Hamza; Abed-Meraim, Karim; Alouini, Mohamed-Slim

    2014-01-01

    An impulsive noise environment is considered in this paper. A new aspect of signal truncation is deployed to reduce the harmful effect of the impulsive noise to the signal. A full rank direct solution is derived followed by an iterative solution

  8. Impulse control disorders in Parkinson's disease: crossroads between neurology, psychiatry and neuroscience.

    Science.gov (United States)

    Bugalho, Paulo; Oliveira-Maia, Albino J

    2013-01-01

    Non-motor symptoms contribute significantly to Parkinson's disease (PD) related disability. Impulse control disorders (ICDs) have been recently added to the behavioural spectrum of PD-related non-motor symptoms. Such behaviours are characterized by an inappropriate drive to conduct repetitive behaviours that are usually socially inadequate or result in harmful consequences. Parkinson disease impulse control disorders (PD-ICDs) have raised significant interest in the scientific and medical community, not only because of their incapacitating nature, but also because they may represent a valid model of ICDs beyond PD and a means to study the physiology of drive, impulse control and compulsive actions in the normal brain. In this review, we discuss some unresolved issues regarding PD-ICDs, including the association with psychiatric co-morbidities such as obsessive-compulsive disorder and with dopamine related side effects, such as hallucinations and dyskinesias; the relationship with executive cognitive dysfunction; and the neural underpinnings of ICDs in PD. We also discuss the contribution of neuroscience studies based on animal-models towards a mechanistic explanation of the development of PD-ICDs, specifically regarding corticostriatal control of goal directed and habitual actions.

  9. Minnesota Impulse Disorders Interview (MIDI): Validation of a structured diagnostic clinical interview for impulse control disorders in an enriched community sample.

    Science.gov (United States)

    Chamberlain, Samuel R; Grant, Jon E

    2018-05-08

    Disorders of impulsivity are common, functionally impairing, and highly relevant across different clinical and research settings. Few structured clinical interviews for the identification and diagnosis of impulse control disorders exist, and none have been validated in a community sample in terms of psychometric properties. The Minnesota Impulse control disorders Interview (MIDI v2.0) was administered to an enriched sample of 293 non-treatment seeking adults aged 18-35 years, recruited using media advertisements in two large US cities. In addition to the MIDI, participants undertook extended clinical interview for other mental disorders, the Barratt impulsiveness questionnaire, and the Padua obsessive-compulsive inventory. The psychometric properties of the MIDI were characterized. In logistic regression, the MIDI showed good concurrent validity against the reference measures (versus gambling disorder interview, p  0.05). Test re-test reliability was excellent (0.95). The MIDI has good psychometric properties and thus may be a valuable interview tool for clinical and research studies involving impulse control disorders. Further research is needed to better understanding the optimal diagnostic classification and neurobiology of these neglected disorders. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

  10. Bounded and Periodic Solutions of Semilinear Impulsive Periodic System on Banach Spaces

    Directory of Open Access Journals (Sweden)

    Wei W

    2008-01-01

    Full Text Available Abstract A class of semilinear impulsive periodic system on Banach spaces is considered. First, we introduce the -periodic PC-mild solution of semilinear impulsive periodic system. By virtue of Gronwall lemma with impulse, the estimate on the PC-mild solutions is derived. The continuity and compactness of the new constructed Poincaré operator determined by impulsive evolution operator corresponding to homogenous linear impulsive periodic system are shown. This allows us to apply Horn's fixed-point theorem to prove the existence of -periodic PC-mild solutions when PC-mild solutions are ultimate bounded. This extends the study on periodic solutions of periodic system without impulse to periodic system with impulse on general Banach spaces. At last, an example is given for demonstration.

  11. Orbitofrontal reward sensitivity and impulsivity in adult attention deficit hyperactivity disorder.

    Science.gov (United States)

    Wilbertz, Gregor; van Elst, Ludger Tebartz; Delgado, Mauricio R; Maier, Simon; Feige, Bernd; Philipsen, Alexandra; Blechert, Jens

    2012-03-01

    Impulsivity symptoms of adult attention deficit hyperactivity disorder (ADHD) such as increased risk taking have been linked with impaired reward processing. Previous studies have focused on reward anticipation or on rewarded executive functioning tasks and have described a striatal hyporesponsiveness and orbitofrontal alterations in adult and adolescent ADHD. Passive reward delivery and its link to behavioral impulsivity are less well understood. To study this crucial aspect of reward processing we used functional magnetic resonance imaging (fMRI) combined with electrodermal assessment in male and female adult ADHD patients (N=28) and matched healthy control participants (N=28) during delivery of monetary and non-monetary rewards. Further, two behavioral tasks assessed risky decision making (game of dice task) and delay discounting. Results indicated that both groups activated ventral and dorsal striatum and the medial orbitofrontal cortex (mOFC) in response to high-incentive (i.e. monetary) rewards. A similar, albeit less strong activation pattern was found for low-incentive (i.e. non-monetary) rewards. Group differences emerged when comparing high and low incentive rewards directly: activation in the mOFC coded for the motivational change in reward delivery in healthy controls, but not ADHD patients. Additionally, this dysfunctional mOFC activity in patients correlated with risky decision making and delay discounting and was paralleled by physiological arousal. Together, these results suggest that the mOFC codes reward value and type in healthy individuals whereas this function is deficient in ADHD. The brain-behavior correlations suggest that this deficit might be related to behavioral impulsivity. Reward value processing difficulties in ADHD should be considered when assessing reward anticipation and emotional learning in research and applied settings. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Does the uptake of wagering inducements predict impulse betting on sport?

    Science.gov (United States)

    Hing, Nerilee; Russell, Alex M T; Li, En; Vitartas, Peter

    2018-03-01

    Background and aims Marketing inducements for addictive products, such as wagering, can prompt impulse purchasing by triggering consumption reminders, urges, and cravings. Wagering inducements incentivize betting by providing bonus bets, money-back guarantees, deposits into betting accounts, and discounts. Their promotion during sporting events, push marketing efforts directed at consumers, and ease of uptake at the point-of-sale, may trigger betting on impulse. This study examined whether the uptake of wagering inducements predicted impulse betting on sport. Methods Australian sports bettors (N = 1,813) completed an online survey measuring their proportion of planned bets, impulse bets before match commencement, and impulse bets during play; frequency of using wagering inducements; and several psychological, behavioral, and demographic variables. Results More frequent users of wagering inducements had a greater tendency to place impulse in-play bets, which were also predicted by problem gambling, higher buying impulsiveness, higher frequency of watching sports, younger age, and higher educational status. Sports bettors with a greater tendency to place impulse bets before match commencement also tended to have higher buying impulsiveness and to be younger, but they used inducements less frequently, and tended to be female, less-educated and non-problem, moderate risk, or problem gamblers. Discussion and conclusions Uptake of wagering inducements appeared to be particularly effective in stimulating impulse in-play betting among problem gamblers and frequent sports viewers. These results suggest that a more cautious approach to the regulation of both in-play bets and wagering inducements may be required to better protect young adults from gambling problems and harm.

  13. Characterization of impulsivity in suicide completers: clinical, behavioral and psychosocial dimensions.

    Science.gov (United States)

    Zouk, Hana; Tousignant, Michel; Seguin, Monique; Lesage, Alain; Turecki, Gustavo

    2006-06-01

    Impulsivity is a personality trait thought to be linked to suicide. Yet, not all suicides are highly impulsive. We aimed to better understand clinical, behavioral and psychosocial correlates of the association between suicide and impulsive behavior. One hundred sixty four suicide cases with impulsivity scores based on the Barratt Impulsivity Scale (BIS) were investigated. To examine the most extreme phenotypes, one hundred suicide cases, representing subjects with BIS scores above the 70th percentile and below the 30th percentile, were compared on clinical, behavioral and psychosocial suicide risk factors assessed by way of structured psychological autopsy methods with best informants. The impulsive suicide cases were significantly younger, exhibited higher measures of aggressive behavior, and were more likely to have a cluster B diagnosis as well as lifetime and 6-month prevalence of alcohol and drug abuse/dependence. They also differed significantly from their non-impulsive counterparts on all subscales of the TCI except for Harm Avoidance and Reward Dependence. Impulsive suicide completers were more likely to have had a history of childhood abuse and to have experienced a triggering life event up to a week preceding their death. A multivariate analysis indicated that 6-month prevalence of substance abuse/dependence and high aggressive behavior remained significant even after controlling for other significant variables. This study was carried out using proxy-based interviews. Most of the known clinical and behavioral risk factors commonly associated with suicide are particularly valid for impulsive suicide completers. Further, triggering and adverse life events seem to play a role primarily in impulsive suicide.

  14. Subtypes of trait impulsivity differentially correlate with neural responses to food choices

    NARCIS (Netherlands)

    van der Laan, Laura N.; Barendse, Marjolein E. A.; Viergever, Max A.; Smeets, Paul A. M.

    2016-01-01

    Impulsivity is a personality trait that is linked to unhealthy eating and overweight. A few studies assessed how impulsivity relates to neural responses to anticipating and tasting food, but it is unknown how impulsivity relates to neural responses during food choice. Although impulsivity is a

  15. Application of Impulse Control in Smart Grid Price System

    Directory of Open Access Journals (Sweden)

    Peng Du

    2013-07-01

    Full Text Available With the development of smart grid, flexible and interactive electricity market will finally emerge. Making full use of price can encourage consumers to use electricity during a low load period and reduce peak load, thus to guarantee electricity market stability. Impulse control is applied to price system in this paper. It is found that giving impulse control to price system can make the system reach stable state well, which is based on the theory of impulsive differential system. The sufficient condition for stable system and the max upper bound of impulse interval are also provided. The proposed method is proved to be feasible and effective by theoretically analysis and numerical simulation.

  16. Impulsive nature in collisional driven reconnection

    International Nuclear Information System (INIS)

    Kitabata, Hideyuki; Hayashi, Takaya; Sato, Tetsuya.

    1995-11-01

    Compressible magnetohydrodynamic simulation is carried out in order to investigate energy relaxation process of the driven magnetic reconnection in an open finite system through a long time calculation. It is found that a very impulsive energy release occurs in an intermittent fashion through magnetic reconnection for a continuous magnetic flux injection on the boundary. In the impulsive phase, the reconnection rate is remarkably enhanced up to more than ten times of the driving rate on the boundary. (author)

  17. Impulsivity and compulsive buying are associated in a non-clinical sample: an evidence for the compulsivity-impulsivity continuum?

    OpenAIRE

    Paula, Jonas J. de; Costa, Danielle de S.; Oliveira, Flavianne; Alves, Joana O.; Passos, Lídia R.; Malloy-Diniz, Leandro F.

    2015-01-01

    Objective:Compulsive buying is controversial in clinical psychiatry. Although it is defined as an obsessive-compulsive disorder, other personality aspects besides compulsivity are related to compulsive buying. Recent studies suggest that compulsivity and impulsivity might represent a continuum, with several psychiatric disorders lying between these two extremes. In this sense, and following the perspective of dimensional psychiatry, symptoms of impulsivity and compulsivity should correlate ev...

  18. Depression in university students: associations with impulse control disorders.

    Science.gov (United States)

    Leppink, Eric W; Lust, Katherine; Grant, Jon E

    2016-09-01

    The purpose of this study was to assess the implications of depression in a sample of university students, particularly relating to impulse control disorders. While previous studies have shown high rates of depression among university students, no study to date has assessed whether levels of depression show associations with the incidence of impulse control disorders in this population. In all, 6000 students participated in the College Student Computer Use Survey. A total of 1717 students completed the scales of interest for this analysis. Participants were assigned to groups based on depression scores: severe (N = 75), mild/moderate (N = 647) and none (N = 995). The three groups were assessed using analysis of variance (ANOVA) or chi-square test. A multinomial logistic regression analysis was used to elucidate associations between depression and impulse control disorder diagnoses. Groups differed across demographic, health and academic variables. The severe depression group reported higher rates of skin-picking disorder, compulsive sexual behaviour and compulsive buying. Results suggest a significant association between depression and impulse control disorders. One possibility is that a facet of impulsivity contributes to both problems, which could be important information for clinicians. Future studies will need to clarify the exact nature of the relationship between depression and impulse control disorders.

  19. Determination of acoustical transfer functions using an impulse method

    Science.gov (United States)

    MacPherson, J.

    1985-02-01

    The Transfer Function of a system may be defined as the relationship of the output response to the input of a system. Whilst recent advances in digital processing systems have enabled Impulse Transfer Functions to be determined by computation of the Fast Fourier Transform, there has been little work done in applying these techniques to room acoustics. Acoustical Transfer Functions have been determined for auditoria, using an impulse method. The technique is based on the computation of the Fast Fourier Transform (FFT) of a non-ideal impulsive source, both at the source and at the receiver point. The Impulse Transfer Function (ITF) is obtained by dividing the FFT at the receiver position by the FFT of the source. This quantity is presented both as linear frequency scale plots and also as synthesized one-third octave band data. The technique enables a considerable quantity of data to be obtained from a small number of impulsive signals recorded in the field, thereby minimizing the time and effort required on site. As the characteristics of the source are taken into account in the calculation, the choice of impulsive source is non-critical. The digital analysis equipment required for the analysis is readily available commercially.

  20. Drug-induced impulse control disorders in Parkinson's disease.

    Science.gov (United States)

    Reiff, J; Jost, W H

    2011-05-01

    Dopamine replacement treatment with excessive or aberrant dopamine receptor stimulation can cause behavioral disturbances in Parkinson's disease, comprising dopamine dysregulation syndrome, punding, and impulse control disorders. Common impulse control disorders are compulsive buying, pathological gambling, binge eating, hypersexuality, and compulsive reckless driving.

  1. Asymptotic behavior of second-order impulsive differential equations

    Directory of Open Access Journals (Sweden)

    Haifeng Liu

    2011-02-01

    Full Text Available In this article, we study the asymptotic behavior of all solutions of 2-th order nonlinear delay differential equation with impulses. Our main tools are impulsive differential inequalities and the Riccati transformation. We illustrate the results by an example.

  2. Attention deficit and impulsivity: Driving, drugs and electrophysiology

    NARCIS (Netherlands)

    Wester, A.E.

    2009-01-01

    Impulsivity can be interpreted as a cognitive dysfunction or as a motivational dysfunction. Motivational dysfunctions are reflected in impulsive decision making such as increased preference for immediate reward over delayed more beneficial reward (delay aversion) or increased risk taking due to poor

  3. The Effect of Individual Differences on Adolescents' Impulsive Buying Behavior

    Science.gov (United States)

    Lin, Chien-Huang; Chuang, Shin-Chieh

    2005-01-01

    This study posits a relationship between Emotional Intelligence (EI) and Impulsive Buying Tendency (IBT). A survey of 574 adolescents found that high-EI adolescents manifested less impulsive behavior than did low-EI adolescents, and high-IBT adolescents were more likely to engage in more impulsive buying behavior than were low-IBT adolescents.…

  4. Relationship between Impulsivity, Social Media Usage and Loneliness

    Directory of Open Access Journals (Sweden)

    Mustafa Savci

    2016-03-01

    Full Text Available The purpose of this study is to examine the relationships between impulsivity, social media usage, and loneliness and to test the structural hypothetical model developed based on the literature. The study was conducted on 307 (164 female, 143 male university students. Data collection instruments of the study were the Barratt Impulsivity Scale Short Form (BIS-11-SF, Social Media Usage Scale (SMUS, and UCLA Loneliness Scale Short Form (ULS-8. The measurement models of the latent variables were tested initially and it was observed that the scales of the latent variables were efficient enough to be included in the structural equation model. In addition, the suggested hypothetical model was tested. According to the analysis, it was observed that impulsivity directly, positively and significantly predicts social media usage, that social media usage directly, positively and significantly predicts loneliness, and that impulsivity indirectly, positively and significantly predicts loneliness.

  5. Factor Analysis of the Brazilian Version of UPPS Impulsive Behavior Scale

    Science.gov (United States)

    Sediyama, Cristina Y. N.; Moura, Ricardo; Garcia, Marina S.; da Silva, Antonio G.; Soraggi, Carolina; Neves, Fernando S.; Albuquerque, Maicon R.; Whiteside, Setephen P.; Malloy-Diniz, Leandro F.

    2017-01-01

    Objective: To examine the internal consistency and factor structure of the Brazilian adaptation of the UPPS Impulsive Behavior Scale. Methods: UPPS is a self-report scale composed by 40 items assessing four factors of impulsivity: (a) urgency, (b) lack of premeditation; (c) lack of perseverance; (d) sensation seeking. In the present study 384 participants (278 women and 106 men), who were recruited from schools, universities, leisure centers and workplaces fulfilled the UPPS scale. An exploratory factor analysis was performed by using Varimax factor rotation and Kaiser Normalization, and we also conducted two confirmatory analyses to test the independency of the UPPS components found in previous analysis. Results: Results showed a decrease in mean UPPS total scores with age and this analysis showed that the youngest participants (below 30 years) scored significantly higher than the other groups over 30 years. No difference in gender was found. Cronbach’s alpha, results indicated satisfactory values for all subscales, with similar high values for the subscales and confirmatory factor analysis indexes also indicated a poor model fit. The results of two exploratory factor analysis were satisfactory. Conclusion: Our results showed that the Portuguese version has the same four-factor structure of the original and previous translations of the UPPS. PMID:28484414

  6. Factor Analysis of the Brazilian Version of UPPS Impulsive Behavior Scale

    Directory of Open Access Journals (Sweden)

    Leandro F. Malloy-Diniz

    2017-04-01

    Full Text Available Objective: To examine the internal consistency and factor structure of the Brazilian adaptation of the UPPS Impulsive Behavior Scale.Methods: UPPS is a self-report scale composed by 40 items assessing four factors of impulsivity: (a urgency, (b lack of premeditation; (c lack of perseverance; (d sensation seeking. In the present study 384 participants (278 women and 106 men, who were recruited from schools, universities, leisure centers and workplaces fulfilled the UPPS scale. An exploratory factor analysis was performed by using Varimax factor rotation and Kaiser Normalization, and we also conducted two confirmatory analyses to test the independency of the UPPS components found in previous analysis.Results: Results showed a decrease in mean UPPS total scores with age and this analysis showed that the youngest participants (below 30 years scored significantly higher than the other groups over 30 years. No difference in gender was found. Cronbach’s alpha, results indicated satisfactory values for all subscales, with similar high values for the subscales and confirmatory factor analysis indexes also indicated a poor model fit. The results of two exploratory factor analysis were satisfactory.Conclusion: Our results showed that the Portuguese version has the same four-factor structure of the original and previous translations of the UPPS.

  7. Factor Analysis of the Brazilian Version of UPPS Impulsive Behavior Scale.

    Science.gov (United States)

    Sediyama, Cristina Y N; Moura, Ricardo; Garcia, Marina S; da Silva, Antonio G; Soraggi, Carolina; Neves, Fernando S; Albuquerque, Maicon R; Whiteside, Setephen P; Malloy-Diniz, Leandro F

    2017-01-01

    Objective: To examine the internal consistency and factor structure of the Brazilian adaptation of the UPPS Impulsive Behavior Scale. Methods: UPPS is a self-report scale composed by 40 items assessing four factors of impulsivity: (a) urgency, (b) lack of premeditation; (c) lack of perseverance; (d) sensation seeking. In the present study 384 participants (278 women and 106 men), who were recruited from schools, universities, leisure centers and workplaces fulfilled the UPPS scale. An exploratory factor analysis was performed by using Varimax factor rotation and Kaiser Normalization, and we also conducted two confirmatory analyses to test the independency of the UPPS components found in previous analysis. Results: Results showed a decrease in mean UPPS total scores with age and this analysis showed that the youngest participants (below 30 years) scored significantly higher than the other groups over 30 years. No difference in gender was found. Cronbach's alpha, results indicated satisfactory values for all subscales, with similar high values for the subscales and confirmatory factor analysis indexes also indicated a poor model fit. The results of two exploratory factor analysis were satisfactory. Conclusion: Our results showed that the Portuguese version has the same four-factor structure of the original and previous translations of the UPPS.

  8. State-Dependent Impulsive Control Strategies for a Tumor-Immune Model

    Directory of Open Access Journals (Sweden)

    Kwang Su Kim

    2016-01-01

    Full Text Available Controlling the number of tumor cells leads us to expect more efficient strategies for treatment of tumor. Towards this goal, a tumor-immune model with state-dependent impulsive treatments is established. This model may give an efficient treatment schedule to control tumor’s abnormal growth. By using the Poincaré map and analogue of Poincaré criterion, some conditions for the existence and stability of a positive order-1 periodic solution of this model are obtained. Moreover, we carry out numerical simulations to illustrate the feasibility of our main results and compare fixed-time impulsive treatment effects with state-dependent impulsive treatment effects. The results of our simulations say that, in determining optimal treatment timing, the model with state-dependent impulsive control is more efficient than that with fixed-time impulsive control.

  9. Efficiency of the generation of impulsion by cyclotron waves currents of the electrons in an Axisymmetric Tokamak; Eficiencia de la generacion de corrientes de impulsion por ondas ciclotronicas de los electrones en un Tokamak axisimetrico

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez T, C.; Beltran P, M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2004-07-01

    The neoclassical theory of transport is used to calculate the current efficiency of electronic cyclotron impulsion (ECCD) in an axisymmetric tokamak in the few collisions regime. The standard parameter of the tokamak is used to obtain a system of equations that describe the hydrodynamic of the plasma, where the ponderomotive force (PM) due to high power radio frequency waves is taken in account. The PM force is produced in the proximity of electron cyclotron resonance surface in a specific poloidal localization. The efficiency ECCD is analyzed in the cases of first and second harmonic (for different angles of injection of radio frequency waves) and it is validated using the experimental values of the TCV and T-10 tokamaks. The results are according to those obtained by means of the techniques of the Green functions. (Author)

  10. Dynamic behaviors of the periodic Lotka-Volterra competing system with impulsive perturbations

    International Nuclear Information System (INIS)

    Liu Bing; Teng Zhidong; Liu Wanbo

    2007-01-01

    In this paper, we investigate a classical periodic Lotka-Volterra competing system with impulsive perturbations. The conditions for the linear stability of trivial periodic solution and semi-trivial periodic solutions are given by applying Floquet theory of linear periodic impulsive equation, and we also give the conditions for the global stability of these solutions as a consequence of some abstract monotone iterative schemes introduced in this paper, which will be also used to get some sufficient conditions for persistence. By using the method of coincidence degree, the conditions for the existence of at least one strictly positive (componentwise) periodic solution are derived. The theoretical results are confirmed by a specific example and numerical simulations. It shows that the dynamic behaviors of the system we consider are quite different from the corresponding system without pulses

  11. Emotion-driven impulsiveness and snack food consumption of European adolescents: Results from the I.Family study.

    Science.gov (United States)

    Coumans, Juul M J; Danner, Unna N; Intemann, Timm; De Decker, Annelies; Hadjigeorgiou, Charalambos; Hunsberger, Monica; Moreno, Luis A; Russo, Paola; Stomfai, Sarolta; Veidebaum, Toomas; Adan, Roger A H; Hebestreit, Antje

    2018-04-01

    We aimed to investigate the association between emotion-driven impulsiveness and snack food consumption in 1039 European adolescents aged 12-18 years. During the cross-sectional examination in 2013/2014, complete information was collected on: emotion-driven impulsiveness (using the negative urgency subscale from the Urgency, Premeditation, Perseverance, Sensation seeking, and Positive urgency (UPPS-P) Impulsive Behaviour Scale) and snacking behaviour operationalised as 1) consumption frequency of daily snacks, 2) consumption frequency of energy-dense snacks (both measured using Food Frequency Questionnaire) and 3) usual energy intake of food consumed per snacking occasion in calories. The latter was measured using online self-administered 24-h dietary recalls and was estimated based on the National Cancer Institute (NCI) Method. Anthropometric variables were measured and BMI z-score (zBMI) calculated. Age, sex, highest education level of the family and country of residence were assessed using a questionnaire. Mixed-effect regression analyses were separately conducted for each snacking behaviour outcome with emotion-driven impulsiveness as the exposure. After controlling for zBMI, age, sex, country and socioeconomic status, emotion-driven impulsiveness was positively associated with daily consumption frequency of snacks (β = 0.07, 95% Confidence Interval (CI) [0.02, 0.12]) and consumption frequency of energy-dense snacks (β = 0.25, 95% CI [0.19, 0.31]), but not with usual energy intake of food per snacking (β = 2.52, 95% CI [-0.55, 5.59]). Adolescents with a stronger emotion-driven impulsiveness tendency reported a higher snacking frequency and specifically more energy-dense snacks, whereas the energy intake of snack food seemed less important. These findings have implications for obesity prevention and treatment as they indicate the importance of targeting emotion-driven impulsiveness as a strategy to avoid excessive snacking. Copyright © 2018

  12. Suicidality in Bipolar Disorder: The Role of Emotion-Triggered Impulsivity.

    Science.gov (United States)

    Johnson, Sheri L; Carver, Charles S; Tharp, Jordan A

    2017-04-01

    A growing body of research suggests that impulsive responses to emotion more robustly predict suicidality than do other forms of impulsivity. This issue has not yet been examined within bipolar disorder, however. Participants diagnosed with bipolar I disorder (n = 133) and control participants (n = 110) diagnosed with no mood or psychotic disorder completed self-report measures of emotion-triggered impulsivity (Negative and Positive Urgency Scales) and interviews concerning lifetime suicidality. Analyses examined the effects of emotion-triggered impulsivity alone and in combination with gender, age of onset, depression severity, comorbid anxiety, comorbid substance use, and medication. A history of suicide ideation and attempts, as well as self-harm, were significantly more common in the bipolar disorder group compared with the control group. Impulsive responses to positive emotions related to suicide ideation, attempts, and self-harm within the bipolar group. Findings extend research on the importance of emotion-triggered impulsivity to a broad range of key outcomes within bipolar disorder. The discussion focuses on limitations and potential clinical implications. © 2016 The American Association of Suicidology.

  13. Impulsivity, aggression and brain structure in high and low lethality suicide attempters with borderline personality disorder.

    Science.gov (United States)

    Soloff, Paul; White, Richard; Diwadkar, Vaibhav A

    2014-06-30

    Impulsivity and aggressiveness are trait dispositions associated with the vulnerability to suicidal behavior across diagnoses. They are associated with structural and functional abnormalities in brain networks involved in regulation of mood, impulse and behavior. They are also core characteristics of borderline personality disorder (BPD), a disorder defined, in part, by recurrent suicidal behavior. We assessed the relationships between personality traits, brain structure and lethality of suicide attempts in 51 BPD attempters using multiple regression analyses on structural MRI data. BPD was diagnosed by the Diagnostic Interview for Borderline Patients-revised, impulsivity by the Barratt Impulsiveness Scale (BIS), aggression by the Brown-Goodwin Lifetime History of Aggression (LHA), and high lethality by a score of 4 or more on the Lethality Rating Scale (LRS). Sixteen High Lethality attempters were compared to 35 Low Lethality attempters, with no significant differences noted in gender, co-morbidity, childhood abuse, BIS or LHA scores. Degree of medical lethality (LRS) was negatively related to gray matter volumes across multiple fronto-temporal-limbic regions. Effects of impulsivity and aggression on gray matter volumes discriminated High from Low Lethality attempters and differed markedly within lethality groups. Lethality of suicide attempts in BPD may be related to the mediation of these personality traits by specific neural networks. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  14. Video Head Impulse Test for Early Diagnosis of Vestibular Neuritis Among Acute Vertigo.

    Science.gov (United States)

    Guan, Qiongfeng; Zhang, Lisan; Hong, Wenke; Yang, Yi; Chen, Zhaoying; Lu, Peilin; Zhang, Dan; Hu, Xingyue

    2017-09-01

    This study assesses the value of the video head impulse test (vHIT) for early diagnosis of vestibular neuritis (VN) among acute vertigo. Thirty-three cases of vestibular neuritis (VN), 96 patients with other acute vertigo (AV), and 50 cases of normal controls used vHIT to quantitatively test a pair of horizontal vestibulo-ocular reflection (VOR) gains, two pairs of vertical VOR gains, and the corresponding three pairs of VOR gain asymmetry. The peculiarity of VOR gains in VN and the differences between VN and other AV, normal controls by vHIT, were collected and analyzed. There were statistically significant differences in the three pairs of VOR gains asymmetry between VN and other AV, and normal controls (Pvertigo by vHIT. This study shows vHIT has advantages in the diagnosis of VN in acute vertigo with good sensitivity and specificity and indicates a widespread clinical application.

  15. A new approach to calculating spatial impulse responses

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    1997-01-01

    Using linear acoustics the emitted and scattered ultrasound field can be found by using spatial impulse responses as developed by Tupholme (1969) and Stepanishen (1971). The impulse response is calculated by the Rayleigh integral by summing the spherical waves emitted from all of the aperture...

  16. A multidimensional approach of impulsivity in adult attention deficit hyperactivity disorder.

    Science.gov (United States)

    Lopez, Régis; Dauvilliers, Yves; Jaussent, Isabelle; Billieux, Joël; Bayard, Sophie

    2015-06-30

    We aimed to compare adult patients with attention deficit hyperactivity disorder (ADHD) and matched controls on four dimensions of impulsivity (urgency, lack of premeditation, lack of perseverance, and sensation seeking) and to examine the association between impulsivity and ADHD symptoms. The study was conducted on 219 participants: 72 adult ADHD patients and 147 aged and gender matched controls. All participants completed questionnaires measuring the various facets of impulsivity (UPPS Impulsive Behavior Scale), ADHD and depressive symptoms severity. Patients were also assessed for ADHD subtypes, mood disorders, and addictive behaviors. ADHD patients exhibited higher urgency, lower premeditation and lower perseverance in comparison to controls. Lack of perseverance showed the strongest association with ADHD (area under curve=0.95). Patients with combined inattentive and hyperactive/impulsive subtypes reported more frequently substance abuse problems and had higher scores on urgency and sensation seeking dimensions of impulsivity than those with predominantly inattentive subtype. We report for the first time a multidimensional evaluation of impulsivity in adult ADHD patients. The UPPS Impulsive Behavior Scale may constitute a useful screening tool for ADHD in adults and may help to further understanding the psychological mechanisms underlying the differences between the ADHD subgroups. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Sex differences in dimensions of impulsivity in a non-clinical sample.

    Science.gov (United States)

    Lage, Guilherme Menezes; Albuquerque, Maicon Rodrigues; Fuentes, Daniel; Corrêa, Humberto; Malloy-Diniz, Leandro Fernandes

    2013-10-01

    Impulsivity has been more closely associated with men than with women because men are more often involved in illegal behaviors. The few studies that have investigated sex differences in impulsivity have used self-report questionnaires and have obtained contradictory results. Two computerized behavioral tests were administered to 125 healthy undergraduate students (75 women, M age 23.8 yr.; 50 men, M age 25.0 yr.). Men exhibited higher scores on motor impulsivity, but there were no significant differences between men and women on attentional and non-planning impulsivity scores. These findings are discussed in terms of the relationship between impulsivity and low- and high-order control.

  18. Individual differences in impulsive action and dopamine transporter function in rat orbitofrontal cortex.

    Science.gov (United States)

    Yates, J R; Darna, M; Beckmann, J S; Dwoskin, L P; Bardo, M T

    2016-01-28

    Impulsivity, which can be subdivided into impulsive action and impulsive choice, is implicated as a factor underlying drug abuse vulnerability. Although previous research has shown that dopamine (DA) systems in prefrontal cortex are involved in impulsivity and substance abuse, it is not known if inherent variation in DA transporter (DAT) function contributes to impulsivity. The current study determined if individual differences in either impulsive action or impulsive choice are related to DAT function in orbitofrontal (OFC) and/or medial prefrontal cortex (mPFC). Rats were first tested both for impulsive action in a cued go/no-go task and for impulsive choice in a delay-discounting task. Following behavioral evaluation, in vitro [(3)H]DA uptake assays were performed in OFC and mPFC isolated from individual rats. Vmax in OFC, but not mPFC, was correlated with performance in the cued go/no-go task, with decreased OFC DAT function being associated with high impulsive action. In contrast, Vmax in OFC and mPFC was not correlated with performance in the delay-discounting task. The current results demonstrate that impulsive behavior in cued go/no-go performance is associated with decreased DAT function in OFC, suggesting that hyperdopaminergic tone in this prefrontal subregion mediates, at least in part, increased impulsive action. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  19. Analysis of Caputo Impulsive Fractional Order Differential Equations with Applications

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    Lakshman Mahto

    2013-01-01

    Full Text Available We use Sadovskii's fixed point method to investigate the existence and uniqueness of solutions of Caputo impulsive fractional differential equations of order with one example of impulsive logistic model and few other examples as well. We also discuss Caputo impulsive fractional differential equations with finite delay. The results proven are new and compliment the existing one.

  20. Sex-Specificity in the Reward Value of Facial Attractiveness.

    Science.gov (United States)

    Hahn, Amanda C; Fisher, Claire I; DeBruine, Lisa M; Jones, Benedict C

    2016-05-01

    Studies of the sex-specificity of sexual arousal in adults (i.e., the tendency to respond more strongly to preferred-sex individuals than non-preferred sex individuals) have suggested that heterosexual men, homosexual men, and homosexual women show stronger sex-specific responses than do heterosexual women. Evidence for a similar pattern of results in studies investigating the reward value of faces is equivocal. Consequently, we investigated the effects of (1) sexual orientation (homosexual vs. heterosexual), (2) sex (male vs. female), (3) image sex (preferred-sex vs. non-preferred-sex), and (4) the physical attractiveness of the individual shown in the image on the reward value of faces. Participants were 130 heterosexual men, 130 homosexual men, 130 heterosexual women, and 130 homosexual women. The reward value of faces was assessed using a standard key-press task. Multilevel modeling of responses indicated that images of preferred-sex individuals were more rewarding than images of non-preferred-sex individuals and that this preferred-sex bias was particularly pronounced when more physically attractive faces were presented. These effects were not qualified by interactions involving either the sexual orientation or the sex of our participants, however, suggesting that the preferred-sex bias in the reward value of faces is similar in heterosexual men, homosexual men, heterosexual women, and homosexual women.

  1. Impulsive behavior in solar soft X-radiation

    Science.gov (United States)

    Hudson, H. S.; Strong, K. T.; Dennis, B. R.; Zarro, D.; Inda, M.; Kosugi, T.; Sakao, T.

    1994-01-01

    The Yohkoh soft X-ray telescope has observed impulsive, thermal, soft X-ray emission at the footpoints of magnetic loops during solar flares. The soft X-ray (thermal) time profiles at the footpoints closely match the hard X-ray (nonthermal) time profiles, directly demonstrating the heating of the lower solar atmosphere on short timescales during the interval of nonthermal energy release. This phenomenon is the rule, rather than the exception, occurring in the majority of flares that we have examined with the Yohkoh data. We illustrate the impulsive behavior with data from the major flare of 1992 January 26. For this flare, the soft X-ray peak times matched the hard X-ray peak times within the time resolution of the soft X-ray measurements (about 10 s), and the soft and hard X-ray locations match within the resolution of the hard X-ray imager. The impulsive soft X-ray emission clearly has a thermal spectral signature, but not at the high temperature of a 'superhot' source. We conclude that the impulsive soft X-ray emission comes from material heated by precipitating electrons at loop footpoints and evaporating from the deeper atmosphere into the flaring flux tube.

  2. The 5-HTTLPR polymorphism, impulsivity and suicide behavior in euthymic bipolar patients.

    Science.gov (United States)

    Malloy-Diniz, Leandro Fernandes; Neves, Fernando Silva; de Moraes, Paulo Henrique Paiva; De Marco, Luiz Armando; Romano-Silva, Marco Aurélio; Krebs, Marie-Odile; Corrêa, Humberto

    2011-09-01

    Suicide behavior is very frequent in Bipolar Disorder (BD) and they are both closely associated with impulsivity. Furthermore they are, impulsivity, BD and suicide behavior, associated with serotonergic function, at least partially, under genetic determinism and somewhat associated with the serotonin transporter gene polymorphism, the 5-HTTLPR. We aimed to assess different impulsivity components in BD sub-grouped by suicidal attempt and healthy controls. We hypothesized that the non-planning/cognitive impulsivity, could be more closely associated with suicidal behavior. We further associated 5-HTTLPR genotypes with neuropsychological results to test the hypothesis that this polymorphism is associated with cognitive impulsivity. We assessed 95 euthymic bipolar patients sub-grouped by suicidal attempt history in comparison with 94 healthy controls. All subjects underwent a laboratory assessment of impulsivity (Continuous Performance Test and Iowa Gambling Test). Furthermore the genotyping of 5-HTTLPR was performed in all subjects. We found that bipolar patients are more impulsive than healthy controls in all impulsivity dimensions we studied. Furthermore bipolar patients with a suicide attempt history have a greater cognitive impulsivity when compared to both bipolar patients without such a history as well when compared to healthy controls. No association was found between 5-HTTLPR genotypes and neuropsychological measures of impulsive behavior. The sample studied can be considered small and a potentially confounding variable - medication status - was not controlled. A lifetime suicide attempt seems associated with cognitive impulsivity independently of the socio-demographic and clinical variables studied as well with 5-HTTLPR genotype. Further studies in larger samples are necessary. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Simulation analysis of impulse characteristics of space debris irradiated by multi-pulse laser

    Science.gov (United States)

    Lin, Zhengguo; Jin, Xing; Chang, Hao; You, Xiangyu

    2018-02-01

    Cleaning space debris with laser is a hot topic in the field of space security research. Impulse characteristics are the basis of cleaning space debris with laser. In order to study the impulse characteristics of rotating irregular space debris irradiated by multi-pulse laser, the impulse calculation method of rotating space debris irradiated by multi-pulse laser is established based on the area matrix method. The calculation method of impulse and impulsive moment under multi-pulse irradiation is given. The calculation process of total impulse under multi-pulse irradiation is analyzed. With a typical non-planar space debris (cube) as example, the impulse characteristics of space debris irradiated by multi-pulse laser are simulated and analyzed. The effects of initial angular velocity, spot size and pulse frequency on impulse characteristics are investigated.

  4. Self-reported impulsivity, rather than sociosexuality, predicts women's preferences for masculine features in male faces.

    Science.gov (United States)

    Boothroyd, Lynda G; Brewer, Gayle

    2014-07-01

    Previous research has suggested that an individual's sociosexual orientation (i.e., their willingness to engage in sexual behavior outside of long-term relationships) may influence the qualities they find attractive in a potential mate. Results, however, have not been consistent and, moreover, studies have tended to draw from specific social groups. Here, we tested the relationship between sociosexuality and female's preferences for masculinity in male faces, using a diverse population. We furthermore investigated impulsivity alongside sociosexuality, as this trait has been suggested as a "root" cause of variation in sexual behavior (Cross, 2010) and thus may better explain variation in mate choice. Results showed a significant association between increases in both sociosexuality and two subcomponents of impulsivity and greater preferences for masculine male features. Regression analysis suggested that a subcomponent of impulsivity, namely lack of planning, was the primary determinant of preferences. We discuss the implications these results have for our understanding of female attraction to masculine features.

  5. Impulsivity and its relationship with anxiety, depression and stress.

    Science.gov (United States)

    Moustafa, Ahmed A; Tindle, Richard; Frydecka, Dorota; Misiak, Błażej

    2017-04-01

    We aimed to assess the association between depression, anxiety, stress and impulsivity with respect to age. The Depression, Anxiety and Stress Scale (DASS-42) and the Barratt Impulsiveness Scale (BIS-11) were administered to 145 individuals. Due to a negative correlation between age, BIS-11 and DASS-42 subscales, participants were divided into three groups: young-aged (18-30years), middle-aged (31-49years) and old-aged (≥50years). Subjects from old-aged group had significantly lower scores of depression, anxiety, stress and impulsivity compared to those from younger groups. Anxiety, followed by stress and depression, was the strongest predictor of BIS-11 total score in young-aged and middle-aged individuals. There were no significant differences in the correlations between BIS-11 total score, depression, anxiety and stress in old-aged individuals. Our results indicate that the levels of depression, anxiety, stress and impulsivity decrease with age. Additionally, age might moderate the effect of depression, anxiety and stress on impulsivity. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Lesions to the subthalamic nucleus decrease impulsive choice but impair autoshaping in rats: the importance of the basal ganglia in Pavlovian conditioning and impulse control.

    Science.gov (United States)

    Winstanley, Catharine A; Baunez, Christelle; Theobald, David E H; Robbins, Trevor W

    2005-06-01

    Although the subthalamic nucleus (STN) is involved in regulating motor function, and inactivation of this structure relieves the motor symptoms in Parkinsonian patients, recent data indicate that corticosubthalamic connections are involved in both the regulation of attention and the ability to withhold from responding. Considerable evidence suggests that the neural circuitry underlying such behavioural disinhibition or impulsive action can be at least partially dissociated from that implicated in impulsive decision-making and it has been suggested that the tendency to choose impulsively is related to the ability to form and use Pavlovian associations. To explore these hypotheses further, STN-lesioned rats were tested on the delay-discounting model of impulsive choice, where impulsivity is defined as the selection of a small immediate over a larger delayed reward, as well as in a rodent autoshaping paradigm. In contrast to previous reports of increased impulsive action, STN lesions decreased impulsive choice but dramatically impaired the acquisition of the autoshaping response. When the STN was lesioned after the establishment of autoshaping behaviour, lesioned subjects were more sensitive to the omission of reward, indicative of a reduction in the use of Pavlovian associations to control autoshaping performance. These results emphasize the importance of the STN in permitting conditioned stimulus-unconditioned stimulus associations to regulate goal-seeking, a function which may relate to the alterations in impulsive choice observed in the delay-discounting task. These data bear a striking similarity to those observed after lesions of the orbitofrontal cortex and are suggestive of an important role for corticosubthalamic connections in complex cognitive behaviour.

  7. Be quick about it. Endogenous estradiol level, menstrual cycle phase and trait impulsiveness predict impulsive choice in the context of reward acquisition.

    Science.gov (United States)

    Diekhof, Esther K

    2015-08-01

    This article is part of a Special Issue "Estradiol and Cognition". Variations in the steroid hormone 17ß-estradiol (E2) may promote intra-individual differences in reward seeking behavior and temporal decision-making (Reimers et al., 2014; Front. Neurosci. 8: 401). Yet, in humans the exact role of E2 in impulsive choice still needs to be determined. The present study assessed the effect of a cycle-dependent rise in endogenous E2 on temporal response adaptation across the follicular phase (FP). For this purpose a reward acquisition paradigm was employed that is sensitive to hormone-induced changes in central dopamine (DA) level. The present data show that women acted more impulsively in the early as opposed to the late FP. Early follicular E2 further correlated with an increased capacity to speed up for reward maximization, while simultaneously the ability to wait for higher reward was compromised. This correlation was most pronounced in women with low trait impulsiveness. In contrast, E2 and optimized response speed failed to correlate in women with high trait impulsiveness and in the late FP, despite a generally higher E2 level. Collectively, these findings support the theory that E2 may act as an endogenous DA agonist. The fact that the hormone-behavior relationship was restricted to women with low trait impulsiveness and thus supposedly lower central DA level provides indirect support for this idea. Yet, choices became relatively less impulsive in the state of heightened E2 (i.e., in the late FP), suggesting that the relationship between E2 and impulsive choice may not be linear, but might resemble an inverted U-function. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Linearization of Nonautonomous Impulsive System with Nonuniform Exponential Dichotomy

    Directory of Open Access Journals (Sweden)

    Yongfei Gao

    2014-01-01

    Full Text Available This paper gives a version of Hartman-Grobman theorem for the impulsive differential equations. We assume that the linear impulsive system has a nonuniform exponential dichotomy. Under some suitable conditions, we proved that the nonlinear impulsive system is topologically conjugated to its linear system. Indeed, we do construct the topologically equivalent function (the transformation. Moreover, the method to prove the topological conjugacy is quite different from those in previous works (e.g., see Barreira and Valls, 2006.

  9. Diet-induced obesity: dopamine transporter function, impulsivity and motivation.

    Science.gov (United States)

    Narayanaswami, V; Thompson, A C; Cassis, L A; Bardo, M T; Dwoskin, L P

    2013-08-01

    A rat model of diet-induced obesity (DIO) was used to determine dopamine transporter (DAT) function, impulsivity and motivation as neurobehavioral outcomes and predictors of obesity. To evaluate neurobehavioral alterations following the development of DIO induced by an 8-week high-fat diet (HF) exposure, striatal D2-receptor density, DAT function and expression, extracellular dopamine concentrations, impulsivity, and motivation for high- and low-fat reinforcers were determined. To determine predictors of DIO, neurobehavioral antecedents including impulsivity, motivation for high-fat reinforcers, DAT function and extracellular dopamine were evaluated before the 8-week HF exposure. Striatal D2-receptor density was determined by in vitro kinetic analysis of [(3)H]raclopride binding. DAT function was determined using in vitro kinetic analysis of [(3)H]dopamine uptake, methamphetamine-evoked [(3)H]dopamine overflow and no-net flux in vivo microdialysis. DAT cell-surface expression was determined using biotinylation and western blotting. Impulsivity and food-motivated behavior were determined using a delay discounting task and progressive ratio schedule, respectively. Relative to obesity-resistant (OR) rats, obesity-prone (OP) rats exhibited 18% greater body weight following an 8-week HF-diet exposure, 42% lower striatal D2-receptor density, 30% lower total DAT expression, 40% lower in vitro and in vivo DAT function, 45% greater extracellular dopamine and twofold greater methamphetamine-evoked [(3)H]dopamine overflow. OP rats exhibited higher motivation for food, and surprisingly, were less impulsive relative to OR rats. Impulsivity, in vivo DAT function and extracellular dopamine concentration did not predict DIO. Importantly, motivation for high-fat reinforcers predicted the development of DIO. Human studies are limited by their ability to determine if impulsivity, motivation and DAT function are causes or consequences of DIO. The current animal model shows that

  10. Diagnostic value of coustic radiation force impulse for BI-RADS category 4 breast lesions of different sizes.

    Science.gov (United States)

    Wu, Rong

    2018-04-14

    To determine the diagnostic value of combined conventional ultrasound (US) and acoustic radiation force impulse (ARFI) imaging for the differential diagnosis of BI-RADS category 4 breast lesions of different sizes. From April 2013 to January 2015, 283 patients (with a total of 292 breast lesions) who underwent US and ARFI examination were included in this retrospective study. The SWV for the lesion and adjacent normal breast tissue were measured and the SWV ratio was calculated. VTI grade was also assessed. The lesions were separated into three groups on the basis of size, and two combinations of ARFI parameters (SWV + VTI and SWV ratio + VTI) were applied to reassess the BI-RADS categories. Diagnoses were confirmed by pathological examination after biopsy or surgery. ROC analysis was performed to assess the diagnostic efficiency of each method. The Z test was used to compare the difference between AUC of the two methods. Significant improvement was seen in the diagnostic performance of US with the use of the ARFI parameters SWV + VTI (77/179 [43.0%] of BI-RADS category 4A breast lesions were downgraded) and SWV ratio + VTI (64/179 [35.8%] of BI-RADS category 4A breast lesions were downgraded, including two malignant cases that were misdiagnosed as benign) (P BI-RADS category 4 breast lesions. The combination of SWV ratio + VTI can improve BI-RADS classification of small lesions (<10 mm size).

  11. Impulsivity and overeating in children in the absence and presence of hunger.

    Science.gov (United States)

    Nederkoorn, Chantal; Dassen, Fania C M; Franken, Loes; Resch, Christine; Houben, Katrijn

    2015-10-01

    Overweight children appear to be more responsive to environmental, hedonic cues and easily overeat in the current obesogenic environment. They are also found to overeat in the absence of hunger, and this overeating seems related to impulsivity: impulsive participants are more prone to external eating. However, some studies showed that impulsive adults are also more prone to hunger cues: impulsive participants overate especially when feeling hungry. This would mean impulsive people are more reactive to both external and internal cues. The overeating was limited to palatable high energy-dense foods: hunger made them fancy a snack. In the current study, we wanted to test the interaction between impulsivity, hunger and consumption of food type in children. Impulsivity was measured in 88 children between the ages of 7 and 9. Next, half of the participants performed a taste test before their own regular lunch and half of the participants immediately after their lunch. During the taste test, low, medium and high energy-dense food items were presented. Results showed that impulsive children ate more high energy-dense foods than low impulsive children, both before and after their lunch. No differences were found on low or medium energy-dense foods. Impulsive children therefore showed normal sensitivity for internal hunger and satiety cues, but abnormal response to high energy-dense foods. This might render them vulnerable to tasty temptation in the environment and to weight gain in their future. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. [Validation of the French translation of the impulsive nonconformity scale].

    Science.gov (United States)

    Foullu, S; Blanc-Foullu, S; Danet, F; Dumas, P; Brunelin, J; Travart, M; Elchardus, J-M; Saoud, M; d'Amato, T

    2008-12-01

    Impulsive traits are key characteristics in a lot of psychiatric disorders and are part of the "normal" behaviour spectrum. Although impulsivity is a controversial concept, some questionnaires have focused on its "dysfunctional" aspect. The Barratt Impulsive Scale (BIS-10) is the scale the most used to explore impulsiveness, but it does not explore antisocial or nonconform behaviour. The Chapman Impulsive and Nonconformity Scale (INCS) is a questionnaire of 51 items that measures the impulsivity and nonconformism. The INCS reflects "failure to internalize societal norms, lack of empathy for the pain of others, and an unrestrained yielding to impulse and self-gratification" and was originally designed to assess psychosis proneness. It has been validated in the USA, but has not yet been validated in France. Interestingly, although it was not predictive of psychosis, high scorers on INCS exceeded controls on depression, and on rates of substance abuse. Furthermore, participants scoring high on hypomanic personality scale and INCS were found to have an especially heightened risk for bipolar disorders. To translate and determine reliability and validity of the French version of the Chapman Impulsive and Nonconformity Scale in young adults by comparison with the BIS. Chapman Impulsive and Nonconformity Scale has been back-translated into French, and filled out by 237 students (males: 104; females: 133; mean age: 20.4 [range 19-25]). BIS-10 was used for convergent validity. Each participant completed the two scales. Reliability and validity of the French form of INCS were assessed with the internal consistency (coefficient alpha of Cronbach and the split half reliability) and the convergent validity. In the French version of the INCS, the 51 items have high internal reliability (Cronbach's alpha=0.81 and split half reliability=0.80). Concerning the BIS, internal reliability is good (Cronbach's alpha=0.72 and split half reliability=0.66). Moreover, Pearson's r of the INCS

  13. Attention switching after dietary brain 5-HT challenge in high impulsive subjects.

    Science.gov (United States)

    Markus, C Rob; Jonkman, Lisa M

    2007-09-01

    High levels of impulsivity have adverse effects on performance in cognitive tasks, particularLy in those tasks that require high attention investment. Furthermore, both animal and human research has indicated that reduced brain serotonin (5-HT) function is associated with increases in impulsive behaviour or decreased inhibition ability, but the effects of 5-HT challenge have not yet been investigated in subjects vulnerable to impulsivity. The present study aimed to investigate whether subjects with high trait impulsivity perform worse than low impulsive subjects in a task switching paradigm in which they have to rapidly shift their attention between two response rules, and to investigate the influence of a 5-HT enhancing diet. Healthy subjects with high ( n = 19) and low (n = 18) trait impulsivity scores participated in a double-blind placebo-controlled study. All subjects performed the attention switch task in the morning following breakfast containing either tryptophan-rich alpha-lactalbumin (4.8 g/100 g TRP) or placebo protein (1.4 g/100 g TRP). Whereas there were no baseline differences between high and low impulsive subjects in task switching abilities, high impulsive subjects made significantly more switch errors and responded slower after dietary 5-HT stimulation, whereas no dietary effects were found on task switching performance in low-impulsive subjects. The deterioration in task switching performance induced by the 5-HT enhancing diet in high impulsive subjects was suggested to be established by general arousal/attention-reducing effects of 5-HT, which might have a larger impact in high impulsive subjects due to either different brain circuitry involved in task switching in this group or lower baseline arousal levels.

  14. Impulsive synchronization of Roessler systems with parameter driven by an external signal

    International Nuclear Information System (INIS)

    Zhang Rong; Hu Manfeng; Xu Zhenyuan

    2007-01-01

    In this Letter, an impulsive control scheme is presented to control two uncoupled identical Roessler systems. By driving the parameter of Roessler systems using external chaotic signal or periodic signal, chaotic synchronization and periodic synchronization can be implemented. This is a special impulsive control, but by using the existing results of impulsive control theory, a less conservative estimation of the upper bound of the impulse interval is given, which can guarantee the global asymptotical stability for the impulsive synchronization of Roessler systems. Numerical results are in accord with our estimation

  15. Near-Capacity Coding for Discrete Multitone Systems with Impulse Noise

    Directory of Open Access Journals (Sweden)

    Kschischang Frank R

    2006-01-01

    Full Text Available We consider the design of near-capacity-achieving error-correcting codes for a discrete multitone (DMT system in the presence of both additive white Gaussian noise and impulse noise. Impulse noise is one of the main channel impairments for digital subscriber lines (DSL. One way to combat impulse noise is to detect the presence of the impulses and to declare an erasure when an impulse occurs. In this paper, we propose a coding system based on low-density parity-check (LDPC codes and bit-interleaved coded modulation that is capable of taking advantage of the knowledge of erasures. We show that by carefully choosing the degree distribution of an irregular LDPC code, both the additive noise and the erasures can be handled by a single code, thus eliminating the need for an outer code. Such a system can perform close to the capacity of the channel and for the same redundancy is significantly more immune to the impulse noise than existing methods based on an outer Reed-Solomon (RS code. The proposed method has a lower implementation complexity than the concatenated coding approach.

  16. Heavy drinking, impulsivity and attentional narrowing following alcohol cue exposure.

    Science.gov (United States)

    Hicks, Joshua A; Fields, Sherecce; Davis, William E; Gable, Philip A

    2015-08-01

    Research shows that alcohol-related stimuli have the propensity to capture attention among individuals motivated to consume alcohol. Research has further demonstrated that impulsive individuals are especially prone to this type of attentional bias. Recently, it is suggested that alcohol cue exposure can also produce a general narrowing of attention consistent with the activation of approach motivational states. Based on previous models of addiction and recent research on the activation of approach motivational states, we predicted that impulsive individuals would demonstrate a constriction of attentional focus in response to alcohol cue exposure. Participants (n = 392) completed a task assessing attentional breadth in response to alcohol and non-alcohol cues, followed by measures of alcohol use and impulsivity. The findings revealed that impulsivity scores predicted narrowing of attentional scope following the presentation of alcohol cues for heavier drinkers but not for light drinkers. These results suggest that impulsive individuals who drink more heavily demonstrate a narrowing of attention in the presence of alcohol-related incentive cues. Implications for how these findings might account for the link between impulsivity and alcohol use and misuse are discussed.

  17. To Take the Stairs or Not to Take the Stairs? Employing the Reflective–Impulsive Model to Predict Spontaneous Physical Activity

    Directory of Open Access Journals (Sweden)

    Marcos Daou

    2017-09-01

    Full Text Available The reflective–impulsive model (RIM has been employed to explain various health behaviors. The present study used RIM to predict a spontaneous physical activity behavior. Specifically, 107 participants (75 females; Mage = 20.6 years, SD = 1.92 years completed measures of (1 reflections about spontaneous physical activity, as indexed by self-report questionnaire; (2 impulse toward physical activity, as indexed by the manikin task; and (3 (state self-control, as indexed by the Stroop task. The dependent variable was whether participants took the stairs or the elevator to the study laboratory. Results revealed reflections toward spontaneous physical activity positively predicted stair-taking. Further, a significant impulse toward physical activity × self-control interaction was observed. This interaction revealed that participants with high self-control who had a high impulse toward PA were more likely to take the stairs than their counterparts with a low impulse toward PA, whereas the opposite was the case for participants with low self-control. However, the impulse × self-control interaction was not significant when employing a self-report measure of trait self-control. Thus, RIM may be a good framework with which to consider spontaneous physical activity, but careful consideration must be given when examining variables within RIM (e.g., the boundary condition of self-control.

  18. Second-to-fourth digit ratio and impulsivity: a comparison between offenders and nonoffenders.

    Science.gov (United States)

    Hanoch, Yaniv; Gummerum, Michaela; Rolison, Jonathan

    2012-01-01

    Personality characteristics, particularly impulsive tendencies, have long been conceived as the primary culprit in delinquent behavior. One crucial question to emerge from this line of work is whether impulsivity has a biological basis. To test this possibility, 44 male offenders and 46 nonoffenders completed the Eysenck Impulsivity Questionnaire, and had their 2D∶4D ratio measured. Offenders exhibited smaller right hand digit ratio measurements compared to non-offenders, but higher impulsivity scores. Both impulsivity and 2D∶4D ratio measurements significantly predicted criminality (offenders vs. nonoffenders). Controlling for education level, the 2D∶4D ratio measurements had remained a significant predictor of criminality, while impulsivity scores no longer predicted criminality significantly. Our data, thus, indicates that impulsivity but not 2D∶4D ratio measurements relate to educational attainment. As offenders varied in their number of previous convictions and the nature of their individual crimes, we also tested for differences in 2D∶4D ratio and impulsivity among offenders. Number of previous convictions did not correlate significantly with the 2D∶4D ratio measurements or impulsivity scores. Our study established a link between a biological marker and impulsivity among offenders (and lack thereof among non-offenders), which emphasise the importance of studying the relationship between biological markers, impulsivity and criminal behavior.

  19. Eyes Wide Shopped: Shopping Situations Trigger Arousal in Impulsive Buyers

    Science.gov (United States)

    Serfas, Benjamin G.; Büttner, Oliver B.; Florack, Arnd

    2014-01-01

    The present study proposes arousal as an important mechanism driving buying impulsiveness. We examined the effect of buying impulsiveness on arousal in non-shopping and shopping contexts. In an eye-tracking experiment, we measured pupil dilation while participants viewed and rated pictures of shopping scenes and non-shopping scenes. The results demonstrated that buying impulsiveness is closely associated with arousal as response to viewing pictures of shopping scenes. This pertained for hedonic shopping situations as well as for utilitarian shopping situations. Importantly, the effect did not emerge for non-shopping scenes. Furthermore, we demonstrated that arousal of impulsive buyers is independent from cognitive evaluation of scenes in the pictures. PMID:25489955

  20. Fixed-time stabilization of impulsive Cohen-Grossberg BAM neural networks.

    Science.gov (United States)

    Li, Hongfei; Li, Chuandong; Huang, Tingwen; Zhang, Wanli

    2018-02-01

    This article is concerned with the fixed-time stabilization for impulsive Cohen-Grossberg BAM neural networks via two different controllers. By using a novel constructive approach based on some comparison techniques for differential inequalities, an improvement theorem of fixed-time stability for impulsive dynamical systems is established. In addition, based on the fixed-time stability theorem of impulsive dynamical systems, two different control protocols are designed to ensure the fixed-time stabilization of impulsive Cohen-Grossberg BAM neural networks, which include and extend the earlier works. Finally, two simulations examples are provided to illustrate the validity of the proposed theoretical results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Eyes wide shopped: shopping situations trigger arousal in impulsive buyers.

    Science.gov (United States)

    Serfas, Benjamin G; Büttner, Oliver B; Florack, Arnd

    2014-01-01

    The present study proposes arousal as an important mechanism driving buying impulsiveness. We examined the effect of buying impulsiveness on arousal in non-shopping and shopping contexts. In an eye-tracking experiment, we measured pupil dilation while participants viewed and rated pictures of shopping scenes and non-shopping scenes. The results demonstrated that buying impulsiveness is closely associated with arousal as response to viewing pictures of shopping scenes. This pertained for hedonic shopping situations as well as for utilitarian shopping situations. Importantly, the effect did not emerge for non-shopping scenes. Furthermore, we demonstrated that arousal of impulsive buyers is independent from cognitive evaluation of scenes in the pictures.

  2. Impulse Control Disorders in Parkinson’s Disease: Crossroads between Neurology, Psychiatry and Neuroscience

    Directory of Open Access Journals (Sweden)

    Paulo Bugalho

    2013-01-01

    Full Text Available Non-motor symptoms contribute significantly to Parkinson’s disease (PD related disability. Impulse control disorders (ICDs have been recently added to the behavioural spectrum of PD-related non-motor symptoms. Such behaviours are characterized by an inappropriate drive to conduct repetitive behaviours that are usually socially inadequate or result in harmful consequences. Parkinson disease impulse control disorders (PD-ICDs have raised significant interest in the scientific and medical community, not only because of their incapacitating nature, but also because they may represent a valid model of ICDs beyond PD and a means to study the physiology of drive, impulse control and compulsive actions in the normal brain. In this review, we discuss some unresolved issues regarding PD-ICDs, including the association with psychiatric co-morbidities such as obsessive-compulsive disorder and with dopamine related side effects, such as hallucinations and dyskinesias; the relationship with executive cognitive dysfunction; and the neural underpinnings of ICDs in PD. We also discuss the contribution of neuroscience studies based on animal-models towards a mechanistic explanation of the development of PD-ICDs, specifically regarding corticostriatal control of goal directed and habitual actions.

  3. Targeting impulsivity in Parkinson’s disease using atomoxetine

    Science.gov (United States)

    Housden, Charlotte R.; Regenthal, Ralf; Barker, Roger A.; Müller, Ulrich; Rowe, James; Sahakian, Barbara J.; Robbins, Trevor W.

    2014-01-01

    Noradrenergic dysfunction may play a significant role in cognition in Parkinson’s disease due to the early degeneration of the locus coeruleus. Converging evidence from patient and animal studies points to the role of noradrenaline in dopaminergically insensitive aspects of the parkinsonian dysexecutive syndrome, yet the direct effects of noradrenergic enhancement have not to date been addressed. Our aim was to directly investigate these, focusing on impulsivity during response inhibition and decision making. To this end, we administered 40 mg atomoxetine, a selective noradrenaline re-uptake inhibitor to 25 patients with Parkinson’s disease (12 female /13 male; 64.4 ± 6.9 years old) in a double blind, randomized, placebo controlled design. Patients completed an extensive battery of neuropsychological tests addressing response inhibition, decision-making, attention, planning and verbal short term memory. Atomoxetine improved stopping accuracy on the Stop Signal Task [F(1,19) = 4.51, P = 0.047] and reduced reflection impulsivity [F(1,9) = 7.86, P = 0.02] and risk taking [F(1,9) = 9.2, P = 0.01] in the context of gambling. The drug also conferred effects on performance as a function of its measured blood plasma concentration: it reduced reflection impulsivity during information sampling [adjusted R2 = 0.23, F(1,16) = 5.83, P = 0.03] and improved problem solving on the One Touch Stockings of Cambridge [adjusted R2 = 0.29, F(1,17) = 8.34, P = 0.01]. It also enhanced target sensitivity during sustained attention [F(1,9) = 5.33, P = 0.046]. The results of this exploratory study represent the basis of specific predictions in future investigations on the effects of atomoxetine in Parkinson’s disease and support the hypothesis that targeting noradrenergic dysfunction may represent a new parallel avenue of therapy in some of the cognitive and behavioural deficits seen in the disorder. PMID:24893708

  4. Dietary restraint and impulsivity modulate neural responses to food in adolescents with obesity and healthy adolescents.

    Science.gov (United States)

    Hofmann, Johannes; Ardelt-Gattinger, Elisabeth; Paulmichl, Katharina; Weghuber, Daniel; Blechert, Jens

    2015-11-01

    Despite alarming prevalence rates, surprisingly little is known about neural mechanisms underlying eating behavior in juveniles with obesity. To simulate reactivity to modern food environments, event-related potentials (ERP) to appetizing food images (relative to control images) were recorded in adolescents with obesity and healthy adolescents. Thirty-four adolescents with obesity (patients) and 24 matched healthy control adolescents watched and rated standardized food and object images during ERP recording. Personality (impulsivity) and eating styles (trait craving and dietary restraint) were assessed as potential moderators. Food relative to object images triggered larger early (P100) and late (P300) ERPs. More impulsive individuals had considerably larger food-specific P100 amplitudes in both groups. Controls with higher restraint scores showed reduced food-specific P300 amplitudes and subjective palatability ratings whereas patients with higher restraint scores showed increased P300 and palatability ratings. This first ERP study in adolescents with obesity and controls revealed impulsivity as a general risk factor in the current obesogenic environment by increasing food-cue salience. Dietary restraint showed paradoxical effects in patients, making them more vulnerable to visual food-cues. Salutogenic therapeutic approaches that deemphasize strict dietary restraint and foster healthy food choice might reduce such paradoxical effects. © 2015 The Obesity Society.

  5. Dopamine D2/3- and μ-opioid receptor antagonists reduce cue-induced responding and reward impulsivity in humans.

    Science.gov (United States)

    Weber, S C; Beck-Schimmer, B; Kajdi, M-E; Müller, D; Tobler, P N; Quednow, B B

    2016-07-05

    Increased responding to drug-associated stimuli (cue reactivity) and an inability to tolerate delayed gratification (reward impulsivity) have been implicated in the development and maintenance of drug addiction. Whereas data from animal studies suggest that both the dopamine and opioid system are involved in these two reward-related processes, their role in humans is less clear. Moreover, dopaminergic and opioidergic drugs have not been directly compared with regard to these functions, even though a deeper understanding of the underlying mechanisms might inform the development of specific treatments for elevated cue reactivity and reward impulsivity. In a randomized, double-blind, between-subject design we administered the selective dopamine D2/D3 receptor antagonist amisulpride (400 mg, n=41), the unspecific opioid receptor antagonist naltrexone (50 mg, n=40) or placebo (n=40) to healthy humans and measured cue-induced responding with a Pavlovian-instrumental transfer task and reward impulsivity with a delay discounting task. Mood was assessed using a visual analogue scale. Compared with placebo, amisulpride significantly suppressed cue-induced responding and reward impulsivity. The effects of naltrexone were similar, although less pronounced. Both amisulpride and naltrexone decreased average mood ratings compared with placebo. Our results demonstrate that a selective blockade of dopamine D2/D3 receptors reduces cue-induced responding and reward impulsivity in healthy humans. Antagonizing μ-opioid receptors has similar effects for cue-induced responding and to a lesser extent for reward impulsivity.

  6. 'Impulsive compulsivity' in obsessive-compulsive disorder: a phenotypic marker of patients with poor clinical outcome.

    Science.gov (United States)

    Kashyap, Himani; Fontenelle, Leonardo F; Miguel, Euripedes C; Ferrão, Ygor A; Torres, Albina R; Shavitt, Roseli G; Ferreira-Garcia, Rafael; do Rosário, Maria C; Yücel, Murat

    2012-09-01

    Although traditionally obsessive-compulsive disorder (OCD) and impulse control disorders (ICD) have represented opposing ends of a continuum, recent research has demonstrated a frequent co-occurrence of impulsive and compulsive behaviours, which may contribute to a worse clinical picture of some psychiatric disorders. We hypothesize that individuals with 'impulsive' OCD as characterized by poor insight, low resistance, and reduced control towards their compulsions will have a deteriorative course, greater severity of hoarding and/or symmetry/ordering symptoms, and comorbid ICD and/or substance use disorders (SUD). The sample consisted of 869 individuals with a minimum score of 16 on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). Of these, 65 had poor insight, low resistance, and reduced control towards compulsions ('poor IRC') and 444 had preserved insight, greater resistance and better control over compulsions ('good IRC'). These two groups were compared on a number of clinical and demographic variables. Individuals with poor IRC were significantly more likely to have a deteriorative course (p disorder (p = 0.026), trichotillomania (p = 0.014) and compulsive buying (p = 0.040). Regression analysis revealed that duration of obsessions (p = 0.037) and hoarding severity (p = 0.005) were significant predictors of poor IRC. In the absence of specific measures for impulsivity in OCD, the study highlights the utility of simple measures such as insight, resistance and control over compulsions as a phenotypic marker of a subgroup of OCD with impulsive features demonstrating poor clinical outcome. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Impulses and pressure waves cause excitement and conduction in the nervous system.

    Science.gov (United States)

    Barz, Helmut; Schreiber, Almut; Barz, Ulrich

    2013-11-01

    It is general accepted, that nerval excitement and conduction is caused by voltage changes. However, the influx of fluid into an elastical tube releases impulses or pressure waves. Therefore an influx of ion currents, respectively fluid motions into the elastic neuronal cells and fibres also induce impulses. This motion of charge carriers are measured by voltage devices as oscillations or action potentials, but the voltage changes may be an epiphenomenon of the (mechanical) impulses. Impulse waves can have a high speed. As stiffer or inelastic a tube wall, the greater is the speed of the impulse. Myelin sheaths cause a significant stiffening of the nerve fibre wall and myelinated fibres have a conduction velocity up to 120 m/s. The influx of fluid at the nodes of Ranvier intensifies periodically the impulse wave in the nerve fibres. The authors suggest that also the muscle end-plate acts as a conductor of axonal impulses to the inner of the muscle fibres and that the exocytosis of acetylcholine into the synaptic cleft may be an amplifier of the axonal impulse. It is discussed that intracellular actin filaments may also influence motions at the neuronal membrane. Many sensory nerve cells are excited due to exogenous or endogenous mechanical impulses. It may plausible that such impulses are conducted directly to the sensory nerve cell bodies in the dorsal root ganglia without the transformation in electric energy. Excitation conduction happens without noteworthy energy consumption because the flow of ion currents through the membranes takes place equivalent to the concentration gradient. Impulse waves cause short extensions of the lipid membranes of the cell- and fibres walls and therefore they can induce opening and closing of the included ion channels. This mechanism acts to "voltage gated" and "ligand-gated" channels likewise. The concept of neuronal impulses can be helpful to the understanding of other points of neurophysiology or neuronal diseases. This includes

  8. Dopaminergic influences on executive function and impulsive behaviour in impulse control disorders in Parkinson's disease.

    Science.gov (United States)

    Leroi, Iracema; Barraclough, Michelle; McKie, Shane; Hinvest, Neal; Evans, Jonathan; Elliott, Rebecca; McDonald, Kathryn

    2013-09-01

    The development of impulse control disorders (ICDs) in Parkinson's disease (PD) may arise from an interaction among cognitive impairment, impulsive responding and dopaminergic state. Dopaminergic state may be influenced by pharmacologic or genotypic (catechol-O-methyltransferase; COMT) factors. We sought to investigate this interaction further by comparing those with (n = 35) and without (n = 55) ICDs on delay-discounting in different pharmacologic conditions (ON or OFF dopaminergic medication) and on response inhibition as well as aspects of executive functioning in the ON state. We then undertook an exploratory sub-group analysis of these same tasks when the overall PD group was divided into different allelic variants of COMT (val/val vs. met/met). A healthy control group (HC; n = 20) was also included. We found that in those with PD and ICDs, 'cognitive flexibility' (set shifting, verbal fluency, and attention) in the ON medication state was not impaired compared with those without ICDs. In contrast, our working memory, or 'cognitive focus', task was impaired in both PD groups compared with the HC group when ON. During the delay-discounting task, the PD with ICDs group expressed greater impulsive choice compared with the PD group without ICDs, when in the ON, but not the OFF, medication state. However, no group difference on the response inhibition task was seen when ON. Finally, the met homozygous group performed differently on tests of executive function compared with the val homozygous group. We concluded that the disparity in levels of impairment among different domains of executive function and impulsive decision-making distinguishes those with ICD in PD from those without ICD, and may in part be affected by dopaminergic status. Both pharmacologic and genotypic influences on dopaminergic state may be important in ICD. © 2013 The British Psychological Society.

  9. Dopa therapy and action impulsivity: subthreshold error activation and suppression in Parkinson's disease

    NARCIS (Netherlands)

    Fluchère, F.; Deveaux, M.; Burle, B.; Vidal, F.; van den Wildenberg, W.P.M.; Witjas, T.; Eusebio, A.; Azulay, J.-P.; Hasbroucq, T.

    2015-01-01

    Rationale: Impulsive actions entail (1) capture of the motor system by an action impulse, which is an urge to act and (2) failed suppression of that impulse in order to prevent a response error. Several studies indicate that dopaminergic treatment can induce action impulsivity in patients diagnosed

  10. Prediction of BMI by impulsivity, eating behavior and activity level

    Directory of Open Access Journals (Sweden)

    Jiang Xiaxia

    2016-01-01

    Full Text Available Objective: Discuss the relationship between the impulsivity, eating behavior and activity level and the body mass index (BMI. Method: Test 147 female college students with the impulsivity questionnaire (BIS-11 and BIS/BAS, Dutch Eating Behavior Questionnaire (DBEQ, Sitting Time Scale (STS and Exercising Time Scale (ETS. Results: (1 The correlation analysis indicates that BMI and impulsivity (r = 0.43 and 0.52 have a significant positive correlation with the sitting time (r = 0.61 and a significant negative correlation with the activity level (r= −0.49. (2 The path analysis indicates that the reward sensitivity directly affects BMI and indirectly affects BMI through the activity level as well; the eating behavior has an insignificantly direct impact on BMI, because its impact is generated by the intermediary role of induced diet. Conclusion: (1 The impulsivity, eating behavior and activity level are closely related to BMI; (2 the activity level, sitting time and induced diet play an intermediary role between the impulsivity and BMI.

  11. Delay discounting, impulsiveness, and addiction severity in opioid-dependent patients.

    Science.gov (United States)

    Robles, Elias; Huang, B Emma; Simpson, Pippa M; McMillan, Donald E

    2011-12-01

    Individuals who abuse drugs show higher delay discounting (DD) rate and impulsiveness scores compared with controls; however, it is unclear if DD rate covaries with severity of the addiction or if an individual's discounting rate can be changed by effective substance abuse treatment. This study compared methadone maintenance treatment (MMT) patients (n = 30) who had not used illegal drugs for 2 years with drug-using MMT patients (n = 30) and controls (n = 25) in terms of addiction severity, DD rate, and impulsiveness. Methadone patients abstinent from illegal drugs scored significantly lower on a number of addiction severity measures than the drug-using methadone patients. In addition, both groups of MMT patients showed significantly higher rates of DD and impulsiveness than the control group; however, no differences in DD rate or impulsiveness were found between the groups of patients. Results suggest that DD rate and impulsiveness may not covary with indicators of addiction severity in MMT patients. Published by Elsevier Inc.

  12. Adolescent impulsivity and soft drink consumption: The role of parental regulation.

    Science.gov (United States)

    Melbye, Elisabeth L; Bergh, Ingunn H; Hausken, Solveig E S; Sleddens, Ester F C; Glavin, Kari; Lien, Nanna; Bjelland, Mona

    2016-01-01

    The present study aimed to explore the process in which impulsivity might influence soft drink consumption in adolescents, addressing potential mediating effects of perceived parental regulation regarding unhealthy eating. A cross-sectional survey was performed among 440 13-15-year-olds in Eastern Norway. The survey questionnaire included measures of impulsivity, six types of maternal and paternal regulation (as perceived by the adolescents), and consumption of sugar-sweetened beverages (SSB). Parallel multiple-mediator analyses were performed to reveal potential mediating effects of perceived parental regulatory behaviors on the association between adolescent impulsivity and SSB consumption. Separate models were run for maternal and paternal regulation. Results from our model analyses (both maternal and paternal models) indicated that all the six measured parental regulatory behaviors jointly acted as mediators on the association between adolescent impulsivity and SSB consumption. However, only perceived maternal and paternal legitimacy of regulation showed a unique contribution to the mediated effect. This finding suggests that adolescents' perception of parental legitimate authority is of particular importance in explaining the relationship between impulsivity and unhealthy eating behaviors in adolescents. Future nutrition interventions targeting adolescents and their parents should take personal factors such as adolescents' level of impulsivity into account. Ultimately; what may be an appropriate approach to impulsive individuals and their parents may diverge from what may be an appropriate approach to less impulsive individuals and their parents. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. The impulsive control synchronization of the drive-response complex system

    International Nuclear Information System (INIS)

    Zhao Yanhong; Yang Yongqing

    2008-01-01

    This Letter investigates projective synchronization between the drive system and response complex dynamical system. An impulsive control scheme is adapted to synchronize the drive-response dynamical system to a desired scalar factor. By using the stability theory of the impulsive differential equation, the criteria for the projective synchronization are derived. The feasibility of the impulsive control of the projective synchronization is demonstrated in the drive-response dynamical system

  14. An analytical approach for predicting the energy capture and conversion by impulsively-excited bistable vibration energy harvesters

    Science.gov (United States)

    Harne, R. L.; Zhang, Chunlin; Li, Bing; Wang, K. W.

    2016-07-01

    Impulsive energies are abundant throughout the natural and built environments, for instance as stimulated by wind gusts, foot-steps, or vehicle-road interactions. In the interest of maximizing the sustainability of society's technological developments, one idea is to capture these high-amplitude and abrupt energies and convert them into usable electrical power such as for sensors which otherwise rely on less sustainable power supplies. In this spirit, the considerable sensitivity to impulse-type events previously uncovered for bistable oscillators has motivated recent experimental and numerical studies on the power generation performance of bistable vibration energy harvesters. To lead to an effective and efficient predictive tool and design guide, this research develops a new analytical approach to estimate the electroelastic response and power generation of a bistable energy harvester when excited by an impulse. Comparison with values determined by direct simulation of the governing equations shows that the analytically predicted net converted energies are very accurate for a wide range of impulse strengths. Extensive experimental investigations are undertaken to validate the analytical approach and it is seen that the predicted estimates of the impulsive energy conversion are in excellent agreement with the measurements, and the detailed structural dynamics are correctly reproduced. As a result, the analytical approach represents a significant leap forward in the understanding of how to effectively leverage bistable structures as energy harvesting devices and introduces new means to elucidate the transient and far-from-equilibrium dynamics of nonlinear systems more generally.

  15. Altered intrinsic hippocmapus declarative memory network and its association with impulsivity in abstinent heroin dependent subjects.

    Science.gov (United States)

    Zhai, Tian-Ye; Shao, Yong-Cong; Xie, Chun-Ming; Ye, En-Mao; Zou, Feng; Fu, Li-Ping; Li, Wen-Jun; Chen, Gang; Chen, Guang-Yu; Zhang, Zheng-Guo; Li, Shi-Jiang; Yang, Zheng

    2014-10-01

    Converging evidence suggests that addiction can be considered a disease of aberrant learning and memory with impulsive decision-making. In the past decades, numerous studies have demonstrated that drug addiction is involved in multiple memory systems such as classical conditioned drug memory, instrumental learning memory and the habitual learning memory. However, most of these studies have focused on the contributions of non-declarative memory, and declarative memory has largely been neglected in the research of addiction. Based on a recent finding that hippocampus, as a core functioning region of declarative memory, was proved biased the decision-making process based on past experiences by spreading associated reward values throughout memory. Our present study focused on the hippocampus. By utilizing seed-based network analysis on the resting-state functional MRI datasets with the seed hippocampus we tested how the intrinsic hippocampal memory network altered toward drug addiction, and examined how the functional connectivity strength within the altered hippocampal network correlated with behavioral index 'impulsivity'. Our results demonstrated that HD group showed enhanced coherence between hippocampus which represents declarative memory system and non-declarative reward-guided learning memory system, and also showed attenuated intrinsic functional link between hippocampus and top-down control system, compared to the CN group. This alteration was furthered found to have behavioral significance over the behavioral index 'impulsivity' measured with Barratt Impulsiveness Scale (BIS). These results provide insights into the mechanism of declarative memory underlying the impulsive behavior in drug addiction. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Outer Synchronization of Complex Networks by Impulse

    International Nuclear Information System (INIS)

    Sun Wen; Yan Zizong; Chen Shihua; Lü Jinhu

    2011-01-01

    This paper investigates outer synchronization of complex networks, especially, outer complete synchronization and outer anti-synchronization between the driving network and the response network. Employing the impulsive control method which is uncontinuous, simple, efficient, low-cost and easy to implement in practical applications, we obtain some sufficient conditions of outer complete synchronization and outer anti-synchronization between two complex networks. Numerical simulations demonstrate the effectiveness of the proposed impulsive control scheme. (general)

  17. Roles of Impulsivity, Motivation, and Emotion Regulation in Procrastination - Path Analysis and Comparison Between Students and Non-students.

    Science.gov (United States)

    Wypych, Marek; Matuszewski, Jacek; Dragan, Wojciech Ł

    2018-01-01

    Procrastination - an irrational delay of intended actions despite expecting to be worse off - is a complex and non-homogenous phenomenon. Previous studies have found a number of correlates of procrastination, some of which seem to be particularly important. Impulsivity is closely connected to procrastination on behavioral, genetic, and neuronal levels. Difficulties in emotion regulation have also been shown to be strongly related to procrastination. Procrastination can also be considered as a motivation-based problem. To try to disentangle the connections of impulsivity, emotion regulation, and motivation to procrastination we collected data from over 600 subjects using multiple questionnaires (PPS - Pure Procrastination Scale; UPPSP - Impulsive Behavior Scale, ERQ - Emotion Regulation Questionnaire and MDT - Motivational Diagnostic Test). Structural equation modeling was performed to test several possible relationships between the measured variables. The effects of student status and age have also been investigated. The final path model was a directional model based on six explanatory variables and accounted for 70% of the variance in procrastination. Path analysis revealed that the strongest contributions to procrastination came from lack of value, delay discounting, and lack of perseverance, suggesting the involvement of motivation and impulsivity. The model also revealed the moderating role of expressive suppression between several aspects of impulsivity and procrastination. Close inspection of the paths' weights suggests that there may be two partly competing strategies for dealing with impulsivity and negative emotions: either to suppress emotions and impulsive reactions or to react impulsively, discarding previous plans, and to procrastinate. Path invariance analysis showed the significant moderating roles of student status and age. Both in non-students and high-age groups, the path leading from suppression to procrastination was insignificant. This suggests

  18. Eyes wide shopped: shopping situations trigger arousal in impulsive buyers.

    Directory of Open Access Journals (Sweden)

    Benjamin G Serfas

    Full Text Available The present study proposes arousal as an important mechanism driving buying impulsiveness. We examined the effect of buying impulsiveness on arousal in non-shopping and shopping contexts. In an eye-tracking experiment, we measured pupil dilation while participants viewed and rated pictures of shopping scenes and non-shopping scenes. The results demonstrated that buying impulsiveness is closely associated with arousal as response to viewing pictures of shopping scenes. This pertained for hedonic shopping situations as well as for utilitarian shopping situations. Importantly, the effect did not emerge for non-shopping scenes. Furthermore, we demonstrated that arousal of impulsive buyers is independent from cognitive evaluation of scenes in the pictures.

  19. Impulsive Noise Characterization in Narrowband Power Line Communication

    Directory of Open Access Journals (Sweden)

    Li Bai

    2018-04-01

    Full Text Available Currently, narrowband Power line communication (PLC is considered an attractive communication system in smart grid environments for applications such as advanced metering infrastructure (AMI. In this paper, we will present a comprehensive comparison and analysis in time and frequency domain of noise measured in China and Italy. In addition, impulsive noise in these two countries are mainly analyzed and modeled using two probability based models, Middleton Class A (MCA model and α stable distribution model. The results prove that noise measured in China is rich in impulsive noise, and can be modeled well by α stable distribution model, while noise measured in Italy has less impulsive noise, and can be better modeled by the MCA model.

  20. Decision-Based Marginal Total Variation Diffusion for Impulsive Noise Removal in Color Images

    Directory of Open Access Journals (Sweden)

    Hongyao Deng

    2017-01-01

    Full Text Available Impulsive noise removal for color images usually employs vector median filter, switching median filter, the total variation L1 method, and variants. These approaches, however, often introduce excessive smoothing and can result in extensive visual feature blurring and thus are suitable only for images with low density noise. A marginal method to reduce impulsive noise is proposed in this paper that overcomes this limitation that is based on the following facts: (i each channel in a color image is contaminated independently, and contaminative components are independent and identically distributed; (ii in a natural image the gradients of different components of a pixel are similar to one another. This method divides components into different categories based on different noise characteristics. If an image is corrupted by salt-and-pepper noise, the components are divided into the corrupted and the noise-free components; if the image is corrupted by random-valued impulses, the components are divided into the corrupted, noise-free, and the possibly corrupted components. Components falling into different categories are processed differently. If a component is corrupted, modified total variation diffusion is applied; if it is possibly corrupted, scaled total variation diffusion is applied; otherwise, the component is left unchanged. Simulation results demonstrate its effectiveness.

  1. Delay or probability discounting in a model of impulsive behavior: effect of alcohol.

    Science.gov (United States)

    Richards, J B; Zhang, L; Mitchell, S H; de Wit, H

    1999-01-01

    Little is known about the acute effects of drugs of abuse on impulsivity and self-control. In this study, impulsivity was assessed in humans using a computer task that measured delay and probability discounting. Discounting describes how much the value of a reward (or punisher) is decreased when its occurrence is either delayed or uncertain. Twenty-four healthy adult volunteers ingested a moderate dose of ethanol (0.5 or 0.8 g/kg ethanol: n = 12 at each dose) or placebo before completing the discounting task. In the task the participants were given a series of choices between a small, immediate, certain amount of money and $10 that was either delayed (0, 2, 30, 180, or 365 days) or probabilistic (i.e., certainty of receipt was 1.0, .9, .75, .5, or .25). The point at which each individual was indifferent between the smaller immediate or certain reward and the $10 delayed or probabilistic reward was identified using an adjusting-amount procedure. The results indicated that (a) delay and probability discounting were well described by a hyperbolic function; (b) delay and probability discounting were positively correlated within subjects; (c) delay and probability discounting were moderately correlated with personality measures of impulsivity; and (d) alcohol had no effect on discounting. PMID:10220927

  2. Development of the relativistic impulse approximation

    International Nuclear Information System (INIS)

    Wallace, S.J.

    1985-01-01

    This talk contains three parts. Part I reviews the developments which led to the relativistic impulse approximation for proton-nucleus scattering. In Part II, problems with the impulse approximation in its original form - principally the low energy problem - are discussed and traced to pionic contributions. Use of pseudovector covariants in place of pseudoscalar ones in the NN amplitude provides more satisfactory low energy results, however, the difference between pseudovector and pseudoscalar results is ambiguous in the sense that it is not controlled by NN data. Only with further theoretical input can the ambiguity be removed. Part III of the talk presents a new development of the relativistic impulse approximation which is the result of work done in the past year and a half in collaboration with J.A. Tjon. A complete NN amplitude representation is developed and a complete set of Lorentz invariant amplitudes are calculated based on a one-meson exchange model and appropriate integral equations. A meson theoretical basis for the important pair contributions to proton-nucleus scattering is established by the new developments. 28 references

  3. Being impulsive and obese increases susceptibility to speeded detection of high-calorie foods.

    Science.gov (United States)

    Bongers, Peggy; van de Giessen, Elsmarieke; Roefs, Anne; Nederkoorn, Chantal; Booij, Jan; van den Brink, Wim; Jansen, Anita

    2015-06-01

    Overeating and obesity are associated with impulsivity. In studies among patients with a substance use disorder, impulsivity was found to be associated with substance-related attentional bias. This study examined whether obesity, impulsivity and food craving are associated with an attentional bias for high-calorie food. Obese (n = 185, mean BMI = 38.18 ± 6.17) and matched healthy-weight (n = 134, mean BMI = 22.35 ± 1.63) men (27.9%) and women (72.1%), aged 18-45 years, took part in the study. Participants were tested on several self-report and behavioral measures of impulsivity (i.e., response inhibition and reward sensitivity) and self-reported trait craving. In addition, they performed a visual search task to measure attentional bias for high- and low-caloric foods. Self-reported impulsivity influenced the relationship between weight status and detection speed of high- and low-caloric food items: High-impulsive participants with obesity were significantly faster than high-impulsive healthy-weight participants in detecting a high-caloric food item among neutral items, whereas no such difference was observed among low-impulsive participants. No significant effects were found on low-caloric food items, for trait craving or any of the behavioral measures of impulsivity. Self-reported impulsivity, but not trait craving or behavioral measures of impulsivity, is associated with an attentional bias for high-caloric foods, but only in people with obesity. It is in particular the speedy detection of high-caloric foods in the environment that characterizes the impulsive person with obesity, which in turn may cause risky eating patterns in a society were high-caloric food is overly present. (c) 2015 APA, all rights reserved).

  4. Impulsivity and negative priming: evidence for diminished cognitive inhibition in impulsive children

    NARCIS (Netherlands)

    Visser, M. R. M.; Das-Smaal, E.; Kwakman, H.

    1996-01-01

    This study addresses the relationship between impulsivity and lack of inhibition. Inhibition was measured both by the interference score and by the negative priming effect in a Stroop colour-word paradigm. The negative priming effect in this paradigm is defined by slower naming of a target colour if

  5. Motor impulsivity differentiates between psychiatric inpatients with multiple versus single lifetime suicide attempts.

    Science.gov (United States)

    Colborn, Victoria A; LaCroix, Jessica M; Neely, Laura L; Tucker, Jennifer; Perera, Kanchana; Daruwala, Samantha E; Grammer, Geoffrey; Weaver, Jennifer; Ghahramanlou-Holloway, Marjan

    2017-07-01

    A history of multiple suicide attempts conveys greater risk for suicide than a single attempt. Impulsivity may partially explain the association between multiple attempts and increased risk. We examined trait impulsivity, ability to engage in goal-directed behaviors, and impulse control among psychiatrically hospitalized United States military personnel and their dependents. Individuals with a history of multiple versus single attempts had significantly higher motor impulsivity, indicating spur of the moment action. Providers are encouraged to directly assess and treat motor impulsivity among suicidal individuals. Further research should explore whether motor impulsivity is a mechanism of change in psychosocial suicide prevention interventions. Copyright © 2017. Published by Elsevier B.V.

  6. Lamotrigine use in patients with binge eating and purging, significant affect dysregulation, and poor impulse control.

    Science.gov (United States)

    Trunko, Mary Ellen; Schwartz, Terry A; Marzola, Enrica; Klein, Angela S; Kaye, Walter H

    2014-04-01

    Some patients with symptoms of binge eating and purging are successfully treated with specific serotonin reuptake inhibitors (SSRIs), but others experience only partial or no benefit. Significant affect dysregulation and poor impulse control may be characteristics that limit responsiveness. We report on the treatment of five patients with bulimia nervosa (BN), anorexia nervosa-binge/purge type (AN-B/P) or eating disorder not otherwise specified (EDNOS), using the anticonvulsant lamotrigine after inadequate response to SSRIs. Following addition of lamotrigine to an antidepressant in four cases, and switch from an antidepressant to lamotrigine in one case, patients experienced substantial improvement in mood reactivity and instability, impulsive drives and behaviors, and eating-disordered symptoms. These findings raise the possibility that lamotrigine, either as monotherapy or as an augmenting agent to antidepressants, may be useful in patients who binge eat and purge, and have significant affect dysregulation with poor impulse control. Copyright © 2013 Wiley Periodicals, Inc.

  7. Dopamine Receptor-Specific Contributions to the Computation of Value.

    Science.gov (United States)

    Burke, Christopher J; Soutschek, Alexander; Weber, Susanna; Raja Beharelle, Anjali; Fehr, Ernst; Haker, Helene; Tobler, Philippe N

    2018-05-01

    Dopamine is thought to play a crucial role in value-based decision making. However, the specific contributions of different dopamine receptor subtypes to the computation of subjective value remain unknown. Here we demonstrate how the balance between D1 and D2 dopamine receptor subtypes shapes subjective value computation during risky decision making. We administered the D2 receptor antagonist amisulpride or placebo before participants made choices between risky options. Compared with placebo, D2 receptor blockade resulted in more frequent choice of higher risk and higher expected value options. Using a novel model fitting procedure, we concurrently estimated the three parameters that define individual risk attitude according to an influential theoretical account of risky decision making (prospect theory). This analysis revealed that the observed reduction in risk aversion under amisulpride was driven by increased sensitivity to reward magnitude and decreased distortion of outcome probability, resulting in more linear value coding. Our data suggest that different components that govern individual risk attitude are under dopaminergic control, such that D2 receptor blockade facilitates risk taking and expected value processing.

  8. Intrinsic brain connectivity predicts impulse control disorders in patients with Parkinson's disease.

    Science.gov (United States)

    Tessitore, Alessandro; De Micco, Rosa; Giordano, Alfonso; di Nardo, Federica; Caiazzo, Giuseppina; Siciliano, Mattia; De Stefano, Manuela; Russo, Antonio; Esposito, Fabrizio; Tedeschi, Gioacchino

    2017-12-01

    Impulse control disorders can be triggered by dopamine replacement therapies in patients with PD. Using resting-state functional MRI, we investigated the intrinsic brain network connectivity at baseline in a cohort of drug-naive PD patients who successively developed impulse control disorders over a 36-month follow-up period compared with patients who did not. Baseline 3-Tesla MRI images of 30 drug-naive PD patients and 20 matched healthy controls were analyzed. The impulse control disorders' presence and severity at follow-up were assessed by the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease Rating Scale. Single-subject and group-level independent component analysis was used to investigate functional connectivity differences within the major resting-state networks. We also compared internetwork connectivity between patients. Finally, a multivariate Cox regression model was used to investigate baseline predictors of impulse control disorder development. At baseline, decreased connectivity in the default-mode and right central executive networks and increased connectivity in the salience network were detected in PD patients with impulse control disorders at follow-up compared with those without. Increased default-mode/central executive internetwork connectivity was significantly associated with impulse control disorders development (P impulse control disorders while on dopaminergic treatment. We hypothesize that these divergent cognitive and limbic network connectivity changes could represent a potential biomarker and an additional risk factor for the emergence of impulse control disorders. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and Movement Disorder Society.

  9. Impulsivity and hopelessness as predictors of suicide-related ideation among older adults.

    Science.gov (United States)

    Neufeld, Eva; O'Rourke, Norm

    2009-10-01

    Research has demonstrated that impulsivity is strongly associated with suicide-related ideation and behaviour among young adults. However, to date, the potential importance of impulsivity as a predictor of suicide-related ideation in later life has yet to be determined. Our study examined impulsivity, hopelessness, depressive symptomatology, and sociodemographic factors vis-à-vis suicide-related ideation among older adults at risk of self-harm. A sample (n = 117) of older adults was recruited from multiple sources for this study over a 1-year period. Suicide-related ideation was measured with the Geriatric Suicide Ideation Scale, a multidimensional measure of suicide-related ideation developed for use with older adults. Canonical correlation identified 2 pairings of linear composites in which impulsivity emerged along both as significantly associated with facets of suicide-related ideation. Of note, the greater proportion of variance in impulsivity was subsumed along the second set of vectors with somatic depressive symptoms. Our findings suggest that the impulse to self-harm may be even more pronounced among older adults less likely to present as typically depressed. It is further suggested that impulsivity is more broadly associated with suicide-related ideation than hopelessness, and that screening for impulsivity as well as hopelessness may increase clinicians' ability to identify older adults at greatest risk of self-harm.

  10. An Impulse Based Substructuring approach for impact analysis and load case simulations

    Science.gov (United States)

    Rixen, Daniel J.; van der Valk, Paul L. C.

    2013-12-01

    In the present paper we outline the basic theory of assembling substructures for which the dynamics are described as Impulse Response Functions. The assembly procedure computes the time response of a system by evaluating per substructure the convolution product between the Impulse Response Functions and the applied forces, including the interface forces that are computed to satisfy the interface compatibility. We call this approach the Impulse Based Substructuring method since it transposes to the time domain the Frequency Based Substructuring approach. In the Impulse Based Substructuring technique the Impulse Response Functions of the substructures can be gathered either from experimental tests using a hammer impact or from time-integration of numerical submodels. In this paper the implementation of the method is outlined for the case when the impulse responses of the substructures are computed numerically. A simple bar example is shown in order to illustrate the concept. The Impulse Based Substructuring allows fast evaluation of impact response of a structure when the impulse response of its components is known. It can thus be used to efficiently optimize designs of consumer products by including impact behavior at the early stage of the design, but also for performing substructured simulations of complex structures such as offshore wind turbines.

  11. The state of online impulse-buying research : a literature analysis.

    OpenAIRE

    Chan, T. K. H.; Cheung, C. M. K.; Lee, Z. W. Y.

    2017-01-01

    Online impulse buying has drawn increasing scholarly attention across disciplines. However, little effort has been made to evaluate the status of research and consolidate the findings in the literature. To address this research gap, we conducted a systematic review of studies of online impulse buying, and used the Stimulus–Organism–Response (SOR) framework to identify and classify the factors that affect online impulse buying. We then built a conceptual framework to explain the interrelations...

  12. Integral φ0-Stability in terms of Two Measures for Impulsive Differential Equations with “Supremum”

    Directory of Open Access Journals (Sweden)

    Peiguang Wang

    2014-01-01

    Full Text Available This paper establishes a criterion on integral φ0-stability in terms of two measures for impulsive differential equations with “supremum” by using the cone-valued piecewise continuous Lyapunov functions, Razumikhin method, and comparative method. Meantime, an example is given to illustrate our result.

  13. Early childhood parenting and child impulsivity as precursors to aggression, substance use, and risky sexual behavior in adolescence and early adulthood.

    Science.gov (United States)

    Hentges, Rochelle F; Shaw, Daniel S; Wang, Ming-Te

    2017-11-20

    The current study utilized a longitudinal design to explore the effect of early child impulsivity and rejecting parenting on the development of problematic behaviors in adolescence and early adulthood. Using a low-income sample of 310 mothers and their sons, we examined the direct and interactive effects of child impulsivity and rejecting parenting at age 2 on aggression and substance use at ages 12, 15, and 22, as well as risky sexual behavior at ages 15 and 22. Results revealed that rejecting parenting at age 2 predicted greater aggression at age 12 and risky sexual behavior at ages 15 and 22. Early impulsivity had few direct effects on later outcomes, with the exception of greater substance use at age 22. Instead, impulsivity emerged as a significant moderator in the link between rejecting parenting and aggression at all three ages and substance use at age 15. Specifically, early rejecting parenting predicted greater aggression and substance use only for children high in impulsivity. Findings highlight the potential for early child and parenting risk factors to have long-term implications for adjustment, with the combination of high impulsivity and rejecting parenting being particularly deleterious for problems of aggression throughout adolescence and into early adulthood.

  14. The influence of serotonin- and other genes on impulsive behavioral aggression and cognitive impulsivity in children with attention-deficit/hyperactivity disorder (ADHD: Findings from a family-based association test (FBAT analysis

    Directory of Open Access Journals (Sweden)

    Gill Michael

    2008-10-01

    Full Text Available Abstract Background Low serotonergic (5-HT activity correlates with increased impulsive-aggressive behavior, while the opposite association may apply to cognitive impulsiveness. Both types of impulsivity are associated with attention-deficit/hyperactivity disorder (ADHD, and genes of functional significance for the 5-HT system are implicated in this disorder. Here we demonstrate the separation of aggressive and cognitive components of impulsivity from symptom ratings and test their association with 5-HT and functionally related genes using a family-based association test (FBAT-PC. Methods Our sample consisted of 1180 offspring from 607 families from the International Multicenter ADHD Genetics (IMAGE study. Impulsive symptoms were assessed using the long forms of the Conners and the Strengths and Difficulties parent and teacher questionnaires. Factor analysis showed that the symptoms aggregated into parent- and teacher-rated behavioral and cognitive impulsivity. We then selected 582 single nucleotide polymorphisms (SNPs from 14 genes directly or indirectly related to 5-HT function. Associations between these SNPs and the behavioral/cognitive groupings of impulsive symptoms were evaluated using the FBAT-PC approach. Results In the FBAT-PC analysis for cognitive impulsivity 2 SNPs from the gene encoding phenylethanolamine N-methyltransferase (PNMT, the rate-limiting enzyme for adrenalin synthesis attained corrected gene-wide significance. Nominal significance was shown for 12 SNPs from BDNF, DRD1, HTR1E, HTR2A, HTR3B, DAT1/SLC6A3, and TPH2 genes replicating reported associations with ADHD. For overt aggressive impulsivity nominal significance was shown for 6 SNPs from BDNF, DRD4, HTR1E, PNMT, and TPH2 genes that have also been reported to be associated with ADHD. Associations for cognitive impulsivity with a SERT/SLC6A4 variant (STin2: 12 repeats and aggressive behavioral impulsivity with a DRD4 variant (exon 3: 3 repeats are also described

  15. Impulse holograms in amorphous semiconductor films

    International Nuclear Information System (INIS)

    Ozols, A.; Ivanovs, G.; Lazarevs, S.

    2002-01-01

    Impulse hologram recording in amorphous chalcogenide semiconductor films with pulse duration from minutes to picoseconds is considered. Nanosecond pulses are shown to be optimal due to the nonlinearity to films. Millisecond impulse hologram recording is experimentally studied. It is found that about 500 times lower exposure is needed to reach the same diffraction efficiency when compared to CW case. The millisecond recording is non-permanent. A nonlinear photoinduced recharging of localized states in the band gap is found to be responsible for the millisecond recording. It can be applied for non-permanent optical storage and optical information processing. (authors)

  16. Spray deposition using impulse atomization technique

    International Nuclear Information System (INIS)

    Ellendt, N.; Schmidt, R.; Knabe, J.; Henein, H.; Uhlenwinkel, V.

    2004-01-01

    A novel technique, impulse atomization, has been used for spray deposition. This single fluid atomization technique leads to different spray characteristics and impact conditions of the droplets compared to gas atomization technique which is the common technique used for spray deposition. Deposition experiments with a Cu-6Sn alloy were conducted to evaluate the appropriateness of impulse atomization to produce dense material. Based on these experiments, a model has been developed to simulate the thermal history and the local solidification rates of the deposited material. A numerical study shows how different cooling conditions affect the solidification rate of the material

  17. Solar flare impulsivity and its relationship with white-light flares and with CMEs

    Science.gov (United States)

    Watanabe, K.; Masuda, S.

    2017-12-01

    There are many types of classification in solar flares. One of them is a classification by flare duration in soft X-rays; so-called impulsive flare and long duration event (LDE). Typically, the duration of an impulsive flare is shorter than 1 hour, and that of an LDE is longer than 1 hour. These two types of flare show different characteristics. In soft X-rays, impulsive flares usually have a compact loop structure. On the other hand, LDEs show a large-scale loop, sometimes a large arcade structure. In hard X-rays (HXRs), the difference appears clear, too. The former shows a strong and short-time (10 minutes) emissions and show a large coronal source. These facts suggest that HXR observation becomes one of a good indicator to classify solar flares, especially for the study on the particle acceleration and the related phenomena. However, HXR data do not always exist due to the satellite orbit and the small sensitivity of HXR instruments. So, in this study, based on the concept of the Neupert effect (Neupert, 1968), we use soft X-ray derivative data as the proxy of HXR. From this data, we define impulsivity (IP) for each flare. Then we investigate solar flares using this new index. First we apply IP index to white-light flare (WLF) research. We investigate how WL enhancement depends on IP, then it is found that WLF tend to have large IP values. So the flare impulsivity (IP) is one of the important factors if WL enhancement appears or not in a solar flare. Next we investigate how CME itself and/or its physical parameters depend on IP index. It has been believed that most of CMEs are associated with LDEs, but we found that there is only a weak correlation between the existence of CME and IP index. Finally, we also search for the relationship between WLF and CME as a function of IP and discuss the physical condition of WLF.

  18. FORCED OSCILLATIONS OF SECOND ORDER SUPER-LINEAR DIFFERENTIAL EQUATION WITH IMPULSES

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    At first,by means of Kartsatos technique,we reduce the impulsive differential equation to a second order nonlinear impulsive homogeneous equation.We find some suitable impulse functions such that all the solutions to the equation are oscillatory.Several criteria on the oscillations of solutions are given.At last,we give an example to demonstrate our results.

  19. Impulsivity and suicidality: the mediating role of painful and provocative experiences.

    Science.gov (United States)

    Bender, Theodore W; Gordon, Kathryn H; Bresin, Konrad; Joiner, Thomas E

    2011-03-01

    Multiple studies have reported a link between high levels of impulsivity and suicidal behavior. Joiner's (2005) explanation for this link is that impulsive individuals have a greater tendency to experience painful and provocative events that habituate them to fear and pain, which leads to an acquired capability for engaging in suicidal behavior. Study 1 tested Joiner's (2005) hypothesis in a sample of 182 undergraduate students who completed self-report questionnaires on impulsivity, frequency of painful and provocative events, and acquired capability for suicide. In addition to self-report, pain tolerance (an aspect of acquired capability for suicide) was measured with a pressure algometer. Study 2 sought to replicate our findings from Study 1 in a sample of 516 clinical outpatients using a multi-faceted measure of impulsivity. Consistent with prediction, product of coefficients tests for mediation (MacKinnon et al., 2002) revealed that impulsivity has an indirect relationship with acquired capability for suicidal behavior, and that this relationship is mediated by painful and provocative events. Data from our studies are cross-sectional in nature, which does not allow for conclusions about the temporal ordering of our variables. In addition, self-report was used to measure most variables. Future research may benefit from a longitudinal design and the inclusion of other modes of assessment (e.g., behavioral measures of impulsivity). Our findings suggest that the link between impulsivity and suicidal behavior occurs because impulsive people tend to have a greater capability for suicidal behavior, which they have acquired through experiencing painful and provocative events. Copyright © 2010 Elsevier B.V. All rights reserved.

  20. Impulse control disorders in Parkinson's disease: decreased striatal dopamine transporter levels.

    Science.gov (United States)

    Voon, Valerie; Rizos, Alexandra; Chakravartty, Riddhika; Mulholland, Nicola; Robinson, Stephanie; Howell, Nicholas A; Harrison, Neil; Vivian, Gill; Ray Chaudhuri, K

    2014-02-01

    Impulse control disorders are commonly associated with dopaminergic therapy in Parkinson's disease (PD). PD patients with impulse control disorders demonstrate enhanced dopamine release to conditioned cues and a gambling task on [(11)C]raclopride positron emission tomography (PET) imaging and enhanced ventral striatal activity to reward on functional MRI. We compared PD patients with impulse control disorders and age-matched and gender-matched controls without impulse control disorders using [(123)I]FP-CIT (2β-carbomethoxy-3β-(4-iodophenyl)tropane) single photon emission computed tomography (SPECT), to assess striatal dopamine transporter (DAT) density. The [(123)I]FP-CIT binding data in the striatum were compared between 15 PD patients with and 15 without impulse control disorders using independent t tests. Those with impulse control disorders showed significantly lower DAT binding in the right striatum with a trend in the left (right: F(1,24)=5.93, p=0.02; left: F(1,24)=3.75, p=0.07) compared to controls. Our findings suggest that greater dopaminergic striatal activity in PD patients with impulse control disorders may be partly related to decreased uptake and clearance of dopamine from the synaptic cleft. Whether these findings are related to state or trait effects is not known. These findings dovetail with reports of lower DAT levels secondary to the effects of methamphetamine and alcohol. Although any regulation of DAT by antiparkinsonian medication appears to be modest, PD patients with impulse control disorders may be differentially sensitive to regulatory mechanisms of DAT expression by dopaminergic medications.

  1. Impulse control disorders and depression in Finnish patients with Parkinson's disease.

    Science.gov (United States)

    Joutsa, Juho; Martikainen, Kirsti; Vahlberg, Tero; Voon, Valerie; Kaasinen, Valtteri

    2012-02-01

    Impulse control disorders occur frequently in patients with Parkinson's disease. However, the frequencies have been investigated mainly in patients from secondary or tertiary care centers, and thus, the prevalence rates in general community are not known. Our objective was to study the prevalence rates of impulse control disorders and related factors in a large, non-selected sample of Parkinson's disease patients. We conducted a cross-sectional survey among Parkinson's disease patients from Finnish Parkinson Association [n = 575; 365 men, 240 women, median age 64 (range 43-90) years]. Problem and pathological gambling were estimated with the South Oaks Gambling Screen, risk for impulse control disorders with the validated Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease, and depression with the Beck Depression Inventory. The frequency of pathological gambling was 7.0%. The overall frequency of a positive screen for an impulse control disorder was 34.8%, and 12.5% of the patients screened positive for multiple disorders. Depressive symptoms were statistically the most important factor in explaining variance in impulse control disorder risk, even more than sex, age, age of disease onset, alcohol use, or medication. The high proportion of patients screened positive for impulse control disorders in a non-selected sample emphasize the importance of routine screening of these disorders in Parkinson's disease. Pathological gambling prevalence in Parkinson's disease is seven times higher than in the general population in Finland. The results underline the importance of depression in impulse control disorders associated with Parkinson's disease. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Microwave emission from lead zirconate titanate induced by impulsive mechanical load

    Energy Technology Data Exchange (ETDEWEB)

    Aman, A., E-mail: alexander.aman@ovgu.de [Department of Engineering, Brandenburg University of Applied Science, 14470 Brandenburg an derHavel (Germany); Packaging Group, Institute of Micro- and Sensorsytems, Otto-von-Guericke University, Universitätsplatz 2, 39106 Magdeburg (Germany); Majcherek, S. [Packaging Group, Institute of Micro- and Sensorsytems, Otto-von-Guericke University, Universitätsplatz 2, 39106 Magdeburg (Germany); Hirsch, S. [Department of Engineering, Brandenburg University of Applied Science, 14470 Brandenburg an derHavel (Germany); Schmidt, B. [Chair of Micorsystem Technology, Institute of Micro- and Sensorsytems, Otto-von-Guericke University, Universitätsplatz 2, 39106 Magdeburg (Germany)

    2015-10-28

    This paper focuses on microwave emission from Lead zirconate titanate Pb [Zr{sub x}Ti{sub 1−x}] O{sub 3} (PZT) induced by mechanical stressing. The mechanical stress was initiated by impact of a sharp tungsten indenter on the upper surface of PZT ceramic. The sequences of microwave and current impulses, which flew from indenter to electric ground, were detected simultaneously. The voltage between the upper and lower surface of ceramic was measured to obtain the behavior of mechanical force acting on ceramic during the impact. It was found that the amplitude, form, and frequency of measured microwave impulses were different by compression and restitution phase of impact. Two different mechanisms of electron emission, responsible for microwave impulse generation, were proposed based on the dissimilar impulse behavior. The field emission from tungsten indenter is dominant during compression, whereas ferroemission dominates during restitution phase. Indeed, it was observed that the direction of the current flow, i.e., sign of current impulses is changed by transitions from compression to restitution phase of impact. The observed dissimilar behavior of microwave impulses, caused by increasing and decreasing applied force, can be used to calculate the contact time and behavior of mechanical force during mechanical impact on ceramic surface. It is shown that the generation of microwave impulses exhibits high reproducibility, impulse intensity, a low damping factor, and high mechanical failure resistance. Based on these microwave emission properties of PZT, the development of new type of stress sensor with spatial resolution of few microns becomes possible.

  3. Forensic Psychiatric Aspects of Impulse Control Disorders

    Directory of Open Access Journals (Sweden)

    Huseyin Soysal

    2015-03-01

    Full Text Available Impulse control disorders is an important psychiatric disorder group which draws attention in recent years. Attention deficit hyperactivity disorder and other classical disorders like pyromania, kleptomania, intermittent explosive disorder and compulsive buying could be evasuated under this topic. The aim of this article is to review forensic psychiatric aspects of impulse control disorders and evaluate the disorders in terms of their legal status. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2015; 7(1: 16-29

  4. Impulsive relaxation process in MHD driven reconnection

    International Nuclear Information System (INIS)

    Kitabata, H.; Hayashi, T.; Sato, T.

    1997-01-01

    Compressible magnetohydrodynamic (MHD) simulation is carried out in order to investigate energy relaxation process of the driven magnetic reconnection in an open finite system through a long time calculation. It is found that a very impulsive energy release occurs in an intermittent fashion through magnetic reconnection for a continuous magnetic flux injection on the boundary. We focus our attention on the detailed process in the impulsive phase, which is the reconnection rate is remarkably enhanced up. (author)

  5. Lone-actor Terrorism and Impulsivity.

    Science.gov (United States)

    Meloy, J Reid; Pollard, Jeffrey W

    2017-11-01

    In some recent cases of lone-actor terrorism, there is evidence the subject acted impulsively, often in response to a triggering event which contained a loss and humiliation. Evidence suggests the subjects acted precipitously, despite planning and preparation carried out in the preceding weeks or months, and their attacks failed to include the often considerable preparation that had been done. The pathway became a runway. The authors recommend the traditional assessment of impulsivity in persons of concern for lone acts of terrorism, as well as other proximal warning behaviors for targeted violence. Both indirect and direct assessment guidelines are proposed, with an emphasis upon self-report, psychological testing, collateral data gathering, and historical records. © 2017 American Academy of Forensic Sciences.

  6. Aggression, impulsivity, and suicide behavior: a review of the literature.

    Science.gov (United States)

    Gvion, Yari; Apter, Alan

    2011-01-01

    This article reviews the literature on the association between impulsivity aggression and suicide. The key words impulsivity, aggression, and suicide were entered into the pubmed, psychlit, and proqest databases. Significant articles were scrutinized for relevant information. Impulsivity and aggression are highly correlated with suicidal behavior across psychiatric samples, nosological borders, and non-psychiatric populations. Impulsivity and aggression are related but the nature of this relationship remains unclear. The literature is confusing and contradictory. This is probably due to the difficulty in defining and separating out these concepts and the fact that there is much overlap between them. Future research should aim at clarifying and refining these concepts as well as their link to all the different forms of suicidal behavior.

  7. Impulsive synchronization and parameter mismatch of the three-variable autocatalator model

    International Nuclear Information System (INIS)

    Li, Yang; Liao, Xiaofeng; Li, Chuandong; Huang, Tingwen; Yang, Degang

    2007-01-01

    The synchronization problems of the three-variable autocatalator model via impulsive control approach are investigated; several theorems on the stability of impulsive control systems are also investigated. These theorems are then used to find the conditions under which the three-variable autocatalator model can be asymptotically controlled to the equilibrium point. This Letter derives some sufficient conditions for the stabilization and synchronization of a three-variable autocatalator model via impulsive control with varying impulsive intervals. Furthermore, we address the chaos quasi-synchronization in the presence of single-parameter mismatch. To illustrate the effectiveness of the new scheme, several numerical examples are given

  8. Impulsive Cluster Synchronization in Community Network with Nonidentical Nodes

    International Nuclear Information System (INIS)

    Deng Liping; Wu Zhaoyan

    2012-01-01

    In this paper, cluster synchronization in community network with nonidentical nodes and impulsive effects is investigated. Community networks with two kinds of topological structure are investigated. Positive weighted network is considered first and external pinning controllers are designed for achieving cluster synchronization. Cooperative and competitive network under some assumptions is investigated as well and can achieve cluster synchronization with only impulsive controllers. Based on the stability analysis of impulsive differential equation and the Lyapunov stability theory, several simple and useful synchronization criteria are derived. Finally, numerical simulations are provided to verify the effectiveness of the derived results.

  9. Clinical value of acoustic radiation force impulse in quantitative prediction of the degree of esophageal varices in patients with liver cirrhosis

    Directory of Open Access Journals (Sweden)

    CHEN Min

    2018-01-01

    Full Text Available Objective To investigate the clinical value of acoustic radiation force impulse (ARFI in quantitative prediction of the degree of esophageal varices in patients with cirrhotic portal hypertension. Methods A total of 116 patients with liver cirrhosis who were admitted to 302 Hospital of PLA from October 2014 to February 2016 were enrolled. ARFI was used to measure real-time liver and spleen stiffness for all patients. With the degree of esophageal varices determined by gastroscopy as the gold standard for diagnosis, these patients were divided into non-varices group (EV0, 16 patients, mild varices group (EV1, 39 patients, moderate varices group (EV2, 26 patients, and severe varices group (EV3, 35 patients. The receiver operating characteristic (ROC curve was used to analyze the clinical value of liver/spleen ARFI in predicting the degree of esophageal varices. An analysis of variance or the Kruskal-Wallis H test was used for comparison of continuous data between multiple groups, and the least significant difference Mann-Whitney U test was used for further comparison between any two groups; the chi-square test was used for comparison of categorical data between groups. The Spearman correlation analysis was used to investigate the correlation between the stiffness measured by ARFI and the degree of esophageal varices. Results The ARFI value of the spleen was 2.54±0.34 m/s for EV0 patients, 3.05±0.34 m/s for EV1 patients, 3.48±0.50 m/s for EV2 patients, and 3.69±0.33 m/s for EV3 patients (χ2=60.121,P<0.001. The ARFI value of the spleen was positively correlated with the grade of esophageal varices (r=0.713, P<0.001. The areas under the ROC curve for the ARFI value of the spleen in the diagnosis of ≥EV1, ≥EV2, or EV3 esophageal varices were 0.93, 0.88, and 0.83, respectively. There was no significant difference in the ARFI value of the liver between groups (P=0.085, and the ARFI value of the liver was not correlated with the degree of

  10. Impulsive buying tendency: Measuring important relationships with a new perspective and an indigenous scale

    Directory of Open Access Journals (Sweden)

    Anant Jyoti Badgaiyan

    2016-12-01

    Full Text Available With the opening up of the economy and the proliferation of mall culture, the economic relevance of impulsive buying behaviour has assumed significance. Impulsive buying behaviour is better understood by examining the impulsive buying tendency that shapes such behaviour, and since consumer behaviour differs across cultures, by incorporating an indigenous perspective in understanding and measuring the tendency. Studies were conducted to develop an Indian scale for measuring impulsive buying tendency and to validate it by examining its association with other relevant variables. A two factor, 8-item scale was developed; a significant positive relationship was seen between impulsive buying tendency and impulsive buying behaviour, and the relationship between impulsive buying tendency and self-control was found to be inversely significant. Results also showed significant relationship between impulsive buying tendency and the two personality constructs of Conscientiousness and Extraversion.

  11. Existence and stability of periodic solutions of an impulsive differential equation and application to CD8 T-cell differentiation.

    Science.gov (United States)

    Girel, Simon; Crauste, Fabien

    2018-06-01

    Unequal partitioning of the molecular content at cell division has been shown to be a source of heterogeneity in a cell population. We propose to model this phenomenon with the help of a scalar, nonlinear impulsive differential equation (IDE). To study the effect of molecular partitioning at cell division on the effector/memory cell-fate decision in a CD8 T-cell lineage, we study an IDE describing the concentration of the protein Tbet in a CD8 T-cell, where impulses are associated to cell division. We discuss how the degree of asymmetry of molecular partitioning can affect the process of cell differentiation and the phenotypical heterogeneity of a cell population. We show that a moderate degree of asymmetry is necessary and sufficient to observe irreversible differentiation. We consider, in a second part, a general autonomous IDE with fixed times of impulse and a specific form of impulse function. We establish properties of the solutions of that equation, most of them obtained under the hypothesis that impulses occur periodically. In particular, we show how to investigate the existence of periodic solutions and their stability by studying the flow of an autonomous differential equation. Then we apply those properties to prove the results presented in the first part.

  12. Impulse response identification with deterministic inputs using non-parametric methods

    International Nuclear Information System (INIS)

    Bhargava, U.K.; Kashyap, R.L.; Goodman, D.M.

    1985-01-01

    This paper addresses the problem of impulse response identification using non-parametric methods. Although the techniques developed herein apply to the truncated, untruncated, and the circulant models, we focus on the truncated model which is useful in certain applications. Two methods of impulse response identification will be presented. The first is based on the minimization of the C/sub L/ Statistic, which is an estimate of the mean-square prediction error; the second is a Bayesian approach. For both of these methods, we consider the effects of using both the identity matrix and the Laplacian matrix as weights on the energy in the impulse response. In addition, we present a method for estimating the effective length of the impulse response. Estimating the length is particularly important in the truncated case. Finally, we develop a method for estimating the noise variance at the output. Often, prior information on the noise variance is not available, and a good estimate is crucial to the success of estimating the impulse response with a nonparametric technique

  13. Efficiency of the generation of impulsion by cyclotron waves currents of the electrons in an Axisymmetric Tokamak

    International Nuclear Information System (INIS)

    Gutierrez T, C.; Beltran P, M.

    2004-01-01

    The neoclassical theory of transport is used to calculate the current efficiency of electronic cyclotron impulsion (ECCD) in an axisymmetric tokamak in the few collisions regime. The standard parameter of the tokamak is used to obtain a system of equations that describe the hydrodynamic of the plasma, where the ponderomotive force (PM) due to high power radio frequency waves is taken in account. The PM force is produced in the proximity of electron cyclotron resonance surface in a specific poloidal localization. The efficiency ECCD is analyzed in the cases of first and second harmonic (for different angles of injection of radio frequency waves) and it is validated using the experimental values of the TCV and T-10 tokamaks. The results are according to those obtained by means of the techniques of the Green functions. (Author)

  14. Impulsive-compulsive behaviors in parkin-associated Parkinson disease.

    Science.gov (United States)

    Morgante, Francesca; Fasano, Alfonso; Ginevrino, Monia; Petrucci, Simona; Ricciardi, Lucia; Bove, Francesco; Criscuolo, Chiara; Moccia, Marcello; De Rosa, Anna; Sorbera, Chiara; Bentivoglio, Anna Rita; Barone, Paolo; De Michele, Giuseppe; Pellecchia, Maria Teresa; Valente, Enza Maria

    2016-10-04

    The aim of this multicenter, case-control study was to investigate the prevalence and severity of impulsive-compulsive behaviors (ICBs) in a cohort of patients with parkin-associated Parkinson disease (PD) compared to a group of patients without the mutation. We compared 22 patients with biallelic parkin mutations (parkin-PD) and 26 patients negative for parkin, PINK1, DJ-1, and GBA mutations (PD-NM), matched for age at onset, disease duration, levodopa, and dopamine agonist equivalent daily dose. A semistructured interview was used to diagnose each of the following ICBs: compulsive sexual behavior, compulsive buying, binge eating, punding, hobbyism, and compulsive medication use. The Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS) was adopted to rate ICB severity. Frequency of patients with at least one ICB was comparable between parkin-PD and PD-NM. Nevertheless, when analyzing the distribution of specific ICBs, a higher frequency of compulsive shopping, binge eating, and punding/hobbyism was found in the parkin-PD group. Compared to PD-NM, parkin-PD patients with ICB had younger onset age and higher frequency of smokers; in 5 patients, ICB had predated PD onset. Total and partial (compulsive buying, compulsive sexual behavior, binge eating, hobbyism/punding) QUIP-RS scores were higher in patients with parkin-PD compared to patients with PD-NM. Logistic regression analysis showed that the presence of parkin mutations was associated with smoking status and higher QUIP-RS total score. Our data expand the parkin-associated phenotypic spectrum demonstrating higher frequency and severity of specific ICBs, and suggesting an association between the parkin genotype, smoking status, and ICB severity. © 2016 American Academy of Neurology.

  15. Passivity analysis of memristor-based impulsive inertial neural networks with time-varying delays.

    Science.gov (United States)

    Wan, Peng; Jian, Jigui

    2018-03-01

    This paper focuses on delay-dependent passivity analysis for a class of memristive impulsive inertial neural networks with time-varying delays. By choosing proper variable transformation, the memristive inertial neural networks can be rewritten as first-order differential equations. The memristive model presented here is regarded as a switching system rather than employing the theory of differential inclusion and set-value map. Based on matrix inequality and Lyapunov-Krasovskii functional method, several delay-dependent passivity conditions are obtained to ascertain the passivity of the addressed networks. In addition, the results obtained here contain those on the passivity for the addressed networks without impulse effects as special cases and can also be generalized to other neural networks with more complex pulse interference. Finally, one numerical example is presented to show the validity of the obtained results. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  16. Cryogenic liquid resettlement activated by impulsive thrust in space-based propulsion system

    Science.gov (United States)

    Hung, R. J.; Shyu, K. L.

    1991-01-01

    The purpose of present study is to investigate the most efficient technique for propellant resettling through the minimization of propellant usage and weight penalties. Comparison between the constant reverse gravity acceleration and impulsive reverse gravity acceleration to be used for the activation of propellant resettlement shows that impulsive reverse gravity thrust is superior to constant reverse gravity thrust for liquid reorientation in a reduced gravity environment. Comparison among impulsive reverse gravity thrust with 0.1, 1.0, and 10 Hz frequencies for liquid-filled level in the range between 30 to 80 percent shows that the selection of a medium frequency of 1.0 Hz impulsive thrust over the other frequency ranges of impulsive thrust is the most proper.

  17. A New Comparison Principle for Impulsive Functional Differential Equations

    Directory of Open Access Journals (Sweden)

    Gang Li

    2015-01-01

    Full Text Available We establish a new comparison principle for impulsive differential systems with time delay. Then, using this comparison principle, we obtain some sufficient conditions for several stabilities of impulsive delay differential equations. Finally, we present an example to show the effectiveness of our results.

  18. Periodic components of hand acceleration/deceleration impulses during telemanipulation

    Energy Technology Data Exchange (ETDEWEB)

    Draper, J.V. [Oak Ridge National Lab., TN (United States); Handel, S. [Tennessee Univ., Knoxville, TN (United States). Dept. of Psychology

    1994-01-01

    Responsiveness is the ability of a telemanipulator to recreate user trajectories and impedance in time and space. For trajectory production, a key determinant of responsiveness is the ability of the system to accept user inputs, which are forces on the master handle generated by user hand acceleration/deceleration (a/d) impulses, and translate them into slave arm acceleration/deceleration. This paper presents observations of master controller a/d impulses during completion of a simple target acquisition task. Power spectral density functions (PSDF`s) calculated from hand controller a/d impulses were used to assess impulse waveform. The relative contributions of frequency intervals ranging up to 25 Hz for three spatially different versions of the task were used to determine which frequencies were most important. The highest relative power was observed in frequencies between 1 Hz and 6 Hz. The key frequencies related to task difficulty were in the range from 2 Hz to 8 Hz. the results provide clues to the source of the performance inhibition.

  19. Impulse response measurements with an off-line cross correlator

    International Nuclear Information System (INIS)

    Corran, E.R.; Cummins, J.D.

    1963-11-01

    The impulse responses of simulated systems have been computed by off-line cross-correlation of the system input and output signals. The input test signal consisted of a discrete interval binary code whose autocorrelation was a triangular pulse at zero lag. The main object of the experiments was to study the inaccuracies introduced in ideal, noise free systems by determining the impulse response digitally from sampled versions of the system input and output signals. A second object was to determine the error introduced by adding controlled amounts of uncorrelated noise at the system outputs. The experimental results showed that for signal to noise ratios greater than 10:1 in the mean square sense, the impulse responses may be determined with reasonable accuracy using only one cycle of the binary code. The method lends itself to on-line computation of system impulse responses. The latter could be used to monitor the stability of the system or to determine control parameters in an adaptive control system. (author)

  20. Impulse response measurements with an off-line cross correlator

    Energy Technology Data Exchange (ETDEWEB)

    Corran, E R; Cummins, J D [Dynamics Group, Control and Instrumentation Division, Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

    1963-11-15

    The impulse responses of simulated systems have been computed by off-line cross-correlation of the system input and output signals. The input test signal consisted of a discrete interval binary code whose autocorrelation was a triangular pulse at zero lag. The main object of the experiments was to study the inaccuracies introduced in ideal, noise free systems by determining the impulse response digitally from sampled versions of the system input and output signals. A second object was to determine the error introduced by adding controlled amounts of uncorrelated noise at the system outputs. The experimental results showed that for signal to noise ratios greater than 10:1 in the mean square sense, the impulse responses may be determined with reasonable accuracy using only one cycle of the binary code. The method lends itself to on-line computation of system impulse responses. The latter could be used to monitor the stability of the system or to determine control parameters in an adaptive control system. (author)