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.

Exponential stability for stochastic delayed recurrent neural networks with mixed time-varying delays and impulses: the continuous-time case

International Nuclear Information System (INIS)

Karthik Raja, U; Leelamani, A; Raja, R; Samidurai, R

2013-01-01

In this paper, the exponential stability for a class of stochastic neural networks with time-varying delays and impulsive effects is considered. By constructing suitable Lyapunov functionals and by using the linear matrix inequality optimization approach, we obtain sufficient delay-dependent criteria to ensure the exponential stability of stochastic neural networks with time-varying delays and impulses. Two numerical examples with simulation results are provided to illustrate the effectiveness of the obtained results over those already existing in the literature. (paper)

Impulsive Control for Continuous-Time Markov Decision Processes: A Linear Programming Approach

Energy Technology Data Exchange (ETDEWEB)

Dufour, F., E-mail: dufour@math.u-bordeaux1.fr [Bordeaux INP, IMB, UMR CNRS 5251 (France); Piunovskiy, A. B., E-mail: piunov@liv.ac.uk [University of Liverpool, Department of Mathematical Sciences (United Kingdom)

2016-08-15

In this paper, we investigate an optimization problem for continuous-time Markov decision processes with both impulsive and continuous controls. We consider the so-called constrained problem where the objective of the controller is to minimize a total expected discounted optimality criterion associated with a cost rate function while keeping other performance criteria of the same form, but associated with different cost rate functions, below some given bounds. Our model allows multiple impulses at the same time moment. The main objective of this work is to study the associated linear program defined on a space of measures including the occupation measures of the controlled process and to provide sufficient conditions to ensure the existence of an optimal control.

Effects of Strategies Marketing of Collective Buying about Impulsive Behavior

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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.

Impulsive effect on global exponential stability of BAM fuzzy cellular neural networks with time-varying delays

Science.gov (United States)

Li, Kelin

2010-02-01

In this article, a class of impulsive bidirectional associative memory (BAM) fuzzy cellular neural networks (FCNNs) with time-varying delays is formulated and investigated. By employing delay differential inequality and M-matrix theory, some sufficient conditions ensuring the existence, uniqueness and global exponential stability of equilibrium point for impulsive BAM FCNNs with time-varying delays are obtained. In particular, a precise estimate of the exponential convergence rate is also provided, which depends on system parameters and impulsive perturbation intention. It is believed that these results are significant and useful for the design and applications of BAM FCNNs. An example is given to show the effectiveness of the results obtained here.

Individual Differences in Impulsive Choice and Timing in Rats

Science.gov (United States)

Galtress, Tiffany; Garcia, Ana; Kirkpatrick, Kimberly

2012-01-01

Individual differences in impulsive choice behavior have been linked to a variety of behavioral problems including substance abuse, smoking, gambling, and poor financial decision-making. Given the potential importance of individual differences in impulsive choice as a predictor of behavioral problems, the present study sought to measure the extent…

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

Time isolation high-voltage impulse generator

International Nuclear Information System (INIS)

Chodorow, A.M.

1975-01-01

Lewis' high-voltage impulse generator is analyzed in greater detail, demonstrating that voltage between adjacent nodes can be equalized by proper selection of parasitic impedances. This permits improved TEM mode propagation to a matched load, with more faithful source waveform preservation

Global Stability of Polytopic Linear Time-Varying Dynamic Systems under Time-Varying Point Delays and Impulsive Controls

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M. de la Sen

2010-01-01

Full Text Available This paper investigates the stability properties of a class of dynamic linear systems possessing several linear time-invariant parameterizations (or configurations which conform a linear time-varying polytopic dynamic system with a finite number of time-varying time-differentiable point delays. The parameterizations may be timevarying and with bounded discontinuities and they can be subject to mixed regular plus impulsive controls within a sequence of time instants of zero measure. The polytopic parameterization for the dynamics associated with each delay is specific, so that (q+1 polytopic parameterizations are considered for a system with q delays being also subject to delay-free dynamics. The considered general dynamic system includes, as particular cases, a wide class of switched linear systems whose individual parameterizations are timeinvariant which are governed by a switching rule. However, the dynamic system under consideration is viewed as much more general since it is time-varying with timevarying delays and the bounded discontinuous changes of active parameterizations are generated by impulsive controls in the dynamics and, at the same time, there is not a prescribed set of candidate potential parameterizations.

Optimal Two-Impulse Trajectories with Moderate Flight Time for Earth-Moon Missions

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Sandro da Silva Fernandes

2012-01-01

describe the motion of the space vehicle: the well-known patched-conic approximation and two versions of the planar circular restricted three-body problem (PCR3BP. In the patched-conic approximation model, the parameters to be optimized are two: initial phase angle of space vehicle and the first velocity impulse. In the PCR3BP models, the parameters to be optimized are four: initial phase angle of space vehicle, flight time, and the first and the second velocity impulses. In all cases, the optimization problem has one degree of freedom and can be solved by means of an algorithm based on gradient method in conjunction with Newton-Raphson method.

Global exponential stability of inertial memristor-based neural networks with time-varying delays and impulses.

Science.gov (United States)

Zhang, Wei; Huang, Tingwen; He, Xing; Li, Chuandong

2017-11-01

In this study, we investigate the global exponential stability of inertial memristor-based neural networks with impulses and time-varying delays. We construct inertial memristor-based neural networks based on the characteristics of the inertial neural networks and memristor. Impulses with and without delays are considered when modeling the inertial neural networks simultaneously, which are of great practical significance in the current study. Some sufficient conditions are derived under the framework of the Lyapunov stability method, as well as an extended Halanay differential inequality and a new delay impulsive differential inequality, which depend on impulses with and without delays, in order to guarantee the global exponential stability of the inertial memristor-based neural networks. Finally, two numerical examples are provided to illustrate the efficiency of the proposed methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

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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.

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.

Event-Based Impulsive Control of Continuous-Time Dynamic Systems and Its Application to Synchronization of Memristive Neural Networks.

Science.gov (United States)

Zhu, Wei; Wang, Dandan; Liu, Lu; Feng, Gang

2017-08-18

This paper investigates exponential stabilization of continuous-time dynamic systems (CDSs) via event-based impulsive control (EIC) approaches, where the impulsive instants are determined by certain state-dependent triggering condition. The global exponential stability criteria via EIC are derived for nonlinear and linear CDSs, respectively. It is also shown that there is no Zeno-behavior for the concerned closed loop control system. In addition, the developed event-based impulsive scheme is applied to the synchronization problem of master and slave memristive neural networks. Furthermore, a self-triggered impulsive control scheme is developed to avoid continuous communication between the master system and slave system. Finally, two numerical simulation examples are presented to illustrate the effectiveness of the proposed event-based impulsive controllers.

A Low-Cost Time-Hopping Impulse Radio System for High Data Rate Transmission

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Jinyun Zhang

2005-03-01

Full Text Available We present an efficient, low-cost implementation of time-hopping impulse radio that fulfills the spectral mask mandated by the FCC and is suitable for high-data-rate, short-range communications. Key features are (i all-baseband implementation that obviates the need for passband components, (ii symbol-rate (not chip rate sampling, A/D conversion, and digital signal processing, (iii fast acquisition due to novel search algorithms, and (iv spectral shaping that can be adapted to accommodate different spectrum regulations and interference environments. Computer simulations show that this system can provide 110 Mbps at 7–10 m distance, as well as higher data rates at shorter distances under FCC emissions limits. Due to the spreading concept of time-hopping impulse radio, the system can sustain multiple simultaneous users, and can suppress narrowband interference effectively.

Time delay estimation in a reverberant environment by low rate sampling of impulsive acoustic sources

KAUST Repository

Omer, Muhammad

2012-07-01

This paper presents a new method of time delay estimation (TDE) using low sample rates of an impulsive acoustic source in a room environment. The proposed method finds the time delay from the room impulse response (RIR) which makes it robust against room reverberations. The RIR is considered a sparse phenomenon and a recently proposed sparse signal reconstruction technique called orthogonal clustering (OC) is utilized for its estimation from the low rate sampled received signal. The arrival time of the direct path signal at a pair of microphones is identified from the estimated RIR and their difference yields the desired time delay. Low sampling rates reduce the hardware and computational complexity and decrease the communication between the microphones and the centralized location. The performance of the proposed technique is demonstrated by numerical simulations and experimental results. © 2012 IEEE.

The clinical assessment of impulsivity

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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.

Femtosecond time-resolved impulsive stimulated Raman spectroscopy using sub-7-fs pulses: Apparatus and applications

Energy Technology Data Exchange (ETDEWEB)

Kuramochi, Hikaru [Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako 351-0198 (Japan); Takeuchi, Satoshi; Tahara, Tahei, E-mail: tahei@riken.jp [Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako 351-0198 (Japan); Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), 2-1 Hirosawa, Wako 351-0198 (Japan)

2016-04-15

We describe details of the setup for time-resolved impulsive stimulated Raman spectroscopy (TR-ISRS). In this method, snapshot molecular vibrational spectra of the photoreaction transients are captured via time-domain Raman probing using ultrashort pulses. Our instrument features transform-limited sub-7-fs pulses to impulsively excite and probe coherent nuclear wavepacket motions, allowing us to observe vibrational fingerprints of transient species from the terahertz to 3000-cm{sup −1} region with high sensitivity. Key optical components for the best spectroscopic performance are discussed. The TR-ISRS measurements for the excited states of diphenylacetylene in cyclohexane are demonstrated, highlighting the capability of our setup to track femtosecond dynamics of all the Raman-active fundamental molecular vibrations.

Impulsive control for a Takagi–Sugeno fuzzy model with time-delay and its application to chaotic systems

International Nuclear Information System (INIS)

Shi-Guo, Peng; Si-Min, Yu

2009-01-01

A control approach where the fuzzy logic methodology is combined with impulsive control is developed for controlling some time-delay chaotic systems in this paper. We first introduce impulses into each subsystem with delay of the Takagi–Sugeno (TS) fuzzy IF–THEN rules and then present a unified TS impulsive fuzzy model with delay for chaos control. Based on the new model, a simple and unified set of conditions for controlling chaotic systems is derived by the Lyapunov–Razumikhin method, and a design procedure for estimating bounds on control matrices is also given. Several numerical examples are presented to illustrate the effectiveness of this method

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...

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.

Nonlinear Variation of Parameters Formula for Impulsive Differential Equations with Initial Time Difference and Application

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Peiguang Wang

2014-01-01

Full Text Available This paper establishes variation of parameters formula for impulsive differential equations with initial time difference. As an application, one of the results is used to investigate stability properties of solutions.

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.

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

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).

Optimal One Bit Time Reversal For UWB Impulse Radio In Multi-User Wireless Communications

DEFF Research Database (Denmark)

Nguyen, Hung Tuan

2008-01-01

In this paper, with the purpose of further reducing the complexity of the system, while keeping its temporal and spatial focusing performance, we investigate the possibility of using optimal one bit time reversal (TR) system for impulse radio ultra wideband multi-user wireless communications...

How passion and impulsivity influence a player's choice of videogame, intensity of playing and time spent playing

OpenAIRE

Puerta-Cortés, Diana Ximena; Panova, Tayana; Carbonell, Xavier; Chamarro, Andrés

2016-01-01

Videogames have received much attention in addiction research due to their popularity and frequent use. However, few studies have addressed the effect of passion and impulsivity in gamers. Therefore, the aim of the current study was to examine the influence of passion and impulsivity on the intensity of play, playing time, and choice of Massive Multiplayer Online Role Play Game (MMORPG) vs. non-MMORPG. A sample of 630 university students (40.7% Colombian, 59.3% Spanish) responded ...

Impulse: Memory System Support for Scientific Applications

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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.

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.

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.

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.

Impaired decisional impulsivity in pathological videogamers.

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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.

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

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

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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

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.

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

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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.

Neuroanatomical and Neurochemical Basis of Impulsivity

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Kemal Yazici

2010-08-01

Full Text Available The term ‘impulsivity’ encompasses a multitude of behaviours that are poorly conceived, premature, inappropriate, and that frequently result in unwanted or deleterious outcomes. Impulsivity manifests as impatience carelessness, risk-taking, sensation-seeking and pleasure-seeking, an underestimated sense of harm, and extroversion. Impulsivity is a core symptom of a broad spectrum of psychiatric disorders. Through focusing on different aspects of impulsive behavior, it has proved possible to devise a variety of behavioral paradigms to measure impulsivity in both human and non-human subjects. These can be broadly divided into two categories: those measuring impulsive action or motoric impulsivity, and those measuring impulsive choice or impulsive decision-making. Impulsive action can be broadly defined as the inability to withhold from making a response. Within the framework of behavioral neuroscience and cognitive psychology, impulse control has been described as an active inhibitory mechanism which modulates the internally or externally driven pre-potent desire for primary reinforcers such as food, sex or other highly desirable rewards. This inhibitory control mechanism may provide the substrate by which rapid conditioned responses and reflexes are transiently suppressed, so that slower cognitive mechanisms can guide behavior. This process is referred to as response inhibition. Two of the most common tests used to study inhibitory processes are the go/no-go and stop-signal reaction time tasks. Impulsivity is also evident in the making of impulsive decisions or choices as well as in impulsive actions. Here, there is no “pre-potent” response that is primed and then forcibly inhibited, but a decision-making processes. Impulsive decision making or impulsive choice is defined as initiating actions without adequately considering other possible choices or consequences. Impulsive choice is typically measured in the delay discounting paradigm. In

State-Dependent Impulsive Control Strategies for a Tumor-Immune Model

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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.

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

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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.

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)

"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).

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

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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.

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)

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.

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

Prediction of BMI by impulsivity, eating behavior and activity level

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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.

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

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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.

Mittag-Leffler synchronization of fractional neural networks with time-varying delays and reaction-diffusion terms using impulsive and linear controllers.

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Stamova, Ivanka; Stamov, Gani

2017-12-01

In this paper, we propose a fractional-order neural network system with time-varying delays and reaction-diffusion terms. We first develop a new Mittag-Leffler synchronization strategy for the controlled nodes via impulsive controllers. Using the fractional Lyapunov method sufficient conditions are given. We also study the global Mittag-Leffler synchronization of two identical fractional impulsive reaction-diffusion neural networks using linear controllers, which was an open problem even for integer-order models. Since the Mittag-Leffler stability notion is a generalization of the exponential stability concept for fractional-order systems, our results extend and improve the exponential impulsive control theory of neural network system with time-varying delays and reaction-diffusion terms to the fractional-order case. The fractional-order derivatives allow us to model the long-term memory in the neural networks, and thus the present research provides with a conceptually straightforward mathematical representation of rather complex processes. Illustrative examples are presented to show the validity of the obtained results. We show that by means of appropriate impulsive controllers we can realize the stability goal and to control the qualitative behavior of the states. An image encryption scheme is extended using fractional derivatives. Copyright © 2017 Elsevier Ltd. All rights reserved.

Multiple modes of impulsivity in Parkinson's disease.

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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

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

Barratt Impulsivity and Neural Regulation of Physiological Arousal.

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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.

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.

Effect on Perceived Stimulation dan Perceived Crowding on the Decision of the Unplanned Purchase (Impulse Buying

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Enggal Sriwardiningsih

2011-11-01

Full Text Available Purchase decisions aren’t made necessarily planned, because impulsive buying is such a result of environmental stimuli shopping. Things affecting unplanned purchasing decisions are perceived by stimulation and crowding. The purpose of this study is to determine whether there are influences between perceived crowding and stimulation of impulse buying simultaneously or partial. The object used is one of the largest retailers in Cilegon. This research design is quantitative analysis of the consumer unit. The collecting data technique includes using questionnaires, interviews, and literature from previous research. Data processed using the SPSS 16.0 program through the validity and reliability, normality test, and regression analysis. The study states that there is significant influence between perceived crowding and perceived stimulation both simultaneous and partial response to impulse buying. 

A theoretical study of thermospheric composition perturbations during an impulsive geomagnetic storm

International Nuclear Information System (INIS)

Burns, A.G.; Killeen, T.L.; Roble, R.G.

1991-01-01

The compositional response of the neutral thermosphere to an impulsive geomagnetic storm has been investigated using a numerical simulation made with the National Center for Atmospheric Research thermospheric general circulation model (NCAR-TGCM). Calculated time-dependent changes in neutral thermospheric composition have been studied, together with detailed neutral parcel trajectories and other diagnostic information from the model, to gain a greater understanding of the physical mechanisms responsible for composition variability during geomagnetic storms and, in particular, to investigate the causes of the positive and negative ionospheric storm effects. The following principal results were obtained from this study. (1) Calculated perturbations in thermospheric composition following the onset of an impulsive geomagnetic storm were found to be in good qualitative agreement with the previous experimental statistical study of storm time thermospheric morphology by Proelss. (2) During the initial (onset) phase of the simulated storm, upward vertical winds occurred in the auroral zone and downward winds occurred in the central magnetic polar cap. (3) The largest perturbations in mass mixing ratio of nitrogen at F region altitudes were found to be associated with parcels of neutral gas that travelled through the cusp region and with parcels that were trapped within the auroral zone for a long time. (4) Storm time enhancements in Ψ N 2 were found to occur in the midnight and early morning sectors both within and equatorward of the auroral zone, and these were determined to be associated with the advective effects of the large antisunward polar cap neutral winds

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...

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.

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.

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.

Razumikhin-type stability criteria for differential equations with delayed impulses

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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.

Tangent-Impulse Interception for a Hyperbolic Target

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Dongzhe Wang

2014-01-01

Full Text Available The two-body interception problem with an upper-bounded tangent impulse for the interceptor on an elliptic parking orbit to collide with a nonmaneuvering target on a hyperbolic orbit is studied. Firstly, four special initial true anomalies whose velocity vectors are parallel to either of the lines of asymptotes for the target hyperbolic orbit are obtained by using Newton-Raphson method. For different impulse points, the solution-existence ranges of the target true anomaly for any conic transfer are discussed in detail. Then, the time-of-flight equation is solved by the secant method for a single-variable piecewise function about the target true anomaly. Considering the sphere of influence of the Earth and the upper bound on the fuel, all feasible solutions are obtained for different impulse points. Finally, a numerical example is provided to apply the proposed technique for all feasible solutions and the global minimum-time solution with initial coasting time.

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.

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.

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.

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...

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.

Relationships between ground reaction impulse and sprint acceleration performance in team sport athletes.

Science.gov (United States)

Kawamori, Naoki; Nosaka, Kazunori; Newton, Robert U

2013-03-01

Large horizontal acceleration in short sprints is a critical performance parameter for many team sport athletes. It is often stated that producing large horizontal impulse at each ground contact is essential for high short sprint performance, but the optimal pattern of horizontal and vertical impulses is not well understood, especially when the sprints are initiated from a standing start. This study was an investigation of the relationships between ground reaction impulses and sprint acceleration performance from a standing start in team sport athletes. Thirty physically active young men with team sport background performed 10-m sprint from a standing start, whereas sprint time and ground reaction forces were recorded during the first ground contact and at 8 m from the start. Associations between sprint time and ground reaction impulses (normalized to body mass) were determined by a Pearson's correlation coefficient (r) analysis. The 10-m sprint time was significantly (p < 0.01) correlated with net horizontal impulse (r = -0.52) and propulsive impulse (r = -0.66) measured at 8 m from the start. No significant correlations were found between sprint time and impulses recorded during the first ground contact after the start. These results suggest that applying ground reaction impulse in a more horizontal direction is important for sprint acceleration from a standing start. This is consistent with the hypothesis of training to increase net horizontal impulse production using sled towing or using elastic resistance devices, which needs to be validated by future longitudinal training studies.

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

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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.

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.

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

A New Comparison Principle for Impulsive Functional Differential Equations

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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.

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.

Optimization of valve opening process for the suppression of impulse exhaust noise

Science.gov (United States)

Li, Jingxiang; Zhao, Shengdun

2017-02-01

Impulse exhaust noise generated by the sudden impact of discharging flow of pneumatic systems has significant temporal characteristics including high sound pressure and rapid sound transient. The impulse noise exposures are more hazardous to hearing than the energy equivalent uniform noise exposures. This paper presents a novel approach to suppress the peak sound pressure as a major indicator of impulsiveness of the impulse exhaust noise by an optimization of the opening process of valve. Relationships between exhaust flow and impulse noise are described by thermodynamics and noise generating mechanism. Then an optimized approach by controlling the valve opening process is derived under a constraint of pre-setting exhaust time. A modified servo-direct-driven valve was designed and assembled in a typical pneumatic system for the verification experiments comparing with an original solenoid valve. Experimental results with groups of initial cylinder pressures and pre-setting exhaust times are shown to verify the effects of the proposed optimization. Some indicators of energy-equivalent and impulsiveness are introduced to discuss the effects of the noise suppressions. Relationship between noise reduction and exhaust time delay is also discussed.

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

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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.

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

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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.

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

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.

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)

A functional NPSR1 gene variant and environment shape personality and impulsive action: a longitudinal study.

Science.gov (United States)

Laas, Kariina; Reif, Andreas; Kiive, Evelyn; Domschke, Katharina; Lesch, Klaus-Peter; Veidebaum, Toomas; Harro, Jaanus

2014-03-01

Neuropeptide S and its receptor NPSR1 are involved in the regulation of arousal, attention and anxiety. We examined whether the NPSR1 gene functional polymorphism Asn¹⁰⁷Ile (rs324981, A>T) influences personality, impulsivity, and attention-deficit/hyperactivity disorder (ADHD)-related symptoms in a population-representative sample, and whether any eventual associations depend on age, sex, family relations and stressful life events (SLE). We used self-reports or teachers' ratings for both the younger (n=593) and older (n=583) cohort of the longitudinal Estonian Children Personality, Behaviour and Health Study. Males with the TT genotype displayed more ADHD-related symptoms. Adaptive impulsivity and Extraversion increased the most from age 18 to 25. While highest increases were observed in AA men, TT women exhibited the largest decreases. For participants with the AA genotype, Warmth in family was inversely associated with Neuroticism, and positively associated with Extraversion and Adaptive impulsivity. High exposure to SLE increased impulsivity and ADHD scores in TT genotype subjects. We conclude that the NPSR1 A/T polymorphism is associated with impulsivity, ADHD symptoms and personality, mirroring the activity- and anxiety-mediating role of NPSR1. Heterozygous individuals were the least sensitive to environmental factors, whereas subjects with the AA genotype and TT genotype reacted to different types of environmental adversities.

Radio and X-ray observations of a multiple impulsive solar burst with high time resolution

International Nuclear Information System (INIS)

Kosugi, T.

1981-01-01

A well-developed multiple impulsive microwave burst occurred on February 17, 1979 simultaneously with a hard X-ray burst and a large group of type III bursts at metric wavelengths. The whole event is composed of serveral subgroups of elementary spike bursts. Detailed comparisons between these three classes of emissions with high time resolution of approx. equal to0.5 s reveal that individual type III bursts coincide in time with corresponding elementary X-ray and microwave spike bursts. It suggests that a non-thermal electron pulse generating a type III spike burst is produced simultaneously with those responsible for the corresponding hard X-ray and microwave spike bursts. The rise and decay characteristic time scales of the elementary spike burst are << 1 s, and approx. equal to1 s and approx. equal to3 s for type III, hard X-ray and microwave emissions respectively. Radio interferometric observations made at 17 GHz reveal that the spatial structure varies from one subgroup to others while it remains unchanged in a subgroup. Spectral evolution of the microwave burst seems to be closely related to the spatial evolution. The spatial evolution together with the spectral evolution suggests that the electron-accelerating region shifts to a different location after it stays at one location for several tens of seconds, duration of a subgroup of elementary spike bursts. We discuss several requirements for a model of the impulsive burst which come out from these observational results, and propose a migrating double-source model. (orig.)

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.

Impulsive moving mirror model and the stability of Schroedinger equation with impulse effect in a Banach space

International Nuclear Information System (INIS)

Kostadinov, S.I.; Petrov, G.

1992-01-01

From a special class of systems has been used a Schroedinger equation with impulse effect in Minkowski space field theory with time dependent boundary conditions, i.e. those of moving mirrors. The field theoretical approach for studying the properties of the vacuum starts from an analysis of the behaviour of local field quantities in Minkowski space with uniformly moving mirrors. For the impulsive moving mirror model is the real process of interaction between the quantum field and the external mirror a subject to disturbances in its evolution acting in time very short compared with the entire duration of the process. So the stability of the solution of the Schroedinger evolution equation for the process in the stability of the vacuum of Casimir. 8 refs

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

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)

The Long Time Behavior of a Stochastic Logistic Model with Infinite Delay and Impulsive Perturbation

OpenAIRE

Lu, Chun; Wu, Kaining

2016-01-01

This paper considers a stochastic logistic model with infinite delay and impulsive perturbation. Firstly, with the space $C_{g}$ as phase space, the definition of solution to a stochastic functional differential equation with infinite delay and impulsive perturbation is established. According to this definition, we show that our model has an unique global positive solution. Then we establish the sufficient and necessary conditions for extinction and stochastic permanence of the...

Impulsive Noise Characterization in Narrowband Power Line Communication

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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.

Dark personality traits and impulsivity among adolescents: Differential links to problem behaviors and family relations.

Science.gov (United States)

Dubas, Judith Semon; Baams, Laura; Doornwaard, Suzan M; van Aken, Marcel A G

2017-10-01

Research on how dark personality traits develop and relate to risky behaviors and family relations during adolescence is scarce. This study used a person-oriented approach to examine (a) whether distinct groups of adolescents could be identified based on their developmental profiles of callous-unemotional (CU), grandiose manipulative (GM), and dysfunctional impulsivity (DI) traits and (b) whether these groups differ in their problem behaviors and parent-adolescent relationship quality. Latent class growth analyses on 4-wave data of 1,131 Dutch adolescents revealed 3 personality profiles: (1) a dark impulsive group (13.9%), with high scores on all 3 traits (CU, GM, and DI) that were stable over time; (2) an impulsive group (26.1%), with high and increasing levels of impulsivity and relatively low scores on CU and GM; and (3) and a low risk group (60.0%), with relatively low levels on all 3 personality characteristics, with impulsivity decreasing over time. Compared with adolescents in the low risk group, adolescents in the dark impulsive and impulsive groups reported higher initial levels of substance use, sexual risk behaviors, permissive sexual attitudes, parent-adolescent conflict, and lower parent-adolescent satisfaction, as well as greater increases in sexual risk behavior over time. Compared with adolescents in the impulsive group, those in the dark impulsive group showed the highest levels of risk behaviors. Hence, dark personality traits coupled with impulsivity may be indicative of an earlier and more severe trajectory of problem behaviors that may differ from the trajectory of youth who are only impulsive. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

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.

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.

Adaptive-impulsive synchronization in drive-response networks of continuous systems and its application

International Nuclear Information System (INIS)

Sun Mei; Zeng Changyan; Tao Yangwei; Tian Lixin

2009-01-01

Based on the comparison theorem for the stability of impulsive control system, adaptive-impulsive synchronization in drive-response networks of continuous systems with time-delay and non-time-delay is investigated. And the continuous control input, the simple updated laws and a linear impulsive controller are proposed. Moreover, two numerical examples are presented to verify the effectiveness and correctness of the theorem, using the energy resource system and Lue's system as the nodes of the networks.

Impulse measurement using an Arduíno

Science.gov (United States)

Espindola, P. R.; Cena, C. R.; Alves, D. C. B.; Bozano, D. F.; Goncalves, A. M. B.

2018-05-01

In this paper, we propose a simple experimental apparatus that can measure the force variation over time to study the impulse-momentum theorem. In this proposal, a body attached to a rubber string falls freely from rest until it stretches and changes the linear momentum. During that process the force due to the tension on the rubber string is measured with a load cell by using an Arduíno board. We check the instrumental results with the basic concept of impulse, finding the area under the force versus time curve and comparing this with the linear momentum variation estimated from software analysis. The apparatus is presented as a simple and low cost alternative to mechanical physics laboratories.

Exponential Stability for Impulsive BAM Neural Networks with Time-Varying Delays and Reaction-Diffusion Terms

Directory of Open Access Journals (Sweden)

Qiankun Song

2007-06-01

Full Text Available Impulsive bidirectional associative memory neural network model with time-varying delays and reaction-diffusion terms is considered. Several sufficient conditions ensuring the existence, uniqueness, and global exponential stability of equilibrium point for the addressed neural network are derived by M-matrix theory, analytic methods, and inequality techniques. Moreover, the exponential convergence rate index is estimated, which depends on the system parameters. The obtained results in this paper are less restrictive than previously known criteria. Two examples are given to show the effectiveness of the obtained results.

Exponential Stability for Impulsive BAM Neural Networks with Time-Varying Delays and Reaction-Diffusion Terms

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Cao Jinde

2007-01-01

Full Text Available Impulsive bidirectional associative memory neural network model with time-varying delays and reaction-diffusion terms is considered. Several sufficient conditions ensuring the existence, uniqueness, and global exponential stability of equilibrium point for the addressed neural network are derived by M-matrix theory, analytic methods, and inequality techniques. Moreover, the exponential convergence rate index is estimated, which depends on the system parameters. The obtained results in this paper are less restrictive than previously known criteria. Two examples are given to show the effectiveness of the obtained results.

Concurrent Validity of a Portable Force Plate Using Vertical Jump Force-Time Characteristics.

Science.gov (United States)

Lake, Jason; Mundy, Peter; Comfort, Paul; McMahon, John J; Suchomel, Timothy J; Carden, Patrick

2018-05-29

This study examined concurrent validity of countermovement vertical jump (CMJ) reactive strength index modified and force-time characteristics recorded using a one dimensional portable and laboratory force plate system. Twenty-eight men performed bilateral CMJs on two portable force plates placed on top of two in-ground force plates, both recording vertical ground reaction force at 1000 Hz. Time to take-off, jump height, reactive strength index modified, braking and propulsion impulse, mean net force, and duration were calculated from the vertical force from both force plate systems. Results from both systems were highly correlated (r≥.99). There were small (dbraking impulse, braking mean net force, propulsion impulse, and propulsion mean net force (psystem (95% CL: .9% to 2.5%), indicating very good agreement across all of the dependent variables. The largest limits of agreement belonged to jump height (2.1%), time to take-off (3.4%), and reactive strength index modified (3.8%). The portable force plate system provides a valid method of obtaining reactive strength measures, and several underpinning force-time variables, from unloaded CMJ and practitioners can use both force plates interchangeably.

Time Domain Characterization of 1-2 GHz Circular-ended Bowtie Antenna Using Normalizad Impulse Response

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Joko Suryana

2010-10-01

Full Text Available Frequency domain analysis is a powerful and compact tool for characterizing the antenna parameters such as gain, radiation pattern and the impedance as a function of frequency. However, if time or space is a major concern, such as in the GPR appication, the time domain analysis would be a very important tool due to their unique capability for determining the echo delay and range profile of target image. In this paper, we will describe the classical theory of system characterization in time domain, and then also propose the mathematical model for characterizing the 1 - 2 GHz circular-ended Bowtie antenna. From the measurement results, we concluded that the implemented Bowtie antenna has good normalized impulse response with very small ringing, so it is suitable for GPR applications.

Firing Control Optimization of Impulse Thrusters for Trajectory Correction Projectiles

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Min Gao

2015-01-01

Full Text Available This paper presents an optimum control scheme of firing time and firing phase angle by taking impact point deviation as optimum objective function which takes account of the difference of longitudinal and horizontal correction efficiency, firing delay, roll rate, flight stability, and so forth. Simulations indicate that this control scheme can assure lateral impulse thrusters are activated at time and phase angle when the correction efficiency is higher. Further simulations show that the impact point dispersion is mainly influenced by the total impulse deployed, and the impulse, number, and firing interval need to be optimized to reduce the impact point dispersion of rockets. Live firing experiments with two trajectory correction rockets indicate that the firing control scheme works effectively.

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...

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.

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.

Assessing personal financial management in patients with bipolar disorder and its relation to impulsivity and response inhibition.

Science.gov (United States)

Cheema, Marvi K; MacQueen, Glenda M; Hassel, Stefanie

2015-01-01

Impulsivity and risk-taking behaviours are reported in bipolar disorder (BD). We examined whether financial management skills are related to impulsivity in patients with BD. We assessed financial management skills using the Executive Personal Finance Scale (EPFS), impulsivity using the Barratt Impulsiveness Scale (BIS) and response inhibition using an emotional go/no-go task in bipolar individuals (N = 21) and healthy controls (HC; N = 23). Patients had fewer financial management skills and higher levels of impulsivity than HC. In patients and controls, increased impulsivity was associated with poorer personal financial management. Patients and HC performed equally on the emotional go/no-go task. Higher BIS scores were associated with faster reaction times in HC. In patients, however, higher BIS scores were associated with slower reaction times, possibly indicating compensatory cognitive strategies to counter increased impulsivity. Patients with BD may have reduced abilities to manage personal finances, when compared against healthy participants. Difficulty with personal finance management may arise in part as a result of increased levels of impulsivity. Patients may learn to compensate for increased impulsivity by modulating response times in our experimental situations although whether such compensatory strategies generalize to real-world situations is unknown.

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.

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.

Increased multiaxial lumbar motion responses during multiple-impulse mechanical force manually assisted spinal manipulation

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Gunzburg Robert

2006-04-01

Full Text Available Abstract Background Spinal manipulation has been found to create demonstrable segmental and intersegmental spinal motions thought to be biomechanically related to its mechanisms. In the case of impulsive-type instrument device comparisons, significant differences in the force-time characteristics and concomitant motion responses of spinal manipulative instruments have been reported, but studies investigating the response to multiple thrusts (multiple impulse trains have not been conducted. The purpose of this study was to determine multi-axial segmental and intersegmental motion responses of ovine lumbar vertebrae to single impulse and multiple impulse spinal manipulative thrusts (SMTs. Methods Fifteen adolescent Merino sheep were examined. Tri-axial accelerometers were attached to intraosseous pins rigidly fixed to the L1 and L2 lumbar spinous processes under fluoroscopic guidance while the animals were anesthetized. A hand-held electromechanical chiropractic adjusting instrument (Impulse was used to apply single and repeated force impulses (13 total over a 2.5 second time interval at three different force settings (low, medium, and high along the posteroanterior axis of the T12 spinous process. Axial (AX, posteroanterior (PA, and medial-lateral (ML acceleration responses in adjacent segments (L1, L2 were recorded at a rate of 5000 samples per second. Peak-peak segmental accelerations (L1, L2 and intersegmental acceleration transfer (L1–L2 for each axis and each force setting were computed from the acceleration-time recordings. The initial acceleration response for a single thrust and the maximum acceleration response observed during the 12 multiple impulse trains were compared using a paired observations t-test (POTT, alpha = .05. Results Segmental and intersegmental acceleration responses mirrored the peak force magnitude produced by the Impulse Adjusting Instrument. Accelerations were greatest for AX and PA measurement axes. Compared to

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.

Time compression of soil erosion by the effect of largest daily event. A regional analysis of USLE database.

Science.gov (United States)

Gonzalez-Hidalgo, J. C.; Batalla, R.; Cerda, A.; de Luis, M.

2009-04-01

When Thornes and Brunsden wrote in 1977 "How often one hears the researcher (and no less the undergraduate) complain that after weeks of observation "nothing happened" only to learn that, the day after his departure, a flood caused unprecedent erosion and channel changes!" (Thornes and Brunsden, 1977, p. 57), they focussed on two different problems in geomorphological research: the effects of extreme events and the temporal compression of geomorphological processes. The time compression is one of the main characteristic of erosion processes. It means that an important amount of the total soil eroded is produced in very short temporal intervals, i.e. few events mostly related to extreme events. From magnitude-frequency analysis we know that few events, not necessarily extreme by magnitude, produce high amount of geomorphological work. Last but not least, extreme isolated events are a classical issue in geomorphology by their specific effects, and they are receiving permanent attention, increased at present because of scenarios of global change. Notwithstanding, the time compression of geomorphological processes could be focused not only on the analysis of extreme events and the traditional magnitude-frequency approach, but on new complementary approach based on the effects of largest events. The classical approach define extreme event as a rare event (identified by its magnitude and quantified by some deviation from central value), while we define largest events by the rank, whatever their magnitude. In a previous research on time compression of soil erosion, using USLE soil erosion database (Gonzalez-Hidalgo et al., EGU 2007), we described a relationship between the total amount of daily erosive events recorded by plot and the percentage contribution to total soil erosion of n-largest aggregated daily events. Now we offer a further refined analysis comparing different agricultural regions in USA. To do that we have analyzed data from 594 erosion plots from USLE

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

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.

Time series analysis of wind speed using VAR and the generalized impulse response technique

Energy Technology Data Exchange (ETDEWEB)

Ewing, Bradley T. [Area of Information Systems and Quantitative Sciences, Rawls College of Business and Wind Science and Engineering Research Center, Texas Tech University, Lubbock, TX 79409-2101 (United States); Kruse, Jamie Brown [Center for Natural Hazard Research, East Carolina University, Greenville, NC (United States); Schroeder, John L. [Department of Geosciences and Wind Science and Engineering Research Center, Texas Tech University, Lubbock, TX (United States); Smith, Douglas A. [Department of Civil Engineering and Wind Science and Engineering Research Center, Texas Tech University, Lubbock, TX (United States)

2007-03-15

This research examines the interdependence in time series wind speed data measured in the same location at four different heights. A multiple-equation system known as a vector autoregression is proposed for characterizing the time series dynamics of wind. Additionally, the recently developed method of generalized impulse response analysis provides insight into the cross-effects of the wind series and their responses to shocks. Findings are based on analysis of contemporaneous wind speed time histories taken at 13, 33, 70 and 160 ft above ground level with a sampling rate of 10 Hz. The results indicate that wind speeds measured at 70 ft was the most variable. Further, the turbulence persisted longer at the 70-ft measurement than at the other heights. The greatest interdependence is observed at 13 ft. Gusts at 160 ft led to the greatest persistence to an 'own' shock and led to greatest persistence in the responses of the other wind series. (author)

Impulsive Synchronization of Reaction-Diffusion Neural Networks With Mixed Delays and Its Application to Image Encryption.

Science.gov (United States)

Chen, Wu-Hua; Luo, Shixian; Zheng, Wei Xing

2016-12-01

This paper presents a new impulsive synchronization criterion of two identical reaction-diffusion neural networks with discrete and unbounded distributed delays. The new criterion is established by applying an impulse-time-dependent Lyapunov functional combined with the use of a new type of integral inequality for treating the reaction-diffusion terms. The impulse-time-dependent feature of the proposed Lyapunov functional can capture more hybrid dynamical behaviors of the impulsive reaction-diffusion neural networks than the conventional impulse-time-independent Lyapunov functions/functionals, while the new integral inequality, which is derived from Wirtinger's inequality, overcomes the conservatism introduced by the integral inequality used in the previous results. Numerical examples demonstrate the effectiveness of the proposed method. Later, the developed impulsive synchronization method is applied to build a spatiotemporal chaotic cryptosystem that can transmit an encrypted image. The experimental results verify that the proposed image-encrypting cryptosystem has the advantages of large key space and high security against some traditional attacks.

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.

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…

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.

Evaluation of the autonomic neuropathy function immediately after a change to upright posture using the impulse response function; Impulse oto kansu wo mochiita shisei henkan katoki ni okeru jiritsu shinkei kino hyoka

Energy Technology Data Exchange (ETDEWEB)

Yokoyama, K. [Nagoya City University, Nagoya (Japan); Moyoshi, M.; Takata, K. [Daido Institute of Technology, Nagoya (Japan); Watanabe, Y. [Toyota College of Technology, Aichi (Japan)

1997-05-20

Autonomic neuropathy function immediately after a change to upright posture has been evaluated by applying transient response function of the system to the blood regulation system. The impulse response function was determined from the change in heart rate before postural change to the upright posture, and was compared with the transient change immediately after a change to the upright posture. The time series of R-R interval of electrocardiogram was used as the time series of the change in heart rate. To determine the impulse response function, an autoregressive model was applied to the R-R interval time series. The impulse response function at the steady state is a transient reaction at the impulse stimulation added to the blood regulation system. The R-R interval decreases rapidly by the autonomic neuropathy reaction in which the blood is rapidly transferred into the legs immediately after a change to upright posture. There is a close correlation between the initial temporary decrease in R-R interval and the impulse response function derived from the change in heart rate immediately after a change to the upright posture. Accordingly, the blood regulation and autonomic neuropathy functions can be evaluated by the impulse response function without actual standing test and load of tested persons. 9 refs., 3 figs., 1 tab.

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.

Narcissism predicts impulsive buying: phenotypic and genetic evidence

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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.

Increased impulsivity associated with severity of suicide attempt history in patients with bipolar disorder.

Science.gov (United States)

Swann, Alan C; Dougherty, Donald M; Pazzaglia, Peggy J; Pham, Mary; Steinberg, Joel L; Moeller, F Gerard

2005-09-01

Impulsivity is a prominent and measurable characteristic of bipolar disorder that can contribute to risk for suicidal behavior. The purpose of this study was to investigate the relationship between impulsivity and severity of past suicidal behavior, a potential predictor of eventual suicide, in patients with bipolar disorder. In bipolar disorder subjects with either a definite history of attempted suicide or no such history, impulsivity was assessed with both a questionnaire (Barratt Impulsiveness Scale) and behavioral laboratory performance measures (immediate memory/delayed memory tasks). Diagnosis was determined with the Structured Clinical Interview for DSM-IV. Interviews of patients and review of records were used to determine the number of past suicide attempts and the medical severity of the most severe attempt. Subjects with a history of suicide attempts had more impulsive errors on the immediate memory task and had shorter response latencies, especially for impulsive responses. Impulsivity was highest in subjects with the most medically severe suicide attempts. Effects were not accounted for by presence of depression or mania at the time of testing. Barratt Impulsiveness Scale scores were numerically, but not significantly, higher in subjects with suicide attempts. A history of alcohol abuse was associated with greater probability of a suicide attempt. Multivariate analysis showed that ethanol abuse history and clinical state at the time of testing did not have a significant effect after impulsivity was taken into account. These results suggest that a history of severe suicidal behavior in patients with bipolar disorder is associated with impulsivity, manifested as a tendency toward rapid, unplanned responses.

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

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.

Periodic components of hand acceleration/deceleration impulses during telemanipulation

International Nuclear Information System (INIS)

Draper, J.V.; Handel, S.

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

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

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.

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.

Parental monitoring may protect impulsive children from overeating.

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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.

Impulsivity and Cluster B Personality Disorders.

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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.

Impulsive behavior and nicotinic acetylcholine receptors.

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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.

Narcissism predicts impulsive buying: phenotypic and genetic evidence

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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

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.

Trait impulsivity in suicide attempters: preliminary study.

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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.

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

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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.

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...

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...

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

Tumour chemotherapy strategy based on impulse control theory.

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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).

Triple positive  solutions of nth order impulsive integro-differential equations

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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.

Impulsivity, self-control, and hypnotic suggestibility.

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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.

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

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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.

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,…

Droplet squeezing through a narrow constriction: Minimum impulse and critical velocity

Science.gov (United States)

Zhang, Zhifeng; Drapaca, Corina; Chen, Xiaolin; Xu, Jie

2017-07-01

Models of a droplet passing through narrow constrictions have wide applications in science and engineering. In this paper, we report our findings on the minimum impulse (momentum change) of pushing a droplet through a narrow circular constriction. The existence of this minimum impulse is mathematically derived and numerically verified. The minimum impulse happens at a critical velocity when the time-averaged Young-Laplace pressure balances the total minor pressure loss in the constriction. Finally, numerical simulations are conducted to verify these concepts. These results could be relevant to problems of energy optimization and studies of chemical and biomedical systems.

Poincare' maps of impulsed oscillators and two-dimensional dynamics

International Nuclear Information System (INIS)

Lupini, R.; Lenci, S.; Gardini, L.; Urbino Univ.

1996-01-01

The Poincare' map of one-dimensional linear oscillators subject to periodic, non-linear and time-delayed impulses is shown to reduce to a family of plane maps with possible non-uniqueness of the inverse. By restricting the analysis to a convenient form of the impulse function, a variety of interesting dynamical behaviours in this family are pointed out, including multistability and homoclinic bifurcations. Critical curves of two-dimensional endomorphisms are used to identify the structure of absorbing areas and their bifurcations

Spectrogram Image Analysis of Error Signals for Minimizing Impulse Noise

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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.

Isolating the delay component of impulsive choice in adolescent rats

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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.

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

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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.

Research of Two Different Impulsive Faults of Rolling Element Bearing

International Nuclear Information System (INIS)

Jiang Zhinong; Xing Chenghong; Feng Kun; Gao Jinji

2012-01-01

Fans and pumps are key machines in process industries such as petrochemical and petroleum industries. Their faults can be catastrophic and result in costly downtime. Bearing fault is almost the most common fault of fans and pumps as rolling element bearings are widely used in these machines. Hence, condition monitoring and diagnosis of bearings are important. Two different impulsive faults of bearings have been observed and studied in previous research. The first fault presents very clear impulsive symptom in envelope spectrum, but the bearing can work for a long time. The other fault shows relatively indistinct symptom, but the bearing will break down in a short time. To overcome the problems of inaccurate diagnosis, a combinational approach based on an impulsive energy indicator and traditional enveloping analysis is proposed in this paper. This approach discriminate these two faults well and can support the maintenance decision for the machines with rolling element bearings.

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.

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.

Random Fuzzy Differential Equations with Impulses

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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.

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...

Extinction and permanence in delayed stage-structure predator-prey system with impulsive effects

International Nuclear Information System (INIS)

Pang Guoping; Wang Fengyan; Chen Lansun

2009-01-01

Based on the classical stage-structured model and Lotka-Volterra predator-prey model, an impulsive delayed differential equation to model the process of periodically releasing natural enemies at fixed times for pest control is proposed and investigated. We show that the conditions for global attractivity of the 'pest-extinction' ('prey-eradication') periodic solution and permanence of the population of the model depend on time delay. We also show that constant maturation time delay and impulsive releasing for the predator can bring great effects on the dynamics of system by numerical analysis. As a result, the pest maturation time delay is considered to establish a procedure to maintain the pests at an acceptably low level in the long term. In this paper, the main feature is that we introduce time delay and pulse into the predator-prey (natural enemy-pest) model with age structure, exhibit a new modelling method which is applied to investigate impulsive delay differential equations, and give some reasonable suggestions for pest management.

Estimation of channel impulse response and FPGA simulation

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YU Longjie

2015-02-01

Full Text Available Wideband code division multiple access (WCDMA is a 3G wireless communication network.The common pilot channel in downlink of WCDMA provides an effective method to estimate the channel impulse response.In this paper,universal software radio peripheral (USRP is utilized to sample and process WCDMA signal which is emitted by China Unicom base station.Firstly,the received signal is pre-processed with filtering and down-sampling.Secondly,fast algorithm of WCDMA cell search is fulfilled.Thirdly,frequency shift caused by USRP′s crystal oscillator is checked and compensated.Eventually,channel impulse response is estimated.In this paper,MATLAB is used to describe the above algorithm and field programmable gate array (FPGA is used to simulate algorithm.In the process of simulation,pipeline and IP core multiplexing are introduced.In the case of 32 MHz clock frequency,FPGA simulation time is 80.861 ms.Simulation results show that FPGA is able to estimate the channel impulse response quickly and accurately with less hardware resources.

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.

Metacognitive ability of male students: difference impulsive-reflective cognitive style

Science.gov (United States)

Muhtarom; Sugiyanti; Utami, R. E.; Indriana, K.

2018-03-01

This study revealed the metacognitive activity of male students in impulsive cognitive and reflective cognitive style in solving mathematical problems, especially in the material of plane. One student of impulsive cognitive style and one student of reflective cognitive-style were selected to be the subjects of the study. Data were collected by giving written test of problem solving and interview. Data analysis was done through data reduction, data presentation, data interpretation and conclusion. The results showed that male student of reflective cognitive style was meticulous and careful in solving the problem so as to obtain correct answers, while the impulsive cognitive style student had the characteristics of using a short time in solving the problem, but less careful so that the answers tended to be wrong

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...

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.

Global attractivity and permanence of a stage-structured pest management SI model with time delay and diseased pest impulsive transmission

International Nuclear Information System (INIS)

Jiao Jianjun; Meng Xinzhu; Chen Lansun

2008-01-01

In this paper, we consider a stage-structured pest management SI model with time delay and diseased pests impulsive transmission. We obtain the sufficient conditions of the global attractivity of pest-extinction boundary periodic solution and the permanence of the system. We also prove that all solutions of the system are uniformly ultimately bounded. Our results provide a reliable tactic basis for the practice of pest management

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 ...

Pinning impulsive control algorithms for complex network

Energy Technology Data Exchange (ETDEWEB)

Sun, Wen [School of Information and Mathematics, Yangtze University, Jingzhou 434023 (China); Lü, Jinhu [Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100190 (China); Chen, Shihua [College of Mathematics and Statistics, Wuhan University, Wuhan 430072 (China); Yu, Xinghuo [School of Electrical and Computer Engineering, RMIT University, Melbourne VIC 3001 (Australia)

2014-03-15

In this paper, we further investigate the synchronization of complex dynamical network via pinning control in which a selection of nodes are controlled at discrete times. Different from most existing work, the pinning control algorithms utilize only the impulsive signals at discrete time instants, which may greatly improve the communication channel efficiency and reduce control cost. Two classes of algorithms are designed, one for strongly connected complex network and another for non-strongly connected complex network. It is suggested that in the strongly connected network with suitable coupling strength, a single controller at any one of the network's nodes can always pin the network to its homogeneous solution. In the non-strongly connected case, the location and minimum number of nodes needed to pin the network are determined by the Frobenius normal form of the coupling matrix. In addition, the coupling matrix is not necessarily symmetric or irreducible. Illustrative examples are then given to validate the proposed pinning impulsive control algorithms.

Pinning impulsive control algorithms for complex network

International Nuclear Information System (INIS)

Sun, Wen; Lü, Jinhu; Chen, Shihua; Yu, Xinghuo

2014-01-01

In this paper, we further investigate the synchronization of complex dynamical network via pinning control in which a selection of nodes are controlled at discrete times. Different from most existing work, the pinning control algorithms utilize only the impulsive signals at discrete time instants, which may greatly improve the communication channel efficiency and reduce control cost. Two classes of algorithms are designed, one for strongly connected complex network and another for non-strongly connected complex network. It is suggested that in the strongly connected network with suitable coupling strength, a single controller at any one of the network's nodes can always pin the network to its homogeneous solution. In the non-strongly connected case, the location and minimum number of nodes needed to pin the network are determined by the Frobenius normal form of the coupling matrix. In addition, the coupling matrix is not necessarily symmetric or irreducible. Illustrative examples are then given to validate the proposed pinning impulsive control algorithms

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

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.

Impulsivity interacts with momentary PTSD symptom worsening to predict alcohol use in male veterans.

Science.gov (United States)

Black, Anne C; Cooney, Ned L; Sartor, Carolyn E; Arias, Albert J; Rosen, Marc I

2018-04-11

Posttraumatic stress disorder (PTSD) is prevalent among veterans who served post-9/11, and co-occurs with problem alcohol and substance use. Studies using ecological momentary assessment have examined the temporal association between time-varying PTSD symptoms and alcohol use. Results suggest individual differences in these associations. We tested hypotheses that alcohol use measured by momentary assessment would be explained by acute increases in PTSD symptoms, and the PTSD-alcohol association would be moderated by trait impulsivity. A sample of 28 male post-9/11-era veterans who reported past-month PTSD symptoms and risky alcohol use were enrolled. On a quasi-random schedule, participants completed three electronic assessments daily for 28 days measuring past 2-h PTSD symptoms, alcohol, and substance use. At baseline, trait impulsivity was measured by the Barratt Impulsiveness Scale. Past-month PTSD symptoms and alcohol use were measured. Using three-level hierarchical models, number of drinks recorded by momentary assessment was modeled as a function of change in PTSD symptoms since last assessment, controlling for lag-1 alcohol and substance use and other covariates. A cross-level interaction tested moderation of the within-time PTSD-alcohol association by impulsivity. A total of 1,522 assessments were completed. A positive within-time association between PTSD symptom change and number of drinks was demonstrated. The association was significantly moderated by impulsivity. Results provide preliminary support for a unique temporal relationship between acute PTSD symptom change and alcohol use among veterans with trait impulsiveness. If replicated in a clinical sample, results may have implications for a targeted momentary intervention.

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.

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.

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.

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.

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.

A Novel Optimal Control Method for Impulsive-Correction Projectile Based on Particle Swarm Optimization

Directory of Open Access Journals (Sweden)

Ruisheng Sun

2016-01-01

Full Text Available This paper presents a new parametric optimization approach based on a modified particle swarm optimization (PSO to design a class of impulsive-correction projectiles with discrete, flexible-time interval, and finite-energy control. In terms of optimal control theory, the task is described as the formulation of minimum working number of impulses and minimum control error, which involves reference model linearization, boundary conditions, and discontinuous objective function. These result in difficulties in finding the global optimum solution by directly utilizing any other optimization approaches, for example, Hp-adaptive pseudospectral method. Consequently, PSO mechanism is employed for optimal setting of impulsive control by considering the time intervals between two neighboring lateral impulses as design variables, which makes the briefness of the optimization process. A modification on basic PSO algorithm is developed to improve the convergence speed of this optimization through linearly decreasing the inertial weight. In addition, a suboptimal control and guidance law based on PSO technique are put forward for the real-time consideration of the online design in practice. Finally, a simulation case coupled with a nonlinear flight dynamic model is applied to validate the modified PSO control algorithm. The results of comparative study illustrate that the proposed optimal control algorithm has a good performance in obtaining the optimal control efficiently and accurately and provides a reference approach to handling such impulsive-correction problem.

Design of shielded voltage divider for impulse voltage measurement

International Nuclear Information System (INIS)

Kato, Shohei; Kouno, Teruya; Maruyama, Yoshio; Kikuchi, Koji.

1976-01-01

The dividers used for the study of the insulation and electric discharge phenomena in high voltage equipments have the problems of the change of response characteristics owing to adjacent bodies and of induced noise. To improve the characteristics, the enclosed type divider shielded with metal has been investigated, and the divider of excellent response has been obtained by adopting the frequency-separating divider system, which is divided into two parts, resistance divider (lower frequency region) and capacitance divider (higher frequency region), for avoiding to degrade the response. Theoretical analysis was carried out in the cases that residual inductance can be neglected or can not be neglected in the small capacitance divider, and that the connecting wires are added. Next, the structure of the divider and the design of the electric field for the divider manufactured on the basis of the theory are described. The response characteristics were measured. The results show that 1 MV impulse voltage can be measured within the response time of 10 ns. Though this divider aims at the impulse voltage, the duration time of which is about that of standard lightning impulse, in view of the heat capacity because of the input resistance of 10.5 kΩ, it is expected that the divider can be applied to the voltage of longer duration time by increasing the input resistance in future. (Wakatsuki, Y.)

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

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.

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.

Impulse Noise Cancellation of Medical Images Using Wavelet Networks and Median Filters

Science.gov (United States)

Sadri, Amir Reza; Zekri, Maryam; Sadri, Saeid; Gheissari, Niloofar

2012-01-01

This paper presents a new two-stage approach to impulse noise removal for medical images based on wavelet network (WN). The first step is noise detection, in which the so-called gray-level difference and average background difference are considered as the inputs of a WN. Wavelet Network is used as a preprocessing for the second stage. The second step is removing impulse noise with a median filter. The wavelet network presented here is a fixed one without learning. Experimental results show that our method acts on impulse noise effectively, and at the same time preserves chromaticity and image details very well. PMID:23493998

Neuronal codes for the inhibitory control of impulsive actions in the rat infralimbic cortex.

Science.gov (United States)

Tsutsui-Kimura, Iku; Ohmura, Yu; Izumi, Takeshi; Matsushima, Toshiya; Amita, Hidetoshi; Yamaguchi, Taku; Yoshida, Takayuki; Yoshioka, Mitsuhiro

2016-01-01

Poor impulse control is a debilitating condition observed in various psychiatric disorders and could be a risk factor for drug addiction, criminal involvement, and suicide. The rat infralimbic cortex (IL), located in the ventral portion of the medial prefrontal cortex, has been implicated in impulse control. To elucidate the neurophysiological basis of impulse control, we recorded single unit activity in the IL of a rat performing a 3-choiceserial reaction time task (3-CSRTT) and 2-choice task (2-CT), which are animal models for impulsivity. The inactivation of IL neuronal activity with an injection of muscimol (0.1 μg /side) disrupted impulse control in the 3-CSRTT. More than 60% (38/56) of isolated IL units were linked to impulse control, while approximately 30% of all units were linked to attentional function in the 3-CSRTT. To avoid confounding motor-related units with the impulse control-related units, we further conducted the 2-CT in which the animals' motor activities were restricted during recording window. More than 30% (14/44) of recorded IL units were linked to impulse control in the 2-CT. Several types of impulse control-related units were identified. Only 16% of all units were compatible with the results of the muscimol experiment, which showed a transient decline in the firing rate immediately before the release of behavioral inhibition. This is the first study to elucidate the neurophysiological basis of impulse control in the IL and to propose that IL neurons control impulsive actions in a more complex manner than previously considered. Copyright © 2015 Elsevier B.V. All rights reserved.

Enhanced vacuum laser-impulse coupling by volume absorption at infrared wavelengths

Science.gov (United States)

Phipps, C. R., Jr.; Harrison, R. F.; Shimada, T.; York, G. W.; Turner, R. F.

1990-03-01

This paper reports measurements of vacuum laser impulse coupling coefficients as large as 90 dyne/W, obtained with single microsec-duration CO2 laser pulses incident on a volume-absorbing, cellulose-nitrate-based plastic. This result is the largest coupling coefficient yet reported at any wavelength for a simple, planar target in vacuum, and partly results from expenditure of internal chemical energy in this material. Enhanced coupling was also observed in several other target materials that are chemically passive, but absorb light in depth at 10- and 3-micron wavelengths. The physical distinctions are discussed between this important case and that of simple, planar surface absorbers (such as metals) which were studied in the same experimental series, in light of the predictions of a simple theoretical model.

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.

Spatio-temporal dynamics of impulse responses to figure motion in optic flow neurons.

Directory of Open Access Journals (Sweden)

Yu-Jen Lee

Full Text Available White noise techniques have been used widely to investigate sensory systems in both vertebrates and invertebrates. White noise stimuli are powerful in their ability to rapidly generate data that help the experimenter decipher the spatio-temporal dynamics of neural and behavioral responses. One type of white noise stimuli, maximal length shift register sequences (m-sequences, have recently become particularly popular for extracting response kernels in insect motion vision. We here use such m-sequences to extract the impulse responses to figure motion in hoverfly lobula plate tangential cells (LPTCs. Figure motion is behaviorally important and many visually guided animals orient towards salient features in the surround. We show that LPTCs respond robustly to figure motion in the receptive field. The impulse response is scaled down in amplitude when the figure size is reduced, but its time course remains unaltered. However, a low contrast stimulus generates a slower response with a significantly longer time-to-peak and half-width. Impulse responses in females have a slower time-to-peak than males, but are otherwise similar. Finally we show that the shapes of the impulse response to a figure and a widefield stimulus are very similar, suggesting that the figure response could be coded by the same input as the widefield response.

Guidance Preconditioning by an Impulse Sequence for Robust Residual Vibration Suppression

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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.

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...

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

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.

Impulsivity in bipolar disorders in a Tunisian sample.

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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.

A Time-Regularized, Multiple Gravity-Assist Low-Thrust, Bounded-Impulse Model for Trajectory Optimization

Science.gov (United States)

Ellison, Donald H.; Englander, Jacob A.; Conway, Bruce A.

2017-01-01

The multiple gravity assist low-thrust (MGALT) trajectory model combines the medium-fidelity Sims-Flanagan bounded-impulse transcription with a patched-conics flyby model and is an important tool for preliminary trajectory design. While this model features fast state propagation via Keplers equation and provides a pleasingly accurate estimation of the total mass budget for the eventual flight suitable integrated trajectory it does suffer from one major drawback, namely its temporal spacing of the control nodes. We introduce a variant of the MGALT transcription that utilizes the generalized anomaly from the universal formulation of Keplers equation as a decision variable in addition to the trajectory phase propagation time. This results in two improvements over the traditional model. The first is that the maneuver locations are equally spaced in generalized anomaly about the orbit rather than time. The second is that the Kepler propagator now has the generalized anomaly as its independent variable instead of time and thus becomes an iteration-free propagation method. The new algorithm is outlined, including the impact that this has on the computation of Jacobian entries for numerical optimization, and a motivating application problem is presented that illustrates the improvements that this model has over the traditional MGALT transcription.

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.

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.

When the party continues: Impulsivity and the effect of employment on young adults' post-college alcohol use.

Science.gov (United States)

Geisner, I M; Koopmann, J; Bamberger, P; Wang, M; Larimer, M E; Nahum-Shani, I; Bacharach, S

2018-02-01

The transition from college to work is both an exciting and potentially high risk time for young adults. As students transition from academic settings to full-time employment, they must navigate new social demands, work demands, and adjust their drinking behaviors accordingly. Research has shown that there are both protective factors and risk factors associated with starting a new job when it comes to alcohol use, and individual differences can moderate these factors. 1361 students were recruited from 4 geographically diverse universities and followed 1month pre- and 1month post-graduation. Drinking frequency, quantity, consequences, and impulsivity were assessed. Full-time employment was related to increased drinking quantity but not related to changes in other drinking outcomes. However, impulsivity moderated the relationship between employment and drinking. For those reporting higher levels of impulsivity at baseline, full-time employment was associated with an increase in drinking variables (quantity and frequency), whereas drinking was unaffected by full-time employment status among those reporting lower levels of impulsivity. Implications for future research are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Infinite horizon optimal impulsive control with applications to Internet congestion control

Science.gov (United States)

Avrachenkov, Konstantin; Habachi, Oussama; Piunovskiy, Alexey; Zhang, Yi

2015-04-01

We investigate infinite-horizon deterministic optimal control problems with both gradual and impulsive controls, where any finitely many impulses are allowed simultaneously. Both discounted and long-run time-average criteria are considered. We establish very general and at the same time natural conditions, under which the dynamic programming approach results in an optimal feedback policy. The established theoretical results are applied to the Internet congestion control, and by solving analytically and nontrivially the underlying optimal control problems, we obtain a simple threshold-based active queue management scheme, which takes into account the main parameters of the transmission control protocols, and improves the fairness among the connections in a given network.

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

IMPULSIVE-COMPULSIVE DISORDERS IN PARKINSON'S DISEASE. CLINICAL CASES

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N. V. Fedorova

2015-01-01

Full Text Available Objective – a description of clinical cases of impulsive­compulsive disorders in Parkinson,s disease. The first clinical case. Patient N., 75 years old, suffering for 15 years from Parkinson,s disease, akinetic­rigid form of the disease, stage 4 by Hyun–Yar. Since 2009, he received levodopa/carbidopa 250/25 mg 5 times/day (daily dose of 1250 mg of levodopa; pramipexole 3.5 mg per day (daily dose 3.5 mg, amantadine sulfate 100 mg 5 times/day (daily dose 500 mg. While taking antiparkinsonian drugs the patient developed behavioral disorders such as dopamine disregulatory syndrome combined with punding, hypersexuality and compulsive shopping accompanied by visual hallucinations. The total equivalent dose of levodopa was 1600 mg per day. The second clinical case. Patient R., 52 years old, suffers from Parkinson,s disease about 5 years, a mixed form. She complained of slowness of movement, tremor in her left hand, sleep disturbances, poor mood. The clinic was appointed piribedil 50 mg 3 times per day. Despite the fact that the patient took only one of dopaminergic drugs in a therapeutic daily dose, she developed impulsive­compulsive disorder as hyper­ sexuality, compulsive shopping and binge eating. Results. In the first clinical case for correction of behavioral disorders in patients with Parkinson,s disease levodopa/carbidopa dose was reduced to 750 mg per day (3/4 Tab. 4 times a day; added to levodopa/benserazide dispersible 100 mg morning and levodopa/benserazide 100 mg before sleep (total dose of levodopa of 950 mg per day. Amantadine sulfate and pramipexole were canceled. It was added to the therapy of atypical neuroleptic clozapine dose 6,25 mg overnight. After 3 months marked improvement, regressed visual hallucina­ tions, improved family relationships, background mood became more stable. The patient continue to sing karaoke, but this hobby has be­ come less intrusive. In the second clinical event correction impulsive

Subscales of the Barratt Impulsiveness Scale differentially relate to the Big Five factors of personality.

Science.gov (United States)

Lange, Florian; Wagner, Adina; Müller, Astrid; Eggert, Frank

2017-06-01

The place of impulsiveness in multidimensional personality frameworks is still unclear. In particular, no consensus has yet been reached with regard to the relation of impulsiveness to Neuroticism and Extraversion. We aim to contribute to a clearer understanding of these relationships by accounting for the multidimensional structure of impulsiveness. In three independent studies, we related the subscales of the Barratt Impulsiveness Scale (BIS) to the Big Five factors of personality. Study 1 investigated the associations between the BIS subscales and the Big Five factors as measured by the NEO Five-Factor Inventory (NEO-FFI) in a student sample (N = 113). Selective positive correlations emerged between motor impulsiveness and Extraversion and between attentional impulsiveness and Neuroticism. This pattern of results was replicated in Study 2 (N = 132) using a 10-item short version of the Big Five Inventory. In Study 3, we analyzed BIS and NEO-FFI data obtained from a sample of patients with pathological buying (N = 68). In these patients, the relationship between motor impulsiveness and Extraversion was significantly weakened when compared to the non-clinical samples. At the same time, the relationship between attentional impulsiveness and Neuroticism was substantially stronger in the clinical sample. Our studies highlight the utility of the BIS subscales for clarifying the relationship between impulsiveness and the Big Five personality factors. We conclude that impulsiveness might occupy multiple places in multidimensional personality frameworks, which need to be specified to improve the interpretability of impulsiveness scales. © 2017 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Impulsive Controller Design for Complex Nonlinear Singular Networked Systems with Packet Dropouts

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Xian-Lin Zhao

2013-01-01

Full Text Available Globally exponential stability of Complex (with coupling Nonlinear Singular Impulsive Networked Control Systems (CNSINCS with packet dropouts and time-delay is investigated. Firstly, the mathematic model of CNSINCS is established. Then, by employing the method of Lyapunov functional, exponential stability criteria are obtained and the impulsive controller design method is given. Finally, some simulation results are provided to demonstrate the effectiveness of the proposed method.

Impulse control disorder comorbidity among patients with bipolar I disorder.

Science.gov (United States)

Karakus, Gonca; Tamam, Lut

2011-01-01

Impulsivity is associated with mood instability, behavioral problems, and action without planning in patients with bipolar disorder. Increased impulsivity levels are reported at all types of mood episodes. This association suggests a high comorbidity between impulse control disorders (ICDs) and bipolar disorder. The aim of this study is to compare the prevalence of ICDs and associated clinical and sociodemographic variables in euthymic bipolar I patients. A total of 124 consecutive bipolar I patients who were recruited from regular attendees from the outpatient clinic of our Bipolar Disorder Unit were included in the study. All patients were symptomatically in remission. Diagnosis of bipolar disorder was confirmed using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Impulse control disorders were investigated using the modified version of the Minnesota Impulsive Disorders Interview. Impulsivity was measured with the Barratt Impulsiveness Scale Version 11. Furthermore, all patients completed the Zuckerman Sensation-Seeking Scale Form V. The prevalence rate of all comorbid ICDs in our sample was 27.4% (n = 34). The most common ICD subtype was pathologic skin picking, followed by compulsive buying, intermittent explosive disorder, and trichotillomania. There were no instances of pyromania or compulsive sexual behavior. There was no statistically significant difference between the sociodemographic characteristics of bipolar patients with and without ICDs with regard to age, sex, education level, or marital status. Comorbidity of alcohol/substance abuse and number of suicide attempts were higher in the ICD(+) group than the ICD(-) group. Length of time between mood episodes was higher in the ICD(-) group than the ICD(+) group. There was a statistically significant difference between the total number of mood episodes between the 2 groups, but the number of depressive episodes was higher in the ICD(+) patients

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

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)

Model Checking Markov Reward Models with Impulse Rewards

NARCIS (Netherlands)

Cloth, Lucia; Katoen, Joost-Pieter; Khattri, Maneesh; Pulungan, Reza; Bondavalli, Andrea; Haverkort, Boudewijn; Tang, Dong

This paper considers model checking of Markov reward models (MRMs), continuous-time Markov chains with state rewards as well as impulse rewards. The reward extension of the logic CSL (Continuous Stochastic Logic) is interpreted over such MRMs, and two numerical algorithms are provided to check the

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...

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.

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.

Comparison principle for impulsive functional differential equations with infinite delays and applications

Science.gov (United States)

Li, Xiaodi; Shen, Jianhua; Akca, Haydar; Rakkiyappan, R.

2018-04-01

We introduce the Razumikhin technique to comparison principle and establish some comparison results for impulsive functional differential equations (IFDEs) with infinite delays, where the infinite delays may be infinite time-varying delays or infinite distributed delays. The idea is, under the help of Razumikhin technique, to reduce the study of IFDEs with infinite delays to the study of scalar impulsive differential equations (IDEs) in which the solutions are easy to deal with. Based on the comparison principle, we study the qualitative properties of IFDEs with infinite delays , which include stability, asymptotic stability, exponential stability, practical stability, boundedness, etc. It should be mentioned that the developed results in this paper can be applied to IFDEs with not only infinite delays but also persistent impulsive perturbations. Moreover, even for the special cases of non-impulsive effects or/and finite delays, the criteria prove to be simpler and less conservative than some existing results. Finally, two examples are given to illustrate the effectiveness and advantages of the proposed results.

Localization in nonuniform media: Exponential decay of the late-time Ginzburg-Landau impulse response

International Nuclear Information System (INIS)

Smith, E.

1998-01-01

Instanton methods have been used, in the context of a classical Ginzburg-Landau field theory, to compute the averaged density of states and probability Green close-quote s function for electrons scattered by statistically uniform site energy perturbations. At tree level, all states below some critical energy appear localized, and all states above extended. The same methods are applied here to macroscopically nonuniform systems, for which it is shown that localized and extended states can be coupled through a tunneling barrier created by the instanton background. Both electronic and acoustic systems are considered. An incoherent exponential decay is predicted for the late-time impulse response in both cases, valid for long-wavelength nonuniformity, and scaling relations are derived for the decay time constant as a function of energy or frequency and spatial dimension. The acoustic results are found to lie within a range of scaling relations obtained empirically from measurements of seismic coda, suggesting a connection between the universal properties of localization and the robustness of the observed scaling. The relation of instantons to the acoustic coherent-potential approximation is demonstrated in the recovery of the uniform limit. copyright 1998 The American Physical Society

Dynamic Systems Driven by Non-Poissonian Impulses

DEFF Research Database (Denmark)

Nielsen, Søren R.K.; Iwankiewicz, R.

interarrival times. The moment equations for the augmented Poisson driven system are derived and closed by an ordinary cumulant neglect closure at the order N=4. The obtained moments are compared with these obtained by Monte Carlo simulations for both the original process with lognormally distributed......Dynamic systems under random trains of impulses driven by renewal point processes are studied. Then the system state variables no longer form a Markov vector as it is in the case of Poisson impulses. A general format is given for the replacing an ordinary renewal process by an equivalent Poisson...... process at the expense of the introduction of auxiliary state variables. A technique is devised for truncating the hierarchy of stochastic equations governing the auxiliary state variables. For the generalized Erlang process, suitable for approximating a wide class of renewal processes, the technique...

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.

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.

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

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.

[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.

Temporal properties of seismicity and largest earthquakes in SE Carpathians

Directory of Open Access Journals (Sweden)

S. Byrdina

2006-01-01

Full Text Available In order to estimate the hazard rate distribution of the largest seismic events in Vrancea, South-Eastern Carpathians, we study temporal properties of historical and instrumental catalogues of seismicity. First, on the basis of Generalized Extreme Value theory we estimate the average return period of the largest events. Then, following Bak et al. (2002 and Corral (2005a, we study scaling properties of recurrence times between earthquakes in appropriate spatial volumes. We come to the conclusion that the seismicity is temporally clustered, and that the distribution of recurrence times is significantly different from a Poisson process even for times largely exceeding corresponding periods of foreshock and aftershock activity. Modeling the recurrence times by a gamma distributed variable, we finally estimate hazard rates with respect to the time elapsed from the last large earthquake.

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…

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

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...

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

Sex differences in succumbing to sexual temptations: a function of impulse or control?

Science.gov (United States)

Tidwell, Natasha D; Eastwick, Paul W

2013-12-01

Men succumb to sexual temptations (e.g., infidelity, mate poaching) more than women. Explanations for this effect vary; some researchers propose that men and women differ in sexual impulse strength, whereas others posit a difference in sexual self-control. These studies are the first to test such underlying mechanisms. In Study 1, participants reported on their impulses and intentional control exertion when they encountered a real-life tempting but forbidden potential partner. Study 2 required participants to perform a reaction-time task in which they accepted/rejected potential partners, and we used process dissociation to separate the effects of impulse and control. In both studies, men succumbed to the sexual temptations more than women, and this sex difference emerged because men experienced stronger impulses, not because they exerted less intentional control. Implications for the integration of evolutionary and self-regulatory perspectives on sex differences are discussed.

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.

Study on the streamer inception characteristics under positive lightning impulse voltage

Directory of Open Access Journals (Sweden)

Zezhong Wang

2017-11-01

Full Text Available The streamer is the main process in an air gap discharge, and the inception characteristics of streamers have been widely applied in engineering. Streamer inception characteristics under DC voltage have been studied by many researchers, but the inception characteristics under impulse voltage, and particularly under lightning impulse voltage with a high voltage rise rate have rarely been studied. A measurement system based on integrated optoelectronic technology has been proposed in this paper, and the streamer inception characteristics in a 1-m-long rod-plane air gap that was energized by a positive lightning impulse voltage have been researched. We have also measured the streamer inception electric field using electrodes with different radii of curvature and different voltage rise rates. As a result, a modified empirical criterion for the streamer inception electric field that considers the voltage rise rate has been proposed, and the wide applicability of this criterion has been proved. Based on the streamer inception time-lag obtained, we determined that the field distribution obeys a Rayleigh distribution, which explains the change law of the streamer inception time-lag. The characteristic parameter of the Rayleigh distribution lies in the range from 0.6 to 2.5 when the radius of curvature of the electrode head is in the range from 0.5 cm to 2.5 cm and the voltage rise rate ranges from 80 kV/μs to 240kV/μs under positive lightning impulse voltage.

TRANSITION REGION AND CHROMOSPHERIC SIGNATURES OF IMPULSIVE HEATING EVENTS. I. OBSERVATIONS

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Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Reep, Jeffrey W. [National Research Council Postdoctoral Fellow, Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Crump, Nicholas A. [Naval Center for Space Technology, Naval Research Laboratory, Washington, DC 20375 (United States); Simões, Paulo J. A. [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

2016-09-20

We exploit the high spatial resolution and high cadence of the Interface Region Imaging Spectrograph ( IRIS ) to investigate the response of the transition region and chromosphere to energy deposition during a small flare. Simultaneous observations from the Reuven Ramaty High Energy Solar Spectroscopic Imager provide constraints on the energetic electrons precipitating into the flare footpoints, while observations of the X-Ray Telescope , Atmospheric Imaging Assembly, and Extreme Ultraviolet Imaging Spectrometer (EIS) allow us to measure the temperatures and emission measures from the resulting flare loops. We find clear evidence for heating over an extended period on the spatial scale of a single IRIS pixel. During the impulsive phase of this event, the intensities in each pixel for the Si iv 1402.770 Å, C ii 1334.535 Å, Mg ii 2796.354 Å, and O i 1355.598 Å emission lines are characterized by numerous small-scale bursts typically lasting 60 s or less. Redshifts are observed in Si iv, C ii, and Mg ii during the impulsive phase. Mg ii shows redshifts during the bursts and stationary emission at other times. The Si iv and C ii profiles, in contrast, are observed to be redshifted at all times during the impulsive phase. These persistent redshifts are a challenge for one-dimensional hydrodynamic models, which predict only short-duration downflows in response to impulsive heating. We conjecture that energy is being released on many small-scale filaments with a power-law distribution of heating rates.

Study on the streamer inception characteristics under positive lightning impulse voltage

Science.gov (United States)

Wang, Zezhong; Geng, Yinan

2017-11-01

The streamer is the main process in an air gap discharge, and the inception characteristics of streamers have been widely applied in engineering. Streamer inception characteristics under DC voltage have been studied by many researchers, but the inception characteristics under impulse voltage, and particularly under lightning impulse voltage with a high voltage rise rate have rarely been studied. A measurement system based on integrated optoelectronic technology has been proposed in this paper, and the streamer inception characteristics in a 1-m-long rod-plane air gap that was energized by a positive lightning impulse voltage have been researched. We have also measured the streamer inception electric field using electrodes with different radii of curvature and different voltage rise rates. As a result, a modified empirical criterion for the streamer inception electric field that considers the voltage rise rate has been proposed, and the wide applicability of this criterion has been proved. Based on the streamer inception time-lag obtained, we determined that the field distribution obeys a Rayleigh distribution, which explains the change law of the streamer inception time-lag. The characteristic parameter of the Rayleigh distribution lies in the range from 0.6 to 2.5 when the radius of curvature of the electrode head is in the range from 0.5 cm to 2.5 cm and the voltage rise rate ranges from 80 kV/μs to 240kV/μs under positive lightning impulse voltage.

Altered Developmental Trajectories for Impulsivity and Sensation Seeking among Adolescent Substance Users

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Charles, Nora E.; Ryan, Stacy R.; Bray, Bethany C.; Mathias, Charles W.; Acheson, Ashley; Dougherty, Donald M.

2016-01-01

A number of studies have associated impulsivity and sensation seeking with level of substance use and risk for developing a substance use disorder. These relationships may be particularly apparent during adolescence, when developmental changes in impulsivity and sensation seeking occur at the same time as increased opportunities for substance use. To examine this, the current study measured impulsivity and sensation seeking from pre-adolescence to mid-adolescence in a sample of youth, the majority of whom were identified as being at risk for developing a substance use disorder based on their family history of substance use disorders. Youth were separated into those who did (n = 117) and did not (n = 269) initiate substance use by mid-adolescence. Results showed that substance users were more impulsive and more sensation seeking during pre-adolescence, prior to any significant substance use, and that greater sensation seeking in pre-adolescence was related to heavier substance use by mid-adolescence. In addition, developmental trajectories for substance-using youth showed a greater increase in sensation seeking but a more modest decrease in impulsivity from pre-adolescence to mid-adolescence. Taken together, these results indicate that increased impulsivity and sensation seeking is apparent in adolescent substance users as early as pre-adolescence, that the difference between substance users and non-users becomes larger across early adolescence as their developmental trajectories diverge, and that greater sensation seeking in pre-adolescence may predict increased substance use by mid-adolescence. PMID:27174219

Subthalamic nucleus stimulation influences expression and suppression of impulsive behaviour in Parkinson’s disease

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Ridderinkhof, K. Richard; Elias, William J.; Frysinger, Robert C.; Bashore, Theodore R.; Downs, Kara E.; van Wouwe, Nelleke C.; van den Wildenberg, Wery P. M.

2010-01-01

Past studies show beneficial as well as detrimental effects of subthalamic nucleus deep-brain stimulation on impulsive behaviour. We address this paradox by investigating individuals with Parkinson’s disease treated with subthalamic nucleus stimulation (n = 17) and healthy controls without Parkinson’s disease (n = 17) on performance in a Simon task. In this reaction time task, conflict between premature response impulses and goal-directed action selection is manipulated. We applied distributional analytic methods to separate the strength of the initial response impulse from the proficiency of inhibitory control engaged subsequently to suppress the impulse. Patients with Parkinson’s disease were tested when stimulation was either turned on or off. Mean conflict interference effects did not differ between controls and patients, or within patients when stimulation was on versus off. In contrast, distributional analyses revealed two dissociable effects of subthalamic nucleus stimulation. Fast response errors indicated that stimulation increased impulsive, premature responding in high conflict situations. Later in the reaction process, however, stimulation improved the proficiency with which inhibitory control was engaged to suppress these impulses selectively, thereby facilitating selection of the correct action. This temporal dissociation supports a conceptual framework for resolving past paradoxical findings and further highlights that dynamic aspects of impulse and inhibitory control underlying goal-directed behaviour rely in part on neural circuitry inclusive of the subthalamic nucleus. PMID:20861152

Alcohol use and drunk driving: the modifying effect of impulsivity.

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Moan, Inger Synnøve; Norström, Thor; Storvoll, Elisabet E

2013-01-01

The aim of this study was twofold: (a) to examine how an increase in the frequency of heavy drinking episodes affects the incidence of drunk driving and (b) to examine whether the effect of alcohol use on drunk driving is contingent on impulsivity. Two waves of the Young in Norway Longitudinal Study were applied (N = 2,603; response rate: 67%), when the respondents were on average 17 (1994) and 28 (2005) years of age. Measurements consisted of self-reported heavy episodic drinking, drunk driving, and impulsivity. The first difference method was applied to estimate the association between heavy episodic drinking and drunk driving. This means that changes in the frequency of drunk driving were regressed on changes in the frequency of drinking. In this way, the effects of time-invariant confounders were eliminated. The results showed that every additional episode of heavy drinking was associated with a 2.6% increase in the frequency of drunk driving. The increase for males was significantly higher than among females. The analyses supported the hypothesis that impulsivity modifies the association between alcohol use and drunk driving. The association between drinking and drunk driving is significantly stronger among those with a high score on impulsivity compared with those who have a low score.

Temperament and impulsivity predictors of smoking cessation outcomes.

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Francisca López-Torrecillas

Full Text Available AIMS: Temperament and impulsivity are powerful predictors of addiction treatment outcomes. However, a comprehensive assessment of these features has not been examined in relation to smoking cessation outcomes. METHODS: Naturalistic prospective study. Treatment-seeking smokers (n = 140 were recruited as they engaged in an occupational health clinic providing smoking cessation treatment between 2009 and 2013. Participants were assessed at baseline with measures of temperament (Temperament and Character Inventory, trait impulsivity (Barratt Impulsivity Scale, and cognitive impulsivity (Go/No Go, Delay Discounting and Iowa Gambling Task. The outcome measure was treatment status, coded as "dropout" versus "relapse" versus "abstinence" at 3, 6, and 12 months endpoints. Participants were telephonically contacted and reminded of follow-up face to face assessments at each endpoint. The participants that failed to answer the phone calls or self-reported discontinuation of treatment and failed to attend the upcoming follow-up session were coded as dropouts. The participants that self-reported continuing treatment, and successfully attended the upcoming follow-up session were coded as either "relapse" or "abstinence", based on the results of smoking behavior self-reports cross-validated with co-oximetry hemoglobin levels. Multinomial regression models were conducted to test whether temperament and impulsivity measures predicted dropout and relapse relative to abstinence outcomes. RESULTS: Higher scores on temperament dimensions of novelty seeking and reward dependence predicted poorer retention across endpoints, whereas only higher scores on persistence predicted greater relapse. Higher scores on the trait dimension of non-planning impulsivity but not performance on cognitive impulsivity predicted poorer retention. Higher non-planning impulsivity and poorer performance in the Iowa Gambling Task predicted greater relapse at 3 and 6 months and 6 months

Modification of an impulse-factoring orbital transfer technique to account for orbit determination and maneuver execution errors

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Kibler, J. F.; Green, R. N.; Young, G. R.; Kelly, M. G.

1974-01-01

A method has previously been developed to satisfy terminal rendezvous and intermediate timing constraints for planetary missions involving orbital operations. The method uses impulse factoring in which a two-impulse transfer is divided into three or four impulses which add one or two intermediate orbits. The periods of the intermediate orbits and the number of revolutions in each orbit are varied to satisfy timing constraints. Techniques are developed to retarget the orbital transfer in the presence of orbit-determination and maneuver-execution errors. Sample results indicate that the nominal transfer can be retargeted with little change in either the magnitude (Delta V) or location of the individual impulses. Additonally, the total Delta V required for the retargeted transfer is little different from that required for the nominal transfer. A digital computer program developed to implement the techniques is described.

Chaotification of complex networks with impulsive control.

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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.

Impulsive differential inclusions a fixed point approach

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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

Beyond discounting: possible experimental models of impulse control.

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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.

Using Dual Process Models to Examine Impulsivity Throughout Neural Maturation.

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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.

Mindful eating reduces impulsive food choice in adolescents and adults.

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Hendrickson, Kelsie L; Rasmussen, Erin B

2017-03-01

The present study tested the extent to which age and obesity predicted impulsive choices for food and monetary outcomes and tested how a brief mindful-eating training would alter delay discounting for food and money choices compared with control groups. First, 172 adolescents (M age = 13.13 years) and 176 (M age = 23.33 years) adults completed the Food Choice Questionnaire (FCQ) and Monetary Choice Questionnaire (MCQ) as measures of food and money delay discounting, respectively. Then, participants returned to the lab and were randomly assigned to complete a brief mindful-eating training, watch a DVD on nutrition, or serve as a control. Participants completed the FCQ and MCQ again as a postmanipulation measure. Participants with high percent body fat (PBF) were more impulsive for food than those with low PBF. Adults with high PBF were also more impulsive for money compared with adults with low PBF; no PBF-related differences were found for adolescents. Participants in the mindful-eating group exhibited more self-controlled choices for food, but not for money. The control conditions did not exhibit changes. The study suggests that individuals with high PBF make more impulsive food choices relative to those with low PBF, which could increase the risk of obesity over time. It also is the first to demonstrate shifts in choice patterns for food and money using a brief mindful-eating training with adolescents. Mindful eating is a beneficial strategy to reduce impulsive food choice, at least temporarily, that may impede weight gain. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Impulsive-compulsive buying disorder: clinical overview.

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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.

Joint Asymptotic Distributions of Smallest and Largest Insurance Claims

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Hansjörg Albrecher

2014-07-01

Full Text Available Assume that claims in a portfolio of insurance contracts are described by independent and identically distributed random variables with regularly varying tails and occur according to a near mixed Poisson process. We provide a collection of results pertaining to the joint asymptotic Laplace transforms of the normalised sums of the smallest and largest claims, when the length of the considered time interval tends to infinity. The results crucially depend on the value of the tail index of the claim distribution, as well as on the number of largest claims under consideration.

Opacity Build-up in Impulsive Relativistic Sources

International Nuclear Information System (INIS)

Granot, Jonathan; Cohen-Tanugi, Johann; Silva, Eduardo do Couto e

2007-01-01

Opacity effects in relativistic sources of high-energy gamma-rays, such as gamma-ray bursts (GRBs) or Blazars, can probe the Lorentz factor of the outflow as well as the distance of the emission site from the source, and thus help constrain the composition of the outflow (protons, pairs, magnetic field) and the emission mechanism. Most previous works consider the opacity in steady state. Here we study the effects of the time dependence of the opacity to pair production (γγ → e + e - ) in an impulsive relativistic source, which may be relevant for the prompt gamma-ray emission in GRBs or flares in Blazars. We present a simple, yet rich, semi-analytic model for the time and energy dependence of the optical depth, τγγ, in which a thin spherical shell expands ultra-relativistically and emits isotropically in its own rest frame over a finite range of radii, R 0 (le) R (le) R 0 +ΔR. This is particularly relevant for GRB internal shocks. We find that in an impulsive source (ΔR ∼ 0 ), while the instantaneous spectrum (which is typically hard to measure due to poor photon statistics) has an exponential cutoff above the photon energy (var e psilon)1(T) where tγγ((var e psilon)1) = 1, the time integrated spectrum (which is easier to measure) has a power-law high-energy tail above the photon energy (var e psilon)1* ∼ (var e psilon)1(ΔT) where ΔT is the duration of the emission episode. Furthermore, photons with energies (var e psilon) > (var e psilon)1* are expected to arrive mainly near the onset of the spike in the light curve or flare, which corresponds to the short emission episode. This arises since in such impulsive sources it takes time to build-up the (target) photon field, and thus the optical depth τγγ((var e psilon)) initially increases with time and (var e psilon)1(T) correspondingly decreases with time, so that photons of energy (var e psilon) > (var e psilon)1* are able to escape the source mainly very early on while (var e psilon)1(T) > (var

Association of Self-reported Impulsivity to Nonsuicidal Self-Injury, Suicidality, and Mortality in Adolescent Psychiatric Inpatients.

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Alasaarela, Lauri; Hakko, Helinä; Riala, Kaisa; Riipinen, Pirkko

2017-05-01

This study examines the association of self-reported impulsivity to nonsuicidal self-injury, suicidal ideation, suicide attempts, and completed suicides in a clinical sample of 508 Finnish adolescents (aged 12-17) treated in psychiatric inpatient care between April 2001 and March 2006. The Schedule for Affective Disorder and Schizophrenia for School-Age Children Present and Lifetime interview was used to gather information on psychiatric disorders, impulsivity, and suicidality of the adolescents. Mortality data were obtained from the national cause of death register. In adolescent girls, impulsivity was significantly associated with suicidal ideation and attempts and completed suicides in adolescent boys. Of adolescent boys with impulsivity, 10.4% had died by suicide during the follow-up time. For preventive purposes, health care professionals are encouraged asked adolescents targeted questions about impulsivity and to consider the associated risk of suicidality identified in this study.

Impulsivity, Mental Disorder, and Suicide in Rural China.

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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.

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.

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

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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.

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

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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.

The short (S) allele of the serotonin transporter polymorphism and acute tryptophan depletion both increase impulsivity in men.

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Walderhaug, Espen; Herman, Aryeh Isaac; Magnusson, Andres; Morgan, Michael John; Landrø, Nils Inge

2010-04-12

Reduced serotonergic neurotransmission is implicated in impulsive behavior. We studied the triallelic system of the serotonin transporter gene linked polymorphic region (5-HTTLPR) and acute manipulation of serotonin together to further delineate the mechanisms by which serotonergic neurotransmission affects impulsivity. Fifty-two healthy participants (38 men and 14 women) underwent acute tryptophan depletion (ATD) or placebo in a randomized, double-blind, parallel group experiment. Impulsive response style was measured on two versions of the Continuous Performance Task (CPT), and calculated using signal detection theory. We observed a dose-dependent effect for the short (S') allele of the 5-HTTLPR on impulsive response style. Individuals who had the S'/S' genotype were more impulsive than individuals with the L/S' genotype. Participants with the L/S' genotype were more impulsive than those with the L/L genotype. ATD increased impulsivity in men, and decreased impulsivity in women. These data demonstrate for the first time that reduced serotonergic tone as a result of either 5-HTTLPR genotype, or experimental ATD, are both independently and additively, associated with elevated impulsive response style in Caucasian men. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Source locations for impulsive electric signals seen in the night ionosphere of Venus

Science.gov (United States)

Russell, C. T.; Von Dornum, M.; Scarf, F. L.

1989-01-01

A mapping of the rate of occurrence of impulsive VLF noise bursts in Venus' dark low altitude ionosphere, which increases rapidly with decreasing altitude, as a function of latitude and longitude indicates enhanced occurrence rates over Atla. In a 30-sec observing period, there are impulsive signals 70 percent of the time at 160 km in the region of maximum occurrence; the occurrence rates, moreover, increase with decreasing latitude, so that the equatorial rate is of the order of 1.6 times that at 30 deg latitude. These phenomena are in keeping with lightning-generated wave sources.

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.

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

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

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.

APPLICATION OF STIMULUS & RESPONSE MODEL TO IMPULSE BUYING BEHAVIOR OF ALGERIAN CONSUMERS

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Amel Graa

2012-02-01

Full Text Available This paper investigates the influence of situational factors on the impulse buying behavior usinga Mehrabian and Russell's (1974 framework (Stimulus & response model. The results suggest thata consumer's emotions can be a mediating factor in the impulse purchase process. In this study, weidentify and explore how situational factors and emotional states may influence various dimensionsof impulse purchase behavior of Algerian shoppers. By tapping the responses of 687 consumers inthe area of Algeria’ west, we obtain that there is a positive relationship between independent anddependent variables.According to the results, pleasure was associated with design, whereas arousal was associatedwith perception of crowding, but dominance was linked to time spent in the store. Retailers can takethese findings to maintain trained their employees and provide adequate signs and best environmentwhenever some relocation of products took place.

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.

Why are you happy with impulse buying? Evidence from Indonesia

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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.

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...

Measuring long impulse responses with pseudorandom sequences and sweep signals

DEFF Research Database (Denmark)

Torras Rosell, Antoni; Jacobsen, Finn

2010-01-01

In architectural acoustics, background noise, loudspeaker nonlinearities, and time variances are the most common disturbances that can compromise a measurement. The effects of such disturbances on measurement of long impulse responses with pseudorandom sequences (maximum-length sequences (MLS) an...

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.

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

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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.

Association between Impulsivity and Weight Status in a General Population

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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.

Association between Impulsivity and Weight Status in a General Population.

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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.

Study of suicidal ideations, hopelessness and impulsivity in elderly

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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.

Minimum-domain impulse theory for unsteady aerodynamic force

Science.gov (United States)

Kang, L. L.; Liu, L. Q.; Su, W. D.; Wu, J. Z.

2018-01-01

We extend the impulse theory for unsteady aerodynamics from its classic global form to finite-domain formulation then to minimum-domain form and from incompressible to compressible flows. For incompressible flow, the minimum-domain impulse theory raises the finding of Li and Lu ["Force and power of flapping plates in a fluid," J. Fluid Mech. 712, 598-613 (2012)] to a theorem: The entire force with discrete wake is completely determined by only the time rate of impulse of those vortical structures still connecting to the body, along with the Lamb-vector integral thereof that captures the contribution of all the rest disconnected vortical structures. For compressible flows, we find that the global form in terms of the curl of momentum ∇ × (ρu), obtained by Huang [Unsteady Vortical Aerodynamics (Shanghai Jiaotong University Press, 1994)], can be generalized to having an arbitrary finite domain, but the formula is cumbersome and in general ∇ × (ρu) no longer has discrete structures and hence no minimum-domain theory exists. Nevertheless, as the measure of transverse process only, the unsteady field of vorticity ω or ρω may still have a discrete wake. This leads to a minimum-domain compressible vorticity-moment theory in terms of ρω (but it is beyond the classic concept of impulse). These new findings and applications have been confirmed by our numerical experiments. The results not only open an avenue to combine the theory with computation-experiment in wide applications but also reveal a physical truth that it is no longer necessary to account for all wake vortical structures in computing the force and moment.

Analysis of Human Standing Balance by Largest Lyapunov Exponent

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Kun Liu

2015-01-01

Full Text Available The purpose of this research is to analyse the relationship between nonlinear dynamic character and individuals’ standing balance by the largest Lyapunov exponent, which is regarded as a metric for assessing standing balance. According to previous study, the largest Lyapunov exponent from centre of pressure time series could not well quantify the human balance ability. In this research, two improvements were made. Firstly, an external stimulus was applied to feet in the form of continuous horizontal sinusoidal motion by a moving platform. Secondly, a multiaccelerometer subsystem was adopted. Twenty healthy volunteers participated in this experiment. A new metric, coordinated largest Lyapunov exponent was proposed, which reflected the relationship of body segments by integrating multidimensional largest Lyapunov exponent values. By using this metric in actual standing performance under sinusoidal stimulus, an obvious relationship between the new metric and the actual balance ability was found in the majority of the subjects. These results show that the sinusoidal stimulus can make human balance characteristics more obvious, which is beneficial to assess balance, and balance is determined by the ability of coordinating all body segments.

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

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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.

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.

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.

Differential effects of social and novelty enrichment on individual differences in impulsivity and behavioral flexibility.

Science.gov (United States)

Wang, Maya Zhe; Marshall, Andrew T; Kirkpatrick, Kimberly

2017-06-01

Early life experience profoundly impacts behavior and cognitive functions in rats. The present study investigated how the presence of conspecifics and/or novel objects, could independently influence individual differences in impulsivity and behavioral flexibility. Twenty-four rats were reared in an isolated condition, an isolated condition with a novel object, a pair-housed social condition, or a pair-housed social condition with a novel object. The rats were then tested on an impulsive choice task, a behavioral flexibility task, and an impulsive action task. Novelty enrichment produced an overall increase in impulsive choice, while social enrichment decreased impulsive choice in the absence of novelty enrichment and also produced an overall increase in impulsive action. In the behavioral flexibility task, social enrichment increased regressive errors, whereas both social and novelty enrichment reduced never-reinforced errors. Individual differences analyses indicated a significant relationship between performance in the behavioral flexibility and impulsive action tasks, which may reflect a common psychological correlate of action inhibition. Moreover, there was a relationship between delay sensitivity in the impulsive choice task and performance on the DRL and behavioral flexibility tasks, suggesting a dual role for timing and inhibitory processes in driving the interrelationship between these tasks. Overall, these results indicate that social and novelty enrichment produce distinct effects on impulsivity and adaptability, suggesting the need to parse out the different elements of enrichment in future studies. Further research is warranted to better understand how individual differences in sensitivity to enrichment affect individuals' interactions with and the resulting consequences of the rearing environment. Copyright © 2017 Elsevier B.V. All rights reserved.

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

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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.

Risk of Gambling Disorder and Impulse Control Disorder With Aripiprazole, Pramipexole, and Ropinirole: A Pharmacoepidemiologic Study.

Science.gov (United States)

Etminan, Mahyar; Sodhi, Mohit; Samii, Ali; Procyshyn, Ric M; Guo, Michael; Carleton, Bruce C

2017-02-01

Recently, the US Food and Drug Administration issued a warning regarding the potential risk of gambling disorder, but large epidemiologic studies are lacking. We used a large health claims database from the United States and conducted a nested case-control study. Cases were defined as subjects newly diagnosed with gambling disorder or impulse control disorder. For each case, 10 controls were selected and matched to cases by age and follow-up time and calendar time. Adjusted rate ratios were computed with conditional logistic regression. There are 355 cases of gambling disorder and 3550 controls along with 4341 cases of impulse control disorder and 43,410 corresponding controls. After adjusting for confounders, users of aripiprazole demonstrated an increased risk of pathologic gambling (rate ratio [RR], 5.23; 95% confidence interval [CI], 1.78-15.38) and impulse control disorder (RR, 7.71; 95% CI, 5.81-10.34). The risk was also elevated for pramipexole or ropinirole for both gambling disorder and impulse control disorder (RR, 7.61; 95% CI, 2.75-21.07; RR, 3.28; 95% CI, 2.31-4.66, respectively). Our study confirms an association between aripiprazole, pramipexole, or ropinirole and impulse control disorder and gambling disorder.

An elegant impulser developed for flat beam injection

International Nuclear Information System (INIS)

Wilson, M.J.; Goerz, D.A.; Speer, R.D.

1998-01-01

The following report describes the design, construction, and checkout of a high-voltage (HV) impulser built for the heavy ion fusion (HIF) project [1]. The purpose of this impulser is to provide an adjustable diode voltage source of sufficient quality and level to allow the optimization of beam transport and accelerator sections of HIF [2, 3]. An elegant, low-impedance, high-energy storage capacitor circuit has been selected for this application. Circuit parameters of the retrofit to the diode region [4] have been included to provide the controlled rise time. The critical part of this circuit that is common to all candidates is the impedance matching component. The following report provides a description of the implemented circuit, the basic circuit variables for wave shaping, screening techniques revealing the weakest circuit component, and the resulting output of the injector

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

Compressive sensing for sparse time-frequency representation of nonstationary signals in the presence of impulsive noise

Science.gov (United States)

Orović, Irena; Stanković, Srdjan; Amin, Moeness

2013-05-01

A modified robust two-dimensional compressive sensing algorithm for reconstruction of sparse time-frequency representation (TFR) is proposed. The ambiguity function domain is assumed to be the domain of observations. The two-dimensional Fourier bases are used to linearly relate the observations to the sparse TFR, in lieu of the Wigner distribution. We assume that a set of available samples in the ambiguity domain is heavily corrupted by an impulsive type of noise. Consequently, the problem of sparse TFR reconstruction cannot be tackled using standard compressive sensing optimization algorithms. We introduce a two-dimensional L-statistics based modification into the transform domain representation. It provides suitable initial conditions that will produce efficient convergence of the reconstruction algorithm. This approach applies sorting and weighting operations to discard an expected amount of samples corrupted by noise. The remaining samples serve as observations used in sparse reconstruction of the time-frequency signal representation. The efficiency of the proposed approach is demonstrated on numerical examples that comprise both cases of monocomponent and multicomponent signals.

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

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.

Effects of atomoxetine on attention and impulsivity in the five-choice serial reaction time task in rats with lesions of dorsal noradrenergic ascending bundle.

Science.gov (United States)

Liu, Yia-Ping; Huang, Teng-Shun; Tung, Che-Se; Lin, Chen-Cheng

2015-01-02

Atomoxetine, a noradrenaline reuptake inhibitor (NRI), which is a non-stimulating medicine that is used for the treatment of patients with attention deficit hyperactivity disorder (ADHD), has been found to be effective in reducing behavioral impulsivity in rodents, but its efficacy in a dorsal noradrenergic ascending bundle (DNAB)-lesioned condition has not been examined. The present study aimed to investigate the effects of DNAB lesions on attention and impulsive control in the five-choice serial reaction time task (5-CSRTT) in rats treated with atomoxetine. The drug-induced changes in noradrenaline efflux in the medial prefrontal cortex were also measured. 5-CSRTT-trained rats were included in one of the following groups: N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4)/Atomoxetine, Sham/Atomoxetine, DSP-4/Saline, or Sham/Saline. Acute atomoxetine (0.3 mg/kg) was administered 14 days after the DSP-4 regime. The behavioral testing included manipulations of the inter-trial interval (ITI), stimulation duration and food satiety. In vivo microdialysis of the noradrenaline efflux in the medial prefrontal cortex and the expression of the noradrenaline transporter (NAT) in the DNAB areas were examined. Atomoxetine reduced impulsivity and perseveration in the long-ITI condition with no effects on any other variables. This phenomenon was not influenced by DSP-4 pre-treatment. The DNAB-lesioned rats had lower noradrenaline efflux in the medial prefrontal cortex. DSP-4 caused no change in NAT expression in the DNAB areas. These findings suggested that noradrenaline reuptake may not be exclusively responsible for the atomoxetine effects in adjusting impulsivity. The role of DNAB should also be considered, particularly in conditions requiring greater behavioral inhibition. Copyright © 2014 Elsevier Inc. All rights reserved.

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.

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.

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.

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.

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

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

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

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

Impulse response measurement in the HgCdTe avalanche photodiode

Science.gov (United States)

Singh, Anand; Pal, Ravinder

2018-04-01

HgCdTe based mid-wave infrared focal plane arrays (MWIR FPAs) are being developed for high resolution imaging and range determination of distant camouflaged targets. Effect of bandgap grading on the response time in the n+/ν/p+ HgCdTe electron avalanche photodiode (e-APD) is evaluated using impulse response measurement. Gain normalized dark current density of 2 × 10-9 A/cm2 at low reverse bias for passive mode and 2 × 10-4 A/cm2 at -8 V for active mode is measured in the fabricated APD device, yielding high gain bandwidth product of 2.4 THZ at the maximum gain. Diffusion of carriers is minimized to achieve transit time limited impulse response by introducing composition grading in the HgCdTe epilayer. The noise equivalent photon performance less than one is achievable in the FPA that is suitable for active cum passive imaging applications.

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.

How birds direct impulse to minimize the energetic cost of foraging flight

Science.gov (United States)

Chin, Diana; Lentink, David

2017-11-01

Foraging arboreal birds frequently hop and fly between branches by extending long-jumps with a few wingbeats. Their legs transfer impulse to the branch during takeoff and landing, and their wings transfer impulse to the air to support their bodyweight during flight. To determine the mechanical energy tradeoffs of this bimodal locomotion, we studied how Pacific parrotlets transfer impulse during voluntary perch-to-perch flights. We tested five foraging flight variations by varying the inclination and distance between instrumented perches inside a novel aerodynamic force platform. This setup enables direct, time-resolved in vivo measurements of both leg and wing forces, which we combined with high-speed kinematics to develop a new bimodal long-jump and flight model. The model demonstrates how parrotlets direct their leg impulse to minimize the mechanical energy needed for each flight, and further shows how even a single proto-wingbeat would have significantly lengthened the long-jump of foraging arboreal dinosaurs. By directing jumps and flapping their wings, both extant and ancestral birds could thus improve foraging effectiveness. Similarly, bimodal robots could also employ these locomotion strategies to traverse cluttered environments more effectively.

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

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.

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.

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.

Mu and delta opioid receptors oppositely regulate motor impulsivity in the signaled nose poke task.

Directory of Open Access Journals (Sweden)

Mary C Olmstead

Full Text Available Impulsivity is a primary feature of many psychiatric disorders, most notably attention deficit hyperactivity disorder and drug addiction. Impulsivity includes a number of processes such as the inability to delay gratification, the inability to withhold a motor response, or acting before all of the relevant information is available. These processes are mediated by neural systems that include dopamine, serotonin, norepinephrine, glutamate and cannabinoids. We examine, for the first time, the role of opioid systems in impulsivity by testing whether inactivation of the mu- (Oprm1 or delta- (Oprd1 opioid receptor gene alters motor impulsivity in mice. Wild-type and knockout mice were examined on either a pure C57BL6/J (BL6 or a hybrid 50% C57Bl/6J-50% 129Sv/pas (HYB background. Mice were trained to respond for sucrose in a signaled nose poke task that provides independent measures of associative learning (responses to the reward-paired cue and motor impulsivity (premature responses. Oprm1 knockout mice displayed a remarkable decrease in motor impulsivity. This was observed on the two genetic backgrounds and did not result from impaired associative learning, as responses to the cue signaling reward did not differ across genotypes. Furthermore, mutant mice were insensitive to the effects of ethanol, which increased disinhibition and decreased conditioned responding in wild-type mice. In sharp contrast, mice lacking the Oprd1 gene were more impulsive than controls. Again, mutant animals showed no deficit in associative learning. Ethanol completely disrupted performance in these animals. Together, our results suggest that mu-opioid receptors enhance, whereas delta-opioid receptors inhibit, motor impulsivity. This reveals an unanticipated contribution of endogenous opioid receptor activity to disinhibition. In a broader context, these data suggest that alterations in mu- or delta-opioid receptor function may contribute to impulse control disorders.

The temporal course and clinical correlates of subjective impulsivity in bipolar disorder as revealed through ecological momentary assessment.

Science.gov (United States)

Depp, Colin A; Moore, Raeanne C; Dev, Sheena I; Mausbach, Brent T; Eyler, Lisa T; Granholm, Eric L

2016-03-15

Impulsivity is frequently linked with bipolar disorder and is associated with mania and negative outcomes. The temporal dynamics of subjective impulsivity are unclear, in particular whether impulsivity precedes or follows changes in positive or negative affect. A total of 41 outpatients with bipolar disorder (I or II) were provided with mobile devices for 11 weeks and completed twice-daily surveys about affective states and subjective impulsivity. We examined the association between aggregate subjective impulsivity with baseline global cognitive function, suicide risk ratings, and medication adherence, as well as concurrent and lagged associations with momentary positive and negative affect ratings. A total of 2902 ratings were available across study subjects. Higher aggregate mean ratings of impulsivity were associated with worse baseline global cognitive function, prior suicide attempts, and self-reported problems with medication adherence, as well as more severe manic (but not depressive) symptoms. Time-lagged models indicated that greater negative affect, but not positive affect, predicted subsequent increases in subjective impulsivity, which, in turn, predicted diminished positive affect. Other measures of impulsivity with which to validate subjective ratings were unavailable and the sample was restricted to generally clinically stable outpatients. Subjective impulsivity as measured by daily monitoring was associated with worse cognitive function and self-rated medication adherence, and higher suicide risk ratings. Impulsivity may be a maladaptive strategy to regulate negative affect in bipolar disorder. Copyright © 2016. Published by Elsevier B.V.

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.

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.

Sensitivity Analysis of a Horizontal Earth Electrode under Impulse ...

African Journals Online (AJOL)

This paper presents the sensitivity analysis of an earthing conductor under the influence of impulse current arising from a lightning stroke. The approach is based on the 2nd order finite difference time domain (FDTD). The earthing conductor is regarded as a lossy transmission line where it is divided into series connected ...

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.

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.

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...

Alcohol-Preferring Rats Show Goal Oriented Behaviour to Food Incentives but Are Neither Sign-Trackers Nor Impulsive.

Directory of Open Access Journals (Sweden)

Yolanda Peña-Oliver

Full Text Available Drug addiction is often associated with impulsivity and altered behavioural responses to both primary and conditioned rewards. Here we investigated whether selectively bred alcohol-preferring (P and alcohol-nonpreferring (NP rats show differential levels of impulsivity and conditioned behavioural responses to food incentives. P and NP rats were assessed for impulsivity in the 5-choice serial reaction time task (5-CSRTT, a widely used translational task in humans and other animals, as well as Pavlovian conditioned approach to measure sign- and goal-tracking behaviour. Drug-naïve P and NP rats showed similar levels of impulsivity on the 5-CSRTT, assessed by the number of premature, anticipatory responses, even when the waiting interval to respond was increased. However, unlike NP rats, P rats were faster to enter the food magazine and spent more time in this area. In addition, P rats showed higher levels of goal-tracking responses than NP rats, as measured by the number of magazine nose-pokes during the presentation of a food conditioned stimulus. By contrast, NP showed higher levels of sign-tracking behaviour than P rats. Following a 4-week exposure to intermittent alcohol we confirmed that P rats had a marked preference for, and consumed more alcohol than, NP rats, but were not more impulsive when re-tested in the 5-CSRTT. These findings indicate that high alcohol preferring and drinking P rats are neither intrinsically impulsive nor do they exhibit impulsivity after exposure to alcohol. However, P rats do show increased goal-directed behaviour to food incentives and this may be associated with their strong preference for alcohol.

Alcohol-Preferring Rats Show Goal Oriented Behaviour to Food Incentives but Are Neither Sign-Trackers Nor Impulsive.

Science.gov (United States)

Peña-Oliver, Yolanda; Giuliano, Chiara; Economidou, Daina; Goodlett, Charles R; Robbins, Trevor W; Dalley, Jeffrey W; Everitt, Barry J

2015-01-01

Drug addiction is often associated with impulsivity and altered behavioural responses to both primary and conditioned rewards. Here we investigated whether selectively bred alcohol-preferring (P) and alcohol-nonpreferring (NP) rats show differential levels of impulsivity and conditioned behavioural responses to food incentives. P and NP rats were assessed for impulsivity in the 5-choice serial reaction time task (5-CSRTT), a widely used translational task in humans and other animals, as well as Pavlovian conditioned approach to measure sign- and goal-tracking behaviour. Drug-naïve P and NP rats showed similar levels of impulsivity on the 5-CSRTT, assessed by the number of premature, anticipatory responses, even when the waiting interval to respond was increased. However, unlike NP rats, P rats were faster to enter the food magazine and spent more time in this area. In addition, P rats showed higher levels of goal-tracking responses than NP rats, as measured by the number of magazine nose-pokes during the presentation of a food conditioned stimulus. By contrast, NP showed higher levels of sign-tracking behaviour than P rats. Following a 4-week exposure to intermittent alcohol we confirmed that P rats had a marked preference for, and consumed more alcohol than, NP rats, but were not more impulsive when re-tested in the 5-CSRTT. These findings indicate that high alcohol preferring and drinking P rats are neither intrinsically impulsive nor do they exhibit impulsivity after exposure to alcohol. However, P rats do show increased goal-directed behaviour to food incentives and this may be associated with their strong preference for alcohol.

Detecting electroporation by assessing the time constants in the exponential response of human skin to voltage controlled impulse electrical stimulation.

Science.gov (United States)

Bîrlea, Sinziana I; Corley, Gavin J; Bîrlea, Nicolae M; Breen, Paul P; Quondamatteo, Fabio; OLaighin, Gearóid

2009-01-01

We propose a new method for extracting the electrical properties of human skin based on the time constant analysis of its exponential response to impulse stimulation. As a result of this analysis an adjacent finding has arisen. We have found that stratum corneum electroporation can be detected using this analysis method. We have observed that a one time-constant model is appropriate for describing the electrical properties of human skin at low amplitude applied voltages (30V). Higher voltage amplitudes (>30V) have been proven to create pores in the skin's stratum corneum which offer a new, lower resistance, pathway for the passage of current through the skin. Our data shows that when pores are formed in the stratum corneum they can be detected, in-vivo, due to the fact that a second time constant describes current flow through them.

Cannabis and alcohol use, affect and impulsivity in psychiatric out-patients' daily lives.

Science.gov (United States)

Trull, Timothy J; Wycoff, Andrea M; Lane, Sean P; Carpenter, Ryan W; Brown, Whitney C

2016-11-01

Cannabis and alcohol are the most commonly used (il)licit drugs world-wide. We compared the effects of cannabis and alcohol use on within-person changes in impulsivity, hostility and positive affect at the momentary and daily levels, as they occurred in daily life. Observational study involving ecological momentary assessments collected via electronic diaries six random times a day for 28 consecutive days. Out-patients' everyday life contexts in Columbia, MO, USA. Ninety-three adult psychiatric out-patients (85% female; mean = 30.9 years old) with borderline personality or depressive disorders, who reported using only cannabis (n = 3), only alcohol (n = 58) or both (n = 32) at least once during the study period. Real-time, standard self-report measures of impulsivity, hostility and positive affect, as impacted by momentary reports of cannabis and alcohol use. Cannabis use was associated with elevated feelings of impulsivity at the day level [b = 0.83, 95% confidence interval (CI) = 0.17-1.49] and increased hostility at the momentary (b = 0.07, 95% CI = 0.01-0.12) and person (b = 0.81, 95% CI = 0.15-1.47) level. Alcohol use was associated with elevated feelings of impulsivity at the momentary (b = 0.42, 95% CI = 0.13-0.71) and day levels (b = 0.82, 95% CI = 0.22-1.41) and increased positive affect at the momentary (b = 0.12, 95% CI = 0.06-0.18) and day (b = 0.33, 95% CI = 0.16-0.49) levels. Cannabis and alcohol use are associated with increases in impulsivity (both), hostility (cannabis) and positive affect (alcohol) in daily life, and these effects are part of separate processes that operate on different time-scales (i.e. momentary versus daily). © 2016 Society for the Study of Addiction.

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.

Dynamic analysis of the ethanol fermentation with the impulsive state feedback control

International Nuclear Information System (INIS)

Zhao, Zhong; Kong, Yinchang; Chen, Ying

2016-01-01

Highlights: • Ethanol fermentation model with the impulsive state feedback control is proposed. • Existence and stability of the order-1 or order-2 periodic solution are investigated. • The complete expression of the order-1 periodic solution is obtained. • Fermentation process can be effectively controlled by monitoring the impulsive period. - Abstract: To keep a sustainable and steady output of ethanol, ethanol fermentation in a bio-reactor with impulsive state feedback control is formulated. The sufficient conditions for existences of order-1 periodic solution and order-2 periodic solution are obtained by using the properties of the periodic solution. The results imply that ethanol fermentation tends to an order-1 periodic solution or order-2 periodic solution. At the same time, we also give the complete expression of the period of the positive period-1 solution. Finally, discussions and numerical simulations are given.

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.

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

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.

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.

Effect of noise and filtering on largest Lyapunov exponent of time series associated with human walking.

Science.gov (United States)

Mehdizadeh, Sina; Sanjari, Mohammad Ali

2017-11-07

This study aimed to determine the effect of added noise, filtering and time series length on the largest Lyapunov exponent (LyE) value calculated for time series obtained from a passive dynamic walker. The simplest passive dynamic walker model comprising of two massless legs connected by a frictionless hinge joint at the hip was adopted to generate walking time series. The generated time series was used to construct a state space with the embedding dimension of 3 and time delay of 100 samples. The LyE was calculated as the exponential rate of divergence of neighboring trajectories of the state space using Rosenstein's algorithm. To determine the effect of noise on LyE values, seven levels of Gaussian white noise (SNR=55-25dB with 5dB steps) were added to the time series. In addition, the filtering was performed using a range of cutoff frequencies from 3Hz to 19Hz with 2Hz steps. The LyE was calculated for both noise-free and noisy time series with different lengths of 6, 50, 100 and 150 strides. Results demonstrated a high percent error in the presence of noise for LyE. Therefore, these observations suggest that Rosenstein's algorithm might not perform well in the presence of added experimental noise. Furthermore, findings indicated that at least 50 walking strides are required to calculate LyE to account for the effect of noise. Finally, observations support that a conservative filtering of the time series with a high cutoff frequency might be more appropriate prior to calculating LyE. Copyright © 2017 Elsevier Ltd. All rights reserved.

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)

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

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

Human factors in cybersecurity; examining the link between Internet addiction, impulsivity, attitudes towards cybersecurity, and risky cybersecurity behaviours.

Science.gov (United States)

Hadlington, Lee

2017-07-01

The present study explored the relationship between risky cybersecurity behaviours, attitudes towards cybersecurity in a business environment, Internet addiction, and impulsivity. 538 participants in part-time or full-time employment in the UK completed an online questionnaire, with responses from 515 being used in the data analysis. The survey included an attitude towards cybercrime and cybersecurity in business scale, a measure of impulsivity, Internet addiction and a 'risky' cybersecurity behaviours scale. The results demonstrated that Internet addiction was a significant predictor for risky cybersecurity behaviours. A positive attitude towards cybersecurity in business was negatively related to risky cybersecurity behaviours. Finally, the measure of impulsivity revealed that both attentional and motor impulsivity were both significant positive predictors of risky cybersecurity behaviours, with non-planning being a significant negative predictor. The results present a further step in understanding the individual differences that may govern good cybersecurity practices, highlighting the need to focus directly on more effective training and awareness mechanisms.

Human factors in cybersecurity; examining the link between Internet addiction, impulsivity, attitudes towards cybersecurity, and risky cybersecurity behaviours

Directory of Open Access Journals (Sweden)

Lee Hadlington

2017-07-01

Full Text Available The present study explored the relationship between risky cybersecurity behaviours, attitudes towards cybersecurity in a business environment, Internet addiction, and impulsivity. 538 participants in part-time or full-time employment in the UK completed an online questionnaire, with responses from 515 being used in the data analysis. The survey included an attitude towards cybercrime and cybersecurity in business scale, a measure of impulsivity, Internet addiction and a ‘risky’ cybersecurity behaviours scale. The results demonstrated that Internet addiction was a significant predictor for risky cybersecurity behaviours. A positive attitude towards cybersecurity in business was negatively related to risky cybersecurity behaviours. Finally, the measure of impulsivity revealed that both attentional and motor impulsivity were both significant positive predictors of risky cybersecurity behaviours, with non-planning being a significant negative predictor. The results present a further step in understanding the individual differences that may govern good cybersecurity practices, highlighting the need to focus directly on more effective training and awareness mechanisms.

STRICT STABILITY OF IMPULSIVE SET VALUED DIFFERENTIAL EQUATIONS

Institute of Scientific and Technical Information of China (English)

无

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.

Human factors in cybersecurity; examining the link between Internet addiction, impulsivity, attitudes towards cybersecurity, and risky cybersecurity behaviours

OpenAIRE

Lee Hadlington

2017-01-01

The present study explored the relationship between risky cybersecurity behaviours, attitudes towards cybersecurity in a business environment, Internet addiction, and impulsivity. 538 participants in part-time or full-time employment in the UK completed an online questionnaire, with responses from 515 being used in the data analysis. The survey included an attitude towards cybercrime and cybersecurity in business scale, a measure of impulsivity, Internet addiction and a ?risky? cybersecurity ...

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.

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

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

Attention impairment in childhood absence epilepsy: an impulsivity problem?

Science.gov (United States)

Cerminara, Caterina; D'Agati, Elisa; Casarelli, Livia; Kaunzinger, Ivo; Lange, Klaus W; Pitzianti, Mariabernarda; Parisi, Pasquale; Tucha, Oliver; Curatolo, Paolo

2013-05-01

Although attention problems have often been described in children with childhood absence epilepsy (CAE), the use of different methodological approaches, neuropsychological tests, and heterogeneous experimental groups has prevented identification of the selective areas of attention deficit in this population. In this study, we investigated several components of attention in children with CAE using a unique computerized test battery for attention performance. Participants included 24 patients with CAE and 24 controls matched for age and sex. They were tested with a computerized test battery, which included the following tasks: selective attention, impulsivity, focused attention, divided attention, alertness, and vigilance. Compared with healthy controls, patients with CAE made more commission errors in the Go/No-Go task and more omission errors in the divided attention task. Childhood absence epilepsy patients also showed decreased reaction times in measures of selective attention and a great variability of reaction times in alertness and Go/No-Go tasks. Our findings suggest that patients with CAE were impaired in tonic and phasic alertness, divided attention, selective attention, and impulsivity. Copyright © 2013 Elsevier Inc. All rights reserved.

Loy Yang A - Australia's largest privatisation

International Nuclear Information System (INIS)

Yenckin, C.

1997-01-01

The recent A$4,746 million privatisation of the 2000MW Loy Yang A power station and the Loy Yang coal mine by the Victorian Government is Australia's largest privatisation and one of 1997's largest project financing deals. (author)

Separation of blended impulsive sources using an iterative estimation-subtraction algorithm

NARCIS (Netherlands)

Doulgeris, P.; Mahdad, A.; Blacquière, G.

2010-01-01

Traditional data acquisition practice dictates the existence of sufficient time intervals between the firing of sequential impulsive sources in the field. However, much attention has been drawn recently to the possibility of shooting in an overlapping fashion. Numerous publications have addressed

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.

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.

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.

[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.

An OFDM Receiver with Frequency Domain Diversity Combined Impulsive Noise Canceller for Underwater Network

Science.gov (United States)

Saotome, Rie; Hai, Tran Minh; Matsuda, Yasuto; Suzuki, Taisaku; Wada, Tomohisa

2015-01-01

In order to explore marine natural resources using remote robotic sensor or to enable rapid information exchange between ROV (remotely operated vehicles), AUV (autonomous underwater vehicle), divers, and ships, ultrasonic underwater communication systems are used. However, if the communication system is applied to rich living creature marine environment such as shallow sea, it suffers from generated Impulsive Noise so-called Shrimp Noise, which is randomly generated in time domain and seriously degrades communication performance in underwater acoustic network. With the purpose of supporting high performance underwater communication, a robust digital communication method for Impulsive Noise environments is necessary. In this paper, we propose OFDM ultrasonic communication system with diversity receiver. The main feature of the receiver is a newly proposed Frequency Domain Diversity Combined Impulsive Noise Canceller. The OFDM receiver utilizes 20–28 KHz ultrasonic channel and subcarrier spacing of 46.875 Hz (MODE3) and 93.750 Hz (MODE2) OFDM modulations. In addition, the paper shows Impulsive Noise distribution data measured at a fishing port in Okinawa and at a barge in Shizuoka prefectures and then proposed diversity OFDM transceivers architecture and experimental results are described. By the proposed Impulsive Noise Canceller, frame bit error rate has been decreased by 20–30%. PMID:26351656

An OFDM Receiver with Frequency Domain Diversity Combined Impulsive Noise Canceller for Underwater Network.

Science.gov (United States)

Saotome, Rie; Hai, Tran Minh; Matsuda, Yasuto; Suzuki, Taisaku; Wada, Tomohisa

2015-01-01

In order to explore marine natural resources using remote robotic sensor or to enable rapid information exchange between ROV (remotely operated vehicles), AUV (autonomous underwater vehicle), divers, and ships, ultrasonic underwater communication systems are used. However, if the communication system is applied to rich living creature marine environment such as shallow sea, it suffers from generated Impulsive Noise so-called Shrimp Noise, which is randomly generated in time domain and seriously degrades communication performance in underwater acoustic network. With the purpose of supporting high performance underwater communication, a robust digital communication method for Impulsive Noise environments is necessary. In this paper, we propose OFDM ultrasonic communication system with diversity receiver. The main feature of the receiver is a newly proposed Frequency Domain Diversity Combined Impulsive Noise Canceller. The OFDM receiver utilizes 20-28 KHz ultrasonic channel and subcarrier spacing of 46.875 Hz (MODE3) and 93.750 Hz (MODE2) OFDM modulations. In addition, the paper shows Impulsive Noise distribution data measured at a fishing port in Okinawa and at a barge in Shizuoka prefectures and then proposed diversity OFDM transceivers architecture and experimental results are described. By the proposed Impulsive Noise Canceller, frame bit error rate has been decreased by 20-30%.

An OFDM Receiver with Frequency Domain Diversity Combined Impulsive Noise Canceller for Underwater Network

Directory of Open Access Journals (Sweden)

Rie Saotome

2015-01-01

Full Text Available In order to explore marine natural resources using remote robotic sensor or to enable rapid information exchange between ROV (remotely operated vehicles, AUV (autonomous underwater vehicle, divers, and ships, ultrasonic underwater communication systems are used. However, if the communication system is applied to rich living creature marine environment such as shallow sea, it suffers from generated Impulsive Noise so-called Shrimp Noise, which is randomly generated in time domain and seriously degrades communication performance in underwater acoustic network. With the purpose of supporting high performance underwater communication, a robust digital communication method for Impulsive Noise environments is necessary. In this paper, we propose OFDM ultrasonic communication system with diversity receiver. The main feature of the receiver is a newly proposed Frequency Domain Diversity Combined Impulsive Noise Canceller. The OFDM receiver utilizes 20–28 KHz ultrasonic channel and subcarrier spacing of 46.875 Hz (MODE3 and 93.750 Hz (MODE2 OFDM modulations. In addition, the paper shows Impulsive Noise distribution data measured at a fishing port in Okinawa and at a barge in Shizuoka prefectures and then proposed diversity OFDM transceivers architecture and experimental results are described. By the proposed Impulsive Noise Canceller, frame bit error rate has been decreased by 20–30%.

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

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.

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

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.

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

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

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

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.

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.

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

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.

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.

Risk preferences impose a hidden distortion on measures of choice impulsivity

Science.gov (United States)

Konova, Anna B.; Louie, Kenway; Glimcher, Paul W.

2018-01-01

Measuring temporal discounting through the use of intertemporal choice tasks is now the gold standard method for quantifying human choice impulsivity (impatience) in neuroscience, psychology, behavioral economics, public health and computational psychiatry. A recent area of growing interest is individual differences in discounting levels, as these may predispose to (or protect from) mental health disorders, addictive behaviors, and other diseases. At the same time, more and more studies have been dedicated to the quantification of individual attitudes towards risk, which have been measured in many clinical and non-clinical populations using closely related techniques. Economists have pointed to interactions between measurements of time preferences and risk preferences that may distort estimations of the discount rate. However, although becoming standard practice in economics, discount rates and risk preferences are rarely measured simultaneously in the same subjects in other fields, and the magnitude of the imposed distortion is unknown in the assessment of individual differences. Here, we show that standard models of temporal discounting —such as a hyperbolic discounting model widely present in the literature which fails to account for risk attitudes in the estimation of discount rates— result in a large and systematic pattern of bias in estimated discounting parameters. This can lead to the spurious attribution of differences in impulsivity between individuals when in fact differences in risk attitudes account for observed behavioral differences. We advance a model which, when applied to standard choice tasks typically used in psychology and neuroscience, provides both a better fit to the data and successfully de-correlates risk and impulsivity parameters. This results in measures that are more accurate and thus of greater utility to the many fields interested in individual differences in impulsivity. PMID:29373590

Risk preferences impose a hidden distortion on measures of choice impulsivity.

Directory of Open Access Journals (Sweden)

Silvia Lopez-Guzman

Full Text Available Measuring temporal discounting through the use of intertemporal choice tasks is now the gold standard method for quantifying human choice impulsivity (impatience in neuroscience, psychology, behavioral economics, public health and computational psychiatry. A recent area of growing interest is individual differences in discounting levels, as these may predispose to (or protect from mental health disorders, addictive behaviors, and other diseases. At the same time, more and more studies have been dedicated to the quantification of individual attitudes towards risk, which have been measured in many clinical and non-clinical populations using closely related techniques. Economists have pointed to interactions between measurements of time preferences and risk preferences that may distort estimations of the discount rate. However, although becoming standard practice in economics, discount rates and risk preferences are rarely measured simultaneously in the same subjects in other fields, and the magnitude of the imposed distortion is unknown in the assessment of individual differences. Here, we show that standard models of temporal discounting -such as a hyperbolic discounting model widely present in the literature which fails to account for risk attitudes in the estimation of discount rates- result in a large and systematic pattern of bias in estimated discounting parameters. This can lead to the spurious attribution of differences in impulsivity between individuals when in fact differences in risk attitudes account for observed behavioral differences. We advance a model which, when applied to standard choice tasks typically used in psychology and neuroscience, provides both a better fit to the data and successfully de-correlates risk and impulsivity parameters. This results in measures that are more accurate and thus of greater utility to the many fields interested in individual differences in impulsivity.

Risk preferences impose a hidden distortion on measures of choice impulsivity.

Science.gov (United States)

Lopez-Guzman, Silvia; Konova, Anna B; Louie, Kenway; Glimcher, Paul W

2018-01-01

Measuring temporal discounting through the use of intertemporal choice tasks is now the gold standard method for quantifying human choice impulsivity (impatience) in neuroscience, psychology, behavioral economics, public health and computational psychiatry. A recent area of growing interest is individual differences in discounting levels, as these may predispose to (or protect from) mental health disorders, addictive behaviors, and other diseases. At the same time, more and more studies have been dedicated to the quantification of individual attitudes towards risk, which have been measured in many clinical and non-clinical populations using closely related techniques. Economists have pointed to interactions between measurements of time preferences and risk preferences that may distort estimations of the discount rate. However, although becoming standard practice in economics, discount rates and risk preferences are rarely measured simultaneously in the same subjects in other fields, and the magnitude of the imposed distortion is unknown in the assessment of individual differences. Here, we show that standard models of temporal discounting -such as a hyperbolic discounting model widely present in the literature which fails to account for risk attitudes in the estimation of discount rates- result in a large and systematic pattern of bias in estimated discounting parameters. This can lead to the spurious attribution of differences in impulsivity between individuals when in fact differences in risk attitudes account for observed behavioral differences. We advance a model which, when applied to standard choice tasks typically used in psychology and neuroscience, provides both a better fit to the data and successfully de-correlates risk and impulsivity parameters. This results in measures that are more accurate and thus of greater utility to the many fields interested in individual differences in impulsivity.

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.

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

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.

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.

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.

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...

IMPULSIVE-COMPULSIVE DISORDERS IN PARKINSON'S DISEASE. CLINICAL CASES

OpenAIRE

N. V. Fedorova; A. V. Nikitina

2015-01-01

Objective – a description of clinical cases of impulsive­compulsive disorders in Parkinson,s disease. The first clinical case. Patient N., 75 years old, suffering for 15 years from Parkinson,s disease, akinetic­rigid form of the disease, stage 4 by Hyun–Yar. Since 2009, he received levodopa/carbidopa 250/25 mg 5 times/day (daily dose of 1250 mg of levodopa); pramipexole 3.5 mg per day (daily dose 3.5 mg), amantadine sulfate 100 mg 5 times/day (daily dose 500 mg). While taking antiparkinsonian...

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.

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.

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.

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.

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

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.…

New exponential stability criteria for stochastic BAM neural networks with impulses

International Nuclear Information System (INIS)

Sakthivel, R; Samidurai, R; Anthoni, S M

2010-01-01

In this paper, we study the global exponential stability of time-delayed stochastic bidirectional associative memory neural networks with impulses and Markovian jumping parameters. A generalized activation function is considered, and traditional assumptions on the boundedness, monotony and differentiability of activation functions are removed. We obtain a new set of sufficient conditions in terms of linear matrix inequalities, which ensures the global exponential stability of the unique equilibrium point for stochastic BAM neural networks with impulses. The Lyapunov function method with the Ito differential rule is employed for achieving the required result. Moreover, a numerical example is provided to show that the proposed result improves the allowable upper bound of delays over some existing results in the literature.

New exponential stability criteria for stochastic BAM neural networks with impulses

Science.gov (United States)

Sakthivel, R.; Samidurai, R.; Anthoni, S. M.

2010-10-01

In this paper, we study the global exponential stability of time-delayed stochastic bidirectional associative memory neural networks with impulses and Markovian jumping parameters. A generalized activation function is considered, and traditional assumptions on the boundedness, monotony and differentiability of activation functions are removed. We obtain a new set of sufficient conditions in terms of linear matrix inequalities, which ensures the global exponential stability of the unique equilibrium point for stochastic BAM neural networks with impulses. The Lyapunov function method with the Itô differential rule is employed for achieving the required result. Moreover, a numerical example is provided to show that the proposed result improves the allowable upper bound of delays over some existing results in the literature.

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.

Chronic Tobacco-Smoking on Psychopathological Symptoms, Impulsivity and Cognitive Deficits in HIV-Infected Individuals.

Science.gov (United States)

Chang, Linda; Lim, Ahnate; Lau, Eric; Alicata, Daniel

2017-09-01

HIV-infected individuals (HIV+) has 2-3 times the rate of tobacco smoking than the general population, and whether smoking may lead to greater psychiatric symptoms or cognitive deficits remains unclear. We evaluated the independent and combined effects of being HIV+ and chronic tobacco-smoking on impulsivity, psychopathological symptoms and cognition. 104 participants [27 seronegative (SN)-non-Smokers, 26 SN-Smokers, 29 HIV+ non-Smokers, 22 HIV+ Smokers] were assessed for psychopathology symptoms (Symptom Checklist-90, SCL-90), depressive symptoms (Center for Epidemiologic Studies-Depression Scale, CES-D), impulsivity (Barratt Impulsiveness Scale, BIS), decision-making (The Iowa Gambling Task, IGT, and Wisconsin Card Sorting Test, WCST), and cognition (seven neurocognitive domains). Both HIV+ and Smoker groups had higher SCL-90 and CES-D scores, with highest scores in HIV+ Smokers. On BIS, both HIV+ and Smokers had higher Total Impulsiveness scores, with higher behavioral impulsivity in Smokers, highest in HIV+ Smokers. Furthermore, across the four groups, HIV+ Smokers lost most money and made fewest advantageous choices on the IGT, and had highest percent errors on WCST. Lastly, HIV+ had lower z-scores on all cognitive domains, with the lowest scores in HIV+ Smokers. These findings suggest that HIV-infection and chronic tobacco smoking may lead to additive deleterious effects on impulsivity, psychopathological (especially depressive) symptoms and cognitive dysfunction. Although greater impulsivity may be premorbid in HIV+ and Smokers, the lack of benefits of nicotine in chronic Smokers on attention and psychopathology, especially those with HIV-infection, may be due to the negative effects of chronic smoking on dopaminergic and cardio-neurovascular systems. Tobacco smoking may contribute to psychopathology and neurocognitive disorders in HIV+ individuals.

Relationship between impulsivity, hyperactivity and working memory: a differential analysis in the rat

Directory of Open Access Journals (Sweden)

Dellu-Hagedorn Françoise

2006-03-01

Full Text Available Abstract Background Impulsivity is a behavioural trait that comprises several distinct processes. It is a key feature of many psychopathologies such as mania, addictive disorders or attention deficit-hyperactivity disorders. To date, the aspects of impulsiveness involved in these pathologies have not yet been explicitly defined. In these disorders, sensation or drug seeking and cognitive deficits are closely related, but the nature of these relationships remains largely unknown. A new animal model of impulsiveness based on spontaneous inter-individual differences is proposed here to help clarify the relationship between characteristic aspects of impulsive-related pathologies. Methods Rats were divided into sub-groups according to their scores in three operant tasks with varying degrees of behavioural inhibition, timing and motor vs. cognitive impulsivity demands. These tasks included a fixed consecutive number schedule (ability to complete an action to receive a reinforcer, a multiple fixed-interval/extinction schedule of reinforcement (high level of responding, and a delayed reward task (delay discounting. In addition, measurements of locomotor responses to novelty and to amphetamine in a circular corridor, and working memory in an 8-arm radial maze were obtained. Results Substantial behavioural inter-individual differences were observed in each task, whereas few inter-task relationships were found. Impulsive rats, as defined in a task requiring inhibition of premature responses, presented a higher increase in amphetamine-induced locomotion. Reduced working memory performance was only observed in hyperactive rats in an extinction schedule. Conclusion This novel approach shows that distinct aspects of impulsiveness and hyperactivity can be expressed based on large inter-individual differences that vary from poorly to highly adapted behaviours ones in a normal population of rats. Inhibitory deficit was related to a higher response to

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.

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...

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.

Individual differences in impulsive action and dopamine transporter function in rat orbitofrontal cortex.

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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.

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.

Relationships between trait impulsivity and cognitive control: the effect of attention switching on response inhibition and conflict resolution.

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Leshem, Rotem

2016-02-01

This study examined the relationship between trait impulsivity and cognitive control, as measured by the Barratt Impulsiveness Scale (BIS) and a focused attention dichotic listening to words task, respectively. In the task, attention was manipulated in two attention conditions differing in their cognitive control demands: one in which attention was directed to one ear at a time for a whole block of trials (blocked condition) and another in which attention was switched pseudo-randomly between the two ears from trial to trial (mixed condition). Results showed that high impulsivity participants exhibited more false alarm and intrusion errors as well as a lesser ability to distinguish between stimuli in the mixed condition, as compared to low impulsivity participants. In the blocked condition, the performance levels of the two groups were comparable with respect to these measures. In addition, total BIS scores were correlated with intrusions and laterality index in the mixed but not the blocked condition. The findings suggest that high impulsivity individuals may be less prone to attentional difficulties when cognitive load is relatively low. In contrast, when attention switching is involved, high impulsivity is associated with greater difficulty in inhibiting responses and resolving cognitive conflict than is low impulsivity, as reflected in error-prone information processing. The conclusion is that trait impulsivity in a non-clinical population is manifested more strongly when attention switching is required than during maintained attention. This may have important implications for the conceptualization and treatment of impulsivity in both non-clinical and clinical populations.

Heavy ion fusion (HIF) impulse injector design, construction, and checkout

Energy Technology Data Exchange (ETDEWEB)

Wilson, M. J., LLNL

1998-05-04

The following report describes the design, construction, and checkout of a high-voltage (HV) impulser built for the heavy ion fusion (HIF) project. The purpose of this impulser is to provide an adjustable diode voltage source of sufficient quality and level to allow the optimization of beam transport and accelerator sections of HIF. An elegant, low-impedance, high-energy storage capacitor circuit has been selected for this application. A retrofit to the diode region has been included to provide additional beam stability and a controlled rise time. The critical part of this circuit that is common to all candidates is the impedance matching component. The following report provides a description of the implemented circuit, the basic circuit variables for wave shaping, component screening techniques, resulting operating parameters, diode modifications, operating considerations, and fault protection.

Speed-accuracy trade-offs in computing spatial impulse responses for simulating medical ultrasound imaging

DEFF Research Database (Denmark)

Jensen, Jørgen Arendt

2001-01-01

sampling frequency is unnecessary in the final signals, since the transducers used in medical ultrasound are band limited. Approaches to reduce the sampling frequency are, thus, needed to make efficient simulation programs. Field II uses time integration of the spatial impulse responses using a continuous......Medical ultrasound imaging can be simulated realistically using linear acoustics. One of the most powerful approaches is to employ spatial impulse responses. Hereby both emitted fields and pulse-echo responses from point scatterers can be determined. Also any kind of dynamic focusing...

Proposal for an experiment at SIN: precision measurements of μ+-impulses from disintegration of arrested pions

International Nuclear Information System (INIS)

Daum, M.; Frosch, R.; Steiner, E.

The proposed experiment of a precision measurement of μ + impulses at the time of decay into μ + ν by discrimination of arrested pions is described as regards the facilities and methods to be used. The relative impulse error is expected to be improved by one order of magnitude. The experiment will result in an important contribution to the determination of the π + and ν/sub μ/ masses. 12 references

The 5-HTTLPR polymorphism, impulsivity and suicide behavior in euthymic bipolar patients.

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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.

Simulation analysis of impulse characteristics of space debris irradiated by multi-pulse laser

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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.

A continuous wavelet transform approach for harmonic parameters estimation in the presence of impulsive noise

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Dai, Yu; Xue, Yuan; Zhang, Jianxun

2016-01-01

Impulsive noise caused by some random events has the main character of short rise-time and wide frequency spectrum range, so it has the potential to degrade the performance and reliability of the harmonic estimation. This paper focuses on the harmonic estimation procedure based on continuous wavelet transform (CWT) when the analyzed signal is corrupted by the impulsive noise. The digital CWT of both the time-varying sinusoidal signal and the impulsive noise are analyzed, and there are two cross ridges in the time-frequency plane of CWT, which are generated by the signal and the noise separately. In consideration of the amplitude of the noise and the number of the spike event, two inequalities are derived to provide limitations on the wavelet parameters. Based on the amplitude distribution of the noise, the optimal wavelet parameters determined by solving these inequalities are used to suppress the contamination of the noise, as well as increase the amplitude of the ridge corresponding to the signal, so the parameters of each harmonic component can be estimated accurately. The proposed procedure is applied to a numerical simulation and a bone vibration signal test giving satisfactory results of stationary and time-varying harmonic parameter estimation.

Impulsivity and its relationship with anxiety, depression and stress.

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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.

Bupropion improves attention but does not affect impulsive behavior in healthy young adults.

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Acheson, Ashley; de Wit, Harriet

2008-04-01

Bupropion is an effective abstinence aid for cessation of smoking and possibly other drug use as well. There is evidence that bupropion improves attention and impulse control in certain patient populations, and improvements in these processes could mediate its efficacy as an abstinence aid. In the present study, we tested the effects of acute bupropion on measures of attention and impulsivity in healthy adults with d-amphetamine included as a positive control. Twenty-two nonsmokers (11 women) and 11 smokers (4 women) completed four 4-hr sessions where they received placebo, bupropion (150 or 300 mg), or d-amphetamine (20 mg) in capsules. Ninety minutes after capsule administration, participants were tested on attention with a simple reaction time task (SRT) and on impulsivity with the stop task, a delay and probability discounting task (DPD), and the balloon analogue risk task (BART). Participants also completed mood questionnaires during sessions. Bupropion (150 mg) decreased lapses in attention on the SRT, but did not affect performance on the stop task, DPD, or BART. Amphetamine decreased lapses in attention and speeded sensory motor processing time on the SRT but did not significantly affect responding on the stop task or DPD. On the BART, d-amphetamine tended to decrease risk taking in men but increased risk taking in women. Bupropion (300 mg) and d-amphetamine increased ratings of arousal. These results suggest that bupropion improves attention without affecting impulsive behavior in healthy adults. Improvements in attention may contribute to the effectiveness of bupropion as a pharmacotherapy for smoking.

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.

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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.

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

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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.

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.

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.

The impact of Environmental Factors on Impulse Buying Behavior Using the Mehrabian and Russell’s Framework

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Amel GRAA

2014-02-01

Full Text Available This study aimed at highlighting the impact of environmental factors on the impulse buying behavior of Algerian shopper using a Stimulus and response model. In this paper, it is identified and explored how factors related to the environment of purchase and emotional states may influence various dimensions of such kind of behavior at food stores in Algeria’ west. According to the results; consumer's emotions cannot be a mediating factor in the impulse purchase process. The results indicate that seller guidance has a significant impact on the impulse buying. We have concluded also that perceived human crowding influence positively the behavior of Algerian shoppers, whereas the time pressure was not approved.

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.

[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.

Linearization of Nonautonomous Impulsive System with Nonuniform Exponential Dichotomy

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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.

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

Periodic solutions for a two-species nonautonomous competition system with diffusion and impulses

International Nuclear Information System (INIS)

Dong Lingzhen; Chen Lansun; Shi Peilin

2007-01-01

By re-estimating the upper bound of ∫ 0 ω e u i (t) dt (i=1,2), we generalize a result about the existence of a positive periodic solution for a two-species nonautonomous patchy competition system with time delay. Based on that system, we consider the impulsive harvesting and stocking, and establish a two-species nonautonomous competition Lotka-Volterra system with diffusion and impulsive effects. With the continuation theorem of coincidence degree theory, we obtain the existence of a positive periodic solution for such a system. At last, two examples are given to demonstrate our results

Modern day addictions: The role of temptations in a reflective-impulsive-interoceptive awareness model of information system use

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Ofir eTurel

2016-04-01

Full Text Available This study examines a behavioral tripartite model developed in the field of addiction, and applied 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 n1=300 and n2=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.

Impulsivity and overeating in children in the absence and presence of hunger.

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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.

[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

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.

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

Intolerance of uncertainty in opioid dependency - Relationship with trait anxiety and impulsivity.

Directory of Open Access Journals (Sweden)

Julia Garami

Full Text Available Intolerance of uncertainty (IU is the tendency to interpret ambiguous situations as threatening and having negative consequences, resulting in feelings of distress and anxiety. IU has been linked to a number of anxiety disorders, and anxiety felt in the face of uncertainty may result in maladaptive behaviors such as impulsive decision making. Although there is strong evidence that anxiety and impulsivity are risk factors for addiction, there is a paucity of research examining the role of IU in this disorder. The rate of opioid addiction, in particular, has been rising steadily in recent years, which necessitates deeper understanding of risk factors in order to develop effective prevention and treatment methods. The current study tested for the first time whether opioid-dependent adults are less tolerant of uncertainty compared to a healthy comparison group. Opioid dependent patients undergoing methadone maintenance therapy (n = 114 and healthy comparisons (n = 69 completed the following scales: Intolerance of Uncertainty Scale, the Barrett Impulsivity Scale, and the State Trait Anxiety Inventory. Analysis revealed that these measures were positively correlated with each other and that opioid-dependent patients had significantly higher IU scores. Regression analysis revealed that anxiety mediated the relationship between IU and impulsivity. Hierarchical moderation regression found an interaction between addiction status and impulsivity on IU scores in that the relationship between these variables was only observed in the patient group. Findings suggest that IU is a feature of addiction but does not necessarily play a unique role. Further research is needed to explore the complex relationship between traits and how they may contribute to the development and maintenance of addiction.

Near-Capacity Coding for Discrete Multitone Systems with Impulse Noise

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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.

Heavy drinking, impulsivity and attentional narrowing following alcohol cue exposure.

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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.

Second-to-fourth digit ratio and impulsivity: a comparison between offenders and nonoffenders.

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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.

Eyes Wide Shopped: Shopping Situations Trigger Arousal in Impulsive Buyers

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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

Eyes wide shopped: shopping situations trigger arousal in impulsive buyers.

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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.

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.

Wideband Impulse Modulation and Receiver Algorithms for Multiuser Power Line Communications

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Andrea M. Tonello

2007-01-01

Full Text Available We consider a bit-interleaved coded wideband impulse-modulated system for power line communications. Impulse modulation is combined with direct-sequence code-division multiple access (DS-CDMA to obtain a form of orthogonal modulation and to multiplex the users. We focus on the receiver signal processing algorithms and derive a maximum likelihood frequency-domain detector that takes into account the presence of impulse noise as well as the intercode interference (ICI and the multiple-access interference (MAI that are generated by the frequency-selective power line channel. To reduce complexity, we propose several simplified frequency-domain receiver algorithms with different complexity and performance. We address the problem of the practical estimation of the channel frequency response as well as the estimation of the correlation of the ICI-MAI-plus-noise that is needed in the detection metric. To improve the estimators performance, a simple hard feedback from the channel decoder is also used. Simulation results show that the scheme provides robust performance as a result of spreading the symbol energy both in frequency (through the wideband pulse and in time (through the spreading code and the bit-interleaved convolutional code.

Atomoxetine reduces hyperactive/impulsive behaviours in neurokinin-1 receptor 'knockout' mice.

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Pillidge, Katharine; Porter, Ashley J; Vasili, Temis; Heal, David J; Stanford, S Clare

2014-12-01

Mice with functional ablation of the neurokinin-1 receptor gene (NK1R(-/-)) display behavioural abnormalities which resemble the hyperactivity, inattention and impulsivity seen in Attention Deficit Hyperactivity Disorder (ADHD). Here, we investigated whether the established ADHD treatment, atomoxetine, alleviates these abnormalities when tested in the light/dark exploration box (LDEB) and 5-Choice Serial Reaction-Time Task (5-CSRTT). Separate cohorts of mice were tested in the 5-CSRTT and LDEB after treatment with no injection, vehicle or atomoxetine (5-CSRTT: 0.3, 3 or 10mg/kg; LDEB: 1, 3 or 10mg/kg). Atomoxetine reduced the hyperactivity displayed by NK1R(-/-) mice in the LDEB at a dose (3mg/kg) which did not affect the locomotor activity of wildtypes. Atomoxetine (10mg/kg) also reduced impulsivity in NK1R(-/-) mice, but not wildtypes, in the 5-CSRTT. No dose of drug affected attention in either genotype. This evidence that atomoxetine reduces hyperactive/impulsive behaviours in NK1R(-/-) mice consolidates the validity of using NK1R(-/-) mice in research of the aetiology and treatment of ADHD. Copyright © 2014. Published by Elsevier Inc.

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

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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.

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.

Sub-sampling-based 2D localization of an impulsive acoustic source in reverberant environments

KAUST Repository

Omer, Muhammad

2014-07-01

This paper presents a robust method for two-dimensional (2D) impulsive acoustic source localization in a room environment using low sampling rates. The proposed method finds the time delay from the room impulse response (RIR) which makes it robust against room reverberations. We consider the RIR as a sparse phenomenon and apply a recently proposed sparse signal reconstruction technique called orthogonal clustering (OC) for its estimation from the sub-sampled received signal. The arrival time of the direct path signal at a pair of microphones is identified from the estimated RIR, and their difference yields the desired time delay estimate (TDE). Low sampling rates reduces the hardware and computational complexity and decreases the communication between the microphones and the centralized location. Simulation and experimental results of an actual hardware setup are presented to demonstrate the performance of the proposed technique.

Sub-sampling-based 2D localization of an impulsive acoustic source in reverberant environments

KAUST Repository

Omer, Muhammad; Quadeer, Ahmed A; Sharawi, Mohammad S; Al-Naffouri, Tareq Y.

2014-01-01

This paper presents a robust method for two-dimensional (2D) impulsive acoustic source localization in a room environment using low sampling rates. The proposed method finds the time delay from the room impulse response (RIR) which makes it robust against room reverberations. We consider the RIR as a sparse phenomenon and apply a recently proposed sparse signal reconstruction technique called orthogonal clustering (OC) for its estimation from the sub-sampled received signal. The arrival time of the direct path signal at a pair of microphones is identified from the estimated RIR, and their difference yields the desired time delay estimate (TDE). Low sampling rates reduces the hardware and computational complexity and decreases the communication between the microphones and the centralized location. Simulation and experimental results of an actual hardware setup are presented to demonstrate the performance of the proposed technique.

Predicting Traffic Flow in Local Area Networks by the Largest Lyapunov Exponent

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Yan Liu

2016-01-01

Full Text Available The dynamics of network traffic are complex and nonlinear, and chaotic behaviors and their prediction, which play an important role in local area networks (LANs, are studied in detail, using the largest Lyapunov exponent. With the introduction of phase space reconstruction based on the time sequence, the high-dimensional traffic is projected onto the low dimension reconstructed phase space, and a reduced dynamic system is obtained from the dynamic system viewpoint. Then, a numerical method for computing the largest Lyapunov exponent of the low-dimensional dynamic system is presented. Further, the longest predictable time, which is related to chaotic behaviors in the system, is studied using the largest Lyapunov exponent, and the Wolf method is used to predict the evolution of the traffic in a local area network by both Dot and Interval predictions, and a reliable result is obtained by the presented method. As the conclusion, the results show that the largest Lyapunov exponent can be used to describe the sensitivity of the trajectory in the reconstructed phase space to the initial values. Moreover, Dot Prediction can effectively predict the flow burst. The numerical simulation also shows that the presented method is feasible and efficient for predicting the complex dynamic behaviors in LAN traffic, especially for congestion and attack in networks, which are the main two complex phenomena behaving as chaos in networks.

Impulses and pressure waves cause excitement and conduction in the nervous system.

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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

Dopaminergic influences on executive function and impulsive behaviour in impulse control disorders in Parkinson's disease.

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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.

Characterizing human activity induced impulse and slip-pulse excitations through structural vibration

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Pan, Shijia; Mirshekari, Mostafa; Fagert, Jonathon; Ramirez, Ceferino Gabriel; Chung, Albert Jin; Hu, Chih Chi; Shen, John Paul; Zhang, Pei; Noh, Hae Young

2018-02-01

Many human activities induce excitations on ambient structures with various objects, causing the structures to vibrate. Accurate vibration excitation source detection and characterization enable human activity information inference, hence allowing human activity monitoring for various smart building applications. By utilizing structural vibrations, we can achieve sparse and non-intrusive sensing, unlike pressure- and vision-based methods. Many approaches have been presented on vibration-based source characterization, and they often either focus on one excitation type or have limited performance due to the dispersion and attenuation effects of the structures. In this paper, we present our method to characterize two main types of excitations induced by human activities (impulse and slip-pulse) on multiple structures. By understanding the physical properties of waves and their propagation, the system can achieve accurate excitation tracking on different structures without large-scale labeled training data. Specifically, our algorithm takes properties of surface waves generated by impulse and of body waves generated by slip-pulse into account to handle the dispersion and attenuation effects when different types of excitations happen on various structures. We then evaluate the algorithm through multiple scenarios. Our method achieves up to a six times improvement in impulse localization accuracy and a three times improvement in slip-pulse trajectory length estimation compared to existing methods that do not take wave properties into account.

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

Delay discounting, impulsiveness, and addiction severity in opioid-dependent patients.

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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.

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

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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.

Adolescent impulsivity and soft drink consumption: The role of parental regulation.

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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.

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

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

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

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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.

Calculation of reactivity using a finite impulse response filter

Energy Technology Data Exchange (ETDEWEB)

Suescun Diaz, Daniel [COPPE/UFRJ, Programa de Engenharia Nuclear, Caixa Postal 68509, CEP 21941-914, RJ (Brazil); Senra Martinez, Aquilino [COPPE/UFRJ, Programa de Engenharia Nuclear, Caixa Postal 68509, CEP 21941-914, RJ (Brazil)], E-mail: aquilino@lmp.ufrj.br; Carvalho Da Silva, Fernando [COPPE/UFRJ, Programa de Engenharia Nuclear, Caixa Postal 68509, CEP 21941-914, RJ (Brazil)

2008-03-15

A new formulation is presented in this paper to solve the inverse kinetics equation. This method is based on the Laplace transform of the point kinetics equations, resulting in an expression equivalent to the inverse kinetics equation as a function of the power history. Reactivity can be written in terms of the summation of convolution with response to impulse, characteristic of a linear system. For its digital form the Z-transform is used, which is the discrete version of the Laplace transform. This new method of reactivity calculation has very special features, amongst which it can be pointed out that the linear part is characterized by a filter named finite impulse response (FIR). The FIR filter will always be, stable and non-varying in time, and, apart from this, it can be implemented in the non-recursive form. This type of implementation does not require feedback, allowing the calculation of reactivity in a continuous way.

The Right Superior Frontal Gyrus and Individual Variation in Proactive Control of Impulsive Response.

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Hu, Sien; Ide, Jaime S; Zhang, Sheng; Li, Chiang-Shan R

2016-12-14

A hallmark of cognitive control is the ability to rein in impulsive responses. Previously, we used a Bayesian model to describe trial-by-trial likelihood of the stop signal or p(Stop) and related regional activations to p(Stop) to response slowing in a stop signal task. Here, we characterized the regional processes of conflict anticipation in association with intersubject variation in impulse control in 114 young adults. We computed the stop signal reaction time (SSRT) and a measure of motor urgency, indexed by the reaction time (RT) difference between go and stop error trials or "GoRT - SERT," where GoRT is the go trial RT and SERT is the stop error RT. Motor urgency and SSRT were positively correlated across subjects. A linear regression identified regional activations to p(Stop), each in correlation with SSRT and motor urgency. We hypothesized that shared neural activities mediate the correlation between motor urgency and SSRT in proactive control of impulsivity. Activation of the ventromedial prefrontal cortex, posterior cingulate cortex and right superior frontal gyrus (SFG) during conflict anticipation correlated negatively with the SSRT. Activation of the right SFG also correlated negatively with GoRT - SERT. Therefore, activation of the right SFG was associated with more efficient response inhibition and less motor urgency. A mediation analysis showed that right SFG activation to conflict anticipation mediates the correlation between SSRT and motor urgency bidirectionally. The current results highlight a specific role of the right SFG in translating conflict anticipation to the control of impulsive response, which is consistent with earlier studies suggesting its function in action restraint. Individuals vary in impulse control. However, the neural bases underlying individual variation in proactive control of impulsive responses remain unknown. Here, in a large sample of young adults, we showed that activation of the right superior frontal gyrus (SFG

Enhanced alcohol self-administration and reinstatement in a highly impulsive, inattentive recombinant inbred mouse strain

Directory of Open Access Journals (Sweden)

Maarten eLoos

2013-10-01

Full Text Available Deficits in executive control have frequently been associated with alcohol use disorder. Here we investigated to what extent pre-existing genetically encoded levels of impulsive/inattentive behavior associate with motivation to take alcohol and vulnerability to cue-induced reinstatement of alcohol seeking in an operant self-administration paradigm. We took advantage of BXD16, a recombinant inbred strain previously shown to have enhanced impulsivity and poor attentional control. We compared BXD16 with C57BL/6J mice in a simple choice reaction time task (SCRTT and confirmed its impulsive/inattentive phenotype. BXD16 mice were less active in a novel open field, and were equally active in an automated home cage environment, showing that increased impulsive responding of BXD16 mice could not be explained by enhanced general activity compared to C57BL/6J mice. After training in a sucrose/alcohol fading self-administration procedure, BXD16 showed increased motivation to earn 10% alcohol solution, both under fixed ratio (FR1 and progressive ratio (PR2 schedules of reinforcement. Responding on the active lever readily decreased during extinction training with no apparent differences between strains. However, upon re-exposure to alcohol-associated cues, alcohol seeking was reinstated to a larger extent in BXD16 than in C57BL/6J mice. Although further studies are needed to determine whether impulsivity/inattention and alcohol seeking depend on common or separate genetic loci, these data show that in mice enhanced impulsivity coincides with increased motivation to take alcohol, as well as relapse vulnerability.

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)

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.

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

Impulse or propagation? How the tides turned in Business Cycle Theory

NARCIS (Netherlands)

Reijnders, J.P.G.

This paper contains a short history of business cycle theory. It is argued that in the course of time the emphasis shifted from a mainly exogenous to a mainly endogenous explanation of the cycle. After the integration of the two approaches in the so-called impulse and propagation theory, the balance

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).

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...