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Sample records for general impulsive biological

  1. 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

  2. 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

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

    Directory of Open Access Journals (Sweden)

    Marc Bénard

    2017-03-01

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

  4. Impulsive Biological Pest Control Strategies of the Sugarcane Borer

    Directory of Open Access Journals (Sweden)

    Marat Rafikov

    2012-01-01

    Full Text Available We propose an impulsive biological pest control of the sugarcane borer (Diatraea saccharalis by its egg parasitoid Trichogramma galloi based on a mathematical model in which the sugarcane borer is represented by the egg and larval stages, and the parasitoid is considered in terms of the parasitized eggs. By using the Floquet theory and the small amplitude perturbation method, we show that there exists a globally asymptotically stable pest-eradication periodic solution when some conditions hold. The numerical simulations show that the impulsive release of parasitoids provides reliable strategies of the biological pest control of the sugarcane borer.

  5. Impulsive gravitational waves in general massive 3D gravity

    Science.gov (United States)

    Baykal, Ahmet; Dereli, Tekin

    2017-10-01

    Impulsive, nondiverging, Petrov-Segre type-N gravitational wave solutions to a general massive three-dimensional gravity in the de Sitter, anti-de Sitter, and flat Minkowski backgrounds are constructed in a unified manner by using the exterior algebra of differential forms.

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

    Directory of Open Access Journals (Sweden)

    Shunyi Li

    2013-01-01

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

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

    Science.gov (United States)

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

    2017-05-01

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

  8. Extinction and Permanence of a General Predator-Prey System with Impulsive Perturbations

    Directory of Open Access Journals (Sweden)

    Xianning Liu

    2012-01-01

    Full Text Available A general predator-prey system is studied in a scheme where there is periodic impulsive perturbations. This scheme has the potential to protect the predator from extinction but under some conditions may also serve to lead to extinction of the prey. Conditions for extinction and permanence are obtained via the comparison methods involving monotone theory of impulsive systems and multiple Liapunov functions, which establish explicit bounds on solutions. The existence of a positive periodic solution is also studied by the bifurcation theory. Application is given to a Lotka-Volterra predator-prey system with periodic impulsive immigration of the predator. It is shown that the results are quite different from the corresponding system without impulsive immigration, where extinction of the prey can never be achieved. The prey will be extinct or permanent independent of whether the system without impulsive effect immigration is permanent or not. The model and its results suggest an approach of pest control which proves more effective than the classical one.

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

    Science.gov (United States)

    Turel, Ofir; Bechara, Antoine

    2016-01-01

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

  10. Generalized stability of motion of impulsive Lurie-Postnikov systems with structural perturbation

    Directory of Open Access Journals (Sweden)

    A. A. Martynyuk

    1998-01-01

    Full Text Available This paper investigates the absolute stability on ℊs of the zero solution of Lurie-Postnikov systems with impulses and structural perturbation. A number of absolutely stable on ℊs theorems of the Lyapunov type for Lurie-Postnikov systems are proved, extending and generalizing previous work on the subject. These results are applied to some fourth-order Lurie-Postnikov type systems decomposed into two systems.

  11. General habit propensity relates to the sensation seeking subdomain of impulsivity but not obesity

    Directory of Open Access Journals (Sweden)

    Anja Dietrich

    2016-11-01

    Full Text Available According to dual-system theory, instrumental learning and performance depend on the balance between goal-directed and habitual action control. Overreliance on habits has been argued to characterize clinical conditions such as drug addiction or obsessive-compulsive disorder as well as obesity and excessive impulsivity. A tendency towards habitual action control in obesity has already been indicated in the food domain. However, impairments might not be restricted to eating behavior. This has been suggested by domain-general obesity-associated disturbances in executive function as well as alterations in corticostriatal circuits underlying the goal-directed and habitual systems. In this study we examined the balance of goal-directed and habitual action control in a sample of normal-weight, overweight, and obese participants (n=105 using the slips-of-action test in a non-food context. We tested for continuous or group-based associations between body weight status (BMI and the devaluation sensitivity index (DSI, a parameter representing the balance of the goal-directed and habitual systems in action control. As personality differences in the domain of impulsivity might affect this relationship, we also examined whether the interaction between BMI and self-reported impulsivity, based on the UPPS Impulsive Behavior Scale, was related to the DSI. In addition to that, we tested for direct, i.e., weight status independent, relationships between UPPS subdomains of impulsivity and the DSI. We failed to find evidence for a relationship between weight status and sensitivity to devaluation as indexed by the DSI. However, independent of weight status, we observed lower sensitivity to devaluation in sensation seekers, a subtype of impulsivity. To conclude, behavioral flexibility in the sense of disturbances in the balance between the habitual and goal-directed systems seems to be unaffected by weight status in a non-food context. Consequently, stimuli and

  12. 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)

  13. Stochastic periodic solution for a perturbed non-autonomous predator-prey model with generalized nonlinear harvesting and impulses

    Science.gov (United States)

    Zhang, Yan; Chen, Shihua; Gao, Shujing; Wei, Xiang

    2017-11-01

    In this paper, stochastic non-autonomous predator-prey models with and without impulses are investigated. The effects of generalized nonlinear harvesting for prey and predator populations are considered. For the stochastic system without impulses, the existence and uniqueness of the positive solution is proven and sufficient conditions that guarantee the extinction and persistence of the population in the mean are achieved. We show the existence of a nontrivial positive periodic solution by constructing appropriate Lyapunov functions and using Khasminskii's theory. Moreover, the global attractiveness and stochastic persistence in probability of the stochastic model are discussed. Results show that the stronger noises and nonlinear harvesting component can significantly influence the dynamics of the system and lead to the extinction of the predator population. Additionally, for the stochastic predator-prey system with impulsive effect, we prove that there exists a positive periodic solution. Numerical simulations are conducted to show the effectiveness and feasibility of the obtained results.

  14. Simulations of impulsive laser scattering of biological protein assemblies: Application to M13 bacteriophage

    Science.gov (United States)

    Dykeman, Eric C.; Benson, Daryn; Tsen, K.-T.; Sankey, Otto F.

    2009-10-01

    We develop a theoretical framework, based on a bond-polarizability model, for simulating the impulsive force experienced on a protein or an assembly of proteins from a pulsed light source by coupling the laser electric field to an atomic distortion. The mechanism is impulsive stimulated Raman scattering (ISRS) where mechanical distortions produce variation in the electronic polarization through atomic displacements similar to vibrational Raman scattering. The magnitude of the impulsive force is determined from the empirical two-body bond-polarizability model and the intensity of the incident light. We apply the method to the M13 bacteriophage protein capsid system by performing several classical molecular-dynamics simulations that include the additional impulsive laser scattering force at various light intensities and pulse widths. The results of the molecular-dynamics simulations are then qualitatively interpreted with a simple harmonic oscillator model driven by ISRS. The intensity of light required to produce damage to the capsid in the simulations was found to be far higher than what was found in recent pulsed laser scattering experiments of M13 phage, suggesting that the observed inactivation of viruses with ultrashort laser pulses involves processes and/or mechanisms not taken into account in the present simulations.

  15. Biological markers of generalized anxiety disorder.

    Science.gov (United States)

    Maron, Eduard; Nutt, David

    2017-06-01

    Generalized anxiety disorder (GAD) is a prevalent and highly disabling mental health condition; however, there is still much to learn with regard to pertinent biomarkers, as well as diagnosis, made more difficult by the marked and common overlap of GAD with affective and anxiety disorders. Recently, intensive research efforts have focused on GAD, applying neuroimaging, genetic, and blood-based approaches toward discovery of pathogenetic and treatment-related biomarkers. In this paper, we review the large amount of available data, and we focus in particular on evidence from neuroimaging, genetic, and neurochemical measurements in GAD in order to better understand potential biomarkers involved in its etiology and treatment. Overall, the majority of these studies have produced results that are solitary findings, sometimes inconsistent and not clearly replicable. For these reasons, they have not yet been translated into clinical practice. Therefore, further research efforts are needed to distinguish GAD from other mental disorders and to provide new biological insights into its pathogenesis and treatment.

  16. 9 CFR 381.80 - General; biological residues.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false General; biological residues. 381.80... Carcasses and Parts § 381.80 General; biological residues. (a) The carcasses or parts of carcasses of all... sound statistical sample that they are adulterated because of the presence of any biological residues. ...

  17. [Kleptomania: an irresistible impulse].

    Science.gov (United States)

    Hatzigeorgiou, K

    2011-01-01

    This review presents the historical-epidemiological and clinical aspects of Kleptomania. The diagnostic criteria, on the basis of which it is categorized in the group of Impulse Control Disorders, are defined precisely. All the aspects of its causative pathogenesis are deeply analyzed, as they are projected through its phenomenological, psychoanalytical and psycho-biological approach. Particular emphasis is given on its differential diagnosis from other psycho-pathological conditions and especially from the co-morbidities that often accompany it. The frame of treatment is established and its course and the final outcome are analyzed. Finally, it is determined what should be the objectives of future research, which will contribute decisively to the ascertainment of the exact incidence of Kleptomania in the general population, to the clarification of its causative pathogenesis and especially to the most effective treatment of this serious mental disorder.

  18. Comparison of agriculture biology and general biology testing outcomes in Utah

    Science.gov (United States)

    Despain, Deric Walter

    Agriculture education can take scientific topics to higher levels, emphasize scientific concepts, involve hands-on learning, and develop interrelationships with the other sciences, thus making the living and non-living world around them relevant for students. Prior to 1996, agriculture education was not considered adequate to prepare Utah high school students to meet state biology requirements. The appropriateness of making that equalizing decision in 1996 was not tested until this 2014 study, comparing student test scores on the state biology test for general biology and agriculture biology students. The 2008-2012 data were collected from the Utah Department of Education Data and Statistics, utilizing a descriptive comparative post-test only analysis. As seen in this study, not only did B/AS students tend to score lower than their General Biology counterparts, in multiple cases this difference was significant (p ≤ .05). This contrary finding challenges the theoretical foundation of this study. As a result of this study three implications were made; (a) the Utah CRT-Biology test is not a reliable gauge of academic achievement in agriculture biology, (b) agriculture students in the sample population have not been taught with rigorous biology standards, and (c) biology standards taught in agricultural biology classes are not aligned with content tested by the biology portion of the Utah CRT-Biology test standards. The results of this study indicate to stakeholders that there is a gap occurring within the B/AS education, and the need to reevaluate the biology curriculum delivery to its population may possibly be in need of immediate action.

  19. 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.

  20. Non-autonomous bifurcation in impulsive systems

    Directory of Open Access Journals (Sweden)

    Marat Akhmet

    2013-12-01

    Full Text Available This is the first paper which considers non-autonomous bifurcations in impulsive differential equations. Impulsive generalizations of the non-autonomous pitchfork and transcritical bifurcation are discussed. We consider scalar differential equation with fixed moments of impulses. It is illustrated by means of certain systems how the idea of pullback attracting sets remains a fruitful concept in the impulsive systems. Basics of the theory are provided.

  1. General introduction into the Ebola virus biology and disease.

    Science.gov (United States)

    Zawilińska, Barbara; Kosz-Vnenchak, Magdalena

    2014-01-01

    Epidemic of Ebola hemorrhagic fever which appeared in the countries of West Africa in 2014, is the largest outbreak which occurred so far. The virus causing this epidemic, Zaire Ebolavirus (ZEBOV), along with four other species of Ebolaviruses is classified to the genus Ebolavirus in the family Filoviridae. ZEBOV is one of the most virulent pathogens among the viral haemorrhagic fevers, and case fatality rates up to 90% have been reported. Mortality is the result of multi-organ failure and severe bleeding complications. The aim of this review is to present the general characteristics of the virus and its biological properties, pathogenicity and epidemiology, with a focus on laboratory methods used in the diagnosis of these infections.

  2. Impulsivity in youth predicts early age-related cognitive deficits in rats.

    Science.gov (United States)

    Dellu-Hagedorn, F; Trunet, S; Simon, H

    2004-04-01

    Impulsivity is a feature of psychiatric disorders such as mania, addictive behaviors or attention deficit-hyperactivity disorder (ADHD), which has recently been related to complaints of forgetfulness in adults. We investigated whether impulsiveness exerts a long-term influence on cognitive function in rats in a longitudinal study. Impulsivity, assessed by the ability to complete a sequence of presses to obtain food (conditioning box), spatial working memory (8-arm radial maze) assessed with varying degree of attentional load and recognition memory (Y-maze) were tested at different ages. Marked individual differences in impulsivity were observed at youth and remained stable at middle-age despite a general decline in the trait. Working memory scores of impulsive and non-impulsive rats did not differ in youth, whereas by middle-age the impulsive group had impaired working memory and was more sensitive to a higher attentional demand. Thus, impulsiveness in youth predicts cognitive performance in middle-age. These findings may help refine the search for early biological substrates of successful aging and for preventive follow-up of subjects at risk of impaired cognitive aging.

  3. Buying impulses : a study on impulsive consumption

    OpenAIRE

    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 understanding of the impulse buying phenomenon. In the first 2 studies (using Dutch and Indonesian samples), a reliable 20-item scale to measure impulse buying tendency was developed. The scale has 2 facets r...

  4. General existence principles for Stieltjes differential equations with applications to mathematical biology

    Science.gov (United States)

    López Pouso, Rodrigo; Márquez Albés, Ignacio

    2018-04-01

    Stieltjes differential equations, which contain equations with impulses and equations on time scales as particular cases, simply consist on replacing usual derivatives by derivatives with respect to a nondecreasing function. In this paper we prove new existence results for functional and discontinuous Stieltjes differential equations and we show that such general results have real world applications. Specifically, we show that Stieltjes differential equations are specially suitable to study populations which exhibit dormant states and/or very short (impulsive) periods of reproduction. In particular, we construct two mathematical models for the evolution of a silkworm population. Our first model can be explicitly solved, as it consists on a linear Stieltjes equation. Our second model, more realistic, is nonlinear, discontinuous and functional, and we deduce the existence of solutions by means of a result proven in this paper.

  5. Optimal control of impulsive Volterra equations with variable impulse times

    OpenAIRE

    Belbas, S. A.; Schmidt, W. H.

    2008-01-01

    We obtain necessary conditions of optimality for impulsive Volterra integral equations with switching and impulsive controls, with variable impulse time-instants. The present work continues and complements our previous work on impulsive Volterra control with fixed impulse times.

  6. Equivalency of general biology (for majors) across a state-system

    Science.gov (United States)

    Regier, Kimberly Fayette

    General biology courses (for majors) are often transferred from one institution to another. These courses must prepare students for upper division courses in biology. A survey of U.S. college biology faculty was conducted and revealed that more 4-year faculty do not believe that all general biology courses are equivalent. An evaluation of course grades in two upper division biology courses at University of Colorado Denver (N = 2129) based upon course grades in general biology and the type of institution where general biology was taken (2-year school, 4-year, in-residence at UCD, AP credit, CLEP credit, or IB credit) was conducted. Students who transferred general biology credit received lower grades in upper division biology courses and withdrew from upper division biology courses more frequently. Syllabi from a small sample (N = 9) of general biology courses offered at Colorado 2- and 4-year schools show variation in course design. Only 30% of the courses had detailed learning objectives. Sample exams reveal a range in variation between 3-69% of questions requiring higher-order thinking according to Bloom's Taxonomy. Increasing communication between high school, 2-year and 4-year biology faculty is necessary if consistency is to be gained. Professional development for faculty to increase awareness about exam development, curriculum alignment, and curriculum mapping may reduce the disparities between the preparation of students in biology. Transfer student grade outcomes should be further investigated across the state.

  7. Course of multi-impulsive bulimia.

    Science.gov (United States)

    Fichter, M M; Quadflieg, N; Rief, W

    1994-08-01

    Thirty-two consecutively admitted females with bulimia nervosa (purging type) according to DSM-IV and additional impulsive behaviours (multi-impulsive bulimia (MIB)) and 32 age-matched female controls with DSM-IV bulimia nervosa (purging type) (uni-impulsive bulimia (UIB)) were assessed longitudinally on admission and at discharge following in-patient therapy and at a 2-year follow-up. Multi-impulsive bulimics were defined as presenting at least three of the six of the following impulsive behaviours in their life-time in addition to their bulimic symptoms at admission: (a) suicidal attempts, (b) severe autoaggression, (c) shop lifting (other than food), (d) alcohol abuse, (e) drug abuse, or (f) sexual promiscuity. Multi-impulsive bulimics were more frequently separated or divorced, had less schooling and held less-skilled jobs. Except for interoceptive awareness (EDI), which was more disturbed in multi-impulsive bulimics, there were no differences concerning scales measuring eating disturbances and related areas. Multi-impulsive bulimics showed more general psychopathology--anxiety, depression, anger and hostility, psychoticism--differed in several personality scales from uni-impulsive bulimics (e.g. increased excitability and anger/hostility) and had overall a less favourable course of illness. Multi-impulsive bulimics also received more in- and out-patient therapy previous to the index treatment and during the follow-up period. The data support the notion that 'multi-impulsive bulimia' or 'multi-impulsive disorder' should be classified as a distinct diagnostic group on axis I or that an 'Impulsive Personality Disorder' should be introduced on axis II. The development of more effective treatment for multi-impulsive bulimia is warranted.

  8. Cancer and Aging: General Principles, Biology, and Geriatric Assessment.

    Science.gov (United States)

    Li, Daneng; de Glas, Nienke A; Hurria, Arti

    2016-02-01

    Cancer is a disease of aging as older adults are much more likely to develop cancer compared with their younger counterparts. Understanding the biology of cancer and aging remains complex, and numerous theories regarding the relationship between the two have been proposed. Cancer treatment decisions in older patients are particularly challenging, because the evidence is scarce and the risk of toxicity increases with age. Determination of biologic age is essential due to heterogeneity of functional status, comorbidity, and physiologic reserves between patients of the same chronologic age. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. 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

  10. General approach to the biological analysis of complex mixtures.

    Science.gov (United States)

    Thilly, W G; Longwell, J; Andon, B M

    1983-02-01

    The study of potential health effects of combustion effluents involves identifying the substances present and estimating the probable health hazards of each. Unfortunately, this second step cannot be done by using present techniques. Approximations of health hazards by bacterial and human cell assays are being used to set priorities for further biological studies and to suggest needs for modifications of combustion systems. The assumptions underlying this approximation are discussed, and several examples of combustion effluents are reviewed.

  11. Impulsivity: differential relationship to depression and mania in bipolar disorder.

    Science.gov (United States)

    Swann, Alan C; Steinberg, Joel L; Lijffijt, Marijn; Moeller, F Gerard

    2008-03-01

    Impulsivity, a component of the initiation of action, may have a central role in the clinical biology of affective disorders. Impulsivity appears clearly to be related to mania. Despite its relationship to suicidal behavior, relationships between impulsivity and depression have been studied less than those with mania. Impulsivity is a complex construct, and it may be related differently to depression and to mania. In subjects with bipolar disorder, we investigated impulsivity in relationship to affective symptoms. Trait-like impulsivity was assessed with the Barratt Impulsiveness Scale (BIS-11). Affective symptoms were measured using the Change version of the Schedule for Affective Disorders and Schizophrenia (SADS-C). Measures were compared using analysis of variance, multiple regression and factor analysis. Impulsivity, as measured by the BIS, was related differentially to measures of depression and mania. Total and attentional impulsivity correlated independently with depression and mania scores. Motor impulsivity correlated with mania scores, while nonplanning impulsivity correlated with depression scores. These relationships were strongest in subjects who had never met criteria for a substance use disorder. Among manic symptoms, visible hyperactivity correlated most strongly with BIS scores, regardless of clinical state. Among depressive symptoms, hopelessness, anhedonia, and suicidality correlated most strongly with BIS scores. Depression and mania are differentially related to impulsivity. Impulsivity is related more strongly to measures of activity or motivation than to depressive or manic affect. The relationship between impulsivity and hopelessness may be an important factor in risk for suicide.

  12. Buying Impulses: A Study on Impulsive Consumption

    NARCIS (Netherlands)

    Herabadi, A.G.

    2003-01-01

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

  13. Generalized anxiety disorder: comorbidity, comparative biology and treatment.

    Science.gov (United States)

    Nutt, David J; Ballenger, James C; Sheehan, David; Wittchen, Hans-Ulrich

    2002-12-01

    Generalized anxiety disorder (GAD) is a severe and chronic anxiety disorder characterized by uncontrollable worrying and somatic anxiety (tension, insomnia and hypervigilance). It is a common condition, with lifetime prevalence rates for DSM-IV GAD in the general population of approx. 5-6% being reported. In addition, like other anxiety disorders, GAD also shows comorbidity with depression and most of the other anxiety disorders. This article reviews data on the prevalence of GAD, its comorbidity with depression, and its social and economic impact. Proposed neurobiological mechanisms for GAD are discussed, since an understanding of these may help in the development of future therapies. Finally, current pharmacological and non-pharmacological treatment options for GAD are reviewed, with particular attention being paid to published clinical-trial data.

  14. Grades and Withdrawal Rates in Cell Biology and Genetics Based upon Institution Type for General Biology and Implications for Transfer Articulation Agreements

    Science.gov (United States)

    Regier, Kimberly Fayette

    2016-01-01

    General biology courses (for majors) are often transferred from one institution to another. These courses must prepare students for upper division courses in biology. In Colorado, a Biology Transfer Articulation Agreement that includes general biology has been created across the state. An evaluation was conducted of course grades in two upper…

  15. 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...

  16. Impulse control disorders in adult psychiatric inpatients.

    Science.gov (United States)

    Grant, Jon E; Levine, Laura; Kim, Daniel; Potenza, Marc N

    2005-11-01

    The authors' goal was to examine the prevalence of impulse control disorders in psychiatric inpatients. They used the Minnesota Impulsive Disorders Interview, a semistructured clinical interview assessing pathological gambling, trichotillomania, kleptomania, pyromania, intermittent explosive disorder, compulsive buying, and compulsive sexual behavior, to screen 204 consecutively admitted psychiatric inpatients. One hundred twelve of the inpatients were women (54.9%), and the mean age of the 204 inpatients was 40.5 years (SD=13.2, range=18-83). Patients whose screen was positive for an impulse control disorder were evaluated with structured clinical interviews. Sixty-three patients (30.9%) were diagnosed with at least one current impulse control disorder. The most common impulse control disorders were compulsive buying (N=19 [9.3%]), kleptomania (N=16 [7.8%]), and pathological gambling (N=14 [6.9%]). Patients with and without co-occurring impulse control disorders did not differ significantly from each other on demographic measures or number or type of psychiatric diagnoses other than impulse control disorders. Impulse control disorders appear common among psychiatric inpatients. Additional, larger studies are needed to examine the prevalence of impulse control disorders in the general population and specific psychiatric groups.

  17. 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...

  18. Glutarimides: Biological activity, general synthetic methods and physicochemical properties

    Directory of Open Access Journals (Sweden)

    Popović-Đorđević Jelena B.

    2015-01-01

    Full Text Available Glutarimides, 2,6-dioxopiperidines are compounds that rarely occur in natural sources, but so far isolated ones exert widespread pharmacological activities, which makes them valuable as potential pharmacotherapeutics. Glutarimides act as androgen receptor antagonists, anti-inflammatory, anxiolytics, antibacterials, and tumor suppressing agents. Some synthetic glutarimide derivatives are already in use as immunosuppressive and sedative (e.g., thalidomide or anxiolytics (buspirone drugs. The wide applicability of this class of compounds, justify the interest of scientists to explore new pathways for its syntheses. General methods for synthesis of six-membered imide ring, are presented in this paper. These methods include: a reaction of dicarboxylic acids with ammonia or primary amine, b reactions of cyclization: amido-acids, diamides, dinitriles, nitrilo-acids, amido-nitriles, amido-esters, amidoacyl-chlorides or diacyl-chlorides, c adition of carbon-monoxide on a,b-unsaturated amides, d oxidation reactions, e Michael adition of active methylen compounds on methacrylamide or conjugated amides. Some of the described methods are used for closing glutarimide ring in syntheses of farmacological active compounds sesbanimide and aldose reductase inhibitors (ARI. Analyses of the geometry, as well as, the spectroscopic analyses (NMR and FT-IR of some glutarimides are presented because of their broad spectrum of pharmacological activity. To elucidate structures of glutarimides, geometrical parameters of newly synthesized tert-pentyl-1-benzyl-4-methyl-glutarimide-3-carboxylate (PBMG are analyzed and compared with the experimental data from X-ray analysis for glutarimide. Moreover, molecular electrostatic potential (MEP surface which is plotted over the optimized geometry to elucidate the reactivity of PBMG molecule is analyzed. The electronic properties of glutarimide derivatives are explained on the example of thalidomide. The Frontier Molecular Orbital

  19. Individual Differences in Cognitive Control Circuit Anatomy Link Sensation Seeking, Impulsivity, and Substance Use

    Science.gov (United States)

    Hollinshead, Marisa O.; Roffman, Joshua L.; Smoller, Jordan W.; Buckner, Randy L.

    2016-01-01

    Individuals vary widely in their tendency to seek stimulation and act impulsively, early developing traits with genetic origins. Failures to regulate these behaviors increase risk for maladaptive outcomes including substance abuse. Here, we explored the neuroanatomical correlates of sensation seeking and impulsivity in healthy young adults. Our analyses revealed links between sensation seeking and reduced cortical thickness that were preferentially localized to regions implicated in cognitive control, including anterior cingulate and middle frontal gyrus (n = 1015). These associations generalized to self-reported motor impulsivity, replicated in an independent group (n = 219), and correlated with heightened alcohol, tobacco, and caffeine use. Critically, the relations between sensation seeking and brain structure were evident in participants without a history of alcohol or tobacco use, suggesting that observed associations with anatomy are not solely a consequence of substance use. These results demonstrate that individual differences in the tendency to seek stimulation, act on impulse, and engage in substance use are correlated with the anatomical structure of cognitive control circuitry. Our findings suggest that, in healthy populations, covariation across these complex multidimensional behaviors may in part originate from a common underlying biology. SIGNIFICANCE STATEMENT Impaired cognitive control may result in a tendency to seek stimulation impulsively and an increased risk for maladaptive outcomes, including substance abuse. Here, we examined the structural correlates of sensation seeking and impulsivity in a large cohort of healthy young adults. Our analyses revealed links between sensation seeking and reduced cortical thickness that were preferentially localized to regions implicated in cognitive control, including anterior cingulate and middle frontal gyrus. The observed associations generalized to motor impulsivity, replicated in an independent group

  20. 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.

  1. Validation and psychometric properties of the State Impulsivity Scale (SIS).

    Science.gov (United States)

    Iribarren, M M; Jiménez-Giménez, M; García-de Cecilia, J M; Rubio-Valladolid, G

    2011-01-01

    Impulsivity is a complex phenomenon that can be evaluated from a trait or state perspective. Impulsive trait is a predisposition relatively stable over time, but not always perceptible by behavior. However, the impulsivity state covers transient variations on impulsivity levels that are dependent on environmental or biologic conditions. This study has aimed to validate a scale to assess impulsivity as a state in a Spanish sample. State Impulsivity Scale (SIS) was designed based on three experimental models: Reward, Automatism and Attentional. All the items in the SIS explore the presence and frequency of impulsive behaviors. Statistical analyses of reliability and validity were done. Convergent validity was examined by means of correlations among SIS and Barratt Impulsiveness Scale (BIS-11), Sensitivity to the punishment and sensitivity to the reward questionnaire (SPSRQ) and Sensations Seeking Scale type V (SSS). We used a Spanish sample of 70 patients who had at least one diagnosis of Impulse Control Disorder (IP), 73 psychiatric patients without impulsive disorders (NIP) and 150 control subjects (CS). The values obtained reveal the high reliability of the SIS (Cronbach's alpha coefficients 0.884), factor analysis confirmed the theoretical three-dimensional structure and convergent validity was excellent. SIS also demonstrated its capacity for discrimination among IP group and NIP and CS groups. SIS is a new impulsive behavior assessment instrument validated in Spanish population. The results obtained indicate adequate psychometric properties for its use in the clinical and research fields. Key Words: State Impulsivity, Trait, Evaluation, Scale.

  2. Correlation between MCAT Biology Content Specifications and Topic Scope and Sequence of General Education College Biology Textbooks

    Science.gov (United States)

    Rissing, Steven W.

    2013-01-01

    Most American colleges and universities offer gateway biology courses to meet the needs of three undergraduate audiences: biology and related science majors, many of whom will become biomedical researchers; premedical students meeting medical school requirements and preparing for the Medical College Admissions Test (MCAT); and students completing general education (GE) graduation requirements. Biology textbooks for these three audiences present a topic scope and sequence that correlates with the topic scope and importance ratings of the biology content specifications for the MCAT regardless of the intended audience. Texts for “nonmajors,” GE courses appear derived directly from their publisher's majors text. Topic scope and sequence of GE texts reflect those of “their” majors text and, indirectly, the MCAT. MCAT term density of GE texts equals or exceeds that of their corresponding majors text. Most American universities require a GE curriculum to promote a core level of academic understanding among their graduates. This includes civic scientific literacy, recognized as an essential competence for the development of public policies in an increasingly scientific and technological world. Deriving GE biology and related science texts from majors texts designed to meet very different learning objectives may defeat the scientific literacy goals of most schools’ GE curricula. PMID:24006392

  3. Correlation between MCAT biology content specifications and topic scope and sequence of general education college biology textbooks.

    Science.gov (United States)

    Rissing, Steven W

    2013-01-01

    Most American colleges and universities offer gateway biology courses to meet the needs of three undergraduate audiences: biology and related science majors, many of whom will become biomedical researchers; premedical students meeting medical school requirements and preparing for the Medical College Admissions Test (MCAT); and students completing general education (GE) graduation requirements. Biology textbooks for these three audiences present a topic scope and sequence that correlates with the topic scope and importance ratings of the biology content specifications for the MCAT regardless of the intended audience. Texts for "nonmajors," GE courses appear derived directly from their publisher's majors text. Topic scope and sequence of GE texts reflect those of "their" majors text and, indirectly, the MCAT. MCAT term density of GE texts equals or exceeds that of their corresponding majors text. Most American universities require a GE curriculum to promote a core level of academic understanding among their graduates. This includes civic scientific literacy, recognized as an essential competence for the development of public policies in an increasingly scientific and technological world. Deriving GE biology and related science texts from majors texts designed to meet very different learning objectives may defeat the scientific literacy goals of most schools' GE curricula.

  4. 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...

  5. Diploid biological evolution models with general smooth fitness landscapes and recombination.

    Science.gov (United States)

    Saakian, David B; Kirakosyan, Zara; Hu, Chin-Kun

    2008-06-01

    Using a Hamilton-Jacobi equation approach, we obtain analytic equations for steady-state population distributions and mean fitness functions for Crow-Kimura and Eigen-type diploid biological evolution models with general smooth hypergeometric fitness landscapes. Our numerical solutions of diploid biological evolution models confirm the analytic equations obtained. We also study the parallel diploid model for the simple case of recombination and calculate the variance of distribution, which is consistent with numerical results.

  6. TargetingImpulsivity

    NARCIS (Netherlands)

    Bergh, Filip Sebastiaan van den

    2006-01-01

    Impulsivity, poorly conceived or prematurely executed behavior, is an important characteristic of human personality, but to some people, impulsivity is debilitating. They are unable to maintain jobs or friends. In this thesis, we study the differences and similarities of two different types of

  7. A Task-Centered Approach to Freshman-Level General Biology

    Science.gov (United States)

    Francom, Greg; Bybee, David; Wolfersberger, Mark; Mendenhall, Anne; Merrill, M. David

    2009-01-01

    Many new instructional theories advocate centering instruction around a set of authentic tasks to improve application and transfer of knowledge and help students take more responsibility for their own learning. At BYU-Hawaii, a general education biology course was redesigned to follow this task-centered approach and then taught to two groups of…

  8. Parallel optical sorting of biological cells using the generalized phase contrast method

    DEFF Research Database (Denmark)

    Rindorf, Lars; Bu, Minqiang; Glückstad, Jesper

    2014-01-01

    Optical forces are used to fixate biological cells with optical tweezers where numerous biological parameters and phenomena can be studied. Optical beams carry a small momentum which generates a weak optical force, but on a cellular level this force is strong enough to allow for manipulation...... of biological cells in microfluidic systems exclusively using light. We demonstrate an optical cell sorter that uses simultaneous manipulation by multiple laser beams using the Generalized Phase Contrast method (GPC). The basic principle in an optical sorter is that the radiation force of the optical beam can...... push the biological cell from one microfluidic sheath flow to another. By incorporating a spatial light modulator the manipulation can be made parallel with multiple laser beams. We claim advantages over the serial optical sorters with only a single laser beam that has been demonstrated by others....

  9. Dimensions and disorder specificity of impulsivity in pathological gambling.

    Science.gov (United States)

    Kräplin, Anja; Bühringer, Gerhard; Oosterlaan, Jaap; van den Brink, Wim; Goschke, Thomas; Goudriaan, Anna E

    2014-11-01

    Impulsivity is a core characteristic of pathological gambling (PG), even though the underlying structure and disorder specificity is unclear. This study aimed to explore different dimensions of impulsivity in a clinical sample including PG. Furthermore, we aimed to test which alterations of the impulsivity-related dimensions are disorder specific for PG. Participants were individuals diagnosed with PG (n=51) and two groups also characterized by various impulsive behaviors: an alcohol dependence (AD; n=45) and a Gilles de la Tourette syndrome (GTS; n=49) group. A healthy control (HC; n=53) group was recruited as comparison group. A comprehensive assessment was used including impulsivity-related and antipodal parameters of the Stop Signal Task, Stroop Task, Tower of London Task, Card Playing Task, Iowa Gambling Task and the Barratt Impulsiveness Scale-11. Principal axis factor analysis revealed four impulsivity-related dimensions that were labeled 'self-reported impulsivity', 'prepotent response impulsivity', 'choice impulsivity' and 'motor impulsivity'. The PG group scored significantly higher on all four dimensions compared to the HC group. In contrast, the PG group did not differ on any of the dimensions from the AD or the GTS group, except for 'choice impulsivity' where the PG group exhibited higher factor scores compared to the GTS group. Altogether, PG is associated with generally heightened impulsivity profiles compared to a HC group, which may be further used for intervention strategies. However, heightened scores in the impulsivity dimensions are not disorder specific for PG. Further research on shared or different underlying mechanisms of these overlapping impulsivity impairments is necessary. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Biological dosimetry laboratory of the Hospital General Gregorio Maranon. A review of cases investigated

    International Nuclear Information System (INIS)

    Gomez-Espi, M.; Herranz, R.; Olivares, P.; Orera, M.

    1992-01-01

    Since 1989, in part because of our initiatory, and due in part to the support of the 'Consejo de Seguridad Nuclear', the biological dosimetry laboratory of the 'Hospital General Gregorio Maranon' is attending the individuals that are sent to the level I and II Radiopathology and Radioprotection Center with a suspicion of ionizing radiation overexposure. We have performed chromosomal aberration analysis in peripheral lymphocytes in 31 cases (June 1991). We present here the first biological dosimetry analysis performed in our Country, to demonstrate the usefulness of a technique that is commonly used outside our Country. (author)

  11. Development of a General Modeling Framework for Investigating Complex Interactions among Biological and Physical Ecosystem Dynamics

    Science.gov (United States)

    Bennett, C.; Poole, G. C.; Kimball, J. S.; Stanford, J. A.; O'Daniel, S. J.; Mertes, L. A.

    2005-05-01

    Historically, physical scientists have developed models with highly accurate governing equations, while biologists have excelled at abstraction (the strategic simplification of system complexity). These different modeling paradigms yield biological (e.g. food web) and physical (e.g. hydrologic) models that can be difficult to integrate. Complex biological dynamics may be impossible to represent with governing equations. Conversely, physical processes may be oversimplified in biological models. Using agent-based modeling, a technique applied widely in social sciences and economics, we are developing a general modeling system to integrate accurate representations of physical dynamics such as water and heat flux with abstracted biological processes such as nutrient transformations. The modeling system represents an ecosystem as a complex integrated network of intelligent physical and biological "agents" that store, transform, and trade ecosystem resources (e.g., water, heat, nutrients, carbon) using equations that describe either abstracted concepts and/or physical laws. The modular design of the system allows resource submodels to be developed independently and installed into the simulation architecture. The modeling system provides a useful heuristic tool to support integrated physical and biological research topics, such as the influence of hydrologic dynamics and spatio-temporal physical heterogeneity on trophic (food web) dynamics and/or nutrient cycling.

  12. 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...

  13. [Impulse control disorders in Parkinson's disease].

    Science.gov (United States)

    Van den Heuvel, O A; Van der Werf, Y D; Groenewegen, H J; Foncke, E M J; Berendse, H W

    2011-01-01

    Parkinson's disease is characterised not only by the classic triad of bradykinesia, rigidity and tremor, but also by the frequent occurrence of various non-motor symptoms such as the impulse control disorders (pathological gambling, hypersexuality, compulsive buying, binge eating, punding and dopamine dependency). To increase insight into the clinical presentation, risk factors, treatment and the underlying pathophysiological mechanisms of impulse control disorders in Parkinson's disease. Relevant literature was reviewed. Impulse control disorders belong to an important group of neuropsychiatric disorders that occur at some point in 5-10% of patients with Parkinson's disease. They generally occur in conjunction with dopaminergic medication and can have a marked social, relational and/ or financial impact. Early recognition of impulse control disorders in Parkinson's disease is important and a close collaboration between the neurologist and the psychiatrist is essential in order to ensure correct diagnosis and the best possible treatment. Impulse control disorders in Parkinson's disease show considerable phenomenological overlap with other repetitive behaviours within the impulsive-compulsive spectrum of disorders to which the obsessive-compulsive disorders and addiction disorders belong. The overlap can possibly be explained by a shared pathophysiological mechanism involving an imbalance between the direct and indirect pathways of the dorsal and ventral frontal-striatal circuits.

  14. Generalized Beer-Lambert model for near-infrared light propagation in thick biological tissues

    Science.gov (United States)

    Bhatt, Manish; Ayyalasomayajula, Kalyan R.; Yalavarthy, Phaneendra K.

    2016-07-01

    The attenuation of near-infrared (NIR) light intensity as it propagates in a turbid medium like biological tissue is described by modified the Beer-Lambert law (MBLL). The MBLL is generally used to quantify the changes in tissue chromophore concentrations for NIR spectroscopic data analysis. Even though MBLL is effective in terms of providing qualitative comparison, it suffers from its applicability across tissue types and tissue dimensions. In this work, we introduce Lambert-W function-based modeling for light propagation in biological tissues, which is a generalized version of the Beer-Lambert model. The proposed modeling provides parametrization of tissue properties, which includes two attenuation coefficients μ0 and η. We validated our model against the Monte Carlo simulation, which is the gold standard for modeling NIR light propagation in biological tissue. We included numerous human and animal tissues to validate the proposed empirical model, including an inhomogeneous adult human head model. The proposed model, which has a closed form (analytical), is first of its kind in providing accurate modeling of NIR light propagation in biological tissues.

  15. Generalized lattice graphs for 2D-visualization of biological information.

    Science.gov (United States)

    González-Díaz, H; Pérez-Montoto, L G; Duardo-Sanchez, A; Paniagua, E; Vázquez-Prieto, S; Vilas, R; Dea-Ayuela, M A; Bolas-Fernández, F; Munteanu, C R; Dorado, J; Costas, J; Ubeira, F M

    2009-11-07

    Several graph representations have been introduced for different data in theoretical biology. For instance, complex networks based on Graph theory are used to represent the structure and/or dynamics of different large biological systems such as protein-protein interaction networks. In addition, Randic, Liao, Nandy, Basak, and many others developed some special types of graph-based representations. This special type of graph includes geometrical constrains to node positioning in space and adopts final geometrical shapes that resemble lattice-like patterns. Lattice networks have been used to visually depict DNA and protein sequences but they are very flexible. However, despite the proved efficacy of new lattice-like graph/networks to represent diverse systems, most works focus on only one specific type of biological data. This work proposes a generalized type of lattice and illustrates how to use it in order to represent and compare biological data from different sources. We exemplify the following cases: protein sequence; mass spectra (MS) of protein peptide mass fingerprints (PMF); molecular dynamic trajectory (MDTs) from structural studies; mRNA microarray data; single nucleotide polymorphisms (SNPs); 1D or 2D-Electrophoresis study of protein polymorphisms and protein-research patent and/or copyright information. We used data available from public sources for some examples but for other, we used experimental results reported herein for the first time. This work may break new ground for the application of Graph theory in theoretical biology and other areas of biomedical sciences.

  16. Impulsive-compulsive buying disorder: clinical overview.

    Science.gov (United States)

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

    2008-04-01

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

  17. Stability Analysis and Design of Impulsive Control Lorenz Systems Family

    International Nuclear Information System (INIS)

    Yu Yongbin; Zhang Fengli; Zhang Hongbin; Yu Juebang; Liao Xiaofeng

    2009-01-01

    Lorenz systems family unifying Lorenz system, Chen system and Lue system is a typical chaotic family. In this paper, we consider impulsive control Lorenz chaotic systems family with time-varying impulse intervals. By establishing an effective tool of a set of inequalities, we analyze the asymptotic stability of impulsive control Lorenz systems family and obtain some new less conservative conditions. Based on the stability analysis, we design a novel impulsive controller with time-varying impulse intervals. Illustrative examples are provided to show the feasibility and effectiveness of our method. The obtained results not only can be used to design impulsive control for Lorenz systems family, but also can be extended to other chaotic systems. (general)

  18. 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.

  19. Physicochemical Properties, Biological Activity, Health Benefits, and General Limitations of Aged Black Garlic: A Review.

    Science.gov (United States)

    Ryu, Ji Hyeon; Kang, Dawon

    2017-06-01

    Garlic (Allium sativum) has been used as a medicinal food since ancient times. However, some people are reluctant to ingest raw garlic due to its unpleasant odor and taste. Therefore, many types of garlic preparations have been developed to reduce these attributes without losing biological functions. Aged black garlic (ABG) is a garlic preparation with a sweet and sour taste and no strong odor. It has recently been introduced to Asian markets as a functional food. Extensive in vitro and in vivo studies have demonstrated that ABG has a variety of biological functions such as antioxidant, anti-inflammatory, anti-cancer, anti-obesity, anti-diabetic, anti-allergic, cardioprotective, and hepatoprotective effects. Recent studies have compared the biological activity and function of ABG to those of raw garlic. ABG shows lower anti-inflammatory, anti-coagulation, immunomodulatory, and anti-allergic effects compared to raw garlic. This paper reviews the physicochemical properties, biological activity, health benefits, adverse effects, and general limitations of ABG.

  20. General Chemistry and Cellular and Molecular Biology: An Experiment in Curricular Symbiosis

    Science.gov (United States)

    Truman Schwartz, A.; Serie, Jan

    2001-11-01

    During the 1998-99 academic year, with the support of the Howard Hughes Medical Institute, we co-taught integrated courses in general chemistry and cell biology to 23 first-year students. The double course was organized around six units: I. Energetics: Harvesting (Bio)Chemical Energy; II. The Regulation of Biological Processes: Chemical Kinetics and Equilibrium; III. Membranes and Electrochemical Gradients; IV. Acids and Bases and the Regulation of pH; V. Intracellular Compartments and Transport; and VI. Cellular Communication. The chemistry and biology were both taught in a manner meant to enhance understanding of these major themes and to emphasize the relationships between the two disciplines. Both of us were present for all class sessions and shared teaching responsibilities. The examinations, which corresponded to the units, also stressed the interdependence of biology and chemistry. The laboratory components were not integrated; rather the students were dispersed among laboratory sections shared with students from more traditional lecture sections. The paper reports on this experiment in curricular symbiosis, which proved to be a challenging and rewarding learning experience for both the students and us.

  1. Physicochemical Properties, Biological Activity, Health Benefits, and General Limitations of Aged Black Garlic: A Review

    Directory of Open Access Journals (Sweden)

    Ji Hyeon Ryu

    2017-06-01

    Full Text Available Garlic (Allium sativum has been used as a medicinal food since ancient times. However, some people are reluctant to ingest raw garlic due to its unpleasant odor and taste. Therefore, many types of garlic preparations have been developed to reduce these attributes without losing biological functions. Aged black garlic (ABG is a garlic preparation with a sweet and sour taste and no strong odor. It has recently been introduced to Asian markets as a functional food. Extensive in vitro and in vivo studies have demonstrated that ABG has a variety of biological functions such as antioxidant, anti-inflammatory, anti-cancer, anti-obesity, anti-diabetic, anti-allergic, cardioprotective, and hepatoprotective effects. Recent studies have compared the biological activity and function of ABG to those of raw garlic. ABG shows lower anti-inflammatory, anti-coagulation, immunomodulatory, and anti-allergic effects compared to raw garlic. This paper reviews the physicochemical properties, biological activity, health benefits, adverse effects, and general limitations of ABG.

  2. Full-wave solution of short impulses in inhomogeneous plasma

    Indian Academy of Sciences (India)

    Permanent link: https://www.ias.ac.in/article/fulltext/pram/064/02/0249-0268. Keywords. Wave propagation; electromagnetic theory; impulses in plasma. Abstract. In this paper the problem of real impulse propagation in arbitrarily inhomogeneous media will be presented on a fundamentally new, general, theoretical way.

  3. Generalized Fokker-Planck theory for electron and photon transport in biological tissues: application to radiotherapy.

    Science.gov (United States)

    Olbrant, Edgar; Frank, Martin

    2010-12-01

    In this paper, we study a deterministic method for particle transport in biological tissues. The method is specifically developed for dose calculations in cancer therapy and for radiological imaging. Generalized Fokker-Planck (GFP) theory [Leakeas and Larsen, Nucl. Sci. Eng. 137 (2001), pp. 236-250] has been developed to improve the Fokker-Planck (FP) equation in cases where scattering is forward-peaked and where there is a sufficient amount of large-angle scattering. We compare grid-based numerical solutions to FP and GFP in realistic medical applications. First, electron dose calculations in heterogeneous parts of the human body are performed. Therefore, accurate electron scattering cross sections are included and their incorporation into our model is extensively described. Second, we solve GFP approximations of the radiative transport equation to investigate reflectance and transmittance of light in biological tissues. All results are compared with either Monte Carlo or discrete-ordinates transport solutions.

  4. Academic beliefs and behaviors in on-campus and online General Education biology classes

    Science.gov (United States)

    Noll, Christopher B.

    This study examined the effect of course delivery mode on academic help-seeking beliefs and behaviors, academic self-efficacy, and the levels of individual interest in biology of students in an entry-level General Education biology course. This intersection of online education, science courses, and academic success factors merits attention because the growing impact of the expansion of online education on undergraduate success, particularly in science courses, has not been fully studied. The specific questions guiding the study examined: whether course delivery mode impacted individual interest in biology; whether course delivery mode impacted help-seeking beliefs and behaviors; and whether course delivery mode, individual interest, and academic self-efficacy predicted academic performance in the course. Participants (N = 183) were enrolled in either online or on-campus sections of a biology course at a large public university in California. Quantitative data for the study were collected through two online surveys in a pre- and post-test design and analyzed via Chi-square, t-tests, and regression analysis using SPSS. The findings of this study indicate that course delivery mode does not impact individual interest in biology. The data further indicate that academic help-seeking beliefs and behaviors vary by course delivery mode. This study also finds that while neither self-efficacy nor individual interest predict performance in the course, course delivery mode is shown to impact performance, although the reasons for this difference are unclear. The results of the study will be useful to course designers and administrators of online education as they seek to maximize the experiences of online students.

  5. Dynamic Properties of Impulse Measuring Systems

    DEFF Research Database (Denmark)

    Pedersen, A.; Lausen, P.

    1971-01-01

    After some basic considerations the dynamic properties of the measuring system are subjected to a general examination based on a number of responses, characteristic of the system. It is demonstrated that an impulse circuit has an internal impedance different from zero, for which reason...

  6. Environment and biology of the Kara Sea: a general view for contamination studies.

    Science.gov (United States)

    Miquel, J C

    2001-01-01

    The recent revelation that over the past 30 years there has been a history of dumping waste including high-level radioactive wastes in the shallow Kara Sea has caused wide-spread concern. The potential impact of these contaminants and other non-nuclear pollutants in the Arctic ecosystem and on human health need to be assessed and, thus, a better insight gained on radioecological processes in cold waters. The present paper proposes a general view on the biology and the environment of the Kara Sea, as a basic tool for the experimental and modelling assessments of the impact of these contaminants.

  7. Periodicity computation of generalized mathematical biology problems involving delay differential equations.

    Science.gov (United States)

    Jasim Mohammed, M; Ibrahim, Rabha W; Ahmad, M Z

    2017-03-01

    In this paper, we consider a low initial population model. Our aim is to study the periodicity computation of this model by using neutral differential equations, which are recognized in various studies including biology. We generalize the neutral Rayleigh equation for the third-order by exploiting the model of fractional calculus, in particular the Riemann-Liouville differential operator. We establish the existence and uniqueness of a periodic computational outcome. The technique depends on the continuation theorem of the coincidence degree theory. Besides, an example is presented to demonstrate the finding.

  8. Learning to improve: using writing to increase critical thinking performance in general education biology.

    Science.gov (United States)

    Quitadamo, Ian J; Kurtz, Martha J

    2007-01-01

    Increasingly, national stakeholders express concern that U.S. college graduates cannot adequately solve problems and think critically. As a set of cognitive abilities, critical thinking skills provide students with tangible academic, personal, and professional benefits that may ultimately address these concerns. As an instructional method, writing has long been perceived as a way to improve critical thinking. In the current study, the researchers compared critical thinking performance of students who experienced a laboratory writing treatment with those who experienced traditional quiz-based laboratory in a general education biology course. The effects of writing were determined within the context of multiple covariables. Results indicated that the writing group significantly improved critical thinking skills whereas the non-writing group did not. Specifically, analysis and inference skills increased significantly in the writing group but not the non-writing group. Writing students also showed greater gains in evaluation skills; however, these were not significant. In addition to writing, prior critical thinking skill and instructor significantly affected critical thinking performance, whereas other covariables such as gender, ethnicity, and age were not significant. With improved critical thinking skill, general education biology students will be better prepared to solve problems as engaged and productive citizens.

  9. The effect of graphic organizers on students' attitudes and academic performance in undergraduate general biology

    Science.gov (United States)

    Cleveland, Lacy

    High attrition among undergraduate Science Technology Engineering and Mathematics (STEM) majors has led national and business leaders in the United States to call for both research and educational reform within the collegiate STEM classrooms. Included among suggestions for reform are ideas to improve retention of first-year students and to improve critical thinking and depth of knowledge, instead of covering large quantities of materials. Past research on graphic organizers suggest these tools assist students in learning information and facilitate conceptual and critical thinking. Despite their widespread use in high school science departments, collegiate humanities departments, and even medical schools, their use is considerably less prevalent in the undergraduate biology classroom. In addition to their lack of use, little research has been conducted on their academic benefits in the collegiate classroom. Based on national calls for improving retention among undergraduate STEM majors and research suggesting that academic success during an individual first major's related course highly determine if that individual will continue on in their intended major, the researcher of this dissertation chose to conduct research on an introductory general biology class. Using both quantitative and qualitative methods, the research in this dissertation examines the effectiveness of graphic organizers in promoting academic success and also examines their influence on student attitudes. This research is grounded in the theories of constructivism and cognitive load theory. Constructivism suggests that individuals must build their knowledge from their personal experiences, while the cognitive load theory recognizes the limited nature of one's working memory and suggests that instructional practices minimize cognitive overload. The results of this dissertation suggest that the use of graphic organizers in an undergraduate general biology classroom can increase students' academic

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

    Directory of Open Access Journals (Sweden)

    Yaniv Hanoch

    Full Text Available 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.

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

    Science.gov (United States)

    Hanoch, Yaniv; Gummerum, Michaela; Rolison, Jonathan

    2012-01-01

    Personality characteristics, particularly impulsive tendencies, have long been conceived as the primary culprit in delinquent behavior. One crucial question to emerge from this line of work is whether impulsivity has a biological basis. To test this possibility, 44 male offenders and 46 nonoffenders completed the Eysenck Impulsivity Questionnaire, and had their 2D∶4D ratio measured. Offenders exhibited smaller right hand digit ratio measurements compared to non-offenders, but higher impulsivity scores. Both impulsivity and 2D∶4D ratio measurements significantly predicted criminality (offenders vs. nonoffenders). Controlling for education level, the 2D∶4D ratio measurements had remained a significant predictor of criminality, while impulsivity scores no longer predicted criminality significantly. Our data, thus, indicates that impulsivity but not 2D∶4D ratio measurements relate to educational attainment. As offenders varied in their number of previous convictions and the nature of their individual crimes, we also tested for differences in 2D∶4D ratio and impulsivity among offenders. Number of previous convictions did not correlate significantly with the 2D∶4D ratio measurements or impulsivity scores. Our study established a link between a biological marker and impulsivity among offenders (and lack thereof among non-offenders), which emphasise the importance of studying the relationship between biological markers, impulsivity and criminal behavior.

  12. A generalized Born formalism for heterogeneous dielectric environments: application to the implicit modeling of biological membranes.

    Science.gov (United States)

    Tanizaki, Seiichiro; Feig, Michael

    2005-03-22

    Reliable computer simulations of complex biological environments such as integral membrane proteins with explicit water and lipid molecules remain a challenging task. We propose a modification of the standard generalized Born theory of homogeneous solvent for modeling the heterogeneous dielectric environments such as lipid/water interfaces. Our model allows the representation of biological membranes in the form of multiple layered dielectric regions with dielectric constants that are different from the solute cavity. The proposed new formalism is shown to predict the electrostatic component of solvation free energy with a relative error of 0.17% compared to exact finite-difference solutions of the Poisson equation for a transmembrane helix test system. Molecular dynamics simulations of melittin and bacteriorhodopsin are carried out and performed over 10 ns and 7 ns of simulation time, respectively. The center of melittin along the membrane normal in these stable simulations is in excellent agreement with the relevant experimental data. Simulations of bacteriorhodopsin started from the experimental structure remained stable and in close agreement with experiment. We also examined the free energy profiles of water and amino acid side chain analogs upon membrane insertion. The results with our implicit membrane model agree well with the experimental transfer free energy data from cyclohexane to water as well as explicit solvent simulations of water and selected side chain analogs.

  13. [The biomonitoring of toxic substances in biological samples of general population].

    Science.gov (United States)

    Ibarluzea, Jesús; Aurrekoetxea, Juan José; Porta, Miquel; Sunyer, Jordi; Ballester, Ferran

    2016-11-01

    Many of the world's most developed countries have adopted biomonitoring of toxic substances in order to ascertain their levels in biological samples. These substances get into the body through different environmental exposures. Monitoring toxic substances in biological samples should allow us to ascertain their levels in vulnerable groups, assess their evolution over time, make comparisons with levels observed in other countries, identify groups at risk or with high toxic levels and promote research. The main objective of biomonitoring is to act as a policy design tool to facilitate the implementation of particular measures in various sectors: health, environmental, agricultural and livestock or food industry sectors. In Spain, information on levels of toxic substances of environmental origin is provided by specific studies on health effects from environmental sources, such as the INMA project (INfancia y Medio Ambiente [childhood and environment]). In addition, biomonitoring projects have been implemented in Catalonia and the Canary Islands, together with a national biomonitoring programme in the adult working population. However, further progress is needed to develop a system that covers the general population as well as subgroups at risk, which relies on the collaboration of the involved authorities and the participation of professionals from different sectors and citizen organisations interested in the relationship between health and the environment. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. 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...... of the emitting aperture. Summing the angles of the arcs within the aperture readily yields the spatial impulse response for a point in space. The approach makes is possible to make very general calculation routines for arbitrary, flat apertures in which the outline of the aperture is either analytically...... be used for finding analytic solutions to the spatial impulse response for new geometries of, for example, ellipsoidal shape. The approach also makes it easy to incorporate any apodization function and the effect from different transducers baffle mountings. Examples of spatial impulse responses...

  15. General Academic or Domain-Specific Vocabulary?: The Impact of Word Selection in High School Biology

    Science.gov (United States)

    Birmingham, Elizabeth A.

    The purpose of this study was to determine the impact of learning various types of words in biology on students' reading comprehension, vocabulary performance, and science content knowledge. The study involved 315 ninth grade biology students who were placed in one of four groups and spent two weeks for ten minutes per day working on independent vocabulary packets in which they practiced a set of 15 words. Group one's list was a combination of domain-specific and general academic words, group two's list was a set of general academic words, and group three's list was a set of domain-specific words. The fourth group, the control group, did no formal vocabulary work but instead completed lessons involving the ecology content. In this quasi-experiment, the independent variable was the instructional group assignment, and the dependent variables were the students' performances on the reading comprehension, vocabulary (broken into various categories), and content assessments. Descriptive statistics for the majority of the vocabulary items and for the comprehension and content post-test measures revealed that the third group had the highest overall achievement. Throughout the two weeks of treatment, the third group worked only with domain-specific words related to ecology. A multivariate analysis of covariance (MANCOVA) found the differences to be statistically significant. The individual dependent variables were analyzed and found two question types on the vocabulary test, the domainspecific and general academic, to be significant in the test of between-subjects effects. Further, instructional group assignment did not have an effect on reading comprehension and content Descriptive statistics for the majority of the vocabulary items and for the comprehension and content post-test measures revealed that the third group had the highest overall achievement. Throughout the two weeks of treatment, the third group worked only with domain-specific words related to ecology. A

  16. Impulsive behaviors in female patients with eating disorders in a university hospital in northern Taiwan

    Directory of Open Access Journals (Sweden)

    Kuei-Yu Liang

    2011-09-01

    Full Text Available Eating disorders (EDs are often associated with various impulsive behaviors. This study investigated the prevalence of impulsive behaviors in ED patients in Taiwan. Three hundred sixteen female outpatients with ED and 142 psychiatric controls were recruited. All participants completed self-administered questionnaires assessing lifetime presence of impulsive behaviors, including suicide, self-injury, stealing, alcohol use, illicit drug use, excessive spending, sexual promiscuity, and general psychopathology. More than 60% of the ED patients had at least one impulsive behavior. The most common impulsive behaviors among ED patients were excessive spending (34.9%, deliberate self-harm (32.7%, and stealing (26.3%. However, there were no significant differences in prevalences of any impulsive behaviors between ED patients and psychiatric controls. Clinicians should routinely assess and treat impulsive behaviors in female psychiatric patients with negative affectivity, regardless of the presence of ED, to help prevent potential adverse outcomes related to impulsive behaviors.

  17. 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.

  18. Quantitative generalized ratiometric fluorescence spectroscopy for turbid media based on probe encapsulated by biologically localized embedding

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Xiu-Fang; Chen, Zeng-Ping, E-mail: zpchen2002@hotmail.com; Cui, Yin-Yin; Hu, Yuan-Liang; Yu, Ru-Qin

    2016-05-19

    PEBBLE (probe encapsulated by biologically localized embedding) nanosensor encapsulating an intensity-based fluorescence indicator and an inert reference fluorescence dye inside the pores of stable matrix can be used as a generalized wavelength-ratiometric probe. However, the lack of an efficient quantitative model render the choices of inert reference dyes and intensity-based fluorescence indicators used in PEBBLEs based generalized wavelength-ratiometric probes rather limited. In this contribution, an extended quantitative fluorescence model was derived specifically for generalized wavelength-ratiometric probes based on PEBBLE technique (QFM{sub GRP}) with a view to simplify the design of PEBBLEs and hence further extend their application potentials. The effectiveness of QFM{sub GRP} has been tested on the quantitative determination of free Ca{sup 2+} in both simulated and real turbid media using a Ca{sup 2+} sensitive PEBBLE nanosensor encapsulating Rhod-2 and eosin B inside the micropores of stable polyacrylamide matrix. Experimental results demonstrated that QFM{sub GRP} could realize precise and accurate quantification of free Ca{sup 2+} in turbid samples, even though there is serious overlapping between the fluorescence excitation peaks of eosin B and Ca{sup 2+} bound Rhod-2. The average relative predictive error value of QFM{sub GRP} for the test simulated turbid samples was 5.9%, about 2–4 times lower than the corresponding values of partial least squares calibration model and the empirical ratiometric model based on the ratio of fluorescence intensities at the excitation peaks of Ca{sup 2+} bound Rhod-2 and eosin B. The recovery rates of QFM{sub GRP} for the real and spiked turbid samples varied from 93.1% to 101%, comparable to the corresponding results of atomic absorption spectrometry. - Highlights: • An advanced model was derived for generalized wavelength-ratiometric PEBBLEs. • The model can simplify the design of generalized wavelength

  19. The relationship between learning communities and student interaction and retention in general biology courses

    Science.gov (United States)

    Wardle, Karen Marie

    The relationship between learning communities and student interaction and retention in community college general biology courses was investigated in this study. The purposes of the study were to discover the students' perceptions of factors influencing their desire to study science, and to examine the use of learning communities as a method of enculturation into the field of science. The learning community in the CCD science courses involved an entry-level science course that was linked with a tutorial enrichment of the underlying principles in scientific research. The coordination between the class and the learning community involved an extensive research project that incorporated important scientific principles. The project goals for student research included an understanding of the scientific method, and an increased engagement in scientific inquiry. Collaboration and communication among students was an additional goal of the leaning communities. A quasi-experiment with pre- and post-measures of student attitudes and perceptions of success in first and second semester biology courses. A premeasure was followed by a quasi experiment in which entry level biology courses were conducted using either learning communities or traditional lecture. Results show the factors students perceived as important to their success in entry-level science courses included their professors and peers. Discriminant results revealed that the factors predicted completion of the courses 75% of the time. Qualitative tests reveal that students in learning communities show a slight increase in community interactions and willingness to explore the content material beyond the material needed for the class, however these results were not significantly higher than the control courses. Future studies include collecting data on the learning communities for longer than a one-year period. The incorporation of the research projects into the courses has lasting value in terms of encouraging new

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

    Directory of Open Access Journals (Sweden)

    Eline W M Scholten

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

  1. 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.

  2. A novel biological 'twin-father' temporal paradox of General Relativity in a Gödel universe - Where reproductive biology meets theoretical physics.

    Science.gov (United States)

    Ashrafian, Hutan

    2018-03-01

    Several temporal paradoxes exist in physics. These include General Relativity's grandfather and ontological paradoxes and Special Relativity's Langevin-Einstein twin-paradox. General relativity paradoxes can exist due to a Gödel universe that follows Gödel's closed timelike curves solution to Einstein's field equations. A novel biological temporal paradox of General Relativity is proposed based on reproductive biology's phenomenon of heteropaternal fecundation. Herein, dizygotic twins from two different fathers are the result of concomitant fertilization during one menstrual cycle. In this case an Oedipus-like individual exposed to a Gödel closed timelike curve would sire a child during his maternal fertilization cycle. As a consequence of heteropaternal superfecundation, he would father his own dizygotic twin and would therefore generate a new class of autofraternal superfecundation, and by doing so creating a 'twin-father' temporal paradox. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Impulsive Delayed Reward Discounting as a Genetically-Influenced Target for Drug Abuse Prevention: A Critical Evaluation

    Directory of Open Access Journals (Sweden)

    Joshua C. Gray

    2015-09-01

    Full Text Available This review evaluates the viability of delayed reward discounting (DRD, an index of how much an individual devalues a future reward based on its delay in time, for genetically-informed drug abuse prevention. A review of the literature suggests that impulsive DRD is robustly associated with drug addiction and meets most of the criteria for being an endophenotype, albeit with mixed findings for specific molecular genetic influences. Several modes of experimental manipulation have been demonstrated to reduce DRD acutely. These include behavioral strategies, such as mindfulness, reward bundling, and episodic future thinking; pharmacological interventions, including noradrengic agonists, adrenergic agonists, and multiple monoamine agonists; and neuromodulatory interventions, such as transcranial magnetic stimulation and transcranial direct current stimulation. However, the generalization of these interventions to positive clinical outcomes remains unclear and no studies to date have examined interventions on DRD in the context of prevention. Collectively, these findings suggest it would be premature to target DRD for genetically-informed prevention. Indeed, given the evidence of environmental contributions such as early life adversity to impulsive DRD, whether genetically-informed secondary prevention would ever be warranted is debatable. However, progress in identifying polymorphisms associated with DRD preference could further clarify the underlying biological systems implicated in impulsive DRD for further progress in pharmacological and neuromodulatory interventions. Furthermore, independent of genetically-informed prevention, impulsive DRD is a qualitatively different risk factor from existing prevention programs and is generally worthy of investigation as a novel and promising drug abuse prevention target.

  4. Can a Diversified Instructional Approach Featuring Active Learning Improve Biology Students' Attitudes toward General Education?

    Science.gov (United States)

    Rutledge, Michael L.; Lampley, Sandra A.

    2017-01-01

    In an effort to make our classes more engaging, we recently reorganized sections of our nonmajors biology course, using current issues in biology and society as a premise to promote coherence among course content and emphasize the relevance of biological concepts to everyday life. A key aspect of the reorganization included the development and…

  5. Modeling fibrous biological tissues with a general invariant that excludes compressed fibers

    Science.gov (United States)

    Li, Kewei; Ogden, Ray W.; Holzapfel, Gerhard A.

    2018-01-01

    Dispersed collagen fibers in fibrous soft biological tissues have a significant effect on the overall mechanical behavior of the tissues. Constitutive modeling of the detailed structure obtained by using advanced imaging modalities has been investigated extensively in the last decade. In particular, our group has previously proposed a fiber dispersion model based on a generalized structure tensor. However, the fiber tension-compression switch described in that study is unable to exclude compressed fibers within a dispersion and the model requires modification so as to avoid some unphysical effects. In a recent paper we have proposed a method which avoids such problems, but in this present study we introduce an alternative approach by using a new general invariant that only depends on the fibers under tension so that compressed fibers within a dispersion do not contribute to the strain-energy function. We then provide expressions for the associated Cauchy stress and elasticity tensors in a decoupled form. We have also implemented the proposed model in a finite element analysis program and illustrated the implementation with three representative examples: simple tension and compression, simple shear, and unconfined compression on articular cartilage. We have obtained very good agreement with the analytical solutions that are available for the first two examples. The third example shows the efficacy of the fibrous tissue model in a larger scale simulation. For comparison we also provide results for the three examples with the compressed fibers included, and the results are completely different. If the distribution of collagen fibers is such that it is appropriate to exclude compressed fibers then such a model should be adopted.

  6. The effects of violence exposure on the development of impulse control and future orientation across adolescence and early adulthood: Time-specific and generalized effects in a sample of juvenile offenders.

    Science.gov (United States)

    Monahan, Kathryn C; King, Kevin M; Shulman, Elizabeth P; Cauffman, Elizabeth; Chassin, Laurie

    2015-11-01

    Impulse control and future orientation increase across adolescence, but little is known about how contextual factors shape the development of these capacities. The present study investigates how stress exposure, operationalized as exposure to violence, alters the developmental pattern of impulse control and future orientation across adolescence and early adulthood. In a sample of 1,354 serious juvenile offenders, higher exposure to violence was associated with lower levels of future orientation at age 15 and suppressed development of future orientation from ages 15 to 25. Increases in witnessing violence or victimization were linked to declines in impulse control 1 year later, but only during adolescence. Thus, beyond previous experiences of exposure to violence, witnessing violence and victimization during adolescence conveys unique risk for suppressed development of self-regulation.

  7. Community-based inquiry improves critical thinking in general education biology.

    Science.gov (United States)

    Quitadamo, Ian J; Faiola, Celia L; Johnson, James E; Kurtz, Martha J

    2008-01-01

    National stakeholders are becoming increasingly concerned about the inability of college graduates to think critically. Research shows that, while both faculty and students deem critical thinking essential, only a small fraction of graduates can demonstrate the thinking skills necessary for academic and professional success. Many faculty are considering nontraditional teaching methods that incorporate undergraduate research because they more closely align with the process of doing investigative science. This study compared a research-focused teaching method called community-based inquiry (CBI) with traditional lecture/laboratory in general education biology to discover which method would elicit greater gains in critical thinking. Results showed significant critical-thinking gains in the CBI group but decreases in a traditional group and a mixed CBI/traditional group. Prior critical-thinking skill, instructor, and ethnicity also significantly influenced critical-thinking gains, with nearly all ethnicities in the CBI group outperforming peers in both the mixed and traditional groups. Females, who showed decreased critical thinking in traditional courses relative to males, outperformed their male counterparts in CBI courses. Through the results of this study, it is hoped that faculty who value both research and critical thinking will consider using the CBI method.

  8. Efficient reconstruction of biological networks via transitive reduction on general purpose graphics processors.

    Science.gov (United States)

    Bošnački, Dragan; Odenbrett, Maximilian R; Wijs, Anton; Ligtenberg, Willem; Hilbers, Peter

    2012-10-30

    Techniques for reconstruction of biological networks which are based on perturbation experiments often predict direct interactions between nodes that do not exist. Transitive reduction removes such relations if they can be explained by an indirect path of influences. The existing algorithms for transitive reduction are sequential and might suffer from too long run times for large networks. They also exhibit the anomaly that some existing direct interactions are also removed. We develop efficient scalable parallel algorithms for transitive reduction on general purpose graphics processing units for both standard (unweighted) and weighted graphs. Edge weights are regarded as uncertainties of interactions. A direct interaction is removed only if there exists an indirect interaction path between the same nodes which is strictly more certain than the direct one. This is a refinement of the removal condition for the unweighted graphs and avoids to a great extent the erroneous elimination of direct edges. Parallel implementations of these algorithms can achieve speed-ups of two orders of magnitude compared to their sequential counterparts. Our experiments show that: i) taking into account the edge weights improves the reconstruction quality compared to the unweighted case; ii) it is advantageous not to distinguish between positive and negative interactions since this lowers the complexity of the algorithms from NP-complete to polynomial without loss of quality.

  9. Facets of impulsivity interactively predict body fat and binge eating in young women.

    Science.gov (United States)

    Meule, Adrian; Platte, Petra

    2015-04-01

    Impulsivity has been positively linked to overeating and obesity, but findings are inconsistent. Studies using the Barratt Impulsiveness Scale (BIS) show that measures of overeating appear to be most consistently associated with scores on the subscale attentional impulsivity in both non-clinical and clinical samples. Additionally, individuals with binge-eating behaviors may have elevated scores on the subscale motor impulsivity. In the current study, young women (N = 133) completed the short form of the BIS (BIS-15), the Eating Disorder Examination - Questionnaire, and height, weight and body composition were measured. Regression analyses showed that attentional and motor impulsivity positively predicted binge eating and general eating pathology, while non-planning impulsivity negatively predicted these variables. Moreover, attentional and motor impulsivity interactively predicted percent body fat, and the number of subjective and objective binge episodes. Results show that only specific aspects of trait impulsivity (attentional and motor impulsivity) are positively associated with body mass and binge eating. Non-planning impulsivity appears to be unrelated or even inversely related to those variables, at least in female students. Elevated levels of attentional impulsivity in conjunction with high motor impulsivity may be a risk factor for overweight and clinically relevant binge eating. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. IMPULSIVITY PARAMETER FOR SOLAR FLARES

    Energy Technology Data Exchange (ETDEWEB)

    Fajardo-Mendieta, W. G.; Alvarado-Gómez, J. D.; Calvo-Mozo, B. [Observatorio Astronómico Nacional, Universidad Nacional de Colombia, Bogotá (Colombia); Martinez-Oliveros, J. C., E-mail: wgfajardom@unal.edu.co, E-mail: bcalvom@unal.edu.co, E-mail: oliveros@ssl.berkeley.edu, E-mail: jalvarad@eso.org [Space Sciences Laboratory, UC Berkeley, Berkeley, CA 94720 (United States)

    2016-02-10

    Three phases are typically observed during solar flares: the preflare, impulsive, and decay phases. During the impulsive phase, it is believed that the electrons and other particles are accelerated after the stored energy in the magnetic field is released by reconnection. The impulsivity of a solar flare is a quantifiable property that shows how quickly this initial energy release occurs. It is measured via the impulsivity parameter, which we define as the inverse of the overall duration of the impulsive phase. We take the latter as the raw width of the most prominent nonthermal emission of the flare. We computed this observable over a work sample of 48 M-class events that occurred during the current Solar Cycle 24 by using three different methods. The first method takes into account all of the nonthermal flare emission and gives very accurate results, while the other two just cover fixed energy intervals (30–40 keV and 25–50 keV) and are useful for fast calculations. We propose an alternative way to classify solar flares according to their impulsivity parameter values, defining three different types of impulsivity, namely, high, medium, and low. This system of classification is independent of the manner used to calculated the impulsivity parameter. Lastly, we show the relevance of this tool as a discriminator of different HXR generation processes.

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

    Science.gov (United States)

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

    2016-10-01

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

  12. A novel theory: biological processes mostly involve two types of mediators, namely general and specific mediators Endogenous small radicals such as superoxide and nitric oxide may play a role of general mediator in biological processes.

    Science.gov (United States)

    Mo, Jian

    2005-01-01

    A great number of papers have shown that free radicals as well as bioactive molecules can play a role of mediator in a wide spectrum of biological processes, but the biological actions and chemical reactivity of the free radicals are quite different from that of the bioactive molecules, and that a wide variety of bioactive molecules can be easily modified by free radicals due to having functional groups sensitive to redox, and the significance of the interaction between the free radicals and the bioactive molecules in biological processes has been confirmed by the results of some in vitro and in vivo studies. Based on these evidence, this article presented a novel theory about the mediators of biological processes. The essentials of the theory are: (a) mediators of biological processes can be classified into general and specific mediators; the general mediators include two types of free radicals, namely superoxide and nitric oxide; the specific mediators include a wide variety of bioactive molecules, such as specific enzymes, transcription factors, cytokines and eicosanoids; (b) a general mediator can modify almost any class of the biomolecules, and thus play a role of mediator in nearly every biological process via diverse mechanisms; a specific mediator always acts selectively on certain classes of the biomolecules, and may play a role of mediator in different biological processes via a same mechanism; (c) biological processes are mostly controlled by networks of their mediators, so the free radicals can regulate the last consequence of a biological process by modifying some types of the bioactive molecules, or in cooperation with these bioactive molecules; the biological actions of superoxide and nitric oxide may be synergistic or antagonistic. According to this theory, keeping the integrity of these networks and the balance between the free radicals and the bioactive molecules as well as the balance between the free radicals and the free radical scavengers

  13. Recent Insights into the Neurobiology of Impulsivity

    Science.gov (United States)

    Mitchell, Marci R.; Potenza, Marc N.

    2014-01-01

    Impulsivity is associated with various psychopathologies, and elevated impulsivity is typically disadvantageous. This manuscript reviews recent investigations into the neurobiology of impulsivity using human imaging techniques and animal models. Both human imaging and preclinical pharmacological manipulations have yielded important insights into the neurobiological underpinnings of impulsivity. A more thorough understanding of the complex neurobiology underlying aspects of impulsivity may provide insight into new treatment options that target elevated impulsivity and psychopathologies such as addictions. PMID:25431750

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

    Science.gov (United States)

    Li, Hongfei; Li, Chuandong; Huang, Tingwen

    2017-10-01

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

  15. General Academic or Domain-Specific Vocabulary?: The Impact of Word Selection in High School Biology

    Science.gov (United States)

    Birmingham, Elizabeth A.

    2013-01-01

    The purpose of this study was to determine the impact of learning various types of words in biology on students' reading comprehension, vocabulary performance, and science content knowledge. The study involved 315 ninth grade biology students who were placed in one of four groups and spent two weeks for ten minutes per day working on independent…

  16. Two Methods of Determining Total Phenolic Content of Foods and Juices in a General, Organic, and Biological (GOB) Chemistry Lab

    Science.gov (United States)

    Shaver, Lee Alan; Leung, Sam H.; Puderbaugh, Amy; Angel, Stephen A.

    2011-01-01

    The determination of total phenolics in foods and fruit juices was used successfully as a laboratory experiment in our undergraduate general, organic, and biological (GOB) chemistry course. Two different colorimetric methods were used over three years and comparative student results indicate that a ferrous ammonium sulfate (FAS) indicator…

  17. Bifurcation Analysis and Application for Impulsive Systems with Delayed Impulses

    Science.gov (United States)

    Church, Kevin E. M.; Liu, Xinzhi

    In this article, we present a systematic approach to bifurcation analysis of impulsive systems with autonomous or periodic right-hand sides that may exhibit delayed impulse terms. Methods include Lyapunov-Schmidt reduction and center manifold reduction. Both methods are presented abstractly in the context of the stroboscopic map associated to a given impulsive system, and are illustrated by way of two in-depth examples: the analysis of a SIR model of disease transmission with seasonality and unevenly distributed moments of treatment, and a scalar logistic differential equation with a delayed census impulsive harvesting effort. It is proven that in some special cases, the logistic equation can exhibit a codimension two bifurcation at a 1:1 resonance point.

  18. Biology

    Indian Academy of Sciences (India)

    I am particularly happy that the Academy is bringing out this document by Professor M S. Valiathan on Ayurvedic Biology. It is an effort to place before the scientific community, especially that of India, the unique scientific opportunities that arise out of viewing Ayurveda from the perspective of contemporary science, its tools ...

  19. The Neurobiology of Impulsive Aggression.

    Science.gov (United States)

    Blair, Robert J R

    2016-02-01

    This selective review provides a model of the neurobiology of impulsive aggression from a cognitive neuroscience perspective. It is argued that prototypical cases of impulsive aggression, those associated with anger, involve the recruitment of the acute threat response system structures; that is, the amygdala, hypothalamus, and periaqueductal gray. It is argued that whether the recruitment of these structures results in impulsive aggression or not reflects the functional roles of ventromedial frontal cortex and dorsomedial frontal and anterior insula cortex in response selection. It is also argued that impulsive aggression may occur because of impaired decision making. The aggression may not be accompanied by anger, but it will reflect disrupted evaluation of the rewards/benefits of the action.

  20. Impulsivity is Associated with Uric Acid: Evidence from Humans and Mice

    Science.gov (United States)

    Sutin, Angelina R.; Cutler, Roy G.; Camandola, Simonetta; Uda, Manuela; Feldman, Neil H.; Cucca, Francesco; Zonderman, Alan B.; Mattson, Mark P.; Ferrucci, Luigi; Schlessinger, David; Terracciano, Antonio

    2013-01-01

    Background The ability to control impulses varies greatly, and difficulty with impulse control can have severe consequences; in the extreme, it is the defining feature of many psychiatric disorders. Evidence from disparate lines of research suggests that uric acid is elevated in psychiatric disorders characterized by high impulsivity, such as ADHD and bipolar disorder. The present research tests the hypothesis that impulsivity is associated with higher uric acid in humans and mice. Methods Using two longitudinal, non-clinical community samples (total N=6883), we test whether there is an association between uric acid and normal variation in trait impulsivity measured with the Revised NEO Personality Inventory. We also examined the effect of uric acid on behavior by comparing wild-type mice (WT), which naturally have low levels of uric acid, to mice genetically modified (UOX) to accumulate high levels of uric acid. Results In both human samples, the emotional aspects of trait impulsivity, specifically Impulsiveness and Excitement-Seeking, were associated with higher levels of uric acid concurrently and when uric acid was measured 3–5 years later. Consistent with the human data, the UOX mice displayed significantly more exploratory and novelty-seeking behavior than the WT mice. Conclusion Higher uric acid was associated with impulsivity in both humans and mice. The identification of biological markers of impulsivity may lead to a better understanding of the physiological mechanisms involved in impulsivity, and may suggest potential targets for therapeutic intervention. PMID:23582268

  1. Regulation of Spatiotemporal Patterns by Biological Variability: General Principles and Applications to Dictyostelium discoideum.

    Directory of Open Access Journals (Sweden)

    Miriam Grace

    2015-11-01

    Full Text Available Spatiotemporal patterns often emerge from local interactions in a self-organizing fashion. In biology, the resulting patterns are also subject to the influence of the systematic differences between the system's constituents (biological variability. This regulation of spatiotemporal patterns by biological variability is the topic of our review. We discuss several examples of correlations between cell properties and the self-organized spatiotemporal patterns, together with their relevance for biology. Our guiding, illustrative example will be spiral waves of cAMP in a colony of Dictyostelium discoideum cells. Analogous processes take place in diverse situations (such as cardiac tissue, where spiral waves occur in potentially fatal ventricular fibrillation so a deeper understanding of this additional layer of self-organized pattern formation would be beneficial to a wide range of applications. One of the most striking differences between pattern-forming systems in physics or chemistry and those in biology is the potential importance of variability. In the former, system components are essentially identical with random fluctuations determining the details of the self-organization process and the resulting patterns. In biology, due to variability, the properties of potentially very few cells can have a driving influence on the resulting asymptotic collective state of the colony. Variability is one means of implementing a few-element control on the collective mode. Regulatory architectures, parameters of signaling cascades, and properties of structure formation processes can be "reverse-engineered" from observed spatiotemporal patterns, as different types of regulation and forms of interactions between the constituents can lead to markedly different correlations. The power of this biology-inspired view of pattern formation lies in building a bridge between two scales: the patterns as a collective state of a very large number of cells on the one hand

  2. Combination of Advanced Oxidation Technologies with Biological Treatment: A General Review

    International Nuclear Information System (INIS)

    Al-Momani; Shawaqfeh, A.

    2007-01-01

    Advanced oxidation processes (AOPs) have been recently proposed as an important wastwater treatment option. This paper provides a broad overview of the use of AOPs alone or combind with a biological process for wastwater treatment and the current state of knowledge about water treatment options. The first part of the paper focuses on combination of AOP's with biological treatment of different kinds of contaminations. Then the review presents methods used to imorove wastwater biodegradability and toxicity measurements as related to coupling processes. The presented STUDIES conclude that the the use AOP'S as a pre-treatment for wastewater is recommended under specific conditions; 1) AOP's can be used efficiently to pre-treat recalcitrant componds, 2) AOP's can be used to enhance the biodegradability of aqueous solutions, 3) Toxic compounds can be converted to non-toxic compounds by means of AOP's 4) Coupling processes(AOP's + biological) give reasonable results in treating wastewater wiyh significant hydraulic retention time (HRT) (Author's) 58 refs

  3. Interval oscillation criteria for second-order forced impulsive delay differential equations with damping term.

    Science.gov (United States)

    Thandapani, Ethiraju; Kannan, Manju; Pinelas, Sandra

    2016-01-01

    In this paper, we present some sufficient conditions for the oscillation of all solutions of a second order forced impulsive delay differential equation with damping term. Three factors-impulse, delay and damping that affect the interval qualitative properties of solutions of equations are taken into account together. The results obtained in this paper extend and generalize some of the the known results for forced impulsive differential equations. An example is provided to illustrate the main result.

  4. Two clusters of child molesters based on impulsiveness

    Directory of Open Access Journals (Sweden)

    Danilo A. Baltieri

    2015-06-01

    Full Text Available Objective:High impulsiveness is a general problem that affects most criminal offenders and is associated with greater recidivism risk. A cluster analysis of impulsiveness measured by the Barratt Impulsiveness Scale - Version 11 (BIS-11 was performed on a sample of hands-on child molesters.Methods:The sample consisted of 208 child molesters enrolled in two different sectional studies carried out in São Paulo, Brazil. Using three factors from the BIS-11, a k-means cluster analysis was performed using the average silhouette width to determine cluster number. Direct logistic regression was performed to analyze the association of criminological and clinical features with the resulting clusters.Results:Two clusters were delineated. The cluster characterized by higher impulsiveness showed higher scores on the Sexual Screening for Pedophilic Interests (SSPI, Static-99, and Sexual Addiction Screening Test.Conclusions:Given that child molesters are an extremely heterogeneous population, the “number of victims” item of the SSPI should call attention to those offenders with the highest motor, attentional, and non-planning impulsiveness. Our findings could have implications in terms of differences in therapeutic management for these two groups, with the most impulsive cluster benefitting from psychosocial strategies combined with pharmacological interventions.

  5. Predictive Model for the Analysis of the Effects of Underwater Impulsive Sources on Marine Life

    National Research Council Canada - National Science Library

    Lazauski, Colin J

    2007-01-01

    A method is provided to predict the biological consequences to marine animals from exposure to multiple underwater impulsive sources by simulating underwater explosions over a defined period of time...

  6. Minimum Learning Essentials: Science. Chemistry, Earth Science, Biology, Physics, General Science. Experimental Edition 0/4.

    Science.gov (United States)

    New York City Board of Education, Brooklyn, NY. Div. of Curriculum and Instruction.

    This guide presents the "minimum teaching essentials" published by the New York City Board of Education, for science education in grades 9-12. Covered are: biology, physics, earth science, and chemistry. Work study skills for all subjects are given with content areas, performance objectives, and suggested classroom activities. (APM)

  7. Geodesics in nonexpanding impulsive gravitational waves with Λ. II

    Science.gov (United States)

    Sämann, Clemens; Steinbauer, Roland

    2017-11-01

    We investigate all geodesics in the entire class of nonexpanding impulsive gravitational waves propagating in an (anti-)de Sitter universe using the distributional metric. We extend the regularization approach of part I [Sämann, C. et al., Classical Quantum Gravity 33(11), 115002 (2016)] to a full nonlinear distributional analysis within the geometric theory of generalized functions. We prove global existence and uniqueness of geodesics that cross the impulsive wave and hence geodesic completeness in full generality for this class of low regularity spacetimes. This, in particular, prepares the ground for a mathematically rigorous account on the "physical equivalence" of the continuous form with the distributional "form" of the metric.

  8. Biological-inorganic hybrid systems as a generalized platform for chemical production.

    Science.gov (United States)

    Nangle, Shannon N; Sakimoto, Kelsey K; Silver, Pamela A; Nocera, Daniel G

    2017-12-01

    An expanding renewable energy market to supplant petrochemicals has motivated synthesis technologies that use renewable feedstocks, such as CO 2 . Hybrid biological-inorganic systems provide a sustainable, efficient, versatile, and inexpensive chemical synthesis platform. These systems comprise biocompatible electrodes that transduce electrical energy either directly or indirectly into bioavailable energy, such as H 2 and NAD(P)H. In combination, specific bacteria use these energetic reducing equivalents to fix CO 2 into multi-carbon organic compounds. As hybrid biological-inorganic technologies have developed, the focus has shifted from phenomenological and proof-of-concept discovery towards enhanced energy efficiency, production rate, product scope, and industrial robustness. In this review, we highlight the progress and the state-of-the-art of this field and describe the advantages and challenges involved in designing bio- and chemo- compatible systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Mechanisms of Individual Differences in Impulsive and Risky Choice in Rats

    Science.gov (United States)

    Kirkpatrick, Kimberly; Marshall, Andrew T.; Smith, Aaron P.

    2016-01-01

    Individual differences in impulsive and risky choice are key risk factors for a variety of maladaptive behaviors such as drug abuse, gambling, and obesity. In our rat model, ordered individual differences are stable across choice parameters, months of testing, and span a broad spectrum, suggesting that rats, like humans, exhibit trait-level impulsive and risky choice behaviors. In addition, impulsive and risky choices are highly correlated, suggesting a degree of correlation between these two traits. An examination of the underlying cognitive mechanisms has suggested an important role for timing processes in impulsive choice. In addition, in an examination of genetic factors in impulsive choice, the Lewis rat strain emerged as a possible animal model for studying disordered impulsive choice, with this strain demonstrating deficient delay processing. Early rearing environment also affected impulsive behaviors, with rearing in an enriched environment promoting adaptable and more self-controlled choices. The combined results with impulsive choice suggest an important role for timing and reward sensitivity in moderating impulsive behaviors. Relative reward valuation also affects risky choice, with manipulation of objective reward value (relative to an alternative reference point) resulting in loss chasing behaviors that predicted overall risky choice behaviors. The combined results are discussed in relation to domain-specific versus domain-general subjective reward valuation processes and the potential neural substrates of impulsive and risky choice. PMID:27695580

  10. Impulse control disorders and depression.

    Science.gov (United States)

    Lejoyeux, Michel; Arbaretaz, Marie; McLoughlin, Mary; Adès, Jean

    2002-05-01

    This study assessed the frequency of impulse control disorders (ICDs) and their association with bulimia, compulsive buying, and suicide attempts in a population of depressed inpatients. We investigated ICDs using the Minnesota Impulsive Disorders Interview. Patients answered the Zuckerman Sensation-Seeking Scale and the Barratt Impulsivity Rating Scale. Among the 31 depressed patients who met criteria for ICD (ICD+ group), we found 18 cases of intermittent explosive disorder, three cases of pathological gambling, four cases of kleptomania, three cases of pyromania, and three cases of trichotillomania. Patients with co-occurring ICDs were significantly younger (mean age = 37.7 versus 42.8 years). Patients with kleptomania had a higher number of previous depressive episodes (5.7 versus 1.3), and patients with pyromania had a higher number of previous depressions (3.3 versus 1.3, p =.01). Bipolar disorders were more frequent in the ICD+ group than in the ICD- group (19% versus 1.3%, p =.002), whereas antisocial personality was not (3% versus 1%, p = ns). Bulimia (42% versus 10.5%, p =.005) and compulsive buying (51% versus 22%, p =.006) were significantly more frequent in the ICD+ group. Patients from the ICD+ group had higher scores of motor impulsivity assessed with the Barratt Impulsivity rating scale (p =.01).

  11. The structure, occurrence and biological activity of ellagitannins: a general review.

    Science.gov (United States)

    Lipińska, Lidia; Klewicka, Elżbieta; Sójka, Michał

    2014-01-01

    The present paper deals with the structure, occurrence and biological activity of ellagitannins. Ellagitannins belong to the class of hydrolysable tannins, they are esters of hexahydroxydiphenoic acid and monosaccharide (most commonly glucose). Ellagitannins are slowly hydrolysed in the digestive tract, releasing the ellagic acid molecule. Their chemical structure determines physical and chemical properties and biological activity. Ellagitannins occur naturally in some fruits (pomegranate, strawberry, blackberry, raspberry), nuts (walnuts, almonds), and seeds. They form a diverse group of bioactive polyphenols with anti-inflammatory, anticancer, antioxidant and antimicrobial (antibacterial, antifungal and antiviral) activity. Furthermore, they improve the health of blood vessels. The paper discusses the metabolism and bioavailability of ellagitannins and ellagic acid. Ellagitannins are metabolized in the gastrointestinal tract by intestinal microbiota. They are stable in the stomach and undergo neither hydrolysis to free ellagic acid nor degradation. In turn, ellagic acid can be absorbed in the stomach. This paper shows the role of cancer cell lines in the studies of ellagitannins and ellagic acid metabolism. The biological activity of these compounds is broad and thus the focus is on their antimicrobial, anti-inflammatory and antitumor properties. Ellagitannins exhibit antimicrobial activity against fungi, viruses, and importantly, bacteria, including antibiotic-resistant strains such as methicillin-resistant Staphylococcus aureus.

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

    Directory of Open Access Journals (Sweden)

    Qing Wang

    2013-01-01

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

  13. The convergence and divergence of impulsivity facets in daily life.

    Science.gov (United States)

    Sperry, Sarah H; Lynam, Donald R; Kwapil, Thomas R

    2017-11-10

    Impulsivity appears to be best conceptualized as a multidimensional construct. For example, the UPPS-P model posits that there are five underlying facets of impulsivity. The present study examined the expression of the UPPS-P facets in daily life using experience sampling methodology. A specific goal of the study was to examine positive urgency, a facet added to the original UPPS model, and its convergence and divergence from the negative urgency facet. A large nonclinical sample of young adults (n = 294) completed the UPPS-P scale and was signaled to complete questionnaires assessing daily affect, cognitions, sense of self, and impulsive behaviors eight times a day for 7 days. Results indicated that the UPPS-P facets are associated with disruptions in affect, cognitions, and behavior in daily life. Furthermore, all of the UPPS-P facets were associated with impulsivity in daily life. Contrary to expectation, positive urgency was associated with negative affect rather than positive affect and had a profile indistinguishable from negative urgency. These results generally support a four-factor model of multidimensional impulsivity with a general overall urgency factor instead of separate positive and negative urgency facets. © 2017 Wiley Periodicals, Inc.

  14. Meteorological Integration for the Biological Warning and Incident Characterization (BWIC) System: General Guidance for BWIC Cities

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, William J.; Wang, Weiguo; Rutz, Frederick C.; Chapman, Elaine G.; Rishel, Jeremy P.; Xie, YuLong; Seiple, Timothy E.; Allwine, K Jerry

    2007-02-16

    The U.S. Department of Homeland Security (DHS) is responsible for developing systems to detect the release of aerosolized bioagents in urban environments. The system that accomplishes this, known as BioWatch, is a robust first-generation monitoring system. In conjunction with the BioWatch detection network, DHS has also developed a software tool for cities to use to assist in their response when a bioagent is detected. This tool, the Biological Warning and Incident Characterization (BWIC) System, will eventually be deployed to all BioWatch cities to aid in the interpretation of the public health significance of indicators from the BioWatch networks. BWIC consists of a set of integrated modules, including meteorological models, that estimate the effect of a biological agent on a city’s population once it has been detected. For the meteorological models in BWIC to successfully calculate the distribution of biological material, they must have as input accurate meteorological data, and wind fields in particular. The purpose of this document is to provide guidance for cities to use in identifying sources of good-quality local meteorological data that BWIC needs to function properly. This process of finding sources of local meteorological data, evaluating the data quality and gaps in coverage, and getting the data into BWIC, referred to as meteorological integration, is described. The good news for many cities is that meteorological measurement networks are becoming increasingly common. Most of these networks allow their data to be distributed in real time via the internet. Thus, cities will often only need to evaluate the quality of available measurements and perhaps add a modest number of stations where coverage is poor.

  15. NORMATIVE MODERATORS OF IMPULSE BUYING BEHAVIOR

    Directory of Open Access Journals (Sweden)

    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.

  16. Runge-Kutta and Hermite Collocation for a biological invasion problem modeled by a generalized Fisher equation

    International Nuclear Information System (INIS)

    Athanasakis, I E; Papadopoulou, E P; Saridakis, Y G

    2014-01-01

    Fisher's equation has been widely used to model the biological invasion of single-species communities in homogeneous one dimensional habitats. In this study we develop high order numerical methods to accurately capture the spatiotemporal dynamics of the generalized Fisher equation, a nonlinear reaction-diffusion equation characterized by density dependent non-linear diffusion. Working towards this direction we consider strong stability preserving Runge-Kutta (RK) temporal discretization schemes coupled with the Hermite cubic Collocation (HC) spatial discretization method. We investigate their convergence and stability properties to reveal efficient HC-RK pairs for the numerical treatment of the generalized Fisher equation. The Hadamard product is used to characterize the collocation discretized non linear equation terms as a first step for the treatment of generalized systems of relevant equations. Numerical experimentation is included to demonstrate the performance of the methods

  17. General

    Indian Academy of Sciences (India)

    Page S20: NMR compound 4i. Page S22: NMR compound 4j. General: Chemicals were purchased from Fluka, Merck and Aldrich Chemical Companies. All the products were characterized by comparison of their IR, 1H NMR and 13C NMR spectroscopic data and their melting points with reported values. General procedure ...

  18. Impulsive delayed reward discounting as a genetically-influenced target for drug abuse prevention: a critical evaluation

    Science.gov (United States)

    Gray, Joshua C.; MacKillop, James

    2015-01-01

    This review evaluates the viability of delayed reward discounting (DRD), an index of how much an individual devalues a future reward based on its delay in time, for genetically-informed drug abuse prevention. A review of the literature suggests that impulsive DRD is robustly associated with drug addiction and meets most of the criteria for being an endophenotype, albeit with mixed findings for specific molecular genetic influences. Several modes of experimental manipulation have been demonstrated to reduce DRD acutely. These include behavioral strategies, such as mindfulness, reward bundling, and episodic future thinking; pharmacological interventions, including noradrenergic agonists, adrenergic agonists, and multiple monoamine agonists; and neuromodulatory interventions, such as transcranial magnetic stimulation and transcranial direct current stimulation. However, the generalization of these interventions to positive clinical outcomes remains unclear and no studies to date have examined interventions on DRD in the context of prevention. Collectively, these findings suggest it would be premature to target DRD for genetically-informed prevention. Indeed, given the evidence of environmental contributions to impulsive DRD, whether genetically-informed secondary prevention would ever be warranted is debatable. Progress in identifying polymorphisms associated with DRD profiles could further clarify the underlying biological systems for pharmacological and neuromodulatory interventions, and, as a qualitatively different risk factor from existing prevention programs, impulsive DRD is worthy of investigation at a more general level as a novel and promising drug abuse prevention target. PMID:26388788

  19. Quasilinearization for the periodic boundary value problem for systems of impulsive differential equations

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available The method of generalized quasilinearization for the system of nonlinear impulsive differential equations with periodic boundary conditions is studied. As a byproduct, the result for the system without impulses can be obtained, which is a new result as well.

  20. Integrating Biology into the General Chemistry Laboratory: Fluorometric Analysis of Chlorophyll "a"

    Science.gov (United States)

    Wesolowski, Meredith C.

    2014-01-01

    A laboratory experiment that introduces fluorometry of chlorophyll "a" at the general chemistry level is described. The use of thin-layer chromatography to isolate chlorophyll "a" from spirulina and leaf matter enables quantification of small amounts of chlorophyll "a" via fluorometry. Student results were reasonably…

  1. Preparing for and implementing the UN secretary-general's mechanism on alleged use investigation for biological weapons

    International Nuclear Information System (INIS)

    Kraatz-Wadsack, G.

    2009-01-01

    The United Nations Global Counter-Terrorism Strategy was adopted by the UN General Assembly in September 2006. Preventing and responding to attacks using WMD were identified amongst the key areas of activities covered by the strategy. The Secretary-General's mechanism to carry out prompt investigations in response to allegations brought to his attention concerning the possible use of chemical and bacteriological (biological) and toxin weapons was developed in the late 1980s. Triggered by a request from any member State, the Secretary-General is authorized to launch an investigation including dispatching a fact-finding team to the site of the alleged incident(s) and to report to all UN Member States. This is to ascertain in an objective and scientific manner facts of alleged violations of the 1925 Geneva Protocol, which bans the use of chemical and biological weapons. Member States encouraged the Secretary-General in September 2006 to update the roster of experts and laboratories, as well as the technical guidelines and procedures, available to him for the timely and efficient investigation of alleged use. The roster of experts and laboratories and the guidelines and procedures constitute the key elements of the special mechanism available to the Secretary-General for investigation of reports by Member States of alleged use of chemical, biological and toxin weapons. The Office for Disarmament Affairs has been working with Member States since March 2007 to update the roster of experts and laboratories and the technical appendices of the guidelines and procedures so that they fully correspond with the rapid and substantial developments that have occurred in the biological area since the 1980s and also to take into account the fact that an Organization for the Prohibition of Chemical Weapons (OPCW) has since been established. Currently, the roster of experts and laboratories has been updated and includes experts from more than 50 countries. The information available in

  2. Evaluation of Immunoassays and General Biological Indicator Tests for Field Screening of Bacillus anthracis and Ricin

    Energy Technology Data Exchange (ETDEWEB)

    Bartholomew, Rachel A.; Ozanich, Richard M.; Arce, Jennifer S.; Engelmann, Heather E.; Heredia-Langner, Alejandro; Hofstad, Beth A.; Hutchison, Janine R.; Jarman, Kristin; Melville, Angela M.; Victry, Kristin D.; Bruckner-Lea, Cynthia J.

    2017-02-01

    The goal of this testing was to evaluate the ability of currently available commercial off-the-shelf (COTS) biological indicator tests and immunoassays to detect Bacillus anthracis (Ba) spores and ricin. In general, immunoassays provide more specific identification of biological threats as compared to indicator tests [3]. Many of these detection products are widely used by first responders and other end users. In most cases, performance data for these instruments are supplied directly from the manufacturer, but have not been verified by an external, independent assessment [1]. Our test plan modules included assessments of inclusivity (ability to generate true positive results), commonly encountered hoax powders (which can cause potential interferences or false positives), and estimation of limit of detection (LOD) (sensitivity) testing.

  3. DATE analysis: A general theory of biological change applied to microarray data.

    Science.gov (United States)

    Rasnick, David

    2009-01-01

    In contrast to conventional data mining, which searches for specific subsets of genes (extensive variables) to correlate with specific phenotypes, DATE analysis correlates intensive state variables calculated from the same datasets. At the heart of DATE analysis are two biological equations of state not dependent on genetic pathways. This result distinguishes DATE analysis from other bioinformatics approaches. The dimensionless state variable F quantifies the relative overall cellular activity of test cells compared to well-chosen reference cells. The variable pi(i) is the fold-change in the expression of the ith gene of test cells relative to reference. It is the fraction phi of the genome undergoing differential expression-not the magnitude pi-that controls biological change. The state variable phi is equivalent to the control strength of metabolic control analysis. For tractability, DATE analysis assumes a linear system of enzyme-connected networks and exploits the small average contribution of each cellular component. This approach was validated by reproducible values of the state variables F, RNA index, and phi calculated from random subsets of transcript microarray data. Using published microarray data, F, RNA index, and phi were correlated with: (1) the blood-feeding cycle of the malaria parasite, (2) embryonic development of the fruit fly, (3) temperature adaptation of Killifish, (4) exponential growth of cultured S. pneumoniae, and (5) human cancers. DATE analysis was applied to aCGH data from the great apes. A good example of the power of DATE analysis is its application to genomically unstable cancers, which have been refractory to data mining strategies. 2009 American Institute of Chemical Engineers Biotechnol.

  4. Caffeine's influence on gambling behavior and other types of impulsivity.

    Science.gov (United States)

    Grant, Jon E; Chamberlain, Samuel R

    2018-01-01

    Young adulthood is a developmental period frequently associated with occurrence of impulsive behaviors including gambling. It is estimated that 73% of children and 87% of adults in the United States regularly use caffeine. Questions remain, however, concerning the role of caffeine in the development and maintenance of impulsive behaviors such as gambling. Sixty-one young adults with at least some degree of disordered gambling were recruited from two Mid-Western university communities in the United States using media advertisements. Caffeine intake over the preceding month was quantified using the Caffeine Use Questionnaire. Clinician rating scales, questionnaires, and cognitive tests germane to impulsivity were completed. Relationships between caffeine intake and demographic, gambling symptom, and neurocognitive measures were evaluated using the statistical technique of partial least squares (PLS). Average weekly caffeine intake in the gamblers was 1218.5mg (a figure higher than previously reported in the general population). PLS yielded an optimal model with one latent factor, which explained 14.8% of variation in demographic/clinical/cognitive measures and 32.3% of variation in caffeine intake. In this model, higher caffeine intake was significantly associated with earlier age at first gambling, higher personality-related impulsiveness, more nicotine consumption, older age, and more impulsive decision-making. These data suggest a particularly strong relationship between caffeine intake, earlier age of first gambling, and certain types of impulsivity in gamblers. Providing education about healthy caffeine use may be especially valuable in gamblers. Future work should explore whether the relationship between caffeine use and gambling is due to a common predisposing factor (impulsive tendencies) or, rather, constitutes a form of self-medication in gamblers (or a means of sustaining gambling habits for longer). Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. The role of impulsivity in relapse vulnerability

    NARCIS (Netherlands)

    Pattij, T.; de Vries, T.J.

    2013-01-01

    Drug dependence in humans is often accompanied by behavioral disturbances such as maladaptive levels of impulsivity. In turn, there is accumulating evidence from preclinical laboratory animal and clinical studies indicating that impulsive behavior might be causally linked to several distinct

  6. Neuroanatomical and Neurochemical Basis of Impulsivity

    Directory of Open Access Journals (Sweden)

    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

  7. Impulse: Memory System Support for Scientific Applications

    Directory of Open Access Journals (Sweden)

    John B. Carter

    1999-01-01

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

  8. 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

  9. Impulsive and hybrid dynamical systems stability, dissipativity, and control

    CERN Document Server

    Haddad, Wassim M; Nersesov, Sergey G

    2014-01-01

    This book develops a general analysis and synthesis framework for impulsive and hybrid dynamical systems. Such a framework is imperative for modern complex engineering systems that involve interacting continuous-time and discrete-time dynamics with multiple modes of operation that place stringent demands on controller design and require implementation of increasing complexity--whether advanced high-performance tactical fighter aircraft and space vehicles, variable-cycle gas turbine engines, or air and ground transportation systems. Impulsive and Hybrid Dynamical Systems goes beyond similar

  10. A general protocol for the generation of Nanobodies for structural biology

    DEFF Research Database (Denmark)

    Pardon, Els; Laeremans, Toon; Triest, Sarah

    2014-01-01

    There is growing interest in using antibodies as auxiliary tools to crystallize proteins. Here we describe a general protocol for the generation of Nanobodies to be used as crystallization chaperones for the structural investigation of diverse conformational states of flexible (membrane) proteins...... display of in vivo-matured Nanobodies that bind conformational epitopes of functional proteins. Three representative examples illustrate that the outlined procedures are robust, making it possible to solve by Nanobody-assisted X-ray crystallography in a time span of 6-12 months....

  11. Full averaging of fuzzy impulsive differential inclusions

    Directory of Open Access Journals (Sweden)

    Natalia V. Skripnik

    2010-09-01

    Full Text Available In this paper the substantiation of the method of full averaging for fuzzy impulsive differential inclusions is studied. We extend the similar results for impulsive differential inclusions with Hukuhara derivative (Skripnik, 2007, for fuzzy impulsive differential equations (Plotnikov and Skripnik, 2009, and for fuzzy differential inclusions (Skripnik, 2009.

  12. Texting while driving, executive function, and impulsivity in college students.

    Science.gov (United States)

    Hayashi, Yusuke; Rivera, Esteban A; Modico, James G; Foreman, Anne M; Wirth, Oliver

    2017-05-01

    The purpose of the present study was to investigate the cognitive processes underlying texting while driving. A sample of 120 college students completed a survey to assess how frequently they send and read a text message while driving. Based on this information, students were assigned to one of two groups: 20 students who frequently text while driving and 20 matched-control students who infrequently text while driving but were similar in gender, age, years of education, and years driving. The groups were compared on the extent to which they differed in self-reported measures of executive function and impulsivity. The groups were also compared on a behavioral measure of impulsivity: the extent to which they discounted hypothetical monetary rewards as a function of the delay. For this measure, the students made repeated choices between smaller monetary rewards available immediately and larger rewards available after delays ranging from 1 week to 6 months. The results show that the group of students who frequently text while driving showed (a) significantly lower levels of executive function and (b) higher levels of self-reported impulsivity, although the groups did not differ significantly on the behavioral measure of impulsivity. These results support a general conclusion that drivers with lower levels of executive function and higher levels of impulsivity are more likely to text while driving. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Impulse noise estimation and removal for OFDM systems

    KAUST Repository

    Al-Naffouri, Tareq Y.

    2014-03-01

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

  14. Antisaccadic training to improve impulsivity in binge eating disorder.

    Science.gov (United States)

    Giel, Katrin Elisabeth; Schag, Kathrin; Plewnia, Christian; Zipfel, Stephan

    2013-11-01

    Patients with binge eating disorder (BED) show generally increased impulsivity and especially increased food-related impulsivity. Both are closely linked to the core pathology of BED, which relates to regular binge eating episodes with experienced loss of control. The antisaccade task is an established paradigm assessing response inhibition as a pivotal component of impulsivity. It requires participants to execute antisaccades; that is, they are supposed to look in the opposite direction of a stimulus that automatically catches attention by appearing in the peripheral visual field. High rates of prosaccades to the peripheral stimuli are considered indicators of increased impulsivity. Presenting food pictures as peripheral stimuli, this task can be used to investigate food-related impulsivity. We propose modifications of this task in order to design it as an antisaccadic training in which BED patients practise the suppression of food-related responses, which should result in enhanced control over their eating behaviour. Copyright © 2013 John Wiley & Sons, Ltd and Eating Disorders Association.

  15. Smoking cessation with teenagers: the relationship between impulsivity, emotional problems, program retention and effectiveness.

    Science.gov (United States)

    Wegmann, Lena; Bühler, Anneke; Strunk, Mareike; Lang, Peter; Nowak, Dennis

    2012-04-01

    This study examines whether individual differences in impulsivity and emotional problems in adolescent smokers are related to initial smoking characteristics of participants, acceptance, retention and outcome of a school-based smoking cessation program. The data was obtained from a feasibility study of a youth-specific, cognitive-behavioral and motivation enhancing program at 22 schools with 139 participating teenage smokers in Germany. A one-group-pre-posttest design was realized. Impulsivity levels were assessed by use of the impulsivity scale of the IVE ("Inventar zur Erfassung von Impulsivität, Risikoverhalten und Empathie", Stadler, Janke, & Schmeck, 2004). To evaluate the extent of emotional problems, the corresponding 5-items scale of the SDQ-Deu ("Strength and difficulties questionnaire", Klasen et al., 2000) was applied. Smoking behavior and acceptance of the program were assessed by students' self-reports. Acceptance and retention did not differ with regard to impulsivity and emotional problems, but initial smoking status did. Cessation rates varied with level of impulsivity: compared to non-impulsive participants, impulsive adolescents succeeded in quitting smoking less often. Emotional problems were not related to the rate of quitting. Impulsive adolescents were similarly compliant to the offered cessation intervention as less impulsive smokers. In spite of their general positive evaluation, impulsive adolescents seem to benefit less from a smoking cessation program than their non-impulsive counterparts. Specific elements supporting impulsive teenage smokers in their goal to quit should be incorporated into youth-specific cessation programs. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Development of the FISH technique for biological dosimetry applications in the Gregorio Maranon General University Hospital

    International Nuclear Information System (INIS)

    Moreno, M.; Jesus Prieto, M.; Olivares, P.; Gomez, M.; Herranz, R.

    1997-01-01

    Since 1989 cytogenetic analysis for dose estimation has been regularly used In the Gregorio Maranon General University Hospital (HGUGM) of Madrid on individuals suspected of having accidentally been exposed to ionizing radiation. The method used is the study of chromosomal aberrations found in lymphocytes of peripheral blood. The technique recommended by the IAEA in 1986 permits to establish a dicentrics/dose ratio through an effective dose calibration curve prepared in-vitro. This methodology of dose estimation presents serious limitations which can partially be eliminated by means of new molecular cytogenetic techniques, such as chromosomal painting through in-situ hybridization with fluorescence (FISH). At HGUGM, research work has been finished for standardization of the above mentioned technique including effective dose calibration curves, the utilization of adequate aberrations and the intercomparision of the results with other centres

  17. Design of a generalized predictive controller for a biological wastewater treatment plant.

    Science.gov (United States)

    Sadeghassadi, M; Macnab, C J B; Westwick, D

    2016-01-01

    This paper presents a generalized predictive control (GPC) technique to regulate the activated sludge process found in a bioreactor used in wastewater treatment. The control strategy can track dissolved oxygen setpoint changes quickly, adapting to the system uncertainties and disturbances. Tests occur on an Activated Sludge Model No. 1 benchmark of an activated sludge process. A T filter added to the GPC framework results in an effective control strategy in the presence of coloured measurement noise. This work also suggests how a constraint on the measured variable can be added as a penalty term to the GPC framework which leads to improved control of the dissolved oxygen concentration in the presence of dynamic input disturbance.

  18. A general framework of persistence strategies for biological systems helps explain domains of life

    Directory of Open Access Journals (Sweden)

    Liudmila S Yafremava

    2013-02-01

    Full Text Available The nature and cause of the division of organisms in superkingdoms is not fully understood. Assuming that environment shapes physiology, here we construct a novel theoretical framework that helps identify general patterns of organism persistence. This framework is based on Jacob von Uexküll’s organism-centric view of the environment and James G. Miller’s view of organisms as matter-energy-information processing molecular machines. Three concepts describe an organism's environmental niche: scope, umwelt and gap. Scope denotes the entirety of environmental events and conditions to which the organism is exposed during its lifetime. Umwelt encompasses an organism's perception of these events. The gap is the organism's blind spot, the scope that is not covered by umwelt. These concepts bring organisms of different complexity to a common ecological denominator. Ecological and physiological data suggest organisms persist using three strategies: flexibility, robustness and economy. All organisms use umwelt information to flexibly adapt to environmental change. They implement robustness against environmental perturbations within the gap generally through redundancy and reliability of internal constituents. Both flexibility and robustness improve survival. However, they also incur metabolic matter-energy processing costs, which otherwise could have been used for growth and reproduction. Lineages evolve unique tradeoff solutions among strategies in the space of what we call a persistence triangle. Protein domain architecture and other evidence support the preferential use of flexibility and robustness properties. Archaea and Bacteria gravitate toward the triangle’s economy vertex, with Archaea biased toward robustness. Eukarya trade economy for survivability. Protista occupy a saddle manifold separating akaryotes from multicellular organisms. Plants and the more flexible Fungi share an economic stratum, and Metazoa are locked in a positive feedback

  19. Fish biological effect monitoring of chemical stressors using a generalized linear model in South Sea, Korea.

    Science.gov (United States)

    Jung, Jee-Hyun; Choi, Seung Bae; Hong, Sang Hee; Chae, Young Sun; Kim, Ha Na; Yim, Un Hyuk; Ha, Sung Yong; Han, Gi Myung; Kim, Dae Jung; Shim, Won Joon

    2014-01-15

    To evaluate the health status at six different study areas, we used the generalized linear model approach with selected biochemical markers in resident fish from uncontaminated and contaminated sites. We also confirmed the independence between the biochemical indices and the morphometric indices including the hepato-somatic index (HSI), gonado-somatic index (GSI), and condition factor (CF) in fish from the sampling areas. The effect of area on the presence of biotransformation markers (ethoxyresorufin-O-deethylase activity; EROD) was significantly high in Masan Bay. The area with the greatest effect on acetylcholinesterase (AChE) activity was Jindong Bay, while there was no significant effect of GSI, HSI, CF, and sex in the EROD model and HSI, CF and sex in the AChE model. These results clarify that fish from Masan, Gwangyang and Jindong Bay were affected by pollutant stress, and the analysis of sensitive biochemical responses allowed for an improved interpretation of the results. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Application of a discretized vortex impulse framework to fish maneuvering

    Science.gov (United States)

    Mendelson, Leah; Techet, Alexandra

    2015-11-01

    In studies of biological propulsion, metrics for quantitative analysis of the vortex wake, including circulation, impulse, and their time derivatives, are a valuable indicator of performance. To better utilize volumetric PIV data in this type of analysis, a discretized method of deriving vortex impulse relying only on velocity data is developed. The impulse formulation is based on the geometry and distribution of circulation along the vortex core line, which can be detected using critical points in the velocity field. This analysis method is then applied to time-resolved velocity data of a turning giant danio (Devario aequipinnatus) and a jumping archer fish (Toxotes microlepis) obtained using Synthetic Aperture PIV (SAPIV). In the case of the danio, the vortex force vector derived from the impulse derivative shows good agreement with the kinematics of the fish tail during the turning maneuver. With the archer fish, the model is used to explore the relationship between the number of tail beats prior to the jump and the jump height.

  1. The Impact of Different Instructional Strategies on Students' Understanding about the Cell Cycle in a General Education Biology Course

    Science.gov (United States)

    Krishnamurthy, Sanjana

    This study investigated the impact of different instructional strategies on students' understanding about the cell cycle in a general education biology course. Although several studies have documented gains in students' cell cycle understanding after instruction, these studies generally use only one instructional method, often without a comparison group. The goal of this study was to learn more about students' misconceptions about the cell cycle and how those ideas change after three different evidence-based learning experiences in undergraduate general education. Undergraduate students in six laboratory sections (n = 24; N = 144) in a large public institution in the western United States were surveyed pre- and post-instruction using a 14-item valid and reliable survey of cell cycle knowledge. Cronbach's alpha for the standard scoring convention was 0.264 and for the alternate scoring convention was 0.360, documenting serious problems with inconsistent validity and reliability of the survey. Operating as though the findings are at least a proxy for actual cell cycle knowledge, score comparisons by groups of interest were explored, including pre- and post-instruction differences among demographic groups of interest and three instructional settings: a bead modeling activity, a role-playing game, and 5E instructional strategy. No significant differences were found across groups of interest or by strategy, but some significant item-level differences were found. Implications and discussion of these shifts is noted in lieu of the literature.

  2. Latent class analysis of eating and impulsive behavioral symptoms in Taiwanese women with bulimia nervosa.

    Science.gov (United States)

    Tseng, Mei-Chih Meg; Hu, Fu-Chang

    2012-01-01

    The implications of impulsivity in its relationship with binge-eating or purging behaviors remain unclear. This study examined the patterns of eating behaviors and co-morbid impulsive behaviors in individuals with bulimia nervosa n optimally homogeneous classes using latent class analysis (LCA). All participants (n=180) were asked to complete a series of self-reported inventories of impulsive behaviors and other psychological measures. Information regarding the lifetime presence of symptoms of eating disorder was assessed by clinical interviews. LCA was conducted using eating disorder symptoms, impulsive behaviors, and the number of purging methods. Three latent classes of bulimic women were identified. These were women who exhibited relatively higher rates of purging, symptoms of impulsive behavior, and multiple purging methods (17.8%), women who used no more than one purging method with a low occurrence of impulsive behavior (41.7%), and women who showed higher rates of purging behaviors and the use of multiple purging methods with a low rate of impulsive behavior (41.7%). The impulsive sub-group had comparable severity of eating-related measures, frequency of binge-eating, and higher levels of general psychopathology than that of the other two sub-groups. This study provides empirical support for the existence of an impulsive subgroup with distinctive features among a non-Western group of BN patients. This study also suggests that mechanisms other than impulse dysregulation may exist for the development of binge-eating and purging behaviors in bulimia nervosa patients, or the mechanisms contributing to binge-eating and impulsive behaviors may be different. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. Trait impulsivity and increased pre-attentional sensitivity to intense stimuli in bipolar disorder and controls.

    Science.gov (United States)

    Lijffijt, Marijn; Lane, Scott D; Moeller, F Gerard; Steinberg, Joel L; Swann, Alan C

    2015-01-01

    Impulsivity and sensation seeking are stimulus-oriented traits. Because they differ in degree of intention and planning, they may have distinct neurophysiological mechanisms. Impulsivity is prominent in bipolar disorder, and may be related to pre-attentional information filtering and stimulus-orientation. We investigated specificity of relationships between impulsivity and sensitivity to stimulus intensity in bipolar disorder and controls, using intensity-sensitivity of auditory evoked potentials. Seventy-six subjects (37 healthy controls, 39 with bipolar disorder) were administered an intensity-sensitivity paradigm. Additional measures included Barratt Impulsiveness Scale (BIS-11) and Eysenck Impulsivity and Venturesomeness scores. State-dependent rapid-response impulsivity was measured using the Immediate Memory Task. Intensity-sensitivities of the auditory evoked P1N1, N1P2, P1, N1, and P2 potentials were assessed as the slope of amplitude relative to loudness. Analyses used general linear models (GLM) with impulsivity-related measures as dependent variables and age, gender, education, and diagnosis as dependent variables. BIS-11 total, motor, and attentional impulsivity scores correlated positively with pre-attentional N1 and P1N1 intensity-sensitivity slopes in bipolar disorder, but not in controls. BIS-11 nonplanning and Eysenck Venturesomeness scores did not correlate with intensity-sensitivity. Intensity-sensitivity slopes did not correlate with rapid-response impulsivity. Correlations between N1 or P1N1 slopes and BIS-11 scores in bipolar disorder were not affected by age, education, WAIS, treatment, symptoms, or gender. Trait impulsivity in bipolar disorder may be related to poorly modulated stimulus-driven late pre-attentional responses to stimuli, potentially resulting in exaggerated responses to intense stimuli even before conscious awareness. Components of trait impulsivity are physiologically heterogenous relative to intensity-sensitivity. Copyright

  4. 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.

  5. 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.

  6. High-fidelity de novo synthesis of pathways using microchip-synthesized oligonucleotides and general molecular biology equipment.

    Science.gov (United States)

    Wan, Wen; Lu, Min; Wang, Dongmei; Gao, Xiaolian; Hong, Jiong

    2017-07-21

    Engineering and evaluation of synthetic routes for generating valuable compounds require accurate and cost-effective de novo synthesis of genetic pathways. Here, we present an economical and streamlined de novo DNA synthesis approach for engineering a synthetic pathway with microchip-synthesized oligonucleotides (oligo). The process integrates entire oligo pool amplification, error-removal, and assembly of long DNA molecules. We utilized this method to construct a functional lycopene biosynthetic pathway (11.9 kb encoding 10 genes) in Escherichia coli using a highly error-prone microchip-synthesized oligo pool (479 oligos) without pre-purification, and the error-frequency was reduced from 14.25/kb to 0.53/kb. This low-equipment-dependent and cost-effective method can be widely applied for rapid synthesis of biosynthetic pathways in general molecular biology laboratories.

  7. Low heart rate as a risk factor for child and adolescent proactive aggressive and impulsive psychopathic behavior.

    Science.gov (United States)

    Raine, Adrian; Fung, Annis Lai Chu; Portnoy, Jill; Choy, Olivia; Spring, Victoria L

    2014-01-01

    Although low resting heart rate has been viewed as a well-replicated biological correlate of child and adolescent antisocial behavior, little is known about how it interacts with psychosocial adversity in predisposing to both reactive-proactive aggression and psychopathy, and whether this relationship generalizes to an East Asian population. This study tests the hypothesis that low resting heart rate will be associated with aggression and psychopathic traits, and that heart rate will interact with adversity in predisposing to these antisocial traits. Resting heart rate was assessed in 334 Hong Kong male and female schoolchildren aged 11-17 years. A social adversity index was calculated from a psychosocial interview of the parent, while parents assessed their children on the Reactive-Proactive Aggression Questionnaire and the Antisocial Personality Screening Device. Low resting heart rate was significantly associated with higher proactive aggression, impulsive features of psychopathy, and total child psychopathy. Low resting heart rate interacted with high psychosocial adversity in explaining higher reactive (but not proactive) aggression, as well as impulsive psychopathy. These findings provide support for a biosocial perspective of reactive aggression and impulsive psychopathy, and document low resting heart rate as a robust correlate of both childhood impulsive psychopathic behavior and proactive aggression. To our knowledge, this study is the first to document low resting heart rate as a correlate of child psychopathy and the second to establish low heart rate as a risk factor of antisocial behavior in an East Asian population. The findings provide further evidence for both low resting heart rate as a potential biomarker for childhood psychopathic and aggressive behavior, and also a biosocial perspective on childhood antisocial behavior. © 2014 Wiley Periodicals, Inc.

  8. 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.

  9. 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.

  10. Stabilization of time-delay neural networks via delayed pinning impulses

    International Nuclear Information System (INIS)

    Liu, Xinzhi; Zhang, Kexue; Xie, Wei-Chau

    2016-01-01

    This paper studies the pinning stabilization problem of time-delay neural networks. A new pinning delayed-impulsive controller is proposed to stabilize the neural networks with delays. First, we consider the general nonlinear time-delay systems with delayed impulses, and establish several global exponential stability criteria by employing the method of Lyapunov functionals. Our results are then applied to obtain sufficient conditions under which the proposed pinning controller can exponentially stabilize the time-delay neural networks. It is shown that the global exponential stabilization of delayed neural networks can be effectively realized by controlling a small portion of neurons in the networks via delayed impulses, and, for fixed impulsive control gain, increasing the impulse delay or decreasing the number of neurons to be pinned at the impulsive moments will lead to high frequency of impulses added the corresponding neurons. Numerical examples are provided to illustrate the theoretical results, which demonstrate that our results are less conservative than the results reported in the existing literatures when the proposed pinning controller reduces to the delayed impulsive controller.

  11. Impulsive differential inclusions a fixed point approach

    CERN Document Server

    Ouahab, Abdelghani; Henderson, Johnny

    2013-01-01

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

  12. 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

  13. Impaired decisional impulsivity in pathological videogamers.

    Directory of Open Access Journals (Sweden)

    Michael A Irvine

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

  14. Dissipative control for singular impulsive dynamical systems

    Directory of Open Access Journals (Sweden)

    Li Yang

    2012-04-01

    Full Text Available The aim of this work is to study the dissipative control problem for singular impulsive dynamical systems. We start by introducing the impulse to the singular systems, and give the definition of the dissipation for singular impulsive dynamical systems. Then we discuss the dissipation of singular impulsive dynamical systems, we obtain some sufficient and necessary conditions for dissipation of these systems by solving some linear matrix inequalities (LMIs. By using this method, we design a state feedback controller to make the closed-loop system dissipative. At last, we testify the feasibility of the method by a numerical example.

  15. Penrose junction conditions extended: Impulsive waves with gyratons

    Science.gov (United States)

    Podolský, J.; Švarc, R.; Steinbauer, R.; Sämann, C.

    2017-09-01

    We generalize the classical junction conditions for constructing impulsive gravitational waves by the Penrose "cut and paste" method. Specifically, we study nonexpanding impulses which propagate in spaces of constant curvature with any value of the cosmological constant (that is, Minkowski, de Sitter, or anti-de Sitter universes) when additional off-diagonal metric components are present. Such components encode a possible angular momentum of the ultrarelativistic source of the impulsive wave—the so-called gyraton. We explicitly derive and analyze a specific transformation that relates the distributional form of the metric to a new form which is (Lipschitz) continuous. Such a transformation automatically implies an extended version of the Penrose junction conditions. It turns out that the conditions for identifying points of the background spacetime across the impulse are the same as in the original Penrose cut and paste construction, but their derivatives now directly represent the influence of the gyraton on the axial motion of test particles. Our results apply both for vacuum and nonvacuum solutions of Einstein's field equations and can also be extended to other theories of gravity.

  16. The role of domain-general cognitive resources in children's construction of a vitalist theory of biology.

    Science.gov (United States)

    Bascandziev, Igor; Tardiff, Nathan; Zaitchik, Deborah; Carey, Susan

    2018-03-24

    Some episodes of learning are easier than others. Preschoolers can learn certain facts, such as "my grandmother gave me this purse," only after one or two exposures (easy to learn; fast mapping), but they require several years to learn that plants are alive or that the sun is not alive (hard to learn). One difference between the two kinds of knowledge acquisition is that hard cases often require conceptual construction, such as the construction of the biological concept alive, whereas easy cases merely involve forming new beliefs formulated over concepts the child already has (belief revision, a form of knowledge enrichment). We asked whether different domain-general cognitive resources support these two types of knowledge acquisition (conceptual construction and knowledge enrichment that supports fast mapping) by testing 82 6-year-olds in a pre-training/training/post-training study. We measured children's improvement in an episode involving theory construction (the beginning steps of acquisition of the framework theory of vitalist biology, which requires conceptual change) and in an episode involving knowledge enrichment alone (acquisition of little known facts about animals, such as the location of crickets' ears and the color of octopus blood). In addition, we measured children's executive functions and receptive vocabulary to directly compare the resources drawn upon in the two episodes of learning. We replicated and extended previous findings highlighting the differences between conceptual construction and knowledge enrichment, and we found that Executive Functions predict improvement on the Vitalism battery but not on the Fun Facts battery and that Receptive Vocabulary predicts improvement the Fun Facts battery but not on the Vitalism battery. This double dissociation provides new evidence for the distinction between the two types of knowledge acquisition, and bears on the nature of the learning mechanisms involved in each. Copyright © 2018 Elsevier Inc. All

  17. Impulsive choice and impulsive action predict vulnerability to distinct stages of nicotine seeking in rats

    NARCIS (Netherlands)

    Diergaarde, L.; Pattij, T.; Poortvliet, I.; Hogenboom, F.; de Vries, W.; Schoffelmeer, A.N.M.; de Vries, T.J.

    2008-01-01

    Background: Although heavy smoking has been associated with impulsivity in humans, it is not clear whether poor impulse control represents a risk factor in the etiology of nicotine dependence. Methods: To address this issue, rats were selected on the basis of individual differences in impulsivity in

  18. 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...

  19. Impulsive choice predicts anxiety-like behavior, but not alcohol or sucrose consumption, in male Long-Evans rats.

    Science.gov (United States)

    Stein, Jeffrey S; Renda, C Renee; Barker, Shayne M; Liston, Kennan J; Shahan, Timothy A; Madden, Gregory J

    2015-05-01

    Prior human research indicates robust, positive relations between impulsive choice (i.e., preference for smaller, immediate over larger, delayed rewards) and alcohol use disorders. However, varied findings in the nonhuman literature reveal a relatively ambiguous relation between impulsive choice and alcohol consumption in rodents. In addition, few rodent studies have investigated potential relations between impulsive choice and common covariates of alcohol consumption (e.g., avidity for sweet substances or anxiety-like behavior). Ninety-two male Long-Evans rats completed an impulsive-choice task. From this larger sample, extreme high- and low-impulsive groups (n = 30 each) were retained for further testing. In separate tests, subsequent open-field behavior and consumption of oral alcohol (12% w/v) and isocaloric sucrose were examined. Impulsive choice was then retested to examine whether behavior remained stable over the course of the experiment. No significant relations emerged between impulsive choice and either alcohol or sucrose consumption. However, impulsive choice predicted greater anxiety-like behavior (avoidance of the center field, defecation) in the open-field test. In turn, greater anxiety predicted lower alcohol and sucrose consumption. Finally, choice remained generally stable across the experiment, although high-impulsive rats tended toward less impulsive choice in the retest. Although impulsive choice and alcohol consumption appear to share some variance with anxiety-like behavior, the present data offer no support for a relation between impulsive choice and alcohol consumption in Long-Evans rats. Together with mixed rodent data from prior reports, these findings attenuate cross-species comparisons to human relations between impulsive choice and alcohol use disorders. Copyright © 2015 by the Research Society on Alcoholism.

  20. Cognitive function and nonfood-related impulsivity in post-bariatric surgery patients

    Directory of Open Access Journals (Sweden)

    Ekaterini eGeorgiadou

    2014-12-01

    Full Text Available Initial evidence that cognitive function improves after bariatric surgery exists. The post-surgery increase in cognitive control might correspond with a decrease of impulsive symptoms after surgery. The present study investigated cognitive function and nonfood-related impulsivity in patients with substantial weight loss due to bariatric surgery by using a comparative cross-sectional design. Fifty post-bariatric surgery patients (postBS group who had significant percent weight loss (M = 75.94, SD = 18.09 after Roux-en-Y gastric bypass (body mass index, BMI Mpost = 30.54 kg/m2, SDpost = 5.14 were compared with 50 age and gender matched bariatric surgery candidates (preBS group (BMI Mpre = 48.01 kg/m2, SDpre = 6.56. To measure cognitive function the following computer-assisted behavioral tasks were utilized: Iowa Gambling Task, Tower of Hanoi, Stroop Test, Trail Making Test-Part B, and Corsi Block Tapping Test. Impulsive symptoms and behaviors were assessed using impulsivity questionnaires and a structured interview for impulse control disorders. No group differences were found with regard to performance-based cognitive control, self-reported impulsive symptoms and impulse control disorders. The results indicate that the general tendency to react impulsively does not differ between pre-surgery and post-surgery patients. The question of whether nonfood-related impulsivity in morbidly obese patients changes post-surgery should be addressed in longitudinal studies given that impulsive symptoms should be considered potential targets for pre- as well post-surgery interventions.

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

    Directory of Open Access Journals (Sweden)

    Meredith S Berry

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

  2. Behavior of impulsive fuzzy cellular neural networks with distributed delays

    Directory of Open Access Journals (Sweden)

    Kelin Li

    2007-04-01

    Full Text Available In this paper, we investigate a generalized model of fuzzy cellular neural networks with distributed delays and impulses. By employing the theory of topological degree, M-matrix and Lypunov functional, we find sufficient conditions for the existence, uniqueness and global exponential stability of both the equilibrium point and the periodic solution. Two examples are given to illustrate the results obtained here.

  3. Almost Periodic Solutions for Impulsive Fractional Stochastic Evolution Equations

    Directory of Open Access Journals (Sweden)

    Toufik Guendouzi

    2014-08-01

    Full Text Available In this paper, we consider the existence of square-mean piecewise almost periodic solutions for impulsive fractional stochastic evolution equations involving Caputo fractional derivative. The main results are obtained by means of the theory of operators semi-group, fractional calculus, fixed point technique and stochastic analysis theory and methods adopted directly from deterministic fractional equations. Some known results are improved and generalized.

  4. Attractor Transformation by Impulsive Control in Boolean Control Network

    Directory of Open Access Journals (Sweden)

    Bo Gao

    2013-01-01

    Full Text Available Boolean control networks have recently been attracting considerable interests as computational models for genetic regulatory networks. In this paper, we present an approach of impulsive control for attractor transitions in Boolean control networks based on the recent developed matrix semitensor product theory. The reachability of attractors is estimated, and the controller is also obtained. The general derivation proposed here is exemplified with a kind of gene model, which is the protein-nucleic acid interactions network, on numerical simulations.

  5. Reliability and Validity of Measures of Impulsive Choice and Impulsive Action in Smokers Trying to Quit

    Science.gov (United States)

    McCarthy, Danielle E.; Bold, Krysten W.; Minami, Haruka; Yeh, Vivian M.; Rutten, Emily; Nadkarni, Shruti G.; Chapman, Gretchen B.

    2016-01-01

    Cross-sectional research suggests that smokers are more impulsive than are non-smokers, but few studies have examined relations between impulsiveness and later success in quitting smoking. The purpose of this study was to investigate the reliability and predictive validity of facets of impulsiveness in adult smokers trying to quit. Baseline behavioral measures of impulsive choice (assessed with a delay discounting task) and impulsive action (assessed with a measure of behavioral disinhibition) were used as predictors of smoking cessation success over 12 weeks. The sample included 116 adult (18 years old or older) daily smokers from central New Jersey. Impulsive choice, impulsive action, and self-reported impulsiveness were not significantly related to one another at baseline. Impulsive choice had high test-retest reliability from pre- to post-quit, whereas impulsive action was less stable. Test-retest reliability from pre-quit to three weeks post-quit was moderated by achievement of seven-day abstinence. Baseline impulsive action was significantly negatively related to quitting for at least one day in the first two weeks of a quit attempt and of prolonged abstinence (no relapse over the next 10 weeks). Baseline impulsive choice was robustly associated with biochemically verified seven-day point-prevalence abstinence 12 weeks post-quit, such that those with lower delay discounting were more likely to achieve abstinence. Facets of impulsiveness appear to function largely independently in adult smokers, as indicated by their lack of inter-correlation, differential stability, and differential relations with abstinence. Impulsive action may impede initial quitting, whereas impulsive choice may be an obstacle to maintaining lasting abstinence. PMID:26751623

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

    Science.gov (United States)

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

    2015-07-01

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

  7. Increased impulsivity retards the transition to dorsolateral striatal dopamine control of cocaine seeking.

    Science.gov (United States)

    Murray, Jennifer E; Dilleen, Ruth; Pelloux, Yann; Economidou, Daina; Dalley, Jeffrey W; Belin, David; Everitt, Barry J

    2014-07-01

    Development of maladaptive drug-seeking habits occurs in conjunction with a ventral-to-dorsal striatal shift in dopaminergic control over behavior. Although these habits readily develop as drug use continues, high impulsivity predicts loss of control over drug seeking and taking. However, whether impulsivity facilitates the transition to dorsolateral striatum (DLS) dopamine-dependent cocaine-seeking habits or whether impulsivity and cocaine-induced intrastriatal shifts are additive processes is unknown. High- and low-impulsive rats identified in the five-choice serial reaction-time task were trained to self-administer cocaine (.25 mg/infusion) with infusions occurring in the presence of a cue-light conditioned stimulus. Dopamine transmission was blocked in the DLS after three stages of training: early, transition, and late-stage, by bilateral intracranial infusions of α-flupenthixol (0, 5, 10, or 15 μg/side) during 15-min cocaine-seeking test sessions in which each response was reinforced by a cocaine-associated conditioned stimulus presentation. In early-stage tests, neither group was affected by DLS dopamine receptor blockade. In transition-stage tests, low-impulsive rats showed a significant dose-dependent reduction in cocaine seeking, whereas high-impulsive rats were still unaffected by α-flupenthixol infusions. In the final, late-stage seeking test, both groups showed dose-dependent sensitivity to dopamine receptor blockade. The results demonstrate that high impulsivity is associated with a delayed transition to DLS-dopamine-dependent control over cocaine seeking. This suggests that, if impulsivity confers an increased propensity to addiction, it is not simply through a more rapid development of habits but instead through interacting corticostriatal and striato-striatal processes that result ultimately in maladaptive drug-seeking habits. © 2013 Society of Biological Psychiatry Published by Society of Biological Psychiatry All rights reserved.

  8. Statistically-Efficient Filtering in Impulsive Environments: Weighted Myriad Filters

    Directory of Open Access Journals (Sweden)

    Gonzalez Juan G

    2002-01-01

    Full Text Available Linear filtering theory has been largely motivated by the characteristics of Gaussian signals. In the same manner, the proposed Myriad Filtering methods are motivated by the need for a flexible filter class with high statistical efficiency in non-Gaussian impulsive environments that can appear in practice. Myriad filters have a solid theoretical basis, are inherently more powerful than median filters, and are very general, subsuming traditional linear FIR filters. The foundation of the proposed filtering algorithms lies in the definition of the myriad as a tunable estimator of location derived from the theory of robust statistics. We prove several fundamental properties of this estimator and show its optimality in practical impulsive models such as the -stable and generalized- . We then extend the myriad estimation framework to allow the use of weights. In the same way as linear FIR filters become a powerful generalization of the mean filter, filters based on running myriads reach all of their potential when a weighting scheme is utilized. We derive the "normal" equations for the optimal myriad filter, and introduce a suboptimal methodology for filter tuning and design. The strong potential of myriad filtering and estimation in impulsive environments is illustrated with several examples.

  9. Calorie Intake and Gambling: Is Fat and Sugar Consumption 'Impulsive'?

    Science.gov (United States)

    Chamberlain, Samuel R; A Redden, Sarah; Grant, Jon E

    2017-09-01

    Excessive calorie intake constitutes a global public health concern, due to its associated range of untoward outcomes. Gambling is commonplace and gambling disorder is now considered a behavioral addiction in DSM-5. The relationships between calorie intake, gambling, and other types of putatively addictive and impulsive behaviors have received virtually no research attention. Two-hundred twenty-five young adults who gamble were recruited from two Mid-Western university communities in the United States using media advertisements. Dietary intake over the preceding year was quantified using the Dietary Fat and Free Sugar Short questionnaire (DFS). Clinician rating scales, questionnaires, and cognitive tests germane to impulsivity were completed. Relationships between dietary fat/sugar intake and gambling behaviors, as well as other measures of psychopathology and cognition germane to addiction, were evaluated using correlational analyses controlling for multiple comparisons. Greater dietary fat and sugar intake were associated with lower educational levels and with male gender. Controlling for these variables, higher dietary fat and sugar intake were correlated significantly with worse gambling pathology and anxiety scores. Dietary sugar intake was also significantly associated with higher depressive scores, more alcohol intake, lower self-esteem, and with greater risk of having one or more mental disorders in general. Dietary intake did not correlate significantly with ADHD symptoms, presence of one or more impulse control disorders, Barratt impulsiveness, or cognitive functioning. These data suggest a particularly strong relationship between fat/sugar intake and symptoms of gambling pathology, but not most other forms of impulsivity and behavioral addiction (excepting alcohol intake). Providing education about healthy diet may be especially valuable in gamblers and in community settings where gambling advertisements feature prominently. Future work should explore

  10. On Some New Impulsive Integral Inequalities

    OpenAIRE

    Jianli Li

    2008-01-01

    We establish some new impulsive integral inequalities related to certain integral inequalities arising in the theory of differential equalities. The inequalities obtained here can be used as handy tools in the theory of some classes of impulsive differential and integral equations.

  11. Robust dissipativity for uncertain impulsive dynamical systems

    Directory of Open Access Journals (Sweden)

    Liu Bin

    2003-01-01

    Full Text Available We discuss the robust dissipativity with respect to the quadratic supply rate for uncertain impulsive dynamical systems. By employing the Hamilton-Jacobi inequality approach, some sufficient conditions of robust dissipativity for this kind of system are established. Finally, we specialize the obtained results to the case of uncertain linear impulsive dynamical systems.

  12. Impulsive Vaccination for an Epidemiology Model

    Science.gov (United States)

    De la Sen, M.; Garrido, A. J.

    2017-03-01

    This paper investigates sufficient conditions of almost periodic sand periodic solutions of an integral model under impulsive controls. Since the model is of generic epidemiological interest, such impulsive controls are either vaccination actions or abrupt variations of the infected population due to infected immigration or lost of infective numbers due to either vaccination or lost of infected population by out-migration.

  13. Impulsivity and Cluster B Personality Disorders.

    Science.gov (United States)

    Turner, Daniel; Sebastian, Alexandra; Tüscher, Oliver

    2017-03-01

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

  14. 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.

  15. Differential relationships between sub-traits of BIS-11 impulsivity and executive processes: an ERP study.

    Science.gov (United States)

    Kam, Julia W Y; Dominelli, Rachelle; Carlson, Scott R

    2012-08-01

    There is mixed evidence for a relationship between impulsivity and executive functions. Although impulsivity is heterogeneous, previous research did not examine partial relationships controlling for shared variance across sub-traits to evaluate the specificity of these associations. Eighty-five undergraduates completed the Barratt Impulsiveness Scale-11 (BIS-11) and the AX-expectancy version of the Continuous Performance Task (AX-CPT). This task engenders a conflict between two response tendencies by manipulating the frequency of specific trial types. We conducted mixed model analyses to determine the unique variance in behavioral and electrophysiological indices of relevant cognitive functions accounted for by the facets of BIS-11. Motor Impulsiveness was associated with smaller P3 across sites and conditions suggesting a general cognitive limitation not specific to the condition requiring the most inhibition, and larger N2 in some conditions indicating heightened conflict detection. Non-Planning Impulsiveness was related to smaller N2 when inhibiting a primed response and with greater P3 in some contexts. Attentional Impulsiveness appeared to be associated with an inefficient conflict detection system indicated by relatively normal engagement in trials involving the non-potent response, but relatively over engagement in the prepotent condition. Our findings suggest that sub-traits of impulsivity are differentially related to executive processes. Copyright © 2012 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    Barz, Helmut; Schreiber, Almut; Barz, Ulrich

    2013-11-01

    It is general accepted, that nerval excitement and conduction is caused by voltage changes. However, the influx of fluid into an elastical tube releases impulses or pressure waves. Therefore an influx of ion currents, respectively fluid motions into the elastic neuronal cells and fibres also induce impulses. This motion of charge carriers are measured by voltage devices as oscillations or action potentials, but the voltage changes may be an epiphenomenon of the (mechanical) impulses. Impulse waves can have a high speed. As stiffer or inelastic a tube wall, the greater is the speed of the impulse. Myelin sheaths cause a significant stiffening of the nerve fibre wall and myelinated fibres have a conduction velocity up to 120 m/s. The influx of fluid at the nodes of Ranvier intensifies periodically the impulse wave in the nerve fibres. The authors suggest that also the muscle end-plate acts as a conductor of axonal impulses to the inner of the muscle fibres and that the exocytosis of acetylcholine into the synaptic cleft may be an amplifier of the axonal impulse. It is discussed that intracellular actin filaments may also influence motions at the neuronal membrane. Many sensory nerve cells are excited due to exogenous or endogenous mechanical impulses. It may plausible that such impulses are conducted directly to the sensory nerve cell bodies in the dorsal root ganglia without the transformation in electric energy. Excitation conduction happens without noteworthy energy consumption because the flow of ion currents through the membranes takes place equivalent to the concentration gradient. Impulse waves cause short extensions of the lipid membranes of the cell- and fibres walls and therefore they can induce opening and closing of the included ion channels. This mechanism acts to "voltage gated" and "ligand-gated" channels likewise. The concept of neuronal impulses can be helpful to the understanding of other points of neurophysiology or neuronal diseases. This includes

  17. Sleep-Wake State Tradeoffs, Impulsivity and Life History Theory

    Directory of Open Access Journals (Sweden)

    Alissa A. Miller

    2012-04-01

    Full Text Available Evolutionary ecological theory predicts that sleep-wake state tradeoffs may be related to local environmental conditions and should therefore correlate to alterations in behavioral life history strategies. It was predicted that firefighters who slept more and reported better quality sleep on average would exhibit lower impulsivity inclinations related to slower life history trajectories. UPPS impulsivity scores and self-reported sleep averages were analyzed and indicated a negative association between sleep variables and urgency and a positive association with premeditation. Perseverance, and in some cases premeditation, however, disclosed an unpredicted marginally significant positive association between increased and emergency nighttime waking-related sleep deprivation. Sensation seeking was not associated with sleep variables, but was strongly associated with number of biological children. This research contributes to understanding the implications of human sleep across ecological and behavioral contexts and implies further research is necessary for constructing evolutionarily oriented measures of impulsivity inclination and its meaning in the context of life history strategies.

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

    Science.gov (United States)

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

    2013-11-01

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

  19. Nitrogen and Sulfur Codoped Reduced Graphene Oxide as a General Platform for Rapid and Sensitive Fluorescent Detection of Biological Species.

    Science.gov (United States)

    Chen, Lu; Song, Liping; Zhang, Yichi; Wang, Ping; Xiao, Zhidong; Guo, Yuguo; Cao, Feifei

    2016-05-11

    Nitrogen (N) and sulfur (S) codoped reduced graphene oxide (N,S-rGO) was synthesized through a facile solvothermal process. The introduction of N and S heteroatoms into GO effectively activated the sp(2)-hybridized carbon lattice and made the material an ideal electron/energy acceptor. Such unique properties enable this material to perform as a general platform for rapid and sensitive detection of various biological species through simple fluorescence quenching and recovering. When quantum dot (QD)-labeled HBV (human being disease-related gene hepatitis B virus DNA) and HIV (human being disease-related gene human immunodeficiency virus DNA) molecular beacon probes were mixed with N,S-rGO, QD fluorescence was quenched; when target HBV and HIV DNA were added, QD fluorescence was recovered. By the recovered fluorescence intensity, the target virus DNA detection limits were reduced to 2.4 nM for HBV and 3.0 nM for HIV with detection time of less than 5 min. It must be stressed out that different viruses in the same homogeneous aqueous media could be discriminated and quantified simultaneously through choosing diverse QD probes with different colors. Moreover, even one mismatched target DNA could be distinguished using this method. When altering the molecular beacon loop domain to protein aptamers, this sensing strategy was also able to detect thrombin and IgE in 5 min with detection limits of 0.17 ng mL(-1) and 0.19 ng mL(-1), respectively, which was far more rapid and sensitive than bare GO-based fluorescence detection strategy.

  20. Risk Factors and Impulsivity in Obesity

    Directory of Open Access Journals (Sweden)

    Bilge Burcak Annagur

    2010-12-01

    Full Text Available In addition to genetic tendency, social, cultural, emotional and diet-related factors play important role in the development of obesity. Impulsivity is the possible predictor of relapse in obesity treatment. Impulsivity is also considered as a predicting factor among patients who quit the treatment. Research has shown that obese people are more impulsive than other people. Impulsive features are especially found to be higher with those who have binge eating disorder. Impulsive people appears to have no control over their behaviors on eating and they have more interest towards food with higher calories. Another issue that strengthens the assocaition between obesity and impulsivity is the obesity in children with attention deficit hyperactivity disorder. Dopaminergic deficiency in the reward centre of the brain can be a common pathway for both attention deficit and obesity. Several approaches have been searched and put forward to sustain the patients’ lost weights after diet. Specific cognitive behavioral approaches developed for the treatment of impulsive behavior could contribute much into obesity treatment . Obesity is a chronic disease that requires long term treatment and follow up.

  1. Design, Development, and Psychometric Analysis of a General, Organic, and Biological Chemistry Topic Inventory Based on the Identified Main Chemistry Topics Relevant to Nursing Clinical Practice

    Science.gov (United States)

    Brown, Corina E.

    2013-01-01

    This two-stage study focused on the undergraduate nursing course that covers topics in general, organic, and biological (GOB) chemistry. In the first stage, the central objective was to identify the main concepts of GOB chemistry relevant to the clinical practice of nursing. The collection of data was based on open-ended interviews of both nursing…

  2. 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.

  3. Optimal impulsive manoeuvres and aerodynamic braking

    Science.gov (United States)

    Jezewski, D. J.

    1985-01-01

    A method developed for obtaining solutions to the aerodynamic braking problem, using impulses in the exoatmospheric phases is discussed. The solution combines primer vector theory and the results of a suboptimal atmospheric guidance program. For a specified initial and final orbit, the solution determines: (1) the minimum impulsive cost using a maximum of four impulses, (2) the optimal atmospheric entry and exit-state vectors subject to equality and inequality constraints, and (3) the optimal coast times. Numerical solutions which illustrate the characteristics of the solution are presented.

  4. [Impulse control disorders in Parkinson's disease].

    Science.gov (United States)

    Joutsa, Juho; Kaasinen, Valtteri

    2013-01-01

    Of the patients having Parkinson's disease, up to third encounters some degree of impulse control problems and one out of seven suffers from true impulse control disorders such as pathological gambling, hypersexuality, compulsive shopping and binge eating. Dopaminergic drugs used in anti-Parkinson therapy, especially dopamine agonists, increase the risk of these disorders. Impulse control disorders are associated with a relatively more active dopamine-mediated neurotransmission of the mesolimbic and mesocortical system. Discontinuation of dopamine agonist medication can thus be considered as the first line treatment of these disorders.

  5. 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)

  6. Poor impulse control predicts inelastic demand for nicotine but not alcohol in rats.

    Science.gov (United States)

    Diergaarde, Leontien; van Mourik, Yvar; Pattij, Tommy; Schoffelmeer, Anton N M; De Vries, Taco J

    2012-05-01

    Tobacco and alcohol dependence are characterized by continued use despite deleterious health, social and occupational consequences, implying that addicted individuals pay a high price for their use. In behavioral economic terms, such persistent consumption despite increased costs can be conceptualized as inelastic demand. Recent animal studies demonstrated that high-impulsive individuals are more willing to work for nicotine or cocaine infusions than their low-impulsive counterparts, indicating that this trait might be causally related to inelastic drug demand. By employing progressive ratio schedules of reinforcement combined with a behavioral economics approach of analysis, we determined whether trait impulsivity is associated with an insensitivity of nicotine or alcohol consumption to price increments. Rats were trained on a delayed discounting task, measuring impulsive choice. Hereafter, high- and low-impulsive rats were selected and trained to nose poke for intravenous nicotine or oral alcohol. Upon stable self-administration on a continuous reinforcement schedule, the price (i.e. response requirement) was increased. Demand curves, depicting the relationship between price and consumption, were produced using Hursh's exponential demand equation. Similar to human observations, nicotine and alcohol consumption in rats fitted this equation, thereby demonstrating the validity of our model. Moreover, high-impulsive rats displayed inelastic nicotine demand, as their nicotine consumption was less sensitive to price increments as compared with that in low-impulsive rats. Impulsive choice was not related to differences in alcohol demand elasticity. Our model seems well suited for studying nicotine and alcohol demand in rats and, as such, might contribute to our understanding of tobacco and alcohol dependence. © 2011 The Authors, Addiction Biology © 2011 Society for the Study of Addiction.

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

    Science.gov (United States)

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

    2011-03-01

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

  8. 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.

  9. Impulse control disorders in Parkinson's disease.

    Science.gov (United States)

    Vilas, Dolores; Pont-Sunyer, Claustre; Tolosa, Eduardo

    2012-01-01

    Impulse control disorders (ICDs), a group of complex behavioral disorders, occur more commonly in Parkinson's disease (PD) patients than in the general population, with a reported prevalence up to 13.6% in some studies. The most common ICDs reported are pathological gambling (PG), hypersexuality (HS), compulsive shopping and compulsive eating. More than a quarter of the patients with ICDs have 2 or more behavioral addictions. These abnormal behaviors impair activities of daily living and have a negative impact on quality of life of patients and their families. As with many other non motor symptoms in PD, ICDs are frequently under-reported by patients and caregivers and may be under-recognized by the treating physicians. Treatment with dopamine agonists (DA) is the main risk factor for developing ICDs, and stimulation of mesolimbic D3 receptors by DA is thought to underlie their development. The DA effect seems to be a class effect and not specific for any DA. Levodopa can also induce ICDs but much less so than the DAs. The management of ICDs in PD is complex. Modifications in dopaminergic drug treatment are frequently necessary. In some cases alternative therapies such as atypical antipsychotics, antidepressants or deep brain stimulation if motor symptoms become incapacitating after adjustment of dopamine replacement therapy should be considered. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Nabarlek evaporation and storage ponds: possible role of biological activity in the escape of toxic substances to the general environment

    International Nuclear Information System (INIS)

    Martinick, W.

    1982-01-01

    An investigation was undertaken to determine whether or not game birds might become contaminated with radionuclides while visiting the evaporating ponds at the Nabarlek uranium mine. The level of biological community development in the ponds and water bird activity were low. It is concluded that at present escape of radionuclides or toxic elements from the ponds as a result of biological activity is not a problem

  11. Xenograft biologic mesh in parietal and general surgery: Technical assessment and review of clinical effectiveness and safety data.

    Science.gov (United States)

    Sainfort, A; Denis Hallouard, I; Hartmann, D; Aulagner, G; Francois, Y; Tiffet, O; Barabino, G; Nuiry, O; Armoiry, X

    2016-12-01

    To describe the main technical characteristics of biologic prostheses used for parietal reinforcement and to present the state of the art on their risk/benefit ratio. We conducted a technical analysis of manufacturer specifications of the biologic prostheses that are currently available in France accompanied by a literature review by selecting meta-analyses and systematic reviews, randomized controlled trials and publications of health technology rating agencies. Biological implants for parietal reinforcement are mainly intended for use in a contaminated environment where the use of synthetic prostheses is contra-indicated. We identified fourteen systematic reviews and meta-analyses and one randomized controlled trial. Six ongoing clinical trials were identified as well as two clinical trials that had been interrupted. In the current state of knowledge, there are no high-level evidence data on the therapeutic contribution of biologic prostheses that allow prioritization of the various biologic prostheses according to their characteristics or their different manufacturing processes. Pending the results of current randomized controlled trials to validate the indications and an eventual specific reimbursement, indications for the use of biologic parietal reinforcement prostheses seems to be limited to rare clinical situations and only after collegial discussion. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  12. 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 ...

  13. Active noise cancellation algorithms for impulsive noise.

    Science.gov (United States)

    Li, Peng; Yu, Xun

    2013-04-01

    Impulsive noise is an important challenge for the practical implementation of active noise control (ANC) systems. The advantages and disadvantages of popular filtered- X least mean square (FXLMS) ANC algorithm and nonlinear filtered-X least mean M-estimate (FXLMM) algorithm are discussed in this paper. A new modified FXLMM algorithm is also proposed to achieve better performance in controlling impulsive noise. Computer simulations and experiments are carried out for all three algorithms and the results are presented and analyzed. The results show that the FXLMM and modified FXLMM algorithms are more robust in suppressing the adverse effect of sudden large amplitude impulses than FXLMS algorithm, and in particular, the proposed modified FXLMM algorithm can achieve better stability without sacrificing the performance of residual noise when encountering impulses.

  14. 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.

  15. Impulsive fractional differential inclusions with infinite delay

    Directory of Open Access Journals (Sweden)

    Khalida Aissani

    2013-11-01

    Full Text Available In this article, we apply Bohnenblust-Karlin's fixed point theorem to prove the existence of mild solutions for a class of impulsive fractional equations inclusions with infinite delay. An example is given to illustrate the theory.

  16. Shock Tube as an Impulsive Application Device

    Directory of Open Access Journals (Sweden)

    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.

  17. Detecting Impulses in Mechanical Signals by Wavelets

    Directory of Open Access Journals (Sweden)

    Yang W-X

    2004-01-01

    Full Text Available The presence of periodical or nonperiodical impulses in vibration signals often indicates the occurrence of machine faults. This knowledge is applied to the fault diagnosis of such machines as engines, gearboxes, rolling element bearings, and so on. The development of an effective impulse detection technique is necessary and significant for evaluating the working condition of these machines, diagnosing their malfunctions, and keeping them running normally over prolong periods. With the aid of wavelet transforms, a wavelet-based envelope analysis method is proposed. In order to suppress any undesired information and highlight the features of interest, an improved soft threshold method has been designed so that the inspected signal is analyzed in a more exact way. Furthermore, an impulse detection technique is developed based on the aforementioned methods. The effectiveness of the proposed technique on the extraction of impulsive features of mechanical signals has been proved by both simulated and practical experiments.

  18. The loudness of decaying impulsive sounds

    Science.gov (United States)

    Namba, S.; Hashimoto, T.; Rice, C. G.

    1987-08-01

    In the case of short duration sounds it is well known that temporal loudness summation occurs within a certain time period (i.e., critical duration), and a trade-off relationship is established between the sound intensity and the duration of the sound. Therefore, for the estimation of the loudness of brief sounds such as impulsive noise the temporal loudness summation must be considered. This paper deals with artificial impulsive sounds with a relatively short rise time and a long decay, as usually observed for actual impulsive sounds, and whether the loudness of an impulsive sound is determined by the peak level of the sound or by the total energy of the sound including the decaying part. L AX in ISO 1996, which is the single event exposure level, is chosen as an energy index of the sound in this paper. It is probable, however, that the time varying pattern of the sound or auditory after effect has an effect on the loudness of impulsive sounds. Such effects, however, are not reflected either in L AX or in the peak level measurement. Accordingly additional experiments have been carried out to examine the temporal characteristics of the hearing mechanism in relation to the loudness of impulsive sounds. As a result, it seems that L AX is a good measure of the loudness of impulsive sounds which are not too short, but when the duration of the sound is less than 60 ms the contribution of the auditory after-effect on the loudness needs to be taken into consideration. No relation could be found between the peak level and the loudness of impulsive sounds.

  19. Forensic Psychiatric Aspects of Impulse Control Disorders

    Directory of Open Access Journals (Sweden)

    Huseyin Soysal

    2015-03-01

    Full Text Available Impulse control disorders is an important psychiatric disorder group which draws attention in recent years. Attention deficit hyperactivity disorder and other classical disorders like pyromania, kleptomania, intermittent explosive disorder and compulsive buying could be evasuated under this topic. The aim of this article is to review forensic psychiatric aspects of impulse control disorders and evaluate the disorders in terms of their legal status. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2015; 7(1: 16-29

  20. Impulsive nature in collisional driven reconnection

    Energy Technology Data Exchange (ETDEWEB)

    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).

  1. 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)

  2. ADHD-hyperactive/impulsive subtype in adults

    OpenAIRE

    Gibbins, Christopher; Weiss, Margaret D.; Goodman, David W.; Hodgkins, Paul S.; Landgraf, Jeanne M.; Faraone, Stephen V.

    2010-01-01

    This is the first study to evaluate ADHD-hyperactive/impulsive subtype in a large clinical sample of adults with ADHD. The Quality of Life, Effectiveness, Safety and Tolerability (QuEST) study included 725 adults who received clinician diagnoses of any ADHD subtype. Cross-sectional baseline data from 691 patients diagnosed with the hyperactive/impulsive (HI), inattentive (IA) and combined subtypes were used to compare the groups on the clinician administered ADHD-RS, clinical features and hea...

  3. 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

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

    Directory of Open Access Journals (Sweden)

    Jodi M Gilman

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

  5. Impulse control and related disorders in Parkinson's disease.

    Science.gov (United States)

    Weintraub, Daniel; Nirenberg, Melissa J

    2013-01-01

    Impulse control disorders (ICDs), such as compulsive gambling, buying, sexual behavior, and eating, are a serious and increasingly recognized complication of dopamine replacement therapy in Parkinson's disease (PD). Other impulsive-compulsive behaviors have been linked to dopaminergic medications; these include punding (stereotyped, repetitive, purposeless behaviors) and dopamine dysregulation syndrome (DDS; compulsive medication overuse). ICDs have been most closely related to the use of dopamine agonists (DAs), particularly at higher dosages; in contrast, DDS is primarily associated with shorter-acting, higher-potency dopaminergic medications, such as apomorphine and levodopa. Risk factors for ICDs may include male sex; younger age; younger age at PD onset; a pre-PD history of ICD(s); personal or family history of substance abuse; bipolar disorder; gambling problems; and impulsive personality traits. The primary treatment of ICDs in PD is discontinuation of DA therapy. Not all patients can tolerate this, however, due to worsening motor symptoms and/or DA withdrawal syndrome (a severe, stereotyped drug withdrawal syndrome similar to that of other psychostimulants). While psychiatric medications are frequently used to treat ICDs in the general population, there is no empirical evidence to suggest that they are effective in PD. Given the paucity of treatment options and potentially serious consequences of ICDs in PD, it is critical for patients to be monitored closely for their development. As empirically validated treatments for ICDs emerge, it will also be important to examine their efficacy and tolerability in individuals with comorbid PD. Copyright © 2012 S. Karger AG, Basel.

  6. 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.

  7. Synchronization of hybrid-coupled delayed dynamical networks with noises by partial mixed impulsive control strategy

    Science.gov (United States)

    Zhao, Yi; Fu, Fangfang; Wang, Jingyi; Feng, Jianwen; Zhang, Haiyu

    2018-02-01

    In this paper, a new control method named partial mixed impulsive control strategy is proposed to investigate the problem of exponential synchronization in mean square for a class of general hybrid-coupled delayed dynamical networks with both internal delay and coupling delay. The partial mixed impulsive effects in this strategy can be taken as local and time-varying, which means that they are not only injected into a fraction of nodes in the whole networks but also contain synchronizing and desynchronizing impulses at the same time. In addition, to be more realistic, a delayed coupling term involving the transmission delay and self-feedback delay is taken into account. By means of the Lyapunov method and the comparison principle for impulsive systems, several sufficient criteria are obtained to guarantee the global exponential synchronization in mean square of the dynamical network. The obtained criteria are closely related to the proportion of the controlled nodes, the strengths of mixed impulses, the impulsive intervals, the time delays and the topology structure of the networks. Finally, a numerical example is given to demonstrate the effectiveness of our results.

  8. Food-related impulsivity in obesity and binge eating disorder--a systematic review.

    Science.gov (United States)

    Schag, K; Schönleber, J; Teufel, M; Zipfel, S; Giel, K E

    2013-06-01

    Impulsivity towards food has been recognized as a potential factor leading to increased food intake in obesity. Patients suffering from binge eating disorder (BED) form a specific subgroup of obese people that might be characterized by increased impulsivity. These assumptions, although, have yet to be verified. Therefore, this review evaluates evidence for food-related impulsivity in obese people with and without BED and examines possible differences between both populations. More precisely, evidence for the two components of impulsivity is analyzed separately: evidence for reward sensitivity, specifically, the urge for appetitive stimuli and evidence for rash-spontaneous behaviour such as acting disinhibited with no regard for the consequences. Our search resulted in 51 articles demonstrating generally increased food-related impulsivity. We found particular emphasis on increased reward sensitivity in obese people, which appeared to be more pronounced in people with BED. There was little and conflicting evidence, however, concerning increased rash-spontaneous behaviour in obese people without BED, but consistent evidence of an increase in obese people with BED. All in all, the evidence supports the view that BED represents a specific phenotype of obesity with increased food-related impulsivity. Taking these specific deficits into account can enhance the effectiveness of weight reduction programmes and psychotherapy. © 2013 The Authors. obesity reviews © 2013 International Association for the Study of Obesity.

  9. Individual differences in impulsive and risky choice: effects of environmental rearing conditions.

    Science.gov (United States)

    Kirkpatrick, Kimberly; Marshall, Andrew T; Smith, Aaron P; Koci, Juraj; Park, Yoonseong

    2014-08-01

    The present experiment investigated early-rearing environment modulation of individual differences in impulsive and risky choice. Rats were reared in an isolated condition (IC; n=12), in which they lived alone without novel stimuli, or an enriched condition (EC; n=11), in which they lived among conspecifics with novel stimuli. The impulsive choice task involved choices between smaller-sooner (SS) versus larger-later (LL) rewards. The risky choice task involved choices between certain-smaller (C-S) versus uncertain-larger (U-L) rewards. Following choice testing, incentive motivation to work for food was measured using a progressive ratio task and correlated with choice behavior. HPLC analyses were conducted to determine how monoamine concentrations within the prefrontal cortex (PFC) and nucleus accumbens (NAC) related to behavior in different tasks. IC rats were more impulsive than EC rats, but they did not differ in risky choice behavior. However, choice behavior across tasks was significantly correlated (i.e., the more impulsive rats were also riskier). There were no group differences in monoamine levels, but noradrenergic and serotonergic concentrations were significantly correlated with impulsive and risky choice. Furthermore, serotonin and norepinephrine concentrations in the NAC significantly correlated with incentive motivation and the timing of the reward delays within the choice tasks. These results suggest a role for domain general processes in impulsive and risky choice and indicate the importance of the NAC and/or PFC in timing, reward processing, and choice behavior. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Variable delay-to-signal: a fast paradigm for assessment of aspects of impulsivity in rats

    Directory of Open Access Journals (Sweden)

    Hugo eLeite-Almeida

    2013-10-01

    Full Text Available Testing impulsive behavior in rodents is challenging and labor-intensive. We developed a new behavioral paradigm – the Variable Delay-to-Signal (VDS test – that provides rapid and simultaneous assessment of response and decision impulsivity in rodents. Presentation of a light at variable delays signals the permission for action (nose poke contingent with a reward. Two blocks of 25 trials at 3s delay flank a block of 70 trials in which light is presented with randomly selected 6s or 12s delays. Exposure to such large delays boosts the rate of premature responses when the delay drops to 3s in the final block, an effect that is blunted by an acute methamphetamine challenge and that correlates with the delay-discounting paradigm (choice impulsivity. Finally, as expected, treatment with the NMDA antagonist MK-801 caused a generalized response increase in all VDS blocks. The pharmacological validation, particularly with methamphetamine which has a well established dual effect on response and decision impulsivity, and the correlations between the impulsive behavior in the delay-discounting and VDS paradigms, suggests that the later is able to provide, in a single session, a multi-dimensional assessment of impulsive behavior.

  11. Dynamics of an impulsively controlled Michaelis-Menten type predator-prey system

    Science.gov (United States)

    Baek, Hunki; Lim, Yongdo

    2011-04-01

    We study a predator-prey system with a Michaelis-Menten functional response and impulsive perturbations which contain chemical and biological control terms. By applying the Floquet theory, we establish conditions for the existence and stability of prey-free solutions of the system. We also show the existence of a positive periodic solution of the system by using the bifurcation theorem and find a sufficient condition that makes the system permanent. Moreover, numerical results on impulsive perturbations show that the system we consider can give birth to various kinds of dynamical behaviors.

  12. An Impulsive Three-Species Model with Square Root Functional Response and Mutual Interference of Predator

    Directory of Open Access Journals (Sweden)

    Zhen Wang

    2016-01-01

    Full Text Available An impulsive two-prey and one-predator model with square root functional responses, mutual interference, and integrated pest management is constructed. By using techniques of impulsive perturbations, comparison theorem, and Floquet theory, the existence and global asymptotic stability of prey-eradication periodic solution are investigated. We use some methods and sufficient conditions to prove the permanence of the system which involve multiple Lyapunov functions and differential comparison theorem. Numerical simulations are given to portray the complex behaviors of this system. Finally, we analyze the biological meanings of these results and give some suggestions for feasible control strategies.

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

    Science.gov (United States)

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

    2017-03-01

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

  14. Impulsivity and compulsivity in drug-naïve patients with Parkinson's disease.

    Science.gov (United States)

    Antonini, Angelo; Siri, Chiara; Santangelo, Gabriella; Cilia, Roberto; Poletti, Michele; Canesi, Margherita; Caporali, Alessandra; Mancini, Francesca; Pezzoli, Gianni; Ceravolo, Roberto; Bonuccelli, Ubaldo; Barone, Paolo

    2011-02-15

    Abnormal repetitive behaviors have been reported in Parkinson's disease (PD) during dopamine replacement therapy (DRT) and associated with individual predisposing features, including impulsivity. However, impulsivity and compulsive symptoms have never been explored in PD patients before initiation of DRT. We previously reported a 20% of impulse control disorders (ICD) in an Italian cohort. 103 consecutive newly diagnosed drug-naïve PD patients (means: age = 60.5 ± 9.2 years; duration = 15.4 ± 15.3 months) were screened for compulsive sexual behavior, compulsive buying, intermittent explosive disorder (Minnesota Impulsive Disorders Interview, MIDI), and pathological gambling (South Oaks Gambling Screen, SOGS). Barratt Impulsiveness Scale (BIS-11) and Maudsley Obsessional-Compulsive Questionnaire (MOCQ/R) assessed impulsivity, obsessive-compulsive symptoms, respectively. Depression (GDS-15) and general cognitive status were additionally assessed. We also compared ICDs frequency with our healthy controls. 17.5% of PD patients screened positive for at least one ICD at MIDI (17/103) and SOGS (1/103), though none had a disorder based on DSM-IV criteria. These frequencies were similar to healthy controls. There was a trend toward higher scores in BIS-11 attentive-impulsivity subscale (15.2 ± 4.8 vs. 18.7 ± 4.9; P = 0.007) and in MOCQ/R-Doubting subscale (0.67 ± 1.1 vs. 1.5 ± 1.2; P = 0.007) in PD with ICD. We also observed a positive correlation between GDS-15 and BIS-11. Similar to our healthy control population, we found a significant proportion of early PD patients positive for ICDs before starting treatment. We also found a relationship between impulsivity and depression. A detailed behavioral assessment before starting dopaminergic therapy is recommended. Copyright © 2011 Movement Disorder Society.

  15. Modeling Nitrous Oxide Production during Biological Nitrogen Removal via Nitrification and Denitrification: Extensions to the General ASM Models

    DEFF Research Database (Denmark)

    Ni, Bing-Jie; Ruscalleda, Maël; Pellicer i Nàcher, Carles

    2011-01-01

    Nitrous oxide (N2O) can be formed during biological nitrogen (N) removal processes. In this work, a mathematical model is developed that describes N2O production and consumption during activated sludge nitrification and denitrification. The well-known ASM process models are extended to capture N2O...

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

    Directory of Open Access Journals (Sweden)

    Jessica Novia

    2015-03-01

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

  17. The relationship between impulsivity and impulse control disorders in Parkinson's disease.

    Science.gov (United States)

    Isaias, Ioannis U; Siri, Chiara; Cilia, Roberto; De Gaspari, Danilo; Pezzoli, Gianni; Antonini, Angelo

    2008-02-15

    A range of behaviors presumed to be related to dopaminergic medications have been recently recognized in Parkinson's disease (PD). We evaluated 50 consecutive cognitively intact PD patients on stable dopamine agonist and levodopa therapy and 100 healthy controls for compulsive sexual behavior, compulsive buying, or intermittent explosive disorders assessed by the Minnesota Impulsive Disorders Interview (MIDI), pathological gambling (South Oaks Gambling Screen, SOGS), impulsivity (Barratt Impulsiveness Scale), compulsivity (Maudsley obsessional-compulsive inventory), and depression scores (Geriatric Depression Scale). Overall 28% PD (14/50) and 20% healthy controls (20/100) reported at least one abnormal behavior at MIDI or pathological SOGS score. PD patients had higher scores than controls for impulsivity (P = 0.006), compulsivity (P compulsivity, and depression scores in PD. Male gender and higher impulsivity score, but not dose and kind of dopaminergic medications, were associated in PD with increased probability of impulsive disorders at MIDI. Impulse control disorders are also common in the control population. Individual susceptibility factors, such as high impulsivity and depression, underline abnormal behaviors in PD patients treated with stable dopaminergic therapy. 2007 Movement Disorder Society

  18. Environmental Technology Verification: Supplement to Test/QA Plan for Biological and Aerosol Testing of General Ventilation Air Cleaners; Bioaerosol Inactivation Efficiency by HVAC In-Duct Ultraviolet Light Air Cleaners

    Science.gov (United States)

    The Air Pollution Control Technology Verification Center has selected general ventilation air cleaners as a technology area. The Generic Verification Protocol for Biological and Aerosol Testing of General Ventilation Air Cleaners is on the Environmental Technology Verification we...

  19. On the performance of piezoelectric harvesters loaded by finite width impulses

    Science.gov (United States)

    Doria, A.; Medè, C.; Desideri, D.; Maschio, A.; Codecasa, L.; Moro, F.

    2018-02-01

    The response of cantilevered piezoelectric harvesters loaded by finite width impulses of base acceleration is studied analytically in the frequency domain in order to identify the parameters that influence the generated voltage. Experimental tests are then performed on harvesters loaded by hammer impacts. The latter are used to confirm analytical results and to validate a linear finite element (FE) model of a unimorph harvester. The FE model is, in turn, used to extend analytical results to more general harvesters (tapered, inverse tapered, triangular) and to more general impulses (heel strike in human gait). From analytical and numerical results design criteria for improving harvester performance are obtained.

  20. Biological computation

    CERN Document Server

    Lamm, Ehud

    2011-01-01

    Introduction and Biological BackgroundBiological ComputationThe Influence of Biology on Mathematics-Historical ExamplesBiological IntroductionModels and Simulations Cellular Automata Biological BackgroundThe Game of Life General Definition of Cellular Automata One-Dimensional AutomataExamples of Cellular AutomataComparison with a Continuous Mathematical Model Computational UniversalitySelf-Replication Pseudo Code Evolutionary ComputationEvolutionary Biology and Evolutionary ComputationGenetic AlgorithmsExample ApplicationsAnalysis of the Behavior of Genetic AlgorithmsLamarckian Evolution Genet

  1. Impulsivity and eating behavior in males

    Science.gov (United States)

    Jáuregui-Lobera, Ignacio; Santiago, María José

    2017-02-01

    Introduction: Impulsivity is a personality trait related with the control of behaviour and emotions and it is found in different psychopathological alterations, including those referred to eating behaviour. Objective: The aim of this study was to analyse the relationship among the infl uence of the aesthetic body shape model, eating behaviour (and risk for specific disorders), body mass index and impulsivity. Method: A total of 178 males were included in the study, with a mean age of 20.18 ± 2.48. Height and weight were assessed in order to obtain the body mass index. All participants fulfilled the following questionnaires: Barratt Impulsivity Scale (BIS-11), Questionnaire of Infl uences on the Body Shape Model for males (CIMEC-V) and the Eating Attitudes Test (EAT-40). Results: With respect to possible cases of eating disorders, 5.06% were found. Scores of some items of BIS-11 correlated significantly with the EAT-40 and CIMEC-V scores. Overweight participants (39.89%) showed higher level of impulsivity as well as those with EAT-40 scores above the cut-off point for that test. Conclusions: The assessment of impulsivity from a psychological point of view might be a preventive tool with regards to disordered eating behaviours. Respecting the patients with eating disorders/overweight/obesity, that assessment might be a relevant aspect in order to improve the therapeutical approach.

  2. Impulsive parametric damping in energy harvesting

    International Nuclear Information System (INIS)

    Tehrani, Maryam Ghandchi; Pumhoessel, Thomas

    2016-01-01

    In this paper, an electro-mechanical system with a time-varying damper, which is capable of changing the damping coefficient impulsively, is considered. The effect of the impulsive parametric damping to the modal energy content of the mechanical system is investigated analytically as well as numerically. First, the governing differential equation is presented and then the solution of the system's response is obtained through numerical integration. The energy dissipated by the damper is then calculated to investigate the amount of the energy that can be harvested, and the results are compared with the results from a system without parametric impulses. It is shown, that the amount of the harvested energy can be increased by introducing parametric impulses. Then, an analytical formulation is derived for the system using Dirac-Delta impulses and the analytical results are validated with numerical simulations. The device is subjected to an initial condition and therefore is vibrating freely without any base excitation. This could be used for applications such as harvesting energy from the passage of a train, where the train vibration can introduce an initial velocity to the harvester and the energy can then be extracted from the free vibration of the harvester. (paper)

  3. Modeling nitrous oxide production during biological nitrogen removal via nitrification and denitrification: extensions to the general ASM models.

    Science.gov (United States)

    Ni, Bing-Jie; Ruscalleda, Maël; Pellicer-Nàcher, Carles; Smets, Barth F

    2011-09-15

    Nitrous oxide (N(2)O) can be formed during biological nitrogen (N) removal processes. In this work, a mathematical model is developed that describes N(2)O production and consumption during activated sludge nitrification and denitrification. The well-known ASM process models are extended to capture N(2)O dynamics during both nitrification and denitrification in biological N removal. Six additional processes and three additional reactants, all involved in known biochemical reactions, have been added. The validity and applicability of the model is demonstrated by comparing simulations with experimental data on N(2)O production from four different mixed culture nitrification and denitrification reactor study reports. Modeling results confirm that hydroxylamine oxidation by ammonium oxidizers (AOB) occurs 10 times slower when NO(2)(-) participates as final electron acceptor compared to the oxic pathway. Among the four denitrification steps, the last one (N(2)O reduction to N(2)) seems to be inhibited first when O(2) is present. Overall, N(2)O production can account for 0.1-25% of the consumed N in different nitrification and denitrification systems, which can be well simulated by the proposed model. In conclusion, we provide a modeling structure, which adequately captures N(2)O dynamics in autotrophic nitrification and heterotrophic denitrification driven biological N removal processes and which can form the basis for ongoing refinements.

  4. Brain Regions Related to Impulsivity Mediate the Effects of Early Adversity on Antisocial Behavior.

    Science.gov (United States)

    Mackey, Scott; Chaarani, Bader; Kan, Kees-Jan; Spechler, Philip A; Orr, Catherine; Banaschewski, Tobias; Barker, Gareth; Bokde, Arun L W; Bromberg, Uli; Büchel, Christian; Cattrell, Anna; Conrod, Patricia J; Desrivières, Sylvane; Flor, Herta; Frouin, Vincent; Gallinat, Jürgen; Gowland, Penny; Heinz, Andreas; Ittermann, Bernd; Paillère Martinot, Marie-Laure; Artiges, Eric; Nees, Frauke; Papadopoulos-Orfanos, Dimitri; Poustka, Luise; Smolka, Michael N; Jurk, Sarah; Walter, Henrik; Whelan, Robert; Schumann, Gunter; Althoff, Robert R; Garavan, Hugh

    2017-08-15

    Individual differences in impulsivity and early adversity are known to be strong predictors of adolescent antisocial behavior. However, the neurobiological bases of impulsivity and their relation to antisocial behavior and adversity are poorly understood. Impulsivity was estimated with a temporal discounting task. Voxel-based morphometry was used to determine the brain structural correlates of temporal discounting in a large cohort (n = 1830) of 14- to 15-year-old children. Mediation analysis was then used to determine whether the volumes of brain regions associated with temporal discounting mediate the relation between adverse life events (e.g., family conflict, serious accidents) and antisocial behaviors (e.g., precocious sexual activity, bullying, illicit substance use). Greater temporal discounting (more impulsivity) was associated with 1) lower volume in frontomedial cortex and bilateral insula and 2) greater volume in a subcortical region encompassing the ventral striatum, hypothalamus and anterior thalamus. The volume ratio between these cortical and subcortical regions was found to partially mediate the relation between adverse life events and antisocial behavior. Temporal discounting is related to regions of the brain involved in reward processing and interoception. The results support a developmental imbalance model of impulsivity and are consistent with the idea that negative environmental factors can alter the developing brain in ways that promote antisocial behavior. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  5. Almost periodic solutions of impulsive differential equations

    CERN Document Server

    Stamov, Gani T

    2012-01-01

    Impulsive differential equations are suitable for the mathematical simulation of evolutionary processes in which the parameters undergo relatively long periods of smooth variation followed by short-term rapid changes (that is, jumps) in their values. Processes of this type are often investigated in various fields of science and technology. The question of the existence and uniqueness of almost periodic solutions of differential equations is an age-old problem of great importance. The qualitative theory of impulsive differential equations is currently undergoing rapid development in relation to the investigation of various processes which are subject to impacts during their evolution, and many findings on the existence and uniqueness of almost periodic solutions of these equations are being made. This book systematically presents findings related to almost periodic solutions of impulsive differential equations and illustrates their potential applications.

  6. Is premature ejaculation an impulse control disorder?

    Science.gov (United States)

    Ozdemir, Özdemir

    2012-07-01

    Premature ejaculation (PE) is defined as persistent or recurrent ejaculation with minimal sexual stimulation that occurs before the participant wishes to ejaculate and is associated with marked distress or interpersonal difficulty. Impulse control disorders (ICDs) are grouped as a heterogeneous cluster of disorders linked by a "failure to resist" impulses to engage in harmful, disturbing or distressing behaviours. I hypothesise that premature ejaculation is an impulse control disorder. ICDs share features with PE aspects of impaired control, rapid responses to stimuli and hypersensitivity. These disorders often occur with subjective and social distress for patients. In addition to these features, the neurotransmitter systems have been similarly implicated in ICDs and PE. The same treatment options further support a relationship between ICDs and PE. The behaviours likely exist on a spectrum. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Improvement of the training process of qualified female athletes engaged in bodybuilding in the general preparatory stage of the preparatory period, taking into account the biological cycle

    Directory of Open Access Journals (Sweden)

    Viacheslav Mulyk

    2017-06-01

    Full Text Available Purpose: substantiation of the methodology of the training process of qualified female athletes engaged in bodybuilding in the general preparatory stage of the preparatory period, taking into account the biological cycle. Material & Methods: in the study participated 18 qualified female athletes engaged in bodybuilding, included in the Kharkov region team of bodybuilding. Results: comparative characteristic of the most frequently used methodology of the training process in bodybuilding are shows. An optimal methodology for qualified female athletes engaged in bodybuilding has been developed and justified, depending on the initial form of the athlete at the beginning of the general preparatory stage of the training. The dependence of the change in the body weight of female athletes from the training process is shows. Conclusion: on the basis of the study, the author suggests an optimal training methodology depending on the mesocycle of training in the preparatory period in the general preparatory stage.

  8. Impulse control disorders in Parkinson's disease

    Directory of Open Access Journals (Sweden)

    HAN Xun

    2013-08-01

    Full Text Available Impulse control disorders (ICDs in Parkinson's disease (PD are common with a frequency of 13.61% , which are associated with impaired functioning and with depressive, anxiety and obsessive symptoms, novelty seeking and impulsivity. These behaviors have a bad influence on PD patients in the quality of life. Different behavioral subtypes suggest pathophysiological differences. Recent large scale studies and converging findings are beginning to provide an understanding of mechanisms underlying ICDs in PD which can guide the prevention of these behaviors and optimize therapeutic approaches. This paper will take a review on the recent advances in the epidemiology, risk factors, pathophysiology, diagnosis and therapy of ICDs in PD.

  9. Minimal Time Problem with Impulsive Controls

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-02-15

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

  10. Hostile Attributional Bias, Negative Emotional Responding, and Aggression in Adults: Moderating Effects of Gender and Impulsivity

    Science.gov (United States)

    Chen, Pan; Coccaro, Emil F.; Jacobson, Kristen C.

    2012-01-01

    The current study examined the main effects of hostile attributional bias (HAB) and negative emotional responding on a variety of aggressive behaviors in adults, including general aggression, physical aggression, relational aggression, and verbal aggression. Effects of both externalizing (anger) and internalizing (embarrassment/upset) negative emotions were considered. In addition, the moderating roles of gender and impulsivity on the effects of HAB and negative emotional responding were explored. Multilevel models were fitted to data from 2,749 adult twins aged 20–55 from the PennTwins cohort. HAB was positively associated with all four forms of aggression. There was also a significant interaction between impulsivity and HAB for general aggression. Specifically, the relationship between HAB and general aggression was only significant for individuals with average or above-average levels of impulsivity. Negative emotional responding was also found to predict all measures of aggression, although in different ways. Anger was positively associated with all forms of aggression, whereas embarrassment/upset predicted decreased levels of general, physical, and verbal aggression but increased levels of relational aggression. The associations between negative emotional responding and aggression were generally stronger for males than females. The current study provides evidence for the utility of HAB and negative emotional responding as predictors of adult aggression and further suggests that gender and impulsivity may moderate their links with aggression. PMID:24833604

  11. [Bacillus thuringiensis: general aspects. An approach to its use in the biological control of lepidopteran insects behaving as agricultural pests].

    Science.gov (United States)

    Sauka, Diego H; Benintende, Graciela B

    2008-01-01

    Bacillus thuringiensis is the most widely applied biological pesticide used to control insects that affect agriculture and forestry and which transmit human and animal pathogens. During the past decades B. thuringiensis has been the subject of intensive research. These efforts have yielded considerable data about the relationships between the structure, mechanism of action, and genetics of their pesticidal crystal proteins. As a result, a coherent picture of these relationships has emerged. Other studies have focused on the ecological role of the B. thuringiensis crystal proteins and their performance in agricultural and other natural settings. With this knowledge as background and the help of biotechnological tools, researchers are now reporting promising results in the development of more useful toxins, recombinant bacteria, new formulations and transgenic plants that express pesticidal activity, in order to assure that these products are utilized with the best efficiency and benefit. This article is an attempt to integrate all these recent developments in the study of B. thuringiensis into a context of biological control of lepidopteran insect pest of agricultural importance.

  12. 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 < .001); impulsive action (r range: .65-.73, ps < .001); and inattention (r range: .38-.42, ps < .001). Additionally, the influence of day-to-day fluctuations in mood, as measured by the Profile of Mood States, was assessed in relation to variability in performance on each of the behavioral tasks. Change in performance on the delay discounting task was significantly associated with change in positive mood and arousal. No other behavioral measures were significantly associated with mood. In sum, the current analysis demonstrates that behavioral measures of impulsivity are reliable measures and thus can be confidently used to assess various facets of impulsivity as intermediate phenotypes for drug abuse.

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

    Directory of Open Access Journals (Sweden)

    Jochen Seitz

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

  14. Generalization of Figure-Ground Segmentation from Binocular to Monocular Vision in an Embodied Biological Brain Model

    Science.gov (United States)

    2011-08-01

    figure and ground the luminance cue breaks down and gestalt contours can fail to pop out. In this case we rely on color, which, having weak stereopsis...have very poor visual acuity, while human vision is rather sharp. This is potentially due, in part, to the longer learning curve human vision...physically changed by conceptual knowledge, allowing us to make certain conceptual generalizations at the speed of visual object recognition [1]. The

  15. Impulse oscillometry and obesity in children.

    Science.gov (United States)

    Assumpção, Maíra S de; Ribeiro, José D; Wamosy, Renata M G; Figueiredo, Fernanda C X S de; Parazzi, Paloma L F; Schivinski, Camila I S

    2017-09-08

    To compare impulse oscillometry system parameters of normal-weight children with overweight and obese children. All participants were submitted to the evaluation of lung function (spirometry and impulse oscillometry) following the American Thoracic Society standards. The evaluation of respiratory mechanics was performed using the Jaeger™ MasterScreen™ Impulse Oscillometry System (Erich Jaeger, Germany), three tests were recorded, with acquisition for at least 20s. The study included 81 children (30 in the control group, 21 in the overweight group, and 30 the in obesity group), matched for age and sex. Regarding spirometry data, obesity group showed higher numerical values in relation to the control group; however, there were no significant differences among the three groups. For impulse oscillometry parameters, there was a difference between control group and obesity group for respiratory impedance (p=0.036), resistance at 5hertz (p=0.026), resonant frequency (p=0.029), and reactance area (p=0.014). For the parameters expressed in percentage of predicted, there were differences in resistance at 5 hertz, resonant frequency, and reactance area between control group and obesity group. Obese children showed increased oscillometry parameters values representative of airway obstruction, compared to normal-weight children. Changes in some oscillometry parameters can already be observed in overweight school-aged children. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  16. Functional impulsivity and reinforcement sensitivity theory.

    Science.gov (United States)

    Smillie, Luke D; Jackson, Chris J

    2006-02-01

    In this article, we attempt to integrate Dickman's (1990) descriptive concept of Functional Impulsivity (FI) with Gray's (1970, 1991) Reinforcement Sensitivity Theory (RST). Specifically, we consider that FI bears great conceptual similarity to Gray's concept of reward-reactivity, which is thought to be caused by the combined effects of a Behavioral Activation System (BAS) and Behavioral Inhibition System (BIS). In our first study, we examine the construct validity and structural correlates of FI. Results indicate that FI is related positively to measures of BAS and Extraversion, negatively to measures of BIS and Neuroticism, and is separate from Psychoticism and typical trait Impulsivity, which Dickman calls Dysfunctional Impulsivity (DI). In our second study, we use a go/no-go discrimination task to examine the relationship between FI and response bias under conditions of rewarding and punishing feedback. Results indicate that FI, along with two measures of BAS, predicted the development of a response bias for the rewarded alternative. In comparison, high DI appeared to reflect indifference toward either reward or punishment. We consider how these findings might reconcile the perspectives of Gray and Dickman and help clarify the broader understanding of Impulsivity.

  17. Impulsive Behaviors in Patients With Pathological Buying

    Science.gov (United States)

    Zander, Heike; Claes, Laurence; Voth, Eva M.; de Zwaan, Martina; Müller, Astrid

    2016-01-01

    Aim To investigate impulsive behaviors in pathological buying (PB). Methods The study included three groups matched for age and gender: treatment seeking outpatients with PB (PB+), treatment seeking psychiatric inpatients without PB (PB−), and a healthy control group (HC). PB was assessed by means of the Compulsive Buying Scale and by the impulse control disorder (ICD) module of the research version of the Structured Clinical Interview for DSM-IV (SCID-ICD). All participants answered questionnaires concerning symptoms of borderline personality disorder, self-harming behaviors, binge eating and symptoms of attention deficit and hyperactivity disorder (ADHD). In addition, comorbid ICDs were assessed using the SCID-ICD. Results The PB+ and PB− groups did not differ with regard to borderline personality disorder or ADHD symptoms, but both groups reported significantly more symptoms than the HC group. Frequencies of self-harming behaviors did not differ between the three groups. Patients with PB were more often diagnosed with any current ICD (excluding PB) compared to those without PB and the HC group (38.7% vs. 12.9% vs. 12.9%, respectively, p=.017). Discussion Our findings confirm prior research suggesting more impulsive behaviors in patients with and without PB compared to healthy controls. The results of the questionnaire-based assessment indicate that outpatients with PB perceive themselves equally impulsive and self-harm as frequently as inpatients without PB; but they seem to suffer more often from an ICD as assessed by means of an interview. PMID:27415604

  18. Impulse Control Disorders - The Continuum Hypothesis.

    Science.gov (United States)

    Stenberg, Georg

    2016-01-01

    The group Parkinson Inside Out is composed of health professionals and academic researchers who have been diagnosed with Parkinson's Disease. In our discussions we try to make use of both our inside perspective as patients, and our outside perspective as professionals. In this paper, we apply the two perspectives to the Impulse Control Disorders. These impulsive behaviour patterns are thought to be relatively uncommon side effects of some of the medication used in dopamine replacement therapy. The phenomenon is usually described as relatively rare (controlling impulses is a very common experience for patients undergoing dopamine replacement therapy. They result from difficulties in decision making engendered by variations in dopamine accessibility in the reward centre of the brain. Only in a minority do the consequences grow to the damaging proportions of a disorder, but most patients are probably affected to some degree. Seeing, and measuring, decision difficulties as a continuous dimension, rather than as a discrete category, brings increased possibilities for early detection and continuous monitoring. With reliable measures of the propensity for impulsive decision making, it may become possible to both reap the benefits and avoid the dangers of the dopamine agonists. We point to ways of empirically testing our continuity hypothesis.

  19. 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.

  20. Impulsive Behaviors in Patients With Pathological Buying.

    Science.gov (United States)

    Zander, Heike; Claes, Laurence; Voth, Eva M; de Zwaan, Martina; Müller, Astrid

    2016-09-01

    Aim To investigate impulsive behaviors in pathological buying (PB). Methods The study included three groups matched for age and gender: treatment seeking outpatients with PB (PB+), treatment seeking psychiatric inpatients without PB (PB-), and a healthy control group (HC). PB was assessed by means of the Compulsive Buying Scale and by the impulse control disorder (ICD) module of the research version of the Structured Clinical Interview for DSM-IV (SCID-ICD). All participants answered questionnaires concerning symptoms of borderline personality disorder, self-harming behaviors, binge eating and symptoms of attention deficit and hyperactivity disorder (ADHD). In addition, comorbid ICDs were assessed using the SCID-ICD. Results The PB+ and PB- groups did not differ with regard to borderline personality disorder or ADHD symptoms, but both groups reported significantly more symptoms than the HC group. Frequencies of self-harming behaviors did not differ between the three groups. Patients with PB were more often diagnosed with any current ICD (excluding PB) compared to those without PB and the HC group (38.7% vs. 12.9% vs. 12.9%, respectively, p=.017). Discussion Our findings confirm prior research suggesting more impulsive behaviors in patients with and without PB compared to healthy controls. The results of the questionnaire-based assessment indicate that outpatients with PB perceive themselves equally impulsive and self-harm as frequently as inpatients without PB; but they seem to suffer more often from an ICD as assessed by means of an interview.

  1. Impulse Plasma In Surface Engineering - a review

    Science.gov (United States)

    Zdunek, K.; Nowakowska-Langier, K.; Chodun, R.; Okrasa, S.; Rabinski, M.; Dora, J.; Domanowski, P.; Halarowicz, J.

    2014-11-01

    The article describes the view of the plasma surface engineering, assuming the role of non-thermal energy effects in the synthesis of materials and coatings deposition. In the following study it was underlined that the vapor excitation through the application of an electric field during coatings deposition gives new possibilities for coatings formation. As an example the IPD method was chosen. During the IPD (Impulse Plasma Deposition) the impulse plasma is generated in the coaxial accelerator by strong periodic electrical pulses. The impulse plasma is distributed in the form of energetic plasma pockets. Due to the almost completely ionization of gas, the nucleation of new phases takes place on ions directly in the plasma itself. As a result the coatings of metastable materials with nano-amorphous structure and excellent adhesion to the non-heated intentionally substrates could be deposited. Recently the novel way of impulse plasma generation during the coatings deposition was proposed and developed by our group. An efficient tool for plasma process control, the plasma forming gas injection to the interelectrode space was used. Periodic changing the gas pressure results in increasing both the degree of dispersion and the dynamics of the plasma pulses. The advantage of the new technique in deposition of coatings with exceptionally good properties has been demonstrated in the industrial scale not only in the case of the IPD method but also in the case of very well known magnetron sputtering method.

  2. ESTIMATION OF IMPULSE RESPONSE FUNCTION BY ...

    African Journals Online (AJOL)

    The method proves stable in both numerical and statistical sense. There was no instability observed up to 80 input variables. KEY WORDS: Iterative multiple regression, impulse response function, error square contribution, time series analysis, transfer function model. Global Jnl of Mathematical Sciences Vol. 3(1) 2004: 47- ...

  3. 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.

  4. Finite-time nonautonomous bifurcation in impulsive systems

    Directory of Open Access Journals (Sweden)

    Marat Akhmet

    2016-08-01

    Full Text Available The purpose of this article is to investigate nonautonomous bifurcation in impulsive differential equations. The impulsive finite-time analogues of transcritical and pitchfork bifurcation are provided.

  5. Optimal Impulse conditions for Deflecting Earth Crossing Asteroids

    National Research Council Canada - National Science Library

    Elder, Jeffrey

    1997-01-01

    .... The solution is based on two dimensional, two body, Earth intersecting elliptical orbits. Given the asteroid eccentricity, time prior to impact and impulse magnitude and direction, an analysis of impulse to minimum separation distance is generated...

  6. Almost periodic evolution systems with impulse action at state-dependent moments

    Czech Academy of Sciences Publication Activity Database

    Hakl, Robert; Pinto, M.; Tkachenko, V.; Trofimchuk, S.

    2017-01-01

    Roč. 446, č. 1 (2017), s. 1030-1045 ISSN 0022-247X Institutional support: RVO:67985840 Keywords : Wexler's almost periodic solution * evolution system * impulse action at variable times Subject RIV: BA - General Mathematics OBOR OECD: Applied mathematics Impact factor: 1.064, year: 2016 http://www.sciencedirect.com/science/article/pii/S0022247X16305273

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

    Czech Academy of Sciences Publication Activity Database

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Archana Chauhan

    2012-12-01

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

  9. Almost periodic evolution systems with impulse action at state-dependent moments

    Czech Academy of Sciences Publication Activity Database

    Hakl, Robert; Pinto, M.; Tkachenko, V.; Trofimchuk, S.

    2017-01-01

    Roč. 446, č. 1 (2017), s. 1030-1045 ISSN 0022-247X Institutional support: RVO:67985840 Keywords : Wexler's almost periodic solution * evolution system * impulse action at variable times Subject RIV: BA - General Mathematics OBOR OECD: Applied mathematics Impact factor: 1.064, year: 2016 http://www. sciencedirect .com/science/article/pii/S0022247X16305273

  10. Effects of the atypical stimulant modafinil on a brief gambling episode in pathological gamblers with high vs. low impulsivity.

    Science.gov (United States)

    Zack, M; Poulos, C X

    2009-08-01

    Pathological gambling (PG) is a serious psychiatric disorder afflicting 1-3% of the general population. Experimental evidence indicates shared neurochemical substrates for PG and psychostimulant addiction. Impulsivity characterizes one key subtype of PG. Therefore, medications that ameliorate psychostimulant addiction and impulsive syndromes might also benefit impulsive PG subjects. The atypical stimulant, modafinil reduces cocaine abuse and impulsivity in patients with ADHD. The present study sought to determine if modafinil (200 mg) would reduce the reinforcing effects of slot machine gambling in PG subjects, and if this effect was stronger in high (H-I) vs. low (L-I) impulsivity subjects (N = 20). A placebo-controlled, double-blind, counterbalanced, repeated measures design was employed. Apart from bet size, which declined uniformly in both groups under drug, modafinil had bi-directional effects in the two groups. In H-I subjects, the drug decreased desire to gamble, salience of Gambling words, disinhibition and risky decision-making. In L-I subjects, modafinil increased scores on these indices. Modafinil also differentially affected blood pressure response to the game in the two groups. These findings for modafinil appear to fit well with a growing literature demonstrating bi-directional effects of D2 agonists as a function of trait impulsivity. Impulsivity could critically moderate medication response in PG.

  11. ADHD-hyperactive/impulsive subtype in adults

    Directory of Open Access Journals (Sweden)

    Stephen V. Faraone

    2010-01-01

    Full Text Available This is the first study to evaluate ADHD-hyperactive/impulsive subtype in a large clinical sample of adults with ADHD. The Quality of Life, Effectiveness, Safety and Tolerability (QuEST study included 725 adults who received clinician diagnoses of any ADHD subtype. Cross-sectional baseline data from 691 patients diagnosed with the hyperactive/impulsive (HI, inattentive (IA and combined subtypes were used to compare the groups on the clinician administered ADHD-RS, clinical features and health-related quality of life. A consistent pattern of differences was found between the ADHD-I and combined subtypes, with the combined subtype being more likely to be diagnosed in childhood, more severe symptom severity and lower HRQL. Twenty-three patients out of the total sample of 691 patients (3% received a clinician diagnosis of ADHD - hyperactive/impulsive subtype. Review of the ratings on the ADHD-RS-IV demonstrated, however, that this group had ratings of inattention comparable to the inattentive group. There were no significant differences found between the ADHD-HI and the other subtypes in symptom severity, functioning or quality of life. The hyperactive/impulsive subtype group identified by clinicians in this study was not significantly different from the rest of the sample. By contrast, significant differences were found between the inattentive and combined types. This suggests that in adults, hyperactivity declines and inattention remains significant, making the hyperactive/impulsive subtype as defined by childhood criteria a very rare condition and raising questions as to the validity of the HI subtype in adults.

  12. A Discretized Method for Deriving Vortex Impulse from Volumetric Datasets

    Science.gov (United States)

    Buckman, Noam; Mendelson, Leah; Techet, Alexandra

    2015-11-01

    Many biological and mechanical systems transfer momentum through a fluid by creating vortical structures. To study this mechanism, we derive a method for extracting impulse and its time derivative from flow fields observed in experiments and simulations. We begin by discretizing a thin-cored vortex filament, and extend the model to account for finite vortex core thickness and asymmetric distributions of vorticity. By solely using velocity fields to extract vortex cores and calculate circulation, this method is applicable to 3D PIV datasets, even with low spatial resolution flow fields and measurement noise. To assess the performance of this analysis method, we simulate vortex rings and arbitrary vortex structures using OpenFOAM computational fluid dynamics software and analyze the wake momentum using this model in order to validate this method. We further examine a piston-vortex experiment, using 3D synthetic particle image velocimetry (SAPIV) to capture velocity fields. Strengths, limitations, and improvements to the framework are discussed.

  13. Hybrid-impulsive second order sliding mode control: Lyapunov approach

    NARCIS (Netherlands)

    Shtessel, Y.; Glumineau, A.; Plestan, F.; Weiss, M.

    2013-01-01

    A perturbed nonlinear system of relative degree two controlled by discontinuous-impulsive feedbacks is studied. The hybrid-impulsive terms serve to drive instantaneously the system trajectories to the origin or to its small vicinity. In particular, impulsive-twisting control exhibits an uniform

  14. The effect of cognitive modelling in the reduction of impulsive ...

    African Journals Online (AJOL)

    The study investigated the effect of cognitive modeling in the reduction of impulsive behaviour among primary school children. A total of twenty impulsive underachieving participants were randomly assigned to cognitive modeling and control groups. Different instruments comprising Impulsiveness Questionnaire for Children ...

  15. 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…

  16. 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.…

  17. Analysis of Caputo Impulsive Fractional Order Differential Equations with Applications

    Directory of Open Access Journals (Sweden)

    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.

  18. 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.

  19. Parental monitoring may protect impulsive children from overeating.

    Science.gov (United States)

    Bennett, C; Blissett, J

    2017-10-01

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

  20. 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

  1. Impulsivity-related traits and their relation to DSM-5 section II and III personality disorders.

    Science.gov (United States)

    Few, Lauren R; Lynam, Donald R; Miller, Joshua D

    2015-07-01

    Difficulties with impulse control are considered a core feature of personality disorders (PDs) as assessed by the Diagnostic and Statistical Manual of Mental Disorders (5th edition [DSM-5]; American Psychiatric Association, 2013). Despite this, there has been relatively little examination of the manner in which DSM-5 PDs are characterized by multidimensional models of impulsivity that parse this broad umbrella construct into smaller, more unidimensional constructs. Using the UPPS model and measure of impulsivity (Whiteside & Lynam, 2001), the relations between 4 impulsivity-related traits and interview-rated scores on both DSM-5 Section II and III PDs and PD traits were examined in a community sample of individuals currently receiving psychological or psychiatric care (N = 106). As expected, the UPPS traits manifested correlations with the new Section III trait model that were generally consistent with the assertion that this new DSM-5 trait model reflects a pathological variant of the Five-Factor Model (FFM; e.g., UPPS traits associated with FFM conscientiousness were most strongly related to DSM-5 disinhibition traits). Overall, the UPPS traits accounted best for variance in DSM-5 Section II and III Cluster B PDs, consistent with these PDs being characterized, in part, by emotionally and cognitively based forms of impulsivity. (c) 2015 APA, all rights reserved).

  2. Global Asymptotic Stability of Impulsive CNNs with Proportional Delays and Partially Lipschitz Activation Functions

    Directory of Open Access Journals (Sweden)

    Xueli Song

    2014-01-01

    Full Text Available This paper researches global asymptotic stability of impulsive cellular neural networks with proportional delays and partially Lipschitz activation functions. Firstly, by means of the transformation vi(t=ui(et, the impulsive cellular neural networks with proportional delays are transformed into impulsive cellular neural networks with the variable coefficients and constant delays. Secondly, we provide novel criteria for the uniqueness and exponential stability of the equilibrium point of the latter by relative nonlinear measure and prove that the exponential stability of equilibrium point of the latter implies the asymptotic stability of one of the former. We furthermore obtain a sufficient condition to the uniqueness and global asymptotic stability of the equilibrium point of the former. Our method does not require conventional assumptions on global Lipschitz continuity, boundedness, and monotonicity of activation functions. Our results are generalizations and improvements of some existing ones. Finally, an example and its simulations are provided to illustrate the correctness of our analysis.

  3. Instinctual impulses in obsessive compulsive disorder: A neuropsychological and psychoanalytic interface.

    Science.gov (United States)

    Mukhopadhyay, Pritha; Tarafder, Sreemoyee; Bilimoria, Dinaz D; Paul, Debika; Bandyopadhyay, Gautam

    2010-12-01

    Psychopathology of obsessive compulsive disorder (OCD) that has been characterized by a conflict between the ego and superego on one hand, and aggressive and sexual impulses emerging from the id on the other, and employment of characteristic defenses to combat intense conflicts being connected with ones' biological disposition from the psychoanalytic school of thought now gets empirical foundation from neuroimaging research. The findings disregard the psychological construct, exclusively establishing the neurobiology of the disorder. With the objective to study the impact of sexual and aggressive impulses on the executive functions and processing speed in the patient group, 20 OCD patients (11 males, 9 females) and 20 normal control subjects, matched for all relevant variables including age, sex, educational level and handedness were studied. Sexual impulse and guilt was assessed on the Sex Guilt Rating Scale (SGRS), aggressive impulses were tested using State-Trait Anger Expression Inventory (STAXI), the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) was used to assess symptom severity, executive functions were assessed through Wisconsin Card Sorting Test (WCST), and processing speed was assessed by employing the Processing Speed Index (PSI) - from WAIS III. It was found that the OCD group differed significantly from the controls, attaining significantly lower percentiles on Processing Speed Index and for all variables of WCST under consideration, namely, perseverative response, perseverative error, non-perseverative error, conceptual level response and number of categories completed. They reported higher scores on subscales of STAXI, specifically related to trait anger and lower scores on anger expression. On the items of SGRS, the OCD group significantly differed with the controls, expressing greater sexual inhibition. In conclusion, we propose an explanation of psychopathology of OCD, which addresses instinctual impulses, executive functions and neural

  4. Biological chromodynamics: a general method for measuring protein occupancy across the genome by calibrating ChIP-seq

    Science.gov (United States)

    Hu, Bin; Petela, Naomi; Kurze, Alexander; Chan, Kok-Lung; Chapard, Christophe; Nasmyth, Kim

    2015-01-01

    Sequencing DNA fragments associated with proteins following in vivo cross-linking with formaldehyde (known as ChIP-seq) has been used extensively to describe the distribution of proteins across genomes. It is not widely appreciated that this method merely estimates a protein's distribution and cannot reveal changes in occupancy between samples. To do this, we tagged with the same epitope orthologous proteins in Saccharomyces cerevisiae and Candida glabrata, whose sequences have diverged to a degree that most DNA fragments longer than 50 bp are unique to just one species. By mixing defined numbers of C. glabrata cells (the calibration genome) with S. cerevisiae samples (the experimental genomes) prior to chromatin fragmentation and immunoprecipitation, it is possible to derive a quantitative measure of occupancy (the occupancy ratio – OR) that enables a comparison of occupancies not only within but also between genomes. We demonstrate for the first time that this ‘internal standard’ calibration method satisfies the sine qua non for quantifying ChIP-seq profiles, namely linearity over a wide range. Crucially, by employing functional tagged proteins, our calibration process describes a method that distinguishes genuine association within ChIP-seq profiles from background noise. Our method is applicable to any protein, not merely highly conserved ones, and obviates the need for the time consuming, expensive, and technically demanding quantification of ChIP using qPCR, which can only be performed on individual loci. As we demonstrate for the first time in this paper, calibrated ChIP-seq represents a major step towards documenting the quantitative distributions of proteins along chromosomes in different cell states, which we term biological chromodynamics. PMID:26130708

  5. [Toxicological analysis of biological material originating from the body of general Władysław Sikorski for organic poisons].

    Science.gov (United States)

    Lechowicz, Wojciech

    2009-01-01

    Toxicological analyses performed in individuals who died in unclear circumstances constitute a key element of research aiming at providing a complete explanation of cause of death. The entire panel of examinations of the corpse of general Sikorski also included toxicological analyses for drugs and organic poisons of synthetic and natural origin. Attention was focused on fast-acting and potent poisons known and used in the forties of the century. The internal organs (stomach, liver, lung, brain) and hair, as well as other materials collected from the body and found in the coffin were analyzed. The classic method of sample preparation, i.e. homogenization, deproteinization, headspace and liquid-liquid extraction were applied. Hyphenated methods, mainly chromatographic with mass spectrometry were used for identification of the analytes. Organic poisons were not identified in the material as a result of the research.

  6. Impulse control disorders in patients with Parkinson's disease.

    Science.gov (United States)

    Gescheidt, Tomás; Bares, Martin

    2011-03-01

    In patients with Parkinson's disease with higher prevalence than in current population there appear pathological behaviours characterized by compulsion, repetitiveness and impulsivity, which are connected with material profit or pleasurable experience. They are, in particular, pathological gambling, hypersexuality, compulsive shopping and compulsive eating (in the literature they are collectively referred to as impulse control disorders). Pathological preoccupation with repeated mechanical activities (so-called punding) and excessive compulsive intake of dopaminergic medication (so-called dopamine dysregulation syndrome or also syndrome of hedonistic homeostatic dysregulation) are of similar nature. The paper treats briefly the risk factors and prevalence of these pathological behaviours. In current clinical practice, these psychiatric complications frequently escape doctors' attention, they are underdiagnosed. Although no generally valid recommendations for their therapy are currently available, they can be influenced medically. Of advantage can be modified dopaminergic medication (usually dose reduction ofdopaminergic agonists); multidisciplinary approach to the problem is appropriate. The pathological behaviours given above can frequently lead to considerable material losses and markedly aggravate patients' handicap in the social sphere; it can be expected that in the future they can become a problem also from the ethical and legal points of view.

  7. Impulse control disorders in eating disorders: clinical and therapeutic implications.

    Science.gov (United States)

    Fernández-Aranda, Fernando; Jiménez-Murcia, Susana; Alvarez-Moya, Eva M; Granero, Roser; Vallejo, Julio; Bulik, Cynthia M

    2006-01-01

    Few studies have explored impulse control disorders (ICDs) in women with bulimia nervosa (BN). We explored the prevalence of lifetime ICDs in women with BN, compared the severity of eating disorder symptoms in women with BN with and without ICD, and compared their personality profiles to females with one form of ICD, namely, pathologic gambling. A total sample of 269 female patients consecutively admitted to our unit participated in the current study (173 BN without comorbid ICD [BN - ICD]; 54 BN with comorbid ICD [BN + ICD]; and 42 pathologic gamblers [PG]). All participants were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria. Assessment measures included the Symptom Checklist-90 revised and the Temperament and Character Inventory-revised, as well as a number of other clinical and psychopathologic indices. In BN, the observed lifetime prevalence of ICD was 23.8%. Lifetime compulsive buying (17.6%) and intermittent explosive disorder (13.2%) were the most frequently reported ICD. Bulimia nervosa subtype was not significantly associated with lifetime ICD (P = .051) or with ICD subtype (P = .253). After using multinomial regression models, we observed that BN + ICD and PG showed the highest scores on novelty seeking (P impulsivity, and general psychopathology than individuals with BN without ICD. On some personality traits, those BN + ICD more closely resembled individuals with PG than those with BN without ICD.

  8. 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......, novelty reactivity and novelty-induced stress responses, and thus has relevance for the aetiology of drug addiction....

  9. [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.

  10. 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.

  11. Narcissism predicts impulsive buying: phenotypic and genetic evidence

    Science.gov (United States)

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

    2015-01-01

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

  12. 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.

  13. [Impulse control behaviors associated with antiparkinsonian medications].

    Science.gov (United States)

    Depierreux-Lahaye, F; Crémers, J; Skawiniak, E; Parmentier, E; Delvaux, V; Garraux, G

    2013-01-01

    In some patients, impulse control behaviours can be triggered by dopaminergic replacement therapy, particularly dopamine agonist drugs: hobbyism, punding (stereotyped behaviours), compulsive buying, binge eating disorder, pathological gamgling, hypersexuality, hedonistic homeostatic dysregulation syndrome ... The pathogenesis of these behaviours: is not well understood, but likely involves aberrant changes in the dopaminergic pathways that mediate motivation i.e., a dopaminergic "overdose" in meso-cortico-limbic circuits, An early diagnosis is difficult, but mandatory to prevent the occurrence of devastating familial, marital, professional, socio-economic, medical and medico-legal consequences. Their management is not yet well standardized. Patients and caregivers should be warned about impulse control behaviours before starting dopamine agonists and monitoring for such behaviours while on therapy is requested.

  14. The Hydraulic Ram (Or Impulse) Pump

    Science.gov (United States)

    Mills, Allan

    2014-01-01

    The hydraulic impulse pump utilizes a fraction of the momentum of a flowing stream to lift a small portion of that water to a higher level. There it may be accumulated in an elevated cistern to provide sufficient water for several families, for the pump works 24 h a day with no additional source of energy. The operation of the pump is described,…

  15. Cigarette cravings, impulsivity and the brain

    Directory of Open Access Journals (Sweden)

    Stéphane ePotvin

    2015-09-01

    Full Text Available Craving is a core feature of tobacco use disorder as well as a significant predictor of smoking relapse. Studies have shown that appetitive smoking-related stimuli (e.g. someone smoking trigger significant cravings in smokers which impedes their self-control capacities and promotes drug seeking behavior. In this review, we begin by an overview of functional magnetic resonance imaging (fMRI studies investigating the neural correlates of smokers to appetitive smoking cues. The literature reveals a complex and vastly distributed neuronal network underlying smokers’ craving response that recruits regions involved in self-referential processing, panning/regulatory processes, emotional responding, attentional biases, and automatic conducts. We then selectively review important factors contributing to the heterogeneity of results that significantly limit the implications of these findings, namely between- (abstinence, smoking expectancies and self-regulation and within-studies factors (severity of smoking dependence, sex-differences, motivation to quit and genetic factors. Remarkably, we found that little to no attention has been devoted to examine the influence of personality traits on the neural correlates of cigarette cravings in fMRI studies. Impulsivity has been linked with craving and relapse in substance and tobacco use, which prompted our research team to examine the influence of impulsivity on cigarette cravings in an fMRI study. We found that the influence of impulsivity on cigarette cravings was mediated by fronto-cingular mechanisms. Given the high prevalence of cigarette smoking in several psychiatric disorders that are characterized by significant levels of impulsivity, we conclude by identifying psychiatric patients as a target population whose tobacco smoking habits deserve further behavioral and neuro-imaging investigation.

  16. CERN 50th Anniversary Official Celebration : keynote speech from Professor Federico Mayor Zaragoza, Professor in the Molecular Biology at the Universidad Autónoma of Madrid, Former Director-General of UNESCO

    CERN Multimedia

    Blanc

    2004-01-01

    CERN 50th Anniversary Official Celebration : keynote speech from Professor Federico Mayor Zaragoza, Professor in the Molecular Biology at the Universidad Autónoma of Madrid, Former Director-General of UNESCO

  17. Impulse noise generated by starter pistols

    Science.gov (United States)

    Meinke, Deanna K.; Finan, Donald S.; Soendergaard, Jacob; Flamme, Gregory A.; Murphy, William J.; Lankford, James E.; Stewart, Michael

    2015-01-01

    Objective This study describes signals generated by .22 and .32 caliber starter pistols in the context of noise-induced hearing loss risk for sports officials and athletes. Design Acoustic comparison of impulses generated from typical .22 and .32 caliber starter pistols firing blanks were made to impulses generated from comparable firearms firing both blanks and live rounds. Acoustic characteristics are described in terms of directionality and distance from the shooter in a simulated outdoor running track. Metrics include peak sound pressure levels (SPL), A-weighted equivalent 8-hour level (LeqA8), and maximum permissible number of individual shots, or maximum permissible exposures (MPE) for the unprotected ear. Results Starter pistols produce peak SPLs above 140 dB. The numbers of MPEs are as few as five for the .22-caliber starter pistol, and somewhat higher (≤25) for the .32-caliber pistol. Conclusion The impulsive sounds produced by starter pistols correspond to MPE numbers that are unacceptably small for unprotected officials and others in the immediate vicinity of the shooter. At the distances included in this study, the risk to athletes appears to be low (when referencing exposure criteria for adults), but the sound associated with the starter pistol will contribute to the athlete’s overall noise exposure. PMID:23373743

  18. Impulse approximation versus elementary particle method

    International Nuclear Information System (INIS)

    Klieb, L.

    1982-01-01

    Calculations are made for radiative muon capture in 3 He, both in impulse approximation and with the elementary particle method, and results are compared. It is argued that a diagrammatic method which takes a selected set of Feynman diagrams into account only provides insufficient warrant that effects not included are small. Therefore low-energy theorems are employed, as first given by Adler and Dothan, to determine the amplitude up to and including all terms linear in photon momentum and momentum transfer at the weak vertex. This amplitude is applied to radiative muon capture with the elementary particle method (EPM). The various form factors needed are discussed. It is shown that the results are particularly sensitive to the π- 3 He- 3 H coupling constant of which many contradictory determinations have been described in the literature. The classification of the nuclear wave function employed in the impulse approximation (IA) is summarized. The ν-decay of 3 H and (radiative muon capture in 3 He is treated and numerical results are given. Next, pion photoproduction and radiative pion capture are considered. IA and EPM for radiative muon capture are compared more closely. It is concluded that two-step processes are inherently difficult; the elementary particle method has convergence problems, and unknown parameters are present. In the impulse approximation, which is perhaps conceptually more difficult, the two-step interaction for the nucleon is considered as effectively point-like with small non-local corrections. (Auth.)

  19. Leupeptin reduces impulse noise induced hearing loss

    Directory of Open Access Journals (Sweden)

    Gavriel Haim

    2011-12-01

    Full Text Available Abstract Background Exposure to continuous and impulse noise can induce a hearing loss. Leupeptin is an inhibitor of the calpains, a family of calcium-activated proteases which promote cell death. The objective of this study is to assess whether Leupeptin could reduce the hearing loss resulting from rifle impulse noise. Methods A polyethelene tube was implanted into middle ear cavities of eight fat sand rats (16 ears. Following determination of auditory nerve brainstem evoked response (ABR threshold in each ear, the animals were exposed to the noise of 10 M16 rifle shots. Immediately after the exposure, saline was then applied to one (control ear and non-toxic concentrations of leupeptin determined in the first phase of the study were applied to the other ear, for four consecutive days. Results Eight days after the exposure, the threshold shift (ABR in the control ears was significantly greater (44 dB than in the leupeptin ears (27 dB. Conclusion Leupeptin applied to the middle ear cavity can reduce the hearing loss resulting from exposure to impulse noise.

  20. Impulse and Movement Space-Time Variability.

    Science.gov (United States)

    Kim, Seonjin; Carlton, Les G.; Liu, Yeou-Teh; Newell, Karl M.

    1999-12-01

    In 3 experiments, the authors examined movement space-time variability as a function of the force-time properties of the initial impulse in a movement timing task. In the range of motion and movement time task conditions, peak force, initial rate of force, and force duration were manipulated either independently or in combination across a range of parameter values. The findings showed that (a) impulse variability is predicted well by the elaboration of the isometric force variability scaling functions of L. G. Carlton, K. H. Kim, Y. T. Liu, and K. M. Newell (1993) to movement, and (b) the movement spatial and temporal outcome variability are complementary and well predicted by an equation treating the variance of force and time in Newton's 2nd law as independent random variables. Collectively, the findings suggest that movement outcome variability is the product of a coherent space-time function that is driven by the nonlinear scaling of the force-time properties of the initial impulse.

  1. Sex differences in impulsive and compulsive behaviors: a focus on drug addiction.

    Science.gov (United States)

    Fattore, Liana; Melis, Miriam

    2016-09-01

    Sex differences in inhibition and self-regulation at a behavioral level have been widely described. From an evolutionary point of view, the different selection pressures placed on male and female hominids led them to differ in their behavioral strategies that allowed our species to survive during natural selection processes. These differences reflect changes in neural and structural plasticity that might be the core of sex differences, and of the susceptibility towards one psychiatric condition rather than another. The goal of the present review is to summarize current evidence for such a dichotomy in impulsive and compulsive behavior with a focus on drug addiction. Sex-dependent differences in drug abuse and dependence will be examined in the context of pathophysiological regulation of impulse and motivation by neuromodulators (i.e. gonadal hormones) and neurotransmitters (i.e. dopamine). Advances in the understanding of the sex differences in the capability to control impulses and motivational states is key for the determination of efficacious biologically based intervention and prevention strategies for several neuropsychiatric disorders where loss of impulse control and compulsivity are the core symptoms. © 2016 Society for the Study of Addiction.

  2. 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.

  3. Cannabinoid CB1 Receptor Activation Mediates the Opposing Effects of Amphetamine on Impulsive Action and Impulsive Choice

    Science.gov (United States)

    Wiskerke, Joost; Stoop, Nicky; Schetters, Dustin; Schoffelmeer, Anton N. M.; Pattij, Tommy

    2011-01-01

    It is well known that acute challenges with psychostimulants such as amphetamine affect impulsive behavior. We here studied the pharmacology underlying the effects of amphetamine in two rat models of impulsivity, the 5-choice serial reaction time task (5-CSRTT) and the delayed reward task (DRT), providing measures of inhibitory control, an aspect of impulsive action, and impulsive choice, respectively. We focused on the role of cannabinoid CB1 receptor activation in amphetamine-induced impulsivity as there is evidence that acute challenges with psychostimulants activate the endogenous cannabinoid system, and CB1 receptor activity modulates impulsivity in both rodents and humans. Results showed that pretreatment with either the CB1 receptor antagonist/inverse agonist SR141716A or the neutral CB1 receptor antagonist O-2050 dose-dependently improved baseline inhibitory control in the 5-CSRTT. Moreover, both compounds similarly attenuated amphetamine-induced inhibitory control deficits, suggesting that CB1 receptor activation by endogenously released cannabinoids mediates this aspect of impulsive action. Direct CB1 receptor activation by Δ9-Tetrahydrocannabinol (Δ9-THC) did, however, not affect inhibitory control. Although neither SR141716A nor O-2050 affected baseline impulsive choice in the DRT, both ligands completely prevented amphetamine-induced reductions in impulsive decision making, indicating that CB1 receptor activity may decrease this form of impulsivity. Indeed, acute Δ9-THC was found to reduce impulsive choice in a CB1 receptor-dependent way. Together, these results indicate an important, though complex role for cannabinoid CB1 receptor activity in the regulation of impulsive action and impulsive choice as well as the opposite effects amphetamine has on both forms of impulsive behavior. PMID:22016780

  4. Increasing URM Undergraduate Student Success through Assessment-Driven Interventions: A Multiyear Study Using Freshman-Level General Biology as a Model System

    Science.gov (United States)

    Carmichael, Mary C.; St. Clair, Candace; Edwards, Andrea M.; Barrett, Peter; McFerrin, Harris; Davenport, Ian; Awad, Mohamed; Kundu, Anup; Ireland, Shubha Kale

    2016-01-01

    Xavier University of Louisiana leads the nation in awarding BS degrees in the biological sciences to African-American students. In this multiyear study with ∼5500 participants, data-driven interventions were adopted to improve student academic performance in a freshman-level general biology course. The three hour-long exams were common and administered concurrently to all students. New exam questions were developed using Bloom’s taxonomy, and exam results were analyzed statistically with validated assessment tools. All but the comprehensive final exam were returned to students for self-evaluation and remediation. Among other approaches, course rigor was monitored by using an identical set of 60 questions on the final exam across 10 semesters. Analysis of the identical sets of 60 final exam questions revealed that overall averages increased from 72.9% (2010) to 83.5% (2015). Regression analysis demonstrated a statistically significant correlation between high-risk students and their averages on the 60 questions. Additional analysis demonstrated statistically significant improvements for at least one letter grade from midterm to final and a 20% increase in the course pass rates over time, also for the high-risk population. These results support the hypothesis that our data-driven interventions and assessment techniques are successful in improving student retention, particularly for our academically at-risk students. PMID:27543637

  5. 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.

  6. Development of impulse control circuitry in children of alcoholics.

    Science.gov (United States)

    Hardee, Jillian E; Weiland, Barbara J; Nichols, Thomas E; Welsh, Robert C; Soules, Mary E; Steinberg, Davia B; Zubieta, Jon-Kar; Zucker, Robert A; Heitzeg, Mary M

    2014-11-01

    Difficulty with impulse control is heightened in children with a family history of alcohol use disorders and is a risk factor for later substance problems. Cross-sectional functional magnetic resonance imaging studies have shown altered impulse control processing in adolescents with a positive family history, yet developmental trajectories have yet to be examined. Longitudinal functional magnetic resonance imaging was conducted in children of alcoholic families (family history positive [FH+]; n = 43) and children of control families (family history negative [FH-]; n = 30) starting at ages 7-12 years. Participants performed a go/no-go task during functional magnetic resonance imaging at intervals of 1-2 years, with two to four scans performed per subject. We implemented a repeated-measures linear model fit across all subjects to conduct a whole-brain search for developmental differences between groups. Performance improved with age in both groups, and there were no performance differences between groups. Significant between-group differences in linear age-related activation changes were found in the right caudate, middle cingulate, and middle frontal gyrus. Post hoc analyses revealed significant activation decreases with age in the caudate and middle frontal gyrus for FH- subjects and a significant increase with age in middle cingulate activation for FH+ subjects. Group differences were evident at age 7-12 years, even in alcohol- and drug-naïve participants, with FH+ subjects showing significantly blunted activation at baseline compared with FH- subjects. Differences in response inhibition circuitry are visible in FH+ individuals during childhood; these differences continue into adolescence, displaying trajectories that are inconsistent with development of normal response inhibition. These patterns precede problem drinking and may be a contributing factor for subsequent substance use problems. Copyright © 2014 Society of Biological Psychiatry. Published by

  7. Synthesis of Room Impulse Responses for Variable Source Characteristics

    Directory of Open Access Journals (Sweden)

    M. Kunkemoeller

    2011-01-01

    Full Text Available Every acoustic source, e.g. a speaker, a musical instrument or a loudspeaker, generally has a frequency dependent characteristic radiation pattern, which is preeminent at higher frequencies. Room acoustic measurements nowadays only account for omnidirectional source characteristics. This motivates a measurement method that is capable of obtaining room impulse responses for these specific radiation patterns by using a superposition approach of several measurements with technically well-defined sound sources. We propose a method based on measurements with a 12-channel independentlydriven dodecahedron loudspeaker array rotated by an automatically controlled turntable.Radiation patterns can be efficiently described with the use of spherical harmonics representation. We propose a method that uses this representation for the spherical loudspeaker array used for the measurements and the target radiation pattern to be used for the synthesis.We show validating results for a deterministic test sound source inside in a small lecture hall.

  8. Impulsive choice and response in dopamine agonist-related impulse control behaviors.

    Science.gov (United States)

    Voon, Valerie; Reynolds, Brady; Brezing, Christina; Gallea, Cecile; Skaljic, Meliha; Ekanayake, Vindhya; Fernandez, Hubert; Potenza, Marc N; Dolan, Raymond J; Hallett, Mark

    2010-01-01

    Dopaminergic medication-related impulse control disorders (ICDs) such as pathological gambling and compulsive shopping have been reported in Parkinson's disease (PD). We hypothesized that dopamine agonists (DAs) would be associated with greater impulsive choice or greater discounting of delayed rewards in PD patients with ICDs (PDI). Fourteen PDI patients, 14 PD controls without ICDs, and 16 medication-free matched normal controls were tested on the Experiential Discounting Task (EDT), a feedback-based intertemporal choice task, spatial working memory, and attentional set shifting. The EDT was used to assess choice impulsivity (hyperbolic K value), reaction time (RT), and decision conflict RT (the RT difference between high conflict and low conflict choices). PDI patients and PD controls were tested on and off DA. On the EDT, there was a group by medication interaction effect [F(1,26) = 5.62; p = 0.03] with pairwise analyses demonstrating that DA status was associated with increased impulsive choice in PDI patients (p = 0.02) but not in PD controls (p = 0.37). PDI patients also had faster RT compared to PD controls [F(1,26) = 7.51, p = 0.01]. DA status was associated with shorter RT [F(3,24) = 8.39, p = 0.001] and decision conflict RT [F(1,26) = 6.16, p = 0.02] in PDI patients but not in PD controls. There were no correlations between different measures of impulsivity. PDI patients on DA had greater spatial working memory impairments compared to PD controls on DA (t = 2.13, df = 26, p = 0.04). Greater impulsive choice, faster RT, faster decision conflict RT, and executive dysfunction may contribute to ICDs in PD.

  9. Study of impulse control disorders among women presenting nicotine dependence.

    Science.gov (United States)

    Lejoyeux, Michel; Kerner, Laurent; Thauvin, Isabelle; Loi, Sabrina

    2006-01-01

    Objective. Impulse control disorders (ICDs) include intermittent explosive disorder, kleptomania, trichotillomania, pyromania and pathological gambling. Several studies have showed an association between ICDs and alcohol use disorders. The rate of co-occurrence ICDs and nicotine dependence has never been investigated. We thus assessed the frequency of all ICDs in a population of nicotine-dependent women compared to non-smoking women. We also checked criteria of two other impulsive behaviours, compulsive buying and bulimia. Methods. Five hundred consecutive patients were assessed by a general practitioner in Paris (France). One hundred and twenty-seven women presenting the DSM-IV-R criteria for nicotine dependence were included. They were compared to 127 women consulting the same practitioner but who did not smoke. Diagnosis of ICD (pyromania, kleptomania, trichotillomania, intermittent explosive disorder, pathological gambling) and of bulimia was based on DSM-IV criteria and a modified version of the Minnesota Impulsive Disorders Interview (MIDI). Diagnosis of compulsive buying was made with the McElroy et al. criteria and a specific questionnaire. Cigarette smoking was studied using the Fagerström questionnaire and the DSM-IV-R criteria for nicotine dependence. Alcohol use disorders were assessed with the DSM-IV-R criteria for dependence and the CAGE and the MAST questionnaires. Results. Thirteen patients presented trichotillomania, 22 explosive intermittent disorder and 12 pathological gambling. All these diagnoses were equally frequent in the nicotine-positive and nicotine-negative groups. We found no case of pyromania. Compulsive buying was the most frequent impulse control disorder. It was significantly more frequent in the nicotine-positive group than in the nicotine-negative group (58 vs. 39 cases, P=0.01). Scores of the compulsive buying scale were higher in the nicotine-positive group (4.07 vs. 2.9, P=0.01). None of the patients presented an association

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

    Directory of Open Access Journals (Sweden)

    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.

  11. [ADH/D and impulsiveness: Prevalence of impulse control disorders and other comorbidities, in 81 adults with attention deficit/hyperactivity disorder (ADH/D)].

    Science.gov (United States)

    Porteret, R; Bouchez, J; Baylé, F J; Varescon, I

    2016-04-01

    3 symptoms at least of one and/or the other category). Regarding the ICDs, we found a proportion of 66 % of patients manifesting at least one, the most frequent ICD being the Intermittent Explosive Disorder (IED): 29.6 %, followed by Compulsive Buying (CB): 23.4 %, Pathological Gambling (PG): 7.4 %, Kleptomania and Compulsive Sexual Behaviour: 2.4 %, and Trichotillomania: 1.2 %. Among the psychiatric comorbidities evaluated, generalized anxiety disorder: 61.7 %, followed by dysthymia: 44.4 %, major depressive episode: 28.3 %, Agoraphobia: 22.2 %, panic disorder: 17.2 %, hypomanic episode: 16 %, social phobia: 11.1 %, bulimia nervosa: 8.6 %, and antisocial personality disorder and obsessive-compulsive disorder: 3.7 %. Regarding the addictive comorbidities, we found a prevalence of 14.8 % of substance abuse (non-alcohol), followed by 7.4 % of alcohol abuse, 6.1 % of substance dependence (non-alcohol), and 3.7 % of alcohol dependence. ADH/D in adults continues to be unrecognized in France. The aim of this study was to evaluate the prevalence of impulse control disorders, psychiatric and addictive comorbidities in adults with ADH/D. The results enable us to appreciate quantitative and qualitative data for 81 French adults with ADH/D. This disorder rarely remains isolated and is often associated with many others, especially anxiety and mood disorders. We also observed that impulsivity stays at the heart of the ADH/D, either through impulsive behaviours or addictive disorders. Considering the lack of studies with ADH/D adults, it is difficult to compare our data. The diagnosis of ADH/D is complex and stays controversial, moreover the strong prevalence of comorbidities points out the importance of differential diagnosis. Copyright © 2015 L’Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

  12. An Impulsively Controlled Three-Species Prey-Predator Model with Stage Structure and Birth Pulse for Predator

    Directory of Open Access Journals (Sweden)

    Yanyan Hu

    2015-01-01

    Full Text Available We investigate the dynamic behaviors of a two-prey one-predator system with stage structure and birth pulse for predator. By using the Floquet theory of linear periodic impulsive equation and small amplitude perturbation method, 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 study the permanence of the investigated model. Our results provide valuable strategy for biological economics management. Numerical analysis is also inserted to illustrate the results.

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

    Science.gov (United States)

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

    2013-01-01

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

  14. Impulse control disorders in elderly patients.

    Science.gov (United States)

    Tamam, Lut; Bican, Mehtap; Keskin, Necla

    2014-05-01

    There is no epidemiological study on the prevalence of impulse control disorders (ICDs) in the elderly population. The studies on ICDs in elderly patients are limited and some of them are case reports about pathological gambling and kleptomania. The comorbidity of other psychiatric disorders makes diagnosis difficult and has negative effects on both treatment and the prognosis of ICDs. The aim of this study was to determine the prevalence of ICDs among elderly patients and to evaluate the related sociodemographic and clinical features. A total of 76 patients aged 60 and over who have been referred to our outpatient clinics in a one-year period were included in the study. A demographic data form was completed. The Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) was used to determine axis I psychiatric disorders. The prevalence of ICDs was investigated by using the modified version of the Minnesota Impulse Disorders Interview (MIDI). Impulsivity was measured with the Barratt Impulsiveness Scale Version 11 (BIS-11). The Mini-Mental State Examination (MMSE) test was performed to evaluate the cognitive status of patients and to exclude the diagnosis of dementia. In addition, all patients completed Symptom Check List-90 (SCL-90). The prevalence rate of at least one comorbid ICD in our sample was 17%. When patients with a diagnosis of ICDs not otherwise specified (ICD-NOS) were included, the prevalence rate increased to 22.4%. The most common ICD was intermittent explosive disorder (15.8%), followed by pathological gambling (9.2%). The majority of the sample was men (54%), married (80%), had a high school education (51%), and mid-level socioeconomic status (79%). The only statistically significant difference between the sociodemographic characteristics of patients with or without ICDs was gender. The lifetime prevalence of ICDs was 34.1% in men and 8.6% in women. The prevalence of childhood conduct disorder

  15. [Impulse control disorders and Parkinson's disease].

    Science.gov (United States)

    Burkhard, P R; Catalano-Chiuvé, S; Gronchi-Perrin, A; Berney, A; Vingerhoets, F J G; Lüscher, C

    2008-05-07

    A variety of behavioral disorders occurring abruptly in patients with Parkinson's disease (PD) has been recently published and attracted considerable attention in the press. Taking the form of pathological gambling, compulsive shopping, addiction to Internet and to other recreational activities, hypersexuality or bulimia, impulse control disorders (ICD) related to PD are probably more frequent than previously appreciated and may have consequences as spectacular as disastrous for the involved patients. ICD are currently viewed as particular adverse reactions to antiparkinsonian medications, notably to dopamine agonists, and, accordingly, tend to improve or disappear when PD therapy is appropriately adjusted.

  16. The genetic correlation between procrastination and impulsivity.

    Science.gov (United States)

    Loehlin, John C; Martin, Nicholas G

    2014-12-01

    The reported genetic correlation of 1.0 between the traits of procrastination and impulsivity (Gustavson, D. E., Miyake, A., Hewitt, J. K., & Friedman, N. P. (2014). Psychological Science), which was held to support an evolutionary origin of the relationship between the two traits, was tested in data from two large samples of twins from Australia. A genetic correlation of 0.299 was obtained. It was concluded that, although the presence of a genetic correlation between the two traits was supported, the modest magnitude of the correlation was such as to be consistent with many possible hypotheses, evolutionary and otherwise, about causal relationships between the traits in question.

  17. Impulsive and compulsive behaviors in Parkinson's disease.

    Science.gov (United States)

    Evans, Andrew H; Strafella, Antonio P; Weintraub, Daniel; Stacy, Mark

    2009-08-15

    Antiparkinson therapy can be the primary cause of a range of nonmotor symptoms that include a set of complex disinhibitory psychomotor pathologies and are linked by their repetitive, reward or incentive-based natures. These behaviors relate to aberrant or excessive dopamine receptor stimulation and encompass impulse control disorders (ICDs), punding, and the dopamine dysregulation syndrome (DDS). Common ICDs include pathological gambling, hypersexuality, compulsive eating, and compulsive buying. This review focuses on the phenomenology, epidemiology, and methods to identify and rate these disorders. The management of dopaminergic drug-related compulsive behaviors is discussed in the light of the current understanding of the neurobiological substrate of these disorders. 2009 Movement Disorder Society.

  18. Memory effect for impulsive gravitational waves

    Science.gov (United States)

    Zhang, P.-M.; Duval, C.; Horvathy, P. A.

    2018-03-01

    Impulsive gravitational plane waves, which have a δ-function singularity on a hypersurface, can be obtained by squeezing smooth plane gravitational waves with a Gaussian profile. They exhibit (as do their smooth counterparts) the velocity memory effect: after the wave has passed, particles initially at rest move apart with non-vanishing constant transverse velocity. A new effect is that, unlike the smooth case, (i) the velocities of particles originally at rest jump, (ii) the spacetime trajectories become discontinuous along the (lightlike) propagation direction of the wave.

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

    OpenAIRE

    Mirela Mihić; Ivana Kursan

    2010-01-01

    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 rese...

  20. Genetic association of impulsivity in young adults: a multivariate study

    OpenAIRE

    Khadka, S; Narayanan, B; Meda, S A; Gelernter, J; Han, S; Sawyer, B; Aslanzadeh, F; Stevens, M C; Hawkins, K A; Anticevic, A; Potenza, M N; Pearlson, G D

    2014-01-01

    Impulsivity is a heritable, multifaceted construct with clinically relevant links to multiple psychopathologies. We assessed impulsivity in young adult (N~2100) participants in a longitudinal study, using self-report questionnaires and computer-based behavioral tasks. Analysis was restricted to the subset (N=426) who underwent genotyping. Multivariate association between impulsivity measures and single-nucleotide polymorphism data was implemented using parallel independent component analysis ...

  1. EXPLORING IMPULSE BUYING BEHAVIOR AMONG IRANIAN TOURIST IN MALAYSIA

    OpenAIRE

    Amir Foroughi; Nor Aishah Buang; Mehrdokht Sherilou

    2011-01-01

    The subject of buying especially impulse buying for many marketing researchers is attractive and fascinating. Retailers interest in work in process of buying and create a situation to pursue individuals to purchase goods. The objectives of this study were to investigate: (a) to determine the level of impulse buying between Iranian( tourists ) in Malaysia, (b) To determine the influence of individuals deference variables such as shopping enjoyment and impulse buying tendency on latent construc...

  2. Impulsivity and negative priming: evidence for diminished cognitive inhibition in impulsive children

    NARCIS (Netherlands)

    Visser, M. R. M.; Das-Smaal, E.; Kwakman, H.

    1996-01-01

    This study addresses the relationship between impulsivity and lack of inhibition. Inhibition was measured both by the interference score and by the negative priming effect in a Stroop colour-word paradigm. The negative priming effect in this paradigm is defined by slower naming of a target colour if

  3. The Relationship Between Impulsivity And Problem Gambling In Adolescence

    Directory of Open Access Journals (Sweden)

    Roberto Secades-Villa

    2016-12-01

    Full Text Available Gambling has become one of the most frequently reported addictive behaviors among young people. Understanding risk factors associated with the onset or maintenance of gambling problems in adolescence has implications for its prevention and treatment. The main aim of the present study was to examine the potential relationships between impulsivity and problem gambling in adolescence. Participants were 874 high school students (average age: 15 years old who were surveyed to provide data on gambling and impulsivity. Self-reported gambling behavior was assessed using the South Oaks Gambling Screen – Revised for Adolescents (SOGS-RA and impulsivity was measured using the Impulsive Sensation Seeking Questionnaire (ZKPQ, the Barratt Impulsiveness Scale (BIS-11-A, and a delay discounting task. The data were analyzed using both a prospective-longitudinal and a cross-sectional design. In the longitudinal analyses, results showed that the impulsivity subscale of the ZKPQ increased the risk of problem gambling (p =.003. In the cross-sectional analyses, all the impulsivity measures were higher in at-risk/problem gamblers than in non-problem gamblers (p = .04; .03 and .01 respectively. These findings further support the relationship between impulsivity and gambling in adolescence. Moreover, our findings suggest a bidirectional relationship between impulsivity and problem gambling in adolescence. These results have consequences for the development of prevention and treatment programs for adolescents with gambling problems.

  4. The Relationship between Impulsivity and Problem Gambling in Adolescence.

    Science.gov (United States)

    Secades-Villa, Roberto; Martínez-Loredo, Victor; Grande-Gosende, Aris; Fernández-Hermida, José R

    2016-01-01

    Gambling has become one of the most frequently reported addictive behaviors among young people. Understanding risk factors associated with the onset or maintenance of gambling problems in adolescence has implications for its prevention and treatment. The main aim of the present study was to examine the potential relationships between impulsivity and problem gambling in adolescence. Participants were 874 high school students (average age: 15 years old) who were surveyed to provide data on gambling and impulsivity. Self-reported gambling behavior was assessed using the South Oaks Gambling Screen - Revised for Adolescents (SOGS-RA) and impulsivity was measured using the Impulsive Sensation Seeking Questionnaire (ZKPQ), the Barratt Impulsiveness Scale (BIS-11-A), and a delay discounting task. The data were analyzed using both a prospective-longitudinal and a cross-sectional design. In the longitudinal analyses, results showed that the impulsivity subscale of the ZKPQ increased the risk of problem gambling ( p = 0.003). In the cross-sectional analyses, all the impulsivity measures were higher in at-risk/problem gamblers than in non-problem gamblers ( p = 0.04; 0.03; and 0.01, respectively). These findings further support the relationship between impulsivity and gambling in adolescence. Moreover, our findings suggest a bidirectional relationship between impulsivity and problem gambling in adolescence. These results have consequences for the development of prevention and treatment programs for adolescents with gambling problems.

  5. 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.

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

    Science.gov (United States)

    Serfas, Benjamin G; Büttner, Oliver B; Florack, Arnd

    2014-01-01

    The present study proposes arousal as an important mechanism driving buying impulsiveness. We examined the effect of buying impulsiveness on arousal in non-shopping and shopping contexts. In an eye-tracking experiment, we measured pupil dilation while participants viewed and rated pictures of shopping scenes and non-shopping scenes. The results demonstrated that buying impulsiveness is closely associated with arousal as response to viewing pictures of shopping scenes. This pertained for hedonic shopping situations as well as for utilitarian shopping situations. Importantly, the effect did not emerge for non-shopping scenes. Furthermore, we demonstrated that arousal of impulsive buyers is independent from cognitive evaluation of scenes in the pictures.

  7. Genetic association of impulsivity in young adults: a multivariate study.

    Science.gov (United States)

    Khadka, S; Narayanan, B; Meda, S A; Gelernter, J; Han, S; Sawyer, B; Aslanzadeh, F; Stevens, M C; Hawkins, K A; Anticevic, A; Potenza, M N; Pearlson, G D

    2014-09-30

    Impulsivity is a heritable, multifaceted construct with clinically relevant links to multiple psychopathologies. We assessed impulsivity in young adult (N~2100) participants in a longitudinal study, using self-report questionnaires and computer-based behavioral tasks. Analysis was restricted to the subset (N=426) who underwent genotyping. Multivariate association between impulsivity measures and single-nucleotide polymorphism data was implemented using parallel independent component analysis (Para-ICA). Pathways associated with multiple genes in components that correlated significantly with impulsivity phenotypes were then identified using a pathway enrichment analysis. Para-ICA revealed two significantly correlated genotype-phenotype component pairs. One impulsivity component included the reward responsiveness subscale and behavioral inhibition scale of the Behavioral-Inhibition System/Behavioral-Activation System scale, and the second impulsivity component included the non-planning subscale of the Barratt Impulsiveness Scale and the Experiential Discounting Task. Pathway analysis identified processes related to neurogenesis, nervous system signal generation/amplification, neurotransmission and immune response. We identified various genes and gene regulatory pathways associated with empirically derived impulsivity components. Our study suggests that gene networks implicated previously in brain development, neurotransmission and immune response are related to impulsive tendencies and behaviors.

  8. Interactions between bipolar disorder and antisocial personality disorder in trait impulsivity and severity of illness.

    Science.gov (United States)

    Swann, A C; Lijffijt, M; Lane, S D; Steinberg, J L; Moeller, F G

    2010-06-01

    We investigated trait impulsivity in bipolar disorder and antisocial personality disorder (ASPD) with respect to severity and course of illness. Subjects included 78 controls, 34 ASPD, 61 bipolar disorder without Axis II disorder, and 24 bipolar disorder with ASPD, by Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) (SCID-I and -II). Data were analyzed using general linear model and probit analysis. Barratt Impulsiveness Scale (BIS-11) scores were higher in ASPD (effect sizes 0.5-0.8) or bipolar disorder (effect size 1.45) than in controls. Subjects with both had more suicide attempts and previous episodes than bipolar disorder alone, and more substance-use disorders and suicide attempts than ASPD alone. BIS-11 scores were not related to severity of crimes. Impulsivity was higher in bipolar disorder with or without ASPD than in ASPD alone, and higher in ASPD than in controls. Adverse effects of bipolar disorder in ASPD, but not of ASPD in bipolar disorder, were accounted for by increased impulsivity.

  9. Neither bipolar nor obsessive-compulsive disorder: compulsive buyers are impulsive acquirers.

    Science.gov (United States)

    Filomensky, Tatiana Zambrano; Almeida, Karla Mathias; Castro Nogueira, Marcelo Campos; Diniz, Juliana Belo; Lafer, Beny; Borcato, Sonia; Tavares, Hermano

    2012-07-01

    Compulsive buying (CB) is currently classified as an impulse control disorder (ICD) not otherwise classified. Compulsive buying prevalence is estimated at around 5% of the general population. There is controversy about whether CB should be classified as an ICD, a subsyndromal bipolar disorder (BD), or an obsessive-compulsive disorder (OCD) akin to a hoarding syndrome. To further investigate the appropriate classification of CB, we compared patients with CB, BD, and OCD for impulsivity, affective instability, hoarding, and other OCD symptoms. Eighty outpatients (24 CB, 21 BD, and 35 OCD) who were neither manic nor hypomanic were asked to fill out self-report questionnaires. Compulsive buying patients scored significantly higher on all impulsivity measures and on acquisition but not on the hoarding subdimensions of clutter and "difficulty discarding." Patients with BD scored higher on the mania dimension from the Structured Clinical Interview for Mood Spectrum scale. Patients with OCD scored higher on obsessive-compulsive symptoms and, particularly, higher on the contamination/washing and checking dimensions from the Padua Inventory; however, they did not score higher on any hoarding dimension. A discriminant model built with these variables correctly classified patients with CB (79%), BD (71%), and OCD (77%). Patients with CB came out as impulsive acquirers, resembling ICD- rather than BD- or OCD-related disorders. Manic symptoms were distinctive of patients with BD. Hoarding symptoms other than acquisition were not particularly associated with any diagnostic group. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Impulse control disorders in Parkinson's disease: the role of personality and cognitive status.

    Science.gov (United States)

    Poletti, Michele; Bonuccelli, Ubaldo

    2012-11-01

    This study reviews empirical findings on two debated issues related to the phenomenon of impulse control disorders (ICD) in patients with Parkinson's disease (PD) treated with dopamine agonists: the role of "premorbid" or "baseline" personality traits and the role of cognitive status. A review of both these issues may help clinicians to understand why only some PD patients, when treated with dopamine agonists, develop an ICD: besides the treatment, which other neuropsychiatric characteristics represent a risk factor to develop an ICD? A literature review was performed on studies of ICD in PD patients, in electronic databases ISI Web of Knowledge, Medline and PsychInfo, conducted in January 2011. In the general population, impulsivity, depression and difficulties with executive functions, especially of inhibitory control, are factors associated with ICD development. As regards cognitive functions, PD patients present executive difficulties, and patients with ICD present more difficulties in comparison to patients without ICD. As regards personality characteristics, PD patients present a trait of negative affect, which could predispose them to affective disorders and could represent an affective risk factor for the development of ICD; as regards impulsivity, preliminary findings support the hypothesis that premorbid "baseline" levels may moderate the decrease of impulsivity because of the progressive dopaminergic deficit in PD patients and therefore also moderate the development of ICD. Longitudinal psychometric and cognitive studies, following PD patients since the clinical diagnosis and during dopaminergic treatment, are needed to confirm the role of personality traits and cognitive status on ICD development in this clinical population.

  11. Effects of the Strain Rate Sensitivity and Strain Hardening on the Saturated Impulse of Plates

    Directory of Open Access Journals (Sweden)

    Ling Zhu

    Full Text Available Abstract This paper studies the stiffening effects of the material strain rate sensitivity and strain hardening on the saturated impulse of elastic, perfectly plastic plates. Finite element (FE code ABAQUS is employed to simulate the elastoplastic response of square plates under rectangular pressure pulse. Rigid-plastic analyses for saturated impulse, which consider strain rate sensitivity and strain hardening, are conducted. Satisfactory agreement between the finite element models (FEM and predictions of the rigid-plastic analysis is obtained, which verifies that the proposed rigid-plastic methods are effective to solve the problem including strain rate sensitivity and strain hardening. The quantitative results for the scale effect of the strain rate sensitivity are given. The results for the stiffening effects suggest that two general stiffening factors n 1 and n 2, which characterizes the strain rate sensitivity and strain hardening effect, respectively can be defined. The saturated displacement is inversely proportional to the stiffening factors (i.e. n 1 and n 2 and saturated impulse is inversely proportional to the square roots of the stiffening factors (i.e. n 1 and n 2. Formulae for displacement and saturated impulse are proposed based on the empirical analysis.

  12. 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

  13. 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

  14. Concrete structures under impact and impulsive loading

    International Nuclear Information System (INIS)

    Plauk, G.

    1982-05-01

    This book contains papers contributed to the RILEM/CEB/IABSE/IASS-Interassociation Symposium on 'Concrete Structures under Impact and Impulsive Loading'. The essential aim of this symposium is to provide an international forum for the exchange of information on existing and current research relating to impact problems as well as to identify areas to which further research activities should be directed. The subject of the symposium is far ranging. Fifty five papers were proposed and arranged in six technical sessions, a task which sometimes posed difficulties for the Organization Committee and the Advisory Group, because some of the papers touched several topics and were difficult to integrate. However, we are confident that these minor difficulties were solved to the satisfaction of everyone involved. Each session of the symposium is devoted to a major subject area and introduced by a distinguished Introductory Reporter. The large international attendance, some 21 countries are represented, and the large number of excellent papers will certainly produce a lively discussion after each session and thus help to further close the gaps in our knowledge about the behaviour of structures and materials under impact and impulsive loading. (orig./RW)

  15. Force-Time Entropy of Isometric Impulse.

    Science.gov (United States)

    Hsieh, Tsung-Yu; Newell, Karl M

    2016-01-01

    The relation between force and temporal variability in discrete impulse production has been viewed as independent (R. A. Schmidt, H. Zelaznik, B. Hawkins, J. S. Frank, & J. T. Quinn, 1979 ) or dependent on the rate of force (L. G. Carlton & K. M. Newell, 1993 ). Two experiments in an isometric single finger force task investigated the joint force-time entropy with (a) fixed time to peak force and different percentages of force level and (b) fixed percentage of force level and different times to peak force. The results showed that the peak force variability increased either with the increment of force level or through a shorter time to peak force that also reduced timing error variability. The peak force entropy and entropy of time to peak force increased on the respective dimension as the parameter conditions approached either maximum force or a minimum rate of force production. The findings show that force error and timing error are dependent but complementary when considered in the same framework with the joint force-time entropy at a minimum in the middle parameter range of discrete impulse.

  16. Impulsive versus Premeditated Aggression in the Prediction of Violent Criminal Recidivism

    Science.gov (United States)

    Swogger, Marc T.; Walsh, Zach; Christie, Michael; Priddy, Brittany M.; Conner, Kenneth R.

    2015-01-01

    Past aggression is a potent predictor of future aggression and informs the prediction of violent criminal recidivism. However, aggression is a heterogeneous construct and different types of aggression may confer different levels of risk for future violence. In this prospective study of 91 adults in a pretrial diversion program, we examined a) premeditated versus impulsive aggression in the prediction of violent recidivism during a one-year follow-up period, and b) whether either type of aggression would have incremental validity in the prediction of violent recidivism after taking into account frequency of past general aggression. Findings indicate that premeditated, but not impulsive, aggression predicts violent recidivism. Moreover, premeditated aggression remained a predictor of recidivism even with general aggression frequency in the model. Results provide preliminary evidence that the assessment of premeditated aggression provides relevant information for the management of violent offenders. PMID:25043811

  17. Existence and stability of periodic solution in impulsive Hopfield neural networks with finite distributed delays

    International Nuclear Information System (INIS)

    Yang Xiaofan; Liao Xiaofeng; Evans, David J.; Tang Yuanyan

    2005-01-01

    In this Letter, we introduce a class of Hopfield neural networks with periodic impulses and finite distributed delays. We then derive a sufficient condition for the existence and global exponential stability of a unique periodic solution of the networks, which assumes neither the differentiability nor the monotonicity of the activation functions. Our condition extends and generalizes a known condition for the global exponential periodicity of continuous Hopfield neural networks with finite distributed delays

  18. [Analysis of biological material originating from the body of general Władysław Sikorski for inorganic poisons and diatoms presence].

    Science.gov (United States)

    Sadlik, Józefa Krystyna; Brozek-Mucha, Zuzanna

    2009-01-01

    Results of the analysis of biological materials originating from the body of general Sikorski are presented in the paper. Samples of the liver, kidney, intestine and lung were analysed for metals and As content, and samples of the lung, liver, kidney, stomach, intestine and bone marrow--for diatoms presence. The analysis for metals and As was performed by atomic absorption spectrometry (AAS) and inductively coupled plasma optical emission spectrometry (ICP-OES). Before the analysis, the samples were wet digested by the classic and microwave assisted method. The analysis did not result in detecting the presence of As, Co, Ni, and Tl in any of the studied materials, while Hg was not revealed in the liver, intestines and lung and Pb in the intestines and lung. The content of Ba, Cd, Cr, Cu, Fe, Mn, Sr and Zn in all the studied materials, Hg in the kidney, and Pb in the liver and kidney did not indicate poisoning by the above-mentioned metals or arsenic. No diatoms were found in the studied materials.

  19. 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…

  20. The effects of heroin administration and drug cues on impulsivity.

    Science.gov (United States)

    Jones, Jermaine D; Vadhan, Nehal P; Luba, Rachel R; Comer, Sandra D

    2016-08-01

    Drug addiction is a chronic relapsing disorder characterized by compulsive drug seeking and continued use despite negative consequences. Behavioral impulsivity is a strong predictor of the initiation and maintenance of drug addiction. Preclinical data suggest that heroin may exacerbate impulsive characteristics in an individual but this has yet to be assessed in clinical samples. The current secondary data analysis sought to investigate the effects of heroin on impulsivity along with the effects of exposure to drug cues. Using the current data set, we also tentatively assessed the etiological relationship between impulsivity and heroin abuse. Sixteen heroin-dependent participants were recruited to complete Immediate Memory Task/Delayed Memory Task (IMT/DMT) and GoStop tasks following repeated heroin administration, following acute heroin administration, and following a drug cue exposure session. Four preceding days of active heroin availability, compared to four preceding days of placebo drug availability, increased impulsivity assessed using the IMT and DMT. Presentation of drug cues similarly acted to increase impulsivity assessments on all three tasks. It also appears that heavier users were more susceptible to the influence of drug cues on impulsivity. The present study represents a step toward a more comprehensive understanding of the interaction between opioid abuse and impulsivity. A better understanding of these factors could provide critical insight into the maintenance of heroin use and relapse.

  1. 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.

  2. A Measure of Impulsiveness and its Relations to Extraversion.

    Science.gov (United States)

    Lorr, Maurice; Wunderlich, Richard A.

    1985-01-01

    The construct validity of the Impulsive scale of the Interpersonal Style Inventory (ISI), and its relation to Eysenck's extraversion were investigated. High school males completed self report personality measures. They were rated by counselors on an impulsive scale. Counselor ratings correlated at a significant level with self-report scores.…

  3. 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

  4. Estimation of Impulsive Wave-induced Loads on a FPSO

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher; Mansour, Alaa E.

    2005-01-01

    The effect of impulsive loads like slamming and green water on deck on the wave-induced bending moment is estimated by a semi-analytical approach. The impulse loads leading to transient vibrations are described in terms of magnitude, phase lag relative to the wave-induced peak and decay rate. The...

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

    Directory of Open Access Journals (Sweden)

    Suzi Elen Ferreira Dias

    2014-08-01

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

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

    Directory of Open Access Journals (Sweden)

    Wiwik Handayani

    2018-05-01

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

  7. A new Calculation Procedure for Spatial Impulse Responses in Ultrasound

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    1999-01-01

    A new procedure for the calculation of spatial impulse responses for linear sound fields is introduced. This calculation procedure uses the well known technique of calculating the spatial impulse response from the intersection of a circle emanating from the projected spherical wave...

  8. 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.

  9. 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

  10. 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.

  11. Sex Differences in Impulsivity: A Meta-Analysis

    Science.gov (United States)

    Cross, Catharine P.; Copping, Lee T.; Campbell, Anne

    2011-01-01

    Men are overrepresented in socially problematic behaviors, such as aggression and criminal behavior, which have been linked to impulsivity. Our review of impulsivity is organized around the tripartite theoretical distinction between reward hypersensitivity, punishment hyposensitivity, and inadequate effortful control. Drawing on evolutionary,…

  12. Dimensions and disorder specificity of impulsivity in pathological gambling

    NARCIS (Netherlands)

    Kräplin, Anja; Bühringer, Gerhard; Oosterlaan, Jaap; van den Brink, Wim; Goschke, Thomas; Goudriaan, Anna E.

    2014-01-01

    Impulsivity is a core characteristic of pathological gambling (PG), even though the underlying structure and disorder specificity is unclear. This study aimed to explore different dimensions of impulsivity in a clinical sample including PG. Furthermore, we aimed to test which alterations of the

  13. The neuroscience of impulsive and self-controlled decisions.

    NARCIS (Netherlands)

    Kalenscher, T.; Ohmann, T.; Güntürkün, O.

    2006-01-01

    Impulsiveness and self-control are two antagonistic choice patterns. Whereas impulsive decisions can be exemplified by the preference for a small, immediate over a large, delayed reward, self-control can be characterised as the opposite preference order. This review focuses on current developments

  14. Towards Ultrahigh Speed Impulse Radio THz Wireless Communications

    DEFF Research Database (Denmark)

    Yu, Xianbin; Galili, Michael; Morioka, Toshio

    2015-01-01

    THz impulse radio technologies promise a new paradigm of fast wireless access with simplified wireless reception. However, huge loss of propagating broad bandwidth THz impulse radio signals limits THz wireless transmission distance and reduces the achievable link data rates. In this paper, we...

  15. Impulsivity-focused group intervention to reduce binge eating episodes in patients with binge eating disorder: study protocol of the randomised controlled IMPULS trial

    OpenAIRE

    Schag, Kathrin; Leehr, Elisabeth J; Martus, Peter; Bethge, Wolfgang; Becker, Sandra; Zipfel, Stephan; Giel, Katrin E

    2015-01-01

    Introduction The core symptom of binge eating disorder (BED) is recurrent binge eating that is accompanied by a sense of loss of control. BED is frequently associated with obesity, one of the main public health challenges today. Experimental studies deliver evidence that general trait impulsivity and disorder-specific food-related impulsivity constitute risk factors for BED. Cognitive-behavioural treatment (CBT) is deemed to be the most effective intervention concerning BED. We developed a gr...

  16. Partial discharge characteristics and mechanism in voids at impulse voltages

    Science.gov (United States)

    Zhao, X. F.; Yao, X.; Guo, Z. F.; Wang, Y. Y.; Li, J. H.; Li, Y. M.

    2011-03-01

    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 (PDIV50) 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.

  17. 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

  18. Impulse control disorders in obese patients.

    Science.gov (United States)

    Schmidt, Frauke; Körber, Stephanie; de Zwaan, Martina; Müller, Astrid

    2012-05-01

    The aim of this study was to determine the prevalence of impulse control disorders (ICDs) in morbidly obese individuals. One hundred bariatric surgery candidates were examined using a module of the Structured Clinical Interview for DSM-IV that has been developed for ICDs. Nineteen per cent suffered from at least one current ICD and 27% met the criteria for any lifetime ICD, most frequently skin picking (current, 8%; lifetime, 9%), compulsive buying (current 6%, lifetime 8%), and intermittent explosive disorder (current, 5%; lifetime, 10%). Patients with regular binge eating (N = 25) reported significantly more often a history of at least one ICD compared with those without binge eating. The results indicate a high prevalence of ICDs among morbidly obese prebariatric surgery patients that are related to regular binge eating. Copyright © 2012 John Wiley & Sons, Ltd and Eating Disorders Association.

  19. Laser impulse coupling at 130 fs

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  20. CO2 impulse response curves for GWP calculations

    International Nuclear Information System (INIS)

    Jain, A.K.; Wuebbles, D.J.

    1993-01-01

    The primary purpose of Global Warming Potential (GWP) is to compare the effectiveness of emission strategies for various greenhouse gases to those for CO 2 , GWPs are quite sensitive to the amount of CO 2 . Unlike all other gases emitted in the atmosphere, CO 2 does not have a chemical or photochemical sink within the atmosphere. Removal of CO 2 is therefore dependent on exchanges with other carbon reservoirs, namely, ocean and terrestrial biosphere. The climatic-induced changes in ocean circulation or marine biological productivity could significantly alter the atmospheric CO 2 lifetime. Moreover, continuing forest destruction, nutrient limitations or temperature induced increases of respiration could also dramatically change the lifetime of CO 2 in the atmosphere. Determination of the current CO 2 sinks, and how these sinks are likely to change with increasing CO 2 emissions, is crucial to the calculations of GWPs. It is interesting to note that the impulse response function is sensitive to the initial state of the ocean-atmosphere system into which CO 2 is emitted. This is due to the fact that in our model the CO 2 flux from the atmosphere to the mixed layer is a nonlinear function of ocean surface total carbon

  1. Impulsivity components measured by the Brazilian version of the Barratt Impulsiveness Scale (BIS-11

    Directory of Open Access Journals (Sweden)

    Alina Gomide Vasconcelos

    2015-03-01

    Full Text Available The main purpose of this study was to investigate the psychometric properties of the Barratt Impulsiveness Scale (BIS-11. Content item analysis was conducted by seven doctoral students. A convenience sample of 897 students was submitted to BIS-11 and they also filled self-reports about Minor Mental Disorder and ADHD symptoms, alcohol use and cigarette smoking. Mean age was 27.32 (SD=8.69 years, 56% were female and 52% had incomplete college degree. Content and factorial analyses revealed that impulsivity was best represented by two latent factors labeled non-planning and inhibition behaviors. Test retest agreement tended to produce similar score patterns seven months after the first evaluation. Additionally, BIS-11 scores discriminated subjects in terms of cigarette smoking and psychopathological symptoms, which indicated evidences regarding criterion-related validity. The theoretical discussion was present based on the neuropsychological model of hot and cool aspects of executive function.

  2. Lateral Habenula Involvement in Impulsive Cocaine Seeking.

    Science.gov (United States)

    Zapata, Agustin; Hwang, Eun-Kyung; Lupica, Carl R

    2017-04-01

    The lateral habenula (LHb) is a brain structure receiving inputs from limbic forebrain areas and innervating major midbrain monoaminergic nuclei. Evidence indicates LHb involvement in sleep control, reward-based decision making, avoidance of punishment, and responses to stress. Additional work has established that the LHb mediates negative feedback in response to aversive events. As a hallmark of drug addiction is the inability to limit drug use despite negative consequences, we hypothesize that LHb dysfunction may have a role in the lack of control over drug seeking. Here we examine the effects of LHb inactivation in control over drug seeking in several cocaine self-administration (SA) paradigms in rats. We find that inhibition of the LHb with GABAergic agonists did not alter cocaine SA under progressive ratio or seeking/taking chained reinforcement schedules, or during punishment-induced suppression of cocaine-reinforced responding. In contrast, LHb inhibition increased cocaine seeking when the drug was not available in rats trained to discriminate its presence using an environmental cue. This effect of LHb inhibition was selective for cocaine, as it did not impair responding for sucrose reinforcement. The effect of LHb injection of GABA agonists was mimicked by intra-LHb muscarinic cholinergic (mACh) antagonist injection, and activation of mACh receptors excited a majority of LHb neurons in in vitro electrophysiology experiments. These results indicate that the LHb participates in the suppression of impulsive responding for cocaine through the activation of a cholinergic circuit, and they suggest that LHb dysfunction may contribute to impaired impulse control associated with drug addiction.

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

    Science.gov (United States)

    Leroi, Iracema; Barraclough, Michelle; McKie, Shane; Hinvest, Neal; Evans, Jonathan; Elliott, Rebecca; McDonald, Kathryn

    2013-09-01

    The development of impulse control disorders (ICDs) in Parkinson's disease (PD) may arise from an interaction among cognitive impairment, impulsive responding and dopaminergic state. Dopaminergic state may be influenced by pharmacologic or genotypic (catechol-O-methyltransferase; COMT) factors. We sought to investigate this interaction further by comparing those with (n = 35) and without (n = 55) ICDs on delay-discounting in different pharmacologic conditions (ON or OFF dopaminergic medication) and on response inhibition as well as aspects of executive functioning in the ON state. We then undertook an exploratory sub-group analysis of these same tasks when the overall PD group was divided into different allelic variants of COMT (val/val vs. met/met). A healthy control group (HC; n = 20) was also included. We found that in those with PD and ICDs, 'cognitive flexibility' (set shifting, verbal fluency, and attention) in the ON medication state was not impaired compared with those without ICDs. In contrast, our working memory, or 'cognitive focus', task was impaired in both PD groups compared with the HC group when ON. During the delay-discounting task, the PD with ICDs group expressed greater impulsive choice compared with the PD group without ICDs, when in the ON, but not the OFF, medication state. However, no group difference on the response inhibition task was seen when ON. Finally, the met homozygous group performed differently on tests of executive function compared with the val homozygous group. We concluded that the disparity in levels of impairment among different domains of executive function and impulsive decision-making distinguishes those with ICD in PD from those without ICD, and may in part be affected by dopaminergic status. Both pharmacologic and genotypic influences on dopaminergic state may be important in ICD. © 2013 The British Psychological Society.

  4. [Biogeography: geography or biology?].

    Science.gov (United States)

    Kafanov, A I

    2009-01-01

    General biogeography is an interdisciplinary science, which combines geographic and biological aspects constituting two distinct research fields: biological geography and geographic biology. These fields differ in the nature of their objects of study, employ different methods and represent Earth sciences and biological sciences, respectively. It is suggested therefore that the classification codes for research fields and the state professional education standard should be revised.

  5. 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.

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

    Science.gov (United States)

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

    2015-01-01

    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. Objectives Identify unique impulsivity traits specific to substance use and overeating. Methods 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). Results A significant overall factor structure revealed three components of impulsivity that explained respectively 50.19% (ppermOvereating: lacks focus, but plans (short and long term). Conclusions 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. PMID:25115831

  7. Partial Extinction, Permanence, and Global Attractivity in Nonautonomous n-Species Gilpin-Ayala Competitive Systems with Impulses

    Directory of Open Access Journals (Sweden)

    Juan Hou

    2012-01-01

    Full Text Available The qualitative properties of general nonautonomous n-species Gilpin-Ayala competitive systems with impulsive effects are studied. Some new criteria on the permanence, extinction, and global attractivity of partial species are established by using the methods of inequalities estimate and Liapunov functions.

  8. Existence of Subharmonic Solutions for a Class of Second-Order p-Laplacian Systems with Impulsive Effects

    Directory of Open Access Journals (Sweden)

    Wen-Zhen Gong

    2012-01-01

    Full Text Available By using minimax methods in critical point theory, a new existence theorem of infinitely many periodic solutions is obtained for a class of second-order p-Laplacian systems with impulsive effects. Our result generalizes many known works in the literature.

  9. Risk and learning in impulsive and non-impulsive patients with Parkinson’s disease

    Science.gov (United States)

    Djamshidian, Atbin; Jha, Ashwani; O’Sullivan, Sean S.; Silveira-Moriyama, Laura; Jacobson, Clare; Brown, Peter; Lees, Andrew; Averbeck, Bruno B.

    2011-01-01

    Relatively little is known about the interaction between behavioural changes, medication and cognitive function in Parkinson’s disease. We examined working memory, learning and risk aversion in patients with Parkinson’s disease (PD) with and without impulsive or compulsive behaviour and compared to a group of age-matched control subjects. Parkinson patients with impulsive or compulsive behaviour (PD+ ICB) had poorer working memory performance than either controls or PD patients without ICB. PD+ICB patients also showed decreased learning from negative feedback and increased learning from positive feedback off compared to on dopaminergic medication. This interaction between medication status and learning was the opposite of that found in the PD patients without a diagnosis of ICB. Finally, the PD group showed increased risk preference on medication relative to controls and the subgroup of PD+ICB patients with pathological gambling were overall more risk prone than the PD group. Thus, medication status and an impulsive behavioural diagnosis differentially affect several behaviors in PD. PMID:20721918

  10. A note on errors and signal to noise ratio of binary cross-correlation measurements of system impulse response

    International Nuclear Information System (INIS)

    Cummins, J.D.

    1964-02-01

    The sources of error in the measurement of system impulse response using test signals of a discrete interval binary nature are considered. Methods of correcting for the errors due to theoretical imperfections are given and the variance of the estimate of the system impulse response due to random noise is determined. Several topics related to the main topic are considered e.g. determination of a theoretical model from experimental results. General conclusions about the magnitude of the errors due to the theoretical imperfections are made. (author)

  11. Quantum Biology

    Directory of Open Access Journals (Sweden)

    Alessandro Sergi

    2009-06-01

    Full Text Available A critical assessment of the recent developmentsof molecular biology is presented.The thesis that they do not lead to a conceptualunderstanding of life and biological systems is defended.Maturana and Varela's concept of autopoiesis is briefly sketchedand its logical circularity avoided by postulatingthe existence of underlying living processes,entailing amplification from the microscopic to the macroscopic scale,with increasing complexity in the passage from one scale to the other.Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces,is criticized. It is suggested that the correct interpretationof quantum dispersion forces (van der Waals, hydrogen bonding, and so onas quantum coherence effects hints at the necessity of includinglong-ranged forces (or mechanisms for them incondensed matter theories of biological processes.Some quantum effects in biology are reviewedand quantum mechanics is acknowledged as conceptually important to biology since withoutit most (if not all of the biological structuresand signalling processes would not even exist. Moreover, it is suggested that long-rangequantum coherent dynamics, including electron polarization,may be invoked to explain signal amplificationprocess in biological systems in general.

  12. Impulsivity is associated with blood pressure and waist circumference among adolescents with bipolar disorder.

    Science.gov (United States)

    Naiberg, Melanie R; Newton, Dwight F; Collins, Jordan E; Bowie, Christopher R; Goldstein, Benjamin I

    2016-12-01

    Cardiovascular risk factors (CVRFs) and impulsivity are common in bipolar disorder (BD), and CVRFs are also linked with impulsivity through a number of mechanisms, both behavioral and biological. This study examines the association between CVRFs and impulsivity in adolescents with BD. Subjects were 34 adolescents with BD and 35 healthy control (HC) adolescents. CVRFs were based on International Diabetes Federation metabolic syndrome criteria (triglycerides, high-density lipoprotein cholesterol, waist circumference, blood pressure (BP) and glucose). Impulsivity was measured using the computerized Cambridge Gambling Task (CGT). Analyses controlled for age, IQ, lifetime attention deficit hyperactivity disorder, and current antipsychotic use. Adolescents with BD had higher diastolic BP (73.36 ± 9.57 mmHg vs. 67.91 ± 8.74 mmHg, U = 401.0, p = 0.03), higher triglycerides (1.13 ± 0.60 mmol/L vs. 0.78 ± 0.38 mmol/L, U = 373.5, p = 0.008), and were more likely to meet high-risk criteria for waist circumference (17.6% vs. 2.9%, p = 0.04) vs. HC. Within the BD group, CGT sub-scores were correlated with CVRFs. For example, overall proportion bet was positively correlated with systolic (r = 0.387, p = 0.026) and diastolic (ρ = 0.404, p = 0.020) BP. Quality of decision-making was negatively correlated with systolic BP (ρ = -0.401, p = 0.021) and waist circumference (ρ = -0.534, p = 0.003). Significant interactions were observed, such that BD diagnosis moderates the relationship between both waist circumference and BP with CGT sub-scores. BP and waist circumference are associated with impulsivity in BD adolescents, but not in HC adolescents. Future studies are warranted to determine temporality and to evaluate whether optimizing CVRFs improves impulsivity among BD adolescents. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Impulsivity is not always associated with student drinking: a moderation study of impulsivity and drinking by positive alcohol expectancies.

    Science.gov (United States)

    Carlson, Scott R; Johnson, Season C

    2012-04-01

    Student drinking is a major problem on North American campuses and impulsivity is a significant risk factor for heavy drinking. The present study investigates the moderation of the impulsivity-drinking relationship by the expectation that having a drink will lead to positive experiences. Undergraduate drinkers (n=292) completed measures of impulsivity (Barratt Impulsiveness Scale 11; BIS-11), positive drinking expectancies, and alcohol use. Expectancies moderated the relationship between BIS-11 scores and alcohol use. BIS-11 scores were significantly related to typical alcohol quantity, frequency, quantity X frequency, and binge drinking frequency for individuals with average and high levels of positive expectancies, but not for those with few positive expectancies. Implications for interventions targeted at highly impulsive students, using expectancy modification are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. FTO Genotype and Aging: Pleiotropic Longitudinal Effects on Adiposity, Brain function, Impulsivity and Diet

    Science.gov (United States)

    Chuang, Yi-Fang; Tanaka, Toshiko; Beason-Held, Lori L.; An, Yang; Terracciano, Antonio; Sutin, Angelina R.; Kraut, Michael; Singleton, Andrew B.; Resnick, Susan M.; Thambisetty, Madhav

    2014-01-01

    While overweight and obesity are associated with poor health outcomes in the elderly, the biological bases of obesity-related behaviors during aging are poorly understood. Common variants in the FTO gene are associated with adiposity in children and younger adults as well as with adverse mental health in older individuals. However, it is unclear whether FTO influences longitudinal trajectories of adiposity and other intermediate phenotypes relevant to mental health during aging. We examined whether a commonly carried obesity risk variant in the FTO gene (rs1421085 single nucleotide polymorphism) influences adiposity and is associated with changes in brain function in participants within the Baltimore Longitudinal Study of Aging (BLSA), one of the longest-running longitudinal aging studies in the United States. Our results show that obesity-related risk allele carriers of FTO gene show dose-dependent increments in body mass index during aging. Moreover, the obesity-related risk allele is associated with reduced medial prefrontal cortical function during aging. Consistent with reduced brain function in regions intrinsic to impulse control and taste responsiveness, risk allele carriers of FTO exhibit dose-dependent increments in both impulsivity and intake of fatty foods. We propose that a common neural mechanism may underlie obesity-associated impulsivity and increased consumption of high calorie foods during aging. PMID:24863145

  15. An analytical approach for predicting the energy capture and conversion by impulsively-excited bistable vibration energy harvesters

    Science.gov (United States)

    Harne, R. L.; Zhang, Chunlin; Li, Bing; Wang, K. W.

    2016-07-01

    Impulsive energies are abundant throughout the natural and built environments, for instance as stimulated by wind gusts, foot-steps, or vehicle-road interactions. In the interest of maximizing the sustainability of society's technological developments, one idea is to capture these high-amplitude and abrupt energies and convert them into usable electrical power such as for sensors which otherwise rely on less sustainable power supplies. In this spirit, the considerable sensitivity to impulse-type events previously uncovered for bistable oscillators has motivated recent experimental and numerical studies on the power generation performance of bistable vibration energy harvesters. To lead to an effective and efficient predictive tool and design guide, this research develops a new analytical approach to estimate the electroelastic response and power generation of a bistable energy harvester when excited by an impulse. Comparison with values determined by direct simulation of the governing equations shows that the analytically predicted net converted energies are very accurate for a wide range of impulse strengths. Extensive experimental investigations are undertaken to validate the analytical approach and it is seen that the predicted estimates of the impulsive energy conversion are in excellent agreement with the measurements, and the detailed structural dynamics are correctly reproduced. As a result, the analytical approach represents a significant leap forward in the understanding of how to effectively leverage bistable structures as energy harvesting devices and introduces new means to elucidate the transient and far-from-equilibrium dynamics of nonlinear systems more generally.

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

    Directory of Open Access Journals (Sweden)

    Katrin E. Giel

    2017-10-01

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

  17. Study on the lightning impulse breakdown characteristics of gaseous insulation media for the design of a high voltage superconducting apparatus

    Science.gov (United States)

    Kang, H.; Na, J. B.; Ahn, M. C.; Bae, D. K.; Kim, Y. H.; Ko, T. K.

    2010-11-01

    In general, the current leads of high voltage superconducting apparatuses cooled by liquid nitrogen are exposed to gaseous insulation media. Therefore, the investigation on the electrical breakdown characteristics of gaseous insulation media should be performed to develop electrically reliable high voltage superconducting power apparatuses. In this study, the lightning impulse breakdown tests on gaseous insulation media are conducted by using sphere-to-plane electrode systems made of stainless steel. Also, the lightning impulse breakdown voltage tests on gaseous insulation media according to various pressures are performed. The experimental results show that the electrical breakdown characteristics under lightning impulse voltage are affected by the gap length between electrode systems, the size of electrodes, and the field utilization factors. From these results, the electrical insulation design criteria to estimate the electrical breakdown voltage are established. The results are expected to be applicable to the design of current leads for high voltage superconducting apparatuses.

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

    Science.gov (United States)

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

    2006-06-01

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

  19. 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.

  20. Interval Oscillation Criteria for Super-Half-Linear Impulsive Differential Equations with Delay

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    Zhonghai Guo

    2012-01-01

    Full Text Available We study the following second-order super-half-linear impulsive differential equations with delay [r(tφγ(x′(t]′+p(tφγ(x(t-σ+q(tf(x(t-σ=e(t, t≠τk, x(t+=akx(t, x′(t+=bkx′(t, t=τk, where t≥t0∈ℝ, φ*(u=|u|*-1u, σ is a nonnegative constant, {τk} denotes the impulsive moments sequence with τ1σ. By some classical inequalities, Riccati transformation, and two classes of functions, we give several interval oscillation criteria which generalize and improve some known results. Moreover, we also give two examples to illustrate the effectiveness and nonemptiness of our results.

  1. Interval Oscillation Criteria of Second Order Mixed Nonlinear Impulsive Differential Equations with Delay

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    Zhonghai Guo

    2012-01-01

    Full Text Available We study the following second order mixed nonlinear impulsive differential equations with delay (r(tΦα(x′(t′+p0(tΦα(x(t+∑i=1npi(tΦβi(x(t-σ=e(t, t≥t0, t≠τk,x(τk+=akx(τk, x'(τk+=bkx'(τk, k=1,2,…, where Φ*(u=|u|*-1u, σ is a nonnegative constant, {τk} denotes the impulsive moments sequence, and τk+1-τk>σ. Some sufficient conditions for the interval oscillation criteria of the equations are obtained. The results obtained generalize and improve earlier ones. Two examples are considered to illustrate the main results.

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  3. Endogenous opioid blockade and impulsive responding in alcoholics and healthy controls.

    Science.gov (United States)

    Mitchell, Jennifer M; Tavares, Venessa C; Fields, Howard L; D'Esposito, Mark; Boettiger, Charlotte A

    2007-02-01

    The opioid receptor antagonist naltrexone (NTX) is one of few approved treatments for alcoholism, yet the mechanism by which it reduces drinking remains unclear. In rats, NTX reduces morphine-induced impulsive choice bias; however, nothing is known about the drug's effect on discrete aspects of impulsive behavior in humans, such as decision-making and inhibitory control. Here, we used a modified delay discounting procedure to investigate whether NTX improves decision-making or inhibitory control in humans. We measured the effect of acute NTX (50 mg) on choice between smaller sooner (SS) and larger later monetary rewards and on response errors (motor mismatch) in a high conflict condition in a group of abstinent alcoholics (AA) and healthy control subjects (CS). We previously reported that AA selected the SS option significantly more often than did CS in this paradigm. If the choice bias of AA is due to enhanced endogenous opioid signaling in response to potential reward, NTX should reduce such bias in the AA group. We found that NTX did not reliably reduce impulsive choice in the AA group; however, NTX's effect on choice bias across individuals was robustly predictable. NTX's effect on choice bias was significantly correlated with scores on Rotter's Locus of Control (LOC) scale; increasingly internal LOC scores predicted increasing likelihood of impulsive choices on NTX. In addition, we found that NTX significantly enhanced control of motor responses, particularly within the CS group. These results suggest that endogenous opioids may impair response selection during decision-making under conflict, and that NTX's effects on explicit decision-making are personality-dependent. Determining the biological basis of this dependence could have important implications for effective alcoholism treatment.

  4. Association of impulsivity and polymorphic microRNA-641 target sites in the SNAP-25 gene.

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    Nóra Németh

    Full Text Available Impulsivity is a personality trait of high impact and is connected with several types of maladaptive behavior and psychiatric diseases, such as attention deficit hyperactivity disorder, alcohol and drug abuse, as well as pathological gambling and mood disorders. Polymorphic variants of the SNAP-25 gene emerged as putative genetic components of impulsivity, as SNAP-25 protein plays an important role in the central nervous system, and its SNPs are associated with several psychiatric disorders. In this study we aimed to investigate if polymorphisms in the regulatory regions of the SNAP-25 gene are in association with normal variability of impulsivity. Genotypes and haplotypes of two polymorphisms in the promoter (rs6077690 and rs6039769 and two SNPs in the 3' UTR (rs3746544 and rs1051312 of the SNAP-25 gene were determined in a healthy Hungarian population (N = 901 using PCR-RFLP or real-time PCR in combination with sequence specific probes. Significant association was found between the T-T 3' UTR haplotype and impulsivity, whereas no association could be detected with genotypes or haplotypes of the promoter loci. According to sequence alignment, the polymorphisms in the 3' UTR of the gene alter the binding site of microRNA-641, which was analyzed by luciferase reporter system. It was observed that haplotypes altering one or two nucleotides in the binding site of the seed region of microRNA-641 significantly increased the amount of generated protein in vitro. These findings support the role of polymorphic SNAP-25 variants both at psychogenetic and molecular biological levels.

  5. Impulse control disorders in non-treatment seeking hair pullers.

    Science.gov (United States)

    Schreiber, Liana R N; Lust, Katherine; Odlaug, Brian; Derbyshire, Katherine L; Grant, Jon

    2013-06-01

    Background and aims Hair pulling is a common body focused repetitive behavior. The purpose of this paper is to examine the prevalence of impulse control disorders (as defined in DSM-IV-TR) in a non-treatment seeking sample of hair pullers. Methods 1,717 college students with (n = 44) and without (n = 1673) hair pulling completed a mental health survey. The college students were sent an online survey assessing hair pulling behavior and other impulse control disorders using the Minnesota Impulsive Disorders Interview. Results Students with hair pulling were significantly more likely to have a co-occurring impulse control disorder (20.5% vs. 8.9%, p = 0.009, OR = 2.71, CI = 1.28-5.75) and were significantly more likely to meet criteria for compulsive buying, compulsive sexual behavior and intermittent explosive disorder than students without hair pulling. Differences seemed to be moderated by the male gender among students with hair pulling. Discussion and conclusions Hair pulling is often comorbid with another impulse control disorder, which suggests that elements of impulsivity may be important in our understanding of hair pulling. Furthermore, gender may moderate impulse control comorbidity in hair pulling disorder.

  6. Causal pathways between impulsiveness, cocaine use consequences, and depression.

    Science.gov (United States)

    Lister, Jamey J; Ledgerwood, David M; Lundahl, Leslie H; Greenwald, Mark K

    2015-02-01

    The present study examined whether lifetime cocaine use consequences mediate the relationship between trait impulsiveness and current depression symptoms among regular cocaine users. Regular cocaine users (N=108) were assessed using: Barratt Impulsiveness Scale subscales (non-planning, attentional, motor sub-scales) to measure trait impulsiveness; a standardized Drug History and Use Questionnaire to measure cocaine use and related consequences; and Beck Depression Inventory to measure current depression symptoms. All impulsiveness subscales were positively associated with an earlier age of first cocaine use, a higher degree of current depression symptoms and a greater number of lifetime cocaine use consequences. In three separate simple mediation tests, lifetime cocaine use consequences partially mediated the relationship between each of the impulsiveness subscales (non-planning: R(2)=.42; attentional: R(2)=.40; motor: R(2)=.24) and current depression symptoms. Separate moderated mediation analyses failed to demonstrate an interaction between lifetime cocaine use and cocaine-related consequences predicting depression symptoms for the mediation models. Cocaine-related consequences function in a more nuanced manner than just an outcome of impulsiveness or cocaine use, but as a pathway between trait impulsiveness and current depression symptoms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Dimensions of impulsivity in relation to eating disorder recovery.

    Science.gov (United States)

    Bardone-Cone, Anna M; Butler, Rachel M; Balk, Margaret R; Koller, Katherine A

    2016-11-01

    Impulsivity is associated with eating pathology, but different dimensions of impulsivity have not been extensively studied in the eating disorders. The current study examined the relationship between four facets of impulsivity and eating disorder recovery status. Females formerly seen for an eating disorder were categorized as having an eating disorder (n = 53), partially recovered (n = 15), or fully recovered (n = 20) based on a diagnostic interview and physical, behavioral, and psychological indices. These groups and non-eating disorder controls were compared on impulsivity facets from the UPPS Impulsive Behavior Scale (UPPS): Urgency (negative urgency), Premeditation (lack of), Perseverance (lack of), and Sensation Seeking. Negative urgency (the tendency to engage in impulsive behavior to alleviate negative affect) was related to recovery. The fully recovered group and controls experienced significantly less negative urgency than those with a current eating disorder; the partially recovered group did not differ from the eating disorder group. Findings suggest that negative urgency may be a particularly important facet of impulsivity to target in therapeutic intervention for eating disorders, especially among those with a history of binge eating and/or purging. Future longitudinal work is needed to test a potential causal relationship between negative urgency and eating disorder recovery. © 2016 Wiley Periodicals, Inc. (Int J Eat Disord 2016; 49:1027-1031). © 2016 Wiley Periodicals, Inc.

  8. 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

  9. An Exploration of Apathy and Impulsivity in Parkinson Disease

    Directory of Open Access Journals (Sweden)

    David J. Ahearn

    2012-01-01

    Full Text Available Background. Apathy and impulsivity in Parkinson disease (PD are associated with clinically significant behavioral disorders. Aim. To explore the phenomenology, distribution, and clinical correlates of these two behaviors. Methods. In PD participants (n=99 without dementia we explored the distribution of measures of motivation and impulsivity using univariate methods. We then undertook factor analysis to define specific underlying dimensions of apathy and impulsivity. Regression models were developed to determine the associated demographic and clinical features of the derived dimensions. Results. The factor analysis of apathy (AES-C revealed a two-factor solution: “cognitive-behavior” and “social indifference”. The factor analysis of impulsivity (BIS-11 revealed a five-factor solution: “inattention”; “impetuosity”; “personal security”; “planning”; and “future orientation”. Apathy was significantly associated with: age, age of motor symptom onset (positive correlation, disease stage, motor symptom severity, and depression. Impulsivity was significantly associated with: age of motor symptom onset (negative correlation, gambling and anxiety scores, and motor complications. We observed an overlap of apathy and impulsivity in some participants. Conclusion. In PD, apathy and impulsivity have specific phenomenological profiles and are associated with particular clinical phenotypes. In spite of this, there is some overlap of behaviors which may suggests common aspects in the pathology underlying motivation and reward processes.

  10. Composite impulsivity-related domains in college students.

    Science.gov (United States)

    Khadka, Sabin; Stevens, Michael C; Aslanzadeh, Farah; Narayanan, Balaji; Hawkins, Keith A; Austad, Carol S; Raskin, Sarah A; Tennen, Howard; Wood, Rebecca M; Fallahi, Carolyn; Potenza, Marc N; Pearlson, Godfrey D

    2017-07-01

    Impulsivity is a complex, multidimensional construct with prior theoretically and empirically derived characterizations of impulsivity-related behaviors varying considerably among studies. We assessed college students (N = 440) longitudinally with five impulsivity-related self-reported assessments and two computerized behavioral measures. Using a combination of exploratory and confirmatory factor analysis (CFA), we derived then validated several composite impulsivity-related domains (CIRDs). These factors replicated, in large part, findings from a previous study conducted by our group in an independent sample that used a similar analytical approach. The four CIRDs derived in current study are: 'Impulsive action', 'Approach/Appetite Motivation', 'Impulsivity/Compulsivity' and 'Experience and thrill seeking/Fearlessness'. Subsequent psychometric analyses found these CIRDs were relatively stable over the two-year period. Moreover, multiple regression analysis found that CIRD profiles associated with clinical and behavioral characteristics including anxiety, depression, attention deficit hyperactivity disorder and substance use symptomology. Overall, our data suggest that empirically-derived CIRDs have potential for organizing previous impulsivity-related constructs into a more naturalistic framework where distinct constructs are often expressed together in the same individuals. This framework might facilitate future research of neuropsychiatric disorder risk and etiology. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Negative emotion-driven impulsivity predicts substance dependence problems.

    Science.gov (United States)

    Verdejo-García, Antonio; Bechara, Antoine; Recknor, Emily C; Pérez-García, Miguel

    2007-12-01

    Impulsivity is predominant among users of several drugs of abuse including alcohol, cocaine, and amphetamines, and it is considered a risk factor for later development of alcohol and substance abuse and dependence. However, there is little consensus on how impulsivity should be defined and measured, and there are few studies on the relationship between separate dimensions of impulsivity and substance dependence. We used a multidimensional measure of impulsivity (the UPPS scale) to examine differences between 36 individuals with substance dependence (ISD) and 36 drug-free controls on the dimensions of urgency, lack of premeditation, lack of perseverance, and sensation seeking. In addition, we examined which dimensions of impulsivity better predicted addiction-related problems as measured with the addiction severity index. Results revealed that ISD show high scores on dimensions of urgency, lack of perseverance, and lack of premeditation (effect sizes ranging from 1.10 to 1.96), but not on sensation seeking. Among the different impulsivity dimensions, urgency was the best predictor of severity of medical, employment, alcohol, drug, family/social, legal and psychiatric problems in ISD, explaining 13-48% of the total variance of these indices. Furthermore, urgency scores alone correctly classified 83% of the participants in the ISD group. Urgency is characterized by a tendency to act impulsively in response to negative emotional states. Thus, our results could have important implications for novel treatment approaches for substance dependence focused on emotional regulation.

  12. Temperament and impulsivity predictors of smoking cessation outcomes.

    Directory of Open Access Journals (Sweden)

    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

  13. Neurobiological correlates of impulsivity in healthy adults: Lower prefrontal gray matter volume and spontaneous eye-blink rate but greater resting-state functional connectivity in basal ganglia-thalamo-cortical circuitry.

    Science.gov (United States)

    Korponay, Cole; Dentico, Daniela; Kral, Tammi; Ly, Martina; Kruis, Ayla; Goldman, Robin; Lutz, Antoine; Davidson, Richard J

    2017-08-15

    Studies consistently implicate aberrance of the brain's reward-processing and decision-making networks in disorders featuring high levels of impulsivity, such as attention-deficit hyperactivity disorder, substance use disorder, and psychopathy. However, less is known about the neurobiological determinants of individual differences in impulsivity in the general population. In this study of 105 healthy adults, we examined relationships between impulsivity and three neurobiological metrics - gray matter volume, resting-state functional connectivity, and spontaneous eye-blink rate, a physiological indicator of central dopaminergic activity. Impulsivity was measured both by performance on a task of behavioral inhibition (go/no-go task) and by self-ratings of attentional, motor, and non-planning impulsivity using the Barratt Impulsiveness Scale (BIS-11). Overall, we found that less gray matter in medial orbitofrontal cortex and paracingulate gyrus, greater resting-state functional connectivity between nodes of the basal ganglia-thalamo-cortical network, and lower spontaneous eye-blink rate were associated with greater impulsivity. Specifically, less prefrontal gray matter was associated with higher BIS-11 motor and non-planning impulsivity scores, but was not related to task performance; greater correlated resting-state functional connectivity between the basal ganglia and thalamus, motor cortices, and prefrontal cortex was associated with worse no-go trial accuracy on the task and with higher BIS-11 motor impulsivity scores; lower spontaneous eye-blink rate was associated with worse no-go trial accuracy and with higher BIS-11 motor impulsivity scores. These data provide evidence that individual differences in impulsivity in the general population are related to variability in multiple neurobiological metrics in the brain's reward-processing and decision-making networks. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Temperamental components of impulsivity in ADHD

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    Małgorzata Lipowska

    2010-09-01

    Full Text Available The aim of the above research was to identify the temperamental profile differentiating children with diagnosed ADHD from their friends who are not affected by developmental deficiency. Moreover, the objective was to examine whether the temperamental profile of hyperactive children can be characterized by the same specific configuration of traits. Material and method: The experimental group comprised 63 children with diagnosed ADHD (32 girls and 31 boys. The control group consisted of children without any diagnosed developmental deficiency (37 girls and 30 boys in the age adequate to the research group (control group aged M=11.5; SD=0.9; ADHD children aged M=11.6; SD=0.4. Temperamental profile was evaluated by means of Buss and Plomin EAS-C Temperament Questionnaire, Polish version adapted by Oniszczenko (1997 and evaluated by parents and teachers. The severity of symptoms criterial for ADHD was described with the use of Wolańczyk and Kołakowski Questionnaire for diagnosing ADHD and behavioural disorders (2005. Results: Correlates were found between the severity of ADHD symptoms and the child’s specific temperamental profile. In case of hyperactive children, teachers ranked shyness significantly higher (t=-5.2; p=0.000, whereas parents ranked emotionality higher (t=5.1; p=0.000. In both examined groups the activity level was estimated as average and high (6-7 sten. It appeared that the trait differentiating the temperamental profile of children from both groups was emotionality – a higher level of this trait was indicated both by parents (t=8.6; p=0.000 and teachers (t=6.4; p=0.000. As far as the relation between particular temperamental traits and criterial ADHD dimensions is concerned, a correlation was found between emotionality and impulsivity (r=3.4; p=0.008 and hyperactivity (r=3.5; p=0.007 in parents’ evaluation and impulsivity (r=3.6; p=0.004 in teachers’ perception. Moreover, the teachers also emphasised the correlation

  15. Impulse control in Kalman-like filtering problems

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    Michael V. Basin

    1998-01-01

    Full Text Available This paper develops the impulse control approach to the observation process in Kalman-like filtering problems, which is based on impulsive modeling of the transition matrix in an observation equation. The impulse control generates the jumps of the estimate variance from its current position down to zero and, as a result, enables us to obtain the filtering equations for the Kalman estimate with zero variance for all post-jump time moments. The filtering equations for the estimates with zero variances are obtained in the conventional linear filtering problem and in the case of scalar nonlinear state and nonlinear observation equations.

  16. Double-impulse magnetic focusing of launched cold atoms

    Science.gov (United States)

    Arnold, Aidan S.; Pritchard, Matthew J.; Smith, David A.; Hughes, Ifan G.

    2006-04-01

    We have theoretically investigated three-dimensional focusing of a launched cloud of cold atoms using a pair of magnetic lens pulses (the alternate-gradient method). Individual lenses focus radially and defocus axially or vice versa. The performance of the two possible pulse sequences are compared and found to be ideal for loading both 'pancake' and 'sausage' shaped magnetic/optical microtraps. It is shown that focusing aberrations are considerably smaller for double-impulse magnetic lenses compared to single-impulse magnetic lenses. An analysis of clouds focused by the double-impulse technique is presented.

  17. SCL-90-R emotional distress ratings in substance use and impulse control disorders

    DEFF Research Database (Denmark)

    Arrindell, Willem A; Urbán, Róbert; Carrozzino, Danilo

    2017-01-01

    in relation to the Symptom Checklist-90-R. In doing so, it utilized a sample comprising 2593 patients with substance use and impulse control disorders. The study also included a test of a one-dimensional model of general psychological distress. Oblique first-order factors were based on the original a priori 9...... as input, three higher-order models were tested with at the second-order levels either (1) General psychological distress; (2) 'Panic with agoraphobia', 'Depression' and 'Extra-punitive behavior'; or (3) 'Irritable-hostile depression' and 'Panic with agoraphobia'. In line with previous studies, no support...

  18. Dynamical Analysis of a Delayed Predator-Prey System with Birth Pulse and Impulsive Harvesting at Different Moments

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    Chen Lansun

    2010-01-01

    Full Text Available We consider a delayed Holling type II predator-prey system with birth pulse and impulsive harvesting on predator population at different moments. Firstly, we prove that all solutions of the investigated system are uniformly ultimately bounded. Secondly, the conditions of the globally attractive prey-extinction boundary periodic solution of the investigated system are obtained. Finally, the permanence of the investigated system is also obtained. Our results provide reliable tactic basis for the practical biological economics management.

  19. The Dynamics of an Impulsive Predator-Prey System with Stage Structure and Holling Type III Functional Response

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    Zhixiang Ju

    2015-01-01

    Full Text Available Based on the biological resource management of natural resources, a stage-structured predator-prey model with Holling type III functional response, birth pulse, and impulsive harvesting at different moments is proposed in this paper. By applying comparison theorem and some analysis techniques, the global attractivity of predator-extinction periodic solution and the permanence of this system are studied. At last, examples and numerical simulations are given to verify the validity of the main results.

  20. Impulse oscillometry: a measure for airway obstruction.

    Science.gov (United States)

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

    2003-03-01

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

  1. Impulse control disorders in psychiatric inpatients.

    Science.gov (United States)

    Müller, Astrid; Rein, Katharina; Kollei, Ines; Jacobi, Andrea; Rotter, Andrea; Schütz, Patricia; Hillemacher, Thomas; de Zwaan, Martina

    2011-08-15

    The aim of this study was to examine the prevalence of impulse control disorders (ICDs) in a European psychiatric inpatient sample. Two hundred thirty four consecutive psychiatric inpatients (62% female) were examined using a module of the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders fourth edition (DSM-IV) that has been developed for ICDs (SCID-ICD). In addition to intermittent explosive disorder, pyromania, kleptomania, pathological gambling, and trichotillomania, the proposed ICDs not otherwise specified were assessed, including compulsive buying, nonparaphilic compulsive sexual behavior, pathological internet use, and pathological skin picking. Based on the SCID-ICD, a lifetime ICD rate of 23.5% and a current ICD rate of 18.8% were found. The most frequent ICDs were pathological skin picking (lifetime 7.3%, current 6.8%), compulsive buying (lifetime 6.8%, current 6.0%), and intermittent explosive disorder (lifetime 5.6%, current 3.4%). In contrast, referring to admission diagnoses taken from patients' charts only 3.8% of the inpatients were diagnosed with any current ICD. Individuals with comorbid ICD were significantly younger and had more admission diagnoses other than ICD. The results suggest high rates of ICDs among psychiatric inpatients that remain to be under-diagnosed in clinical routine. 2011 Elsevier Ireland Ltd. All rights reserved.

  2. [Impulsive-compulsive syndrome in Parkinson's disease].

    Science.gov (United States)

    Nikitina, A V; Fedorova, N V

    2013-01-01

    Dopaminergic replacement therapy (DRT) is effective in treatment the motor symptoms of Parkinson's disease (PD) but can lead to impulse control disorders (ICD) in some patients. ICD include pathological gambling, hypersexuality, compulsive shopping, binge eating, punding, dopamine dysregulation syndrome (DDS). Authors studied the prevalence of ICD and its impact on the quality of life and daily activities of PD patients and their relatives. Among 246 patients studied, 55 patients (23%) (28 men, mean age 66.5±9.4 years) were diagnosed with ICD. DDS was noted in 36.4%, punding in 36.4%, binge eating in 23.6%, hypersexuality in 14.5%, compulsive shopping in 14.5% and pathological gambling in 1.8%. Of these 55 patients, 10 (18.1%) had symptoms of 2 of the ICDs: 3 (5.45%) had 3 of the ICDs and 2 (3.63%) patients had 5 of the ICDs. Quality of life ranged from 25% to 89%. Treatment approaches including the adjustment of doses of levodopa and dopamine receptor agonists in PD patients with ICD are presented.

  3. Adiabatic heating in impulsive solar flares

    Science.gov (United States)

    Maetzler, C.; Bai, T.; Crannell, C. J.; Frost, K. J.

    1978-01-01

    A study is made of adiabatic heating in two impulsive solar flares on the basis of dynamic X-ray spectra in the 28-254 keV range, H-alpha, microwave, and meter-wave radio observations. It is found that the X-ray spectra of the events are like those of thermal bremsstrahlung from single-temperature plasmas in the 10-60 keV range if photospheric albedo is taken into account. The temperature-emission correlation indicates adiabatic compression followed by adiabatic expansion and that the electron distribution remains isotropic. H-alpha data suggest compressive energy transfer. The projected areas and volumes of the flares are estimated assuming that X-ray and microwave emissions are produced in a single thermal plasma. Electron densities of about 10 to the 9th/cu cm are found for homogeneous, spherically symmetric sources. It is noted that the strong self-absorption of hot-plasma gyrosynchrotron radiation reveals low magnetic field strengths.

  4. In Situ Methylene Capping: A General Strategy for Efficient Stereoretentive Catalytic Olefin Metathesis. The Concept, Methodological Implications, and Applications to Synthesis of Biologically Active Compounds.

    Science.gov (United States)

    Xu, Chaofan; Shen, Xiao; Hoveyda, Amir H

    2017-08-09

    In situ methylene capping is introduced as a practical and broadly applicable strategy that can expand the scope of catalyst-controlled stereoselective olefin metathesis considerably. By incorporation of commercially available Z-butene together with robust and readily accessible Ru-based dithiolate catalysts developed in these laboratories, a large variety of transformations can be made to proceed with terminal alkenes, without the need for a priori synthesis of a stereochemically defined disubstituted olefin. Reactions thus proceed with significantly higher efficiency and Z selectivity as compared to when other Ru-, Mo-, or W-based complexes are utilized. Cross-metathesis with olefins that contain a carboxylic acid, an aldehyde, an allylic alcohol, an aryl olefin, an α substituent, or amino acid residues was carried out to generate the desired products in 47-88% yield and 90:10 to >98:2 Z:E selectivity. Transformations were equally efficient and stereoselective with a ∼70:30 Z-:E-butene mixture, which is a byproduct of crude oil cracking. The in situ methylene capping strategy was used with the same Ru catechothiolate complex (no catalyst modification necessary) to perform ring-closing metathesis reactions, generating 14- to 21-membered ring macrocyclic alkenes in 40-70% yield and 96:4-98:2 Z:E selectivity; here too, reactions were more efficient and Z-selective than when the other catalyst classes are employed. The utility of the approach is highlighted by applications to efficient and stereoselective syntheses of several biologically active molecules. This includes a platelet aggregate inhibitor and two members of the prostaglandin family of compounds by catalytic cross-metathesis reactions, and a strained 14-membered ring stapled peptide by means of macrocyclic ring-closing metathesis. The approach presented herein is likely to have a notable effect on broadening the scope of olefin metathesis, as the stability of methylidene complexes is a generally

  5. Impulse Control and Related Disorders in Parkinson's Disease.

    Science.gov (United States)

    Weintraub, Daniel; Claassen, Daniel O

    2017-01-01

    Impulse control disorders (ICDs), such as compulsive gambling, buying, sexual, and eating behaviors, are a serious and increasingly recognized complication in Parkinson's disease (PD), occurring in up to 20% of PD patients over the course of their illness. Related behaviors include punding (stereotyped, repetitive, purposeless behaviors), dopamine dysregulation syndrome (DDS) (compulsive medication overuse), and hobbyism (e.g., compulsive internet use, artistic endeavors, and writing). These disorders have a significant impact on quality of life and function, strain interpersonal relationships, and worsen caregiver burden, and are associated with significant psychiatric comorbidity. ICDs have been most closely related to the use of dopamine agonists (DAs), while DDS is primarily associated with shorter acting, higher potency dopamine replacement therapy (DRT), such as levodopa. However, in preliminary research ICDs have also been reported to occur with monoamine oxidase inhibitor-B and amantadine treatment, and after deep brain stimulation (DBS) surgery. Other risk factors for ICDs may include sex (e.g., male sex for compulsive sexual behavior, and female sex for compulsive buying behavior); younger age overall at PD onset; a pre-PD history of an ICD; personal or family history of substance abuse, bipolar disorder, or gambling problems; and impulsive personality traits. Dysregulation of the mesocorticolimbic dopamine system is thought to be the major neurobiological substrate for ICDs in PD, but there is preliminary evidence for alterations in opiate and serotonin systems too. The primary treatment of ICDs in PD is discontinuation of the offending treatment, but not all patients can tolerate this due to worsening motor symptoms or DA withdrawal syndrome. While psychiatric medications and psychosocial treatments are frequently used to treat ICDs in the general population, there is limited empirical evidence for their use in PD, so it is critical for patients to be

  6. High-intensity drying processes: Impulse drying. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Orloff, D.I.; Phelan, P.M.

    1993-12-01

    Experiments were conducted on a sheet-fed pilot-scale shoe press to compare impulse drying and double-felted pressing. Both an IPST (Institute of Paper Science and Technology) ceramic coated and Beloit Type A press roll were evaluated for lienrboard sheet structures having a wide range of z-direction permeability. Purpose was to find ways of correcting sheet sticking problems observed in previous pilot-scale shoe press experiments. Results showed that impulse drying was superior to double felted pressing in both press dryness and in important paper physical properties. Impulse drying critical temperature was found to depend on specific surface of the heated layer of the sheet, thermal properties of the press roll surface, and choice of felt. Impulse drying of recycled and two-ply liner was demonstrated for both Southern Pile and Douglas fir-containing furnishes.

  7. JOLT: A Highly Directive, Very Intensive, Impulse-Like Radiator

    National Research Council Canada - National Science Library

    Baum, Carl E; Baker, W. L; Prather, W. D; Lehr, J. M; O'Loughlin, J. P; Giri, D. V; Smith, I. D; Altes, Robert; Fockler, James; McLemore, Donald; Abdalla, M. D; Skipper, M. C

    2006-01-01

    Ultra-wideband (UWB) systems that radiate very high-level transient waveforms and exhibit operating bandwidths of over two decades are now in demand for a number of applications Such systems are known to radiate impulse...

  8. 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

  9. Comorbidity of impulse control disorders in pathological gamblers.

    Science.gov (United States)

    Grant, J E; Kim, S W

    2003-09-01

    To investigate the rate of impulse control disorders among pathological gamblers and examine the relationship of comorbidity to gambling severity. Ninety-six adult pathological gamblers [mean age: 46.7 +/- 11.0 years; female: 44 (45.8%)] completed the following: Minnesota Impulsive Disorders Interview, Yale-Brown Obsessive-Compulsive Scale Modified for Pathological Gambling, and Gambling Symptom Assessment Scale. Twenty-two subjects (22.9%) reported a comorbid impulse control disorder, most commonly compulsive sexual behaviour and compulsive buying. Subjects with comorbidity reported significantly greater intensity of urges (t = -2.021; df = 94; P = 0.046) and thoughts (t = -2.147; df = 42.3; P = 0.038) related to gambling, and greater interference (t = -3.913; df = 48.1; P Impulse control disorders appear common among pathological gamblers and are associated with more severe gambling symptoms.

  10. Artificial Heads for High-Level Impulse Sound Measurement

    National Research Council Canada - National Science Library

    Buck, K

    1999-01-01

    If the Insertion Loss (IL) of hearing protectors has to be determined with very high impulse or continuous noise levels, the acoustic insulation of the Artificial Test Fixture has to exceed at least the Insertion Loss (IL...

  11. Amygdala reactivity to fearful faces correlates positively with impulsive aggression

    DEFF Research Database (Denmark)

    da Cunha-Bang, Sofi; Fisher, Patrick M; Hjordt, Liv V

    2018-01-01

    Facial expressions robustly activate the amygdala, a brain structure playing a critical role in aggression. Whereas previous studies suggest that amygdala reactivity is related to various measures of impulsive aggression, we here estimate a composite measure of impulsive aggression and evaluate...... whether it is associated with amygdala reactivity to angry and fearful faces. We estimated amygdala reactivity with functional magnetic resonance imaging in 47 men with varying degree of aggressive traits (19 incarcerated violent offenders and 28 healthy controls). We modeled a composite "impulsive...... aggression" trait construct (LVagg) using a linear structural equation model, with a single latent variable capturing the shared correlation between five self-report measures of trait aggression, anger and impulsivity. We tested for associations between amygdala reactivity and the LVagg, adjusting for age...

  12. Existence and uniqueness of solutions to impulsive fractional differential equations

    Directory of Open Access Journals (Sweden)

    Boualem Attou Slimani

    2009-01-01

    Full Text Available In this article, we establish sufficient conditions for the existence of solutions for a class of initial value problem for impulsive fractional differential equations involving the Caputo fractional derivative.

  13. Multiple solutions for nonresonance impulsive functional differential equations

    Directory of Open Access Journals (Sweden)

    Mouffak Benchohra

    2003-05-01

    Full Text Available In this paper we investigate the existence of multiple solutions for first and second order impulsive functional differential equations with boundary conditions. Our main tool is the Leggett and Williams fixed point theorem.

  14. Statistical Control Paradigm for Aerospace Structures Under Impulsive Disturbances

    National Research Council Canada - National Science Library

    Pham, Khanh D; Robertson, Lawrence M

    2006-01-01

    In this paper, the newly developed statistical control theory is revisited to autonomously control the satellite attitude as well as to provide a means of actively attenuating impulsive disturbances...

  15. 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.

  16. 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.

  17. 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

  18. Numerical Analysis of Impulse Turbine for Isolated Pilot OWC System

    Directory of Open Access Journals (Sweden)

    Zhen Liu

    2013-01-01

    Full Text Available Oscillating water column (OWC is the most widely used wave energy converting technology in the world. The impulse turbine is recently been employed as the radial turbine in OWC facilities to convert bidirectional mechanical air power into electricity power. 3D numerical model for the impulse turbine is established in this paper to investigate its operating performance of the designed impulse turbine for the pilot OWC system which is under the construction on Jeju Island, Republic of Korea. The proper mesh style, turbulence model, and numerical solutions are employed to study the velocity and air pressure distribution especially around the rotor blade. The operating coefficients obtained from the numerical simulation are compared with corresponding experimental data, which demonstrates that the 3D numerical model proposed here can be applied to the research of impulse turbines for OWC system. Effects of tip clearances on flow field distribution characteristics and operating performances are also studied.

  19. 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.

  20. Solitary impulse wave run-up and overland flow

    International Nuclear Information System (INIS)

    Fuchs, H.

    2013-04-01

    Impulse waves are generated by landslides, rockfalls or avalanches impacting a reservoir or natural lake. These long waves generated by the impulse transferred to the water body in combination with the usually short propagation distance within a lake lead to a large damage potential due to wave run-up or dam overtopping. Damages are then caused by (1) direct wave load on structures, (2) driftwood and float impact and (3) their deposits after water retreat. Major historic events occurred at Lituya Bay, Alaska, in 1958, or at the Vaiont Reservoir, Italy, in 1963. Recent events were observed at Lake Chehalis, Canada, or Lake Lucerne, Switzerland, both in 2007, or at the Lower Grindelwald proglacial lake, Switzerland, in 2009. Whereas previous VAW research aimed at the generation phase of landslide-generated impulse waves with a special focus on the wave characteristics, the current research concentrates on the opposite wave-shore interaction. A particular focus is given to the transition point from the shore slope to the horizontal plane where the orbital wave motion is transformed into a shore-parallel flow. As most literature relates only to plain wave run-up on a linearly-inclined plane and the few studies focussing on wave-induced overland flow are case studies considering only a specific bathymetry, currently no general conclusions on wave-induced overland flow can be drawn. The present study therefore intends to fill in this gap by physical modeling. Testing involved a new test-setup including a piston-type wave maker to generate solitary waves, and a smooth impermeable PVC shore of height w = 0.25 m with a connected horizontal overland flow portion. By varying the shore slope tanβ = 1/1.5, 1/2.5 and 1/5.0, the still water depth h = 0.16 - 0.24 m, and the relative wave height H/h = 0.1 -0.7, a wide range of basic parameters was covered. Overland flow depths and front velocities were measured along the shore using Ultrasonic Distance Sensors. Further, flow

  1. A STUDY ON IMPULSIVE CONSUMER BEHAVIOUR AND ITS DETERMINANTS

    OpenAIRE

    Dr. V. Seetha; J. Suganya

    2017-01-01

    Impulse buying is an emerging phenomenon, which has been the focus of the retailers to attract the customers. Impulse behaviour is the outcome of emotional reactions that generate unpredicted urge to buy. Consumer behaviour is nowadays gaining much importance for retailers. Due to expansion of organized retail in India, retailers are trying to understand the behaviour of consumers that what product the consumer seeks for, why they need a particular product, when they need it and how they are...

  2. Relationship between Impulsivity, Social Media Usage and Loneliness

    OpenAIRE

    Mustafa Savci; Ferda Aysan

    2016-01-01

    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 w...

  3. Associations between impulsivity, aggression, and suicide in Chinese college students

    OpenAIRE

    Wang, Lin; He, Chang Zhi; Yu, Yun Miao; Qiu, Xiao Hui; Yang, Xiu Xian; Qiao, Zheng Xue; Sui, Hong; Zhu, Xiong Zhao; Yang, Yan Jie

    2014-01-01

    Background Although there are accumulating data regarding the epidemiology of suicide in China, there are meager data on suicidal ideation and attempts among college students. Interestingly, elevated impulsivity is thought to facilitate the transition from suicidal thoughts to suicidal behavior. Therefore, the objective of this research was to identify the associations between suicide and the personality factors of impulsivity and aggression. Methods This study’s sampling method employed stra...

  4. Comparative Analysis Of Impulse Buying Based On Gender Differences

    OpenAIRE

    Tulungen, Christina Ester

    2013-01-01

    Consumer Buying Decision is one important indicator for the actual impulse buying from customers in the marketplace and is influenced by Emotion, Life Style, Factor Situational and Promotion. This research is purposed to analyze the differences of impulse buying between male and female in Manado. This research used the Independent sample t-test as the method of this research. Population in this research is mainly in this research is people in Manado. The sample of this research is 100 respon...

  5. Development and validation of the Impulse Buying Tendency Scale.

    Science.gov (United States)

    Weun, S; Jones, M A; Beatty, S E

    1998-06-01

    Previous research suggests that individuals vary in their proclivity to purchase products on impulse. This paper presents the results of four studies (Study 1, n = 212; Study 2, n = 152; Study 3, n = 124; and Study 4, n = 550) designed to develop and validate the Impulse Buying Tendency Scale. Data from the first three studies indicate that the scale is unidimensional and internally consistent. The third study provides evidence supporting convergent validity and discriminant validity and the fourth of predictive validity.

  6. 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.

  7. Impulsive Flocking of Dynamical Multiagent Systems with External Disturbances

    Directory of Open Access Journals (Sweden)

    Fujun Han

    2017-01-01

    Full Text Available Flocking motion of multiagent systems is influenced by various external disturbances in complex environment. By applying disturbance observer, flocking of multiagent systems with exogenous disturbances is studied. Based on the robust features of impulsive control, a distributed impulsive control protocol is presented with disturbance observer, and flocking motion of multiagent systems is analyzed. Moreover, a sufficient condition is obtained to ensure the flocking motion of multiagent systems following a leader. Finally, simulation results show the validity of the theoretical conclusion.

  8. Reduced Rank Adaptive Filtering in Impulsive Noise Environments

    KAUST Repository

    Soury, Hamza

    2014-01-06

    An impulsive noise environment is used 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. The reduced rank adaptive filter is presented in this environment by using two methods for rank reduction. The minimized objective function is defined using the Lp norm. The results are presented and the efficiency of each algorithm is discussed.

  9. Dopa therapy and action impulsivity: subthreshold error activation and suppression in Parkinson's disease

    NARCIS (Netherlands)

    Fluchère, F.; Deveaux, M.; Burle, B.; Vidal, F.; van den Wildenberg, W.P.M.; Witjas, T.; Eusebio, A.; Azulay, J.-P.; Hasbroucq, T.

    2015-01-01

    Rationale: Impulsive actions entail (1) capture of the motor system by an action impulse, which is an urge to act and (2) failed suppression of that impulse in order to prevent a response error. Several studies indicate that dopaminergic treatment can induce action impulsivity in patients diagnosed

  10. Global stability of discrete-time recurrent neural networks with impulse effects

    International Nuclear Information System (INIS)

    Zhou, L; Li, C; Wan, J

    2008-01-01

    This paper formulates and studies a class of discrete-time recurrent neural networks with impulse effects. A stability criterion, which characterizes the effects of impulse and stability property of the corresponding impulse-free networks on the stability of the impulsive networks in an aggregate form, is established. Two simplified and numerically tractable criteria are also provided

  11. Subtypes of trait impulsivity differentially correlate with neural responses to food choices

    NARCIS (Netherlands)

    Laan, van der Laura N.; Barendse, Marjolein E.A.; Viergever, M.A.; Smeets, P.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

  12. Impulsivity-focused group intervention to reduce binge eating episodes in patients with binge eating disorder: study protocol of the randomised controlled IMPULS trial.

    Science.gov (United States)

    Schag, Kathrin; Leehr, Elisabeth J; Martus, Peter; Bethge, Wolfgang; Becker, Sandra; Zipfel, Stephan; Giel, Katrin E

    2015-12-18

    The core symptom of binge eating disorder (BED) is recurrent binge eating that is accompanied by a sense of loss of control. BED is frequently associated with obesity, one of the main public health challenges today. Experimental studies deliver evidence that general trait impulsivity and disorder-specific food-related impulsivity constitute risk factors for BED. Cognitive-behavioural treatment (CBT) is deemed to be the most effective intervention concerning BED. We developed a group intervention based on CBT and especially focusing on impulsivity. We hypothesise that such an impulsivity-focused group intervention is able to increase control over impulsive eating behaviour, that is, reduce binge eating episodes, further eating pathology and impulsivity. Body weight might also be influenced in the long term. The present randomised controlled trial investigates the feasibility, acceptance and efficacy of this impulsivity-focused group intervention in patients with BED. We compare 39 patients with BED in the experimental group to 39 patients with BED in the control group at three appointments: before and after the group intervention and in a 3-month follow-up. Patients with BED in the experimental group receive 8 weekly sessions of the impulsivity-focused group intervention with 5-6 patients per group. Patients with BED in the control group receive no group intervention. The primary outcome is the binge eating frequency over the past 4 weeks. Secondary outcomes comprise further eating pathology, general impulsivity and food-related impulsivity assessed by eye tracking methodology, and body weight. Additionally, we assess binge eating and other impulsive behaviour weekly in process analyses during the time period of the group intervention. This study has been approved by the ethics committee of the medical faculty of Eberhard Karls University Tübingen and the University Hospital Tübingen. Data are monitored by the Centre of Clinical Studies, University Hospital T

  13. The role of depression and impulsivity in the psychopathology of bulimia nervosa.

    Science.gov (United States)

    Vaz-Leal, Francisco J; Rodríguez-Santos, Laura; García-Herráiz, M Angustias; Chimpén-López, Carlos A; Rojo-Moreno, Luís; Beato-Fernández, Luís; Ramos-Fuentes, María Isabel

    2014-01-01

    The study aimed to analyze the role of depression and impulsivity in the psychopathology of bulimia nervosa (BN). Seventy female patients with DSM-IV BN, purging subtype, were assessed for eating-related symptoms, body dissatisfaction, affective symptoms, impulsivity, and personality traits. Factor analysis and structural equation modeling methods were used for statistical analysis. BN appeared as a condition which incorporated 5 general dimensions: a) binge eating and compensatory behaviours; b) restrictive eating; c) body dissatisfaction; d) dissocial personality traits; and e) a cluster of features which was called «emotional instability» The 5 obtained dimensions can be grouped into 2 basic factors: body dissatisfaction/eating behaviour and personality traits/psychopathology. The first one contains the clinical items used for the definition of BN as a clinical condition in the DSM-V and the International Classification of Diseases 10, and reflects the morphology and the severity of the eating-related symptoms. The second dimension includes a cluster of symptoms (depressive symptoms, impulsivity, and borderline, self-defeating and dissocial personality traits) which could be regarded as the «psychopathological core» of BN and may be able to condition the course and the prognosis of BN. Copyright © 2013 SEP y SEPB. Published by Elsevier España. All rights reserved.

  14. A nonlinear fractional derivative model of impulse motion for viscoelastic materials

    International Nuclear Information System (INIS)

    Fukunaga, Masataka; Shimizu, Nobuyuki; Nasuno, Hiroshi

    2009-01-01

    Generally, force can be described as a function of displacement in the mechanical model. A nonlinear fractional derivative model with respect to displacement is proposed to describe force for a viscoelastic material based on the measured data of impulsive motion. In the model, the nonlinearity is assumed to appear in the term of the fractional derivative. Three types of nonlinearity in the fractional derivative term are considered as candidates for a suitable model for reproducing the impulsive responses of the measured data. The first one is the case where the nonlinearity appears in the coefficient of the fractional derivative and the second in the fractionally differentiated term. The third one is the case where the nonlinearity appears as the combination of the above two types. The equation of motion and the initial conditions are derived by employing the above nonlinear models for head-on collisions of a rigid body onto the viscoelastic material. The property of the impulsive responses for the system that is derived above is characterized by the time when the acceleration shows its maximum. The symmetry property of increasing and decreasing acceleration response about the time of maximum acceleration is also considered. The second-type nonlinearity in the model seems to be adequate for reproducing the measured response.

  15. Dietary restraint and impulsivity modulate neural responses to food in adolescents with obesity and healthy adolescents.

    Science.gov (United States)

    Hofmann, Johannes; Ardelt-Gattinger, Elisabeth; Paulmichl, Katharina; Weghuber, Daniel; Blechert, Jens

    2015-11-01

    Despite alarming prevalence rates, surprisingly little is known about neural mechanisms underlying eating behavior in juveniles with obesity. To simulate reactivity to modern food environments, event-related potentials (ERP) to appetizing food images (relative to control images) were recorded in adolescents with obesity and healthy adolescents. Thirty-four adolescents with obesity (patients) and 24 matched healthy control adolescents watched and rated standardized food and object images during ERP recording. Personality (impulsivity) and eating styles (trait craving and dietary restraint) were assessed as potential moderators. Food relative to object images triggered larger early (P100) and late (P300) ERPs. More impulsive individuals had considerably larger food-specific P100 amplitudes in both groups. Controls with higher restraint scores showed reduced food-specific P300 amplitudes and subjective palatability ratings whereas patients with higher restraint scores showed increased P300 and palatability ratings. This first ERP study in adolescents with obesity and controls revealed impulsivity as a general risk factor in the current obesogenic environment by increasing food-cue salience. Dietary restraint showed paradoxical effects in patients, making them more vulnerable to visual food-cues. Salutogenic therapeutic approaches that deemphasize strict dietary restraint and foster healthy food choice might reduce such paradoxical effects. © 2015 The Obesity Society.

  16. 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.

  17. Impulsive Personality and Alcohol Use: Bidirectional Relations Over One Year

    Science.gov (United States)

    Kaiser, Alison; Bonsu, Jacqueline A.; Charnigo, Richard J.; Milich, Richard; Lynam, Donald R.

    2016-01-01

    Objective: Impulsive personality traits have been found to be robust predictors of substance use and problems in both cross-sectional and longitudinal research. Studies examining the relations of substance use and impulsive personality over time indicate a bidirectional relation, where substance use is also predictive of increases in later impulsive personality. The present study sought to build on these findings by examining the bidirectional relations among the different impulsive personality traits assessed by the UPPS-P Impulsive Behavior Scale, with an interest in urgency (the tendency to act rashly when experiencing strong affect). Method: Participants were 525 first-year college students (48.0% male, 81.1% White), who completed self-report measures assessing personality traits and a structured interview assessing past and current substance use. Data collection took place at two different time points: the first occurred during the participants’ first year of college, and the second occurred approximately 1 year later. Bidirectional relations were examined using structural equation modeling. Results: Time 1 (T1) positive urgency predicted higher levels of alcohol use at Time 2 (T2), whereas T1 lack of perseverance predicted lower levels of alcohol use at T2. T1 alcohol use predicted higher levels of positive urgency, negative urgency, sensation seeking, and lack of premeditation at T2. Conclusions: Findings provide greater resolution in characterizing the bidirectional relation between impulsive personality traits and substance use. PMID:27172580

  18. 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.

  19. 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.

  20. Personality Disorders, Impulsiveness, and Novelty Seeking in Persons with DSM-IV Pathological Gambling and Their First-Degree Relatives.

    Science.gov (United States)

    Black, Donald W; Coryell, William H; Crowe, Raymond R; Shaw, Martha; McCormick, Brett; Allen, Jeff

    2015-12-01

    This study investigates the presence of personality disorders, impulsiveness, and novelty seeking in probands with DSM-IV pathological gambling (PG), controls, and their respective first-degree relatives using a blind family study methodology. Ninety-three probands with DSM-IV PG, 91 controls, and their 395 first-degree relatives were evaluated for the presence of personality disorder with the Structured Interview for DSM-IV Personality. Impulsiveness was assessed with the Barratt Impulsiveness Scale (BIS). Novelty seeking was evaluated using questions from Cloninger's Temperament and Character Inventory. Results were analyzed using logistic regression by the method of generalized estimating equations to account for within family correlations. PG probands had a significantly higher prevalence of personality disorders than controls (41 vs. 7 %, OR = 9.0, P personality disorder had more severe gambling symptoms; earlier age at PG onset; more suicide attempts; greater psychiatric comorbidity; and a greater family history of psychiatric illness than PG probands without a personality disorder. PG relatives had a significantly higher prevalence of personality disorder than relatives of controls (24 vs. 9%, OR = 3.2, P personality disorder and increases along with rising BIS Non-Planning and Total scale scores. Personality disorders, impulsiveness, and novelty seeking are common in people with PG and their first-degree relatives. The presence of a personality disorder appears to be a marker of PG severity and earlier age of onset. Risk for PG in relatives is associated with the presence of personality disorder and trait impulsiveness. These findings suggest that personality disorder and impulsiveness may contribute to a familial diathesis for PG.

  1. Interaction mechanisms and biological effects of static magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Tenforde, T.S.

    1994-06-01

    Mechanisms through which static magnetic fields interact with living systems are described and illustrated by selected experimental observations. These mechanisms include electrodynamic interactions with moving, ionic charges (blood flow and nerve impulse conduction), magnetomechanical interactions (orientation and translation of molecules structures and magnetic particles), and interactions with electronic spin states in charge transfer reactions (photo-induced electron transfer in photosynthesis). A general summary is also presented of the biological effects of static magnetic fields. There is convincing experimental evidence for magnetoreception mechanisms in several classes of lower organisms, including bacteria and marine organisms. However, in more highly evolved species of animals, there is no evidence that the interactions of static magnetic fields with flux densities up to 2 Tesla (1 Tesla [T] = 10{sup 4} Gauss) produce either behavioral or physiolocical alterations. These results, based on controlled studies with laboratory animals, are consistent with the outcome of recent epidemiological surveys on human populations exposed occupationally to static magnetic fields.

  2. Biological interactions and human health effects of static magnetic fields

    International Nuclear Information System (INIS)

    Tenforde, T.S.

    1994-09-01

    Mechanisms through which static magnetic fields interact with living systems will be described and illustrated by selected experimental observations. These mechanisms include electrodynamic interactions with moving ionic charges (blood flow and nerve impulse conduction), magnetomechanical interactions (orientation and translation of molecular structures and magnetic particles), and interactions with electronic spin states in charge transfer reactions (photo-induced electron transfer in photosynthesis). A general summary will also be presented of the biological effects of static magnetic fields studied in the laboratory and in natural settings. One aspect of magnetic field effects that merits special concern is their influence on implanted medical electronic devices such as cardiac pacemakers. Several extensive studies have demonstrated closure of the reed switch in pacemakers exposed to relatively weak static magnetic fields, thereby causing them to revert to an asynchronous mode of operation that is potentially hazardous. Recommendations for human exposure limits are provided

  3. Impulsivity and AMPA receptors: aniracetam ameliorates impulsive behavior induced by a blockade of AMPA receptors in rats.

    Science.gov (United States)

    Nakamura, K; Kurasawa, M; Shirane, M

    2000-04-17

    The study aimed to ascertain the involvement of central AMPA receptors in impulsive behaviors of aged rats and to examine the effects of aniracetam. Premature response in the two-lever choice reaction task was assessed as an index of impulsivity. Intracerebroventricular injection of 2, 3-dihydroxy-6-nitro-7-sulfamoyl-benzo(F)quinoxaline (NBQX), an AMPA receptor antagonist, dose-dependently (10.1-1009 ng/rat) increased only premature response without altering responding speed and choice accuracy 30 min after the injection. Aniracetam (30 mg/kg p.o.), a positive allosteric modulator of AMPA receptors, or AMPA (55.9 ng/rat, co-injected with NBQX) completely restored the NBQX-induced increase in impulsivity. These results indicate that AMPA receptors are tonically involved in the regulation of impulsivity.

  4. Water waves generated by impulsively moving obstacle

    Science.gov (United States)

    Makarenko, Nikolay; Kostikov, Vasily

    2017-04-01

    There are several mechanisms of tsunami-type wave formation such as piston displacement of the ocean floor due to a submarine earthquake, landslides, etc. We consider simplified mathematical formulation which involves non-stationary Euler equations of infinitely deep ideal fluid with submerged compact wave-maker. We apply semi-analytical method [1] based on the reduction of fully nonlinear water wave problem to the integral-differential system for the wave elevation together with normal and tangential fluid velocities at the free surface. Recently, small-time asymptotic solutions were constructed by this method for submerged piston modeled by thin elliptic cylinder which starts with constant acceleration from rest [2,3]. By that, the leading-order solution terms describe several regimes of non-stationary free surface flow such as formation of inertial fluid layer, splash jets and diverging waves over the obstacle. Now we construct asymptotic solution taking into account higher-order nonlinear terms in the case of submerged circular cylinder. The role of non-linearity in the formation mechanism of surface waves is clarified in comparison with linear approximations. This work was supported by RFBR (grant No 15-01-03942). References [1] Makarenko N.I. Nonlinear interaction of submerged cylinder with free surface, JOMAE Trans. ASME, 2003, 125(1), 75-78. [2] Makarenko N.I., Kostikov V.K. Unsteady motion of an elliptic cylinder under a free surface, J. Appl. Mech. Techn. Phys., 2013, 54(3), 367-376. [3] Makarenko N.I., Kostikov V.K. Non-linear water waves generated by impulsive motion of submerged obstacle, NHESS, 2014, 14(4), 751-756.

  5. Acoustic radiation force impulse of the liver

    Science.gov (United States)

    D’Onofrio, Mirko; Crosara, Stefano; De Robertis, Riccardo; Canestrini, Stefano; Demozzi, Emanuele; Gallotti, Anna; Pozzi Mucelli, Roberto

    2013-01-01

    Acoustic radiation force impulse (ARFI) imaging is a new and promising ultrasound-based diagnostic technique that, evaluating the wave propagation speed, allows the assessment of the tissue stiffness. ARFI is implemented in the ultrasound scanner. By short-duration acoustic radiation forces (less than 1 ms), localized displacements are generated in a selected region of interest not requiring any external compression so reducing the operator dependency. The generated wave scan provides qualitative or quantitative (wave velocity values) responses. Several non-invasive methods for assessing the staging of fibrosis are used, in order to avoid liver biopsy. Liver function tests and transient elastography are non-invasive, sensitive and accurate tools for the assessment of liver fibrosis and for the discrimination between cirrhotic and non-cirrhotic liver. Many published studies analyse ARFI performance and feasibility in studying diffuse liver diseases and compare them to other diagnostic imaging modalities such as conventional ultrasonography and transient elastography. Solid focal liver lesions, both benign and malignant, are common findings during abdominal examinations. The accurate characterization and differential diagnosis are important aims of all the imaging modalities available today. Only few papers describe the application of ARFI technology in the study of solid focal liver lesions, with different results. In the present study, the existing literature, to the best of our knowledge, about ARFI application on diffuse and focal liver pathology has been evaluated and results and statistical analyses have been compared, bringing to the conclusion that ARFI can be used in the study of the liver with similar accuracy as transient elastography in diagnosing significant fibrosis or cirrhosis and has got some advantages in respect to transient elastography since it does not require separate equipment, better displays anatomical structures and measurements can be

  6. Impulse control disorders in Parkinson's disease.

    Science.gov (United States)

    Marques, Ana; Durif, Franck; Fernagut, Pierre-Olivier

    2018-03-07

    Impulse control disorders (ICD) are frequent side effects of dopamine replacement therapy (DRT) used in Parkinson's disease (PD) with devastating consequences on the patients and caregivers. ICD are behavioural addictions including compulsive gambling, shopping, sexual behaviour, and binge eating that are mainly associated with dopamine D2/D3 agonists. Their management is a real clinical challenge due to the lack of therapeutic alternative. Clinical studies have identified demographic and clinical risk factors for ICD such as younger age at disease onset, male gender, prior history of depression or substance abuse, REM sleep behaviour disorders and higher rate of dyskinesia. PD patients with ICD may also have a specific pattern of dopaminergic denervation in the ventral striatum. Specific evaluation tools have now been designed to better evaluate the severity and impact of ICD in PD. Patients with ICD display altered processing of reward and loss, and decisional bias associated with altered activity in cortical and subcortical areas such as the orbitofrontal cortex, amygdala, insula, anterior cingular cortex, and ventral striatum. Preclinical studies have demonstrated that D2/D3 agonists induce impairments in behavioural processes likely relevant to ICD such as risk-taking behaviour, preference for uncertainty, perseverative responding and sustained drive to engage in gambling-like behaviour. Whether interactions between dopamine denervation and DRT significantly contribute to the pathogenesis of ICD remains poorly understood so far, although features unique to PD have been identified in patients with ICD. Large-scale longitudinal studies are needed to better identify subjects with increased risk to develop ICD and develop therapeutic options.

  7. 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...

  8. Relatoría general de relación entre historia, epistemología y enseñanza de la biología

    Directory of Open Access Journals (Sweden)

    Jesús David Perilla

    2015-12-01

    Full Text Available El equipo conformado por Maira Zulied Andrade Otálora, Luz Edith Narváez Chamorro, Glidian Carolina Dussan Petevi, Elkin Aguilar Fonseca, Santiago Guevara Garzón, Jesús David Perilla Nieves y Alix Dayanna Quiroga León, trabajó en la temática “relación entre historia, epistemología y enseñanza de la biología” durante los tres días, del III congreso nacional de investigación en enseñanza de la biología – VIII encuentro nacional de experiencias en enseñanza de la biología y de la educación ambiental.

  9. Relatoría general de relación entre historia, epistemología y enseñanza de la biología

    OpenAIRE

    Jesús David Perilla

    2015-01-01

    El equipo conformado por Maira Zulied Andrade Otálora, Luz Edith Narváez Chamorro, Glidian Carolina Dussan Petevi, Elkin Aguilar Fonseca, Santiago Guevara Garzón, Jesús David Perilla Nieves y Alix Dayanna Quiroga León, trabajó en la temática “relación entre historia, epistemología y enseñanza de la biología” durante los tres días, del III congreso nacional de investigación en enseñanza de la biología – VIII encuentro nacional de experiencias en enseñanza de la biología y de la educación ambie...

  10. Tsunamis - General

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tsunami is a Japanese word meaning harbor wave. It is a water wave or a series of waves generated by an impulsive vertical displacement of the surface of the ocean...

  11. Impulse-control disorders in a college sample: results from the self-administered Minnesota Impulse Disorders Interview (MIDI).

    Science.gov (United States)

    Odlaug, Brian L; Grant, Jon E

    2010-01-01

    This study sought to examine the prevalence rates of and gender differences among impulse-control disorders in a college sample. During the fall semester of 2006, 791 college students from 2 private colleges in the Midwest completed a self-administered, modified version of the Minnesota Impulse Disorders Interview to assess lifetime rates of DSM-IV-TR-diagnosed impulse-control disorders. Participation was voluntary and anonymous. The mean age of the sample was 20.0 +/- 1.25 years, with females comprising 67.9% of the respondents. Of the individuals, 10.4% (n = 82) met criteria for at least 1 lifetime impulse-control disorder. The most common disorders were trichotillomania (3.91%) and compulsive sexual behavior (3.66%). Kleptomania was the least common (0.38%). Males were significantly more likely to screen positive for pathological gambling (P = .003) and compulsive sexual behavior (P = .002). Females were more likely to have compulsive buying (P = .033). Impulse-control disorders appear to be common among college students. The high rates indicate that these disorders may be incipient during late adolescence and early adulthood and should be addressed prior to onset of clinical versions of the impulse-control disorder.

  12. 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.

  13. 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.

  14. 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

  15. Apathy and impulsivity in frontotemporal lobar degeneration syndromes.

    Science.gov (United States)

    Lansdall, Claire J; Coyle-Gilchrist, Ian T S; Jones, P Simon; Vázquez Rodríguez, Patricia; Wilcox, Alicia; Wehmann, Eileen; Dick, Katrina M; Robbins, Trevor W; Rowe, James B

    2017-06-01

    Apathy and impulsivity are common and disabling consequences of frontotemporal lobar degeneration. They cause substantial carer distress, but their aetiology remains elusive. There are critical limitations to previous studies in this area including (i) the assessment of either apathy or impulsivity alone, despite their frequent co-existence; (ii) the assessment of behavioural changes within single diagnostic groups; and (iii) the use of limited sets of tasks or questions that relate to just one aspect of these multifactorial constructs. We proposed an alternative, dimensional approach that spans behavioural and language variants of frontotemporal dementia, progressive supranuclear palsy and corticobasal syndrome. This accommodates the commonalities of apathy and impulsivity across disorders and reveals their cognitive and anatomical bases. The ability to measure the components of apathy and impulsivity and their associated neural correlates across diagnostic groups would provide better novel targets for pharmacological manipulations, and facilitate new treatment strategies and strengthen translational models. We therefore sought to determine the neurocognitive components of apathy and impulsivity in frontotemporal lobar degeneration syndromes. The frequency and characteristics of apathy and impulsivity were determined by neuropsychological and behavioural assessments in 149 patients and 50 controls from the PIck's disease and Progressive supranuclear palsy Prevalence and INcidence study (PiPPIN). We derived dimensions of apathy and impulsivity using principal component analysis and employed these in volumetric analyses of grey and white matter in a subset of 70 patients (progressive supranuclear palsy, n = 22; corticobasal syndrome, n = 13; behavioural variant, n = 14; primary progressive aphasias, n = 21) and 27 control subjects. Apathy and impulsivity were present across diagnostic groups, despite being criteria for behavioural variant frontotemporal dementia

  16. Promoting an active form of learning out-of-class via answering online "study questions" leads to higher than expected exam scores in General Biology.

    Science.gov (United States)

    Gibson, Susan I

    2015-01-01

    A rising need for workers in science, technology, engineering and mathematics (STEM) fields has fueled interest in improving teaching within STEM disciplines. Numerous studies have demonstrated the benefits of active learning approaches on student learning outcomes. However, many of these studies have been conducted in experimental, rather than real-life class, settings. In addition, most of these studies have focused on in-class active learning exercises. This study tested the effects of answering questions outside of class on exam performance for General Biology students at the University of Minnesota. An online database of 1,020 multiple-choice questions covering material from the first half of the course was generated. Students in seven course sections (with an average of ∼265 students per section) were given unlimited access to the online study questions. These students made extensive use of the online questions, with students answering an average of 1,323 questions covering material from the half of the semester for which the questions were available. After students answered a set of questions, they were shown the correct answers for those questions. More specific feedback describing how to arrive at the correct answer was provided for the 73% of the questions for which the correct answers were not deemed to be self-explanatory. The extent to which access to the online study questions improved student learning outcomes was assessed by comparing the performance on exam questions of students in the seven course sections with access to the online study questions with the performance of students in course sections without access to the online study questions. Student performance was analyzed for a total of 89 different exams questions that were not included in the study questions, but that covered the same material covered by the study questions. Each of these 89 questions was used on one to five exams given to students in course sections that had access to the

  17. Promoting an active form of learning out-of-class via answering online “study questions” leads to higher than expected exam scores in General Biology

    Directory of Open Access Journals (Sweden)

    Susan I. Gibson

    2015-10-01

    Full Text Available A rising need for workers in science, technology, engineering and mathematics (STEM fields has fueled interest in improving teaching within STEM disciplines. Numerous studies have demonstrated the benefits of active learning approaches on student learning outcomes. However, many of these studies have been conducted in experimental, rather than real-life class, settings. In addition, most of these studies have focused on in-class active learning exercises. This study tested the effects of answering questions outside of class on exam performance for General Biology students at the University of Minnesota. An online database of 1,020 multiple-choice questions covering material from the first half of the course was generated. Students in seven course sections (with an average of ∼265 students per section were given unlimited access to the online study questions. These students made extensive use of the online questions, with students answering an average of 1,323 questions covering material from the half of the semester for which the questions were available. After students answered a set of questions, they were shown the correct answers for those questions. More specific feedback describing how to arrive at the correct answer was provided for the 73% of the questions for which the correct answers were not deemed to be self-explanatory. The extent to which access to the online study questions improved student learning outcomes was assessed by comparing the performance on exam questions of students in the seven course sections with access to the online study questions with the performance of students in course sections without access to the online study questions. Student performance was analyzed for a total of 89 different exams questions that were not included in the study questions, but that covered the same material covered by the study questions. Each of these 89 questions was used on one to five exams given to students in course sections that

  18. An On-Campus Botanical Tour to Promote Student Satisfaction and Learning in a University Level Biodiversity or General Biology Course

    Science.gov (United States)

    Ratnayaka, Harish H.

    2017-01-01

    Outdoor, hands-on and experiential learning, as opposed to instruction-based learning in classroom, increases student satisfaction and motivation leading to a deeper understanding of the subject. However, the use of outdoor exercises in undergraduate biology courses is declining due to a variety of constraints. Thus, the goal of this paper is to…

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

    Science.gov (United States)

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

    2017-05-01

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

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

    Science.gov (United States)

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

    2011-05-01

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

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

    Science.gov (United States)

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

    2011-01-01

    Impulse control disorders are common in Parkinson's; disease, occurring in 13.6% of patients. Using a pharmacological manipulation and a novel risk taking task while performing functional magnetic resonance imaging, we investigated the relationship between dopamine agonists and risk taking in patients with Parkinson's; disease with and without impulse control disorders. During functional magnetic resonance imaging, subjects chose between two choices of equal expected value: a ‘Sure’ choice and a ‘Gamble’ choice of moderate risk. To commence each trial, in the ‘Gain’ condition, individuals started at $0 and in the ‘Loss’ condition individuals started at −$50 below the ‘Sure’ amount. The difference between the maximum and minimum outcomes from each gamble (i.e. range) was used as an index of risk (‘Gamble Risk’). Sixteen healthy volunteers were behaviourally tested. Fourteen impulse control disorder (problem gambling or compulsive shopping) and 14 matched Parkinson's; disease controls were tested ON and OFF dopamine agonists. Patients with impulse control disorder made more risky choices in the ‘Gain’ relative to the ‘Loss’ condition along with decreased orbitofrontal cortex and anterior cingulate activity, with the opposite observed in Parkinson's; disease controls. In patients with impulse control disorder, dopamine agonists were associated with enhanced sensitivity to risk along with decreased ventral striatal activity again with the opposite in Parkinson's; disease controls. Patients with impulse control disorder appear to have a bias towards risky choices independent of the effect of loss aversion. Dopamine agonists enhance sensitivity to risk in patients with impulse control disorder possibly by impairing risk evaluation in the striatum. Our results provide a potential explanation of why dopamine agonists may lead to an unconscious bias towards risk in susceptible individuals. PMID:21596771

  2. Acute vestibular syndrome: clinical head impulse test versus video head impulse test.

    Science.gov (United States)

    Celebisoy, Nese

    2018-03-05

    HINTS battery involving head impulse test (HIT), nystagmus, and test of skew is the critical bedside examination to differentiate acute unilateral peripheral vestibulopathy from posterior circulation stroke (PCS) in acute vestibular syndrome (AVS). The highest sensitivity component of the battery has been reported to be the horizontal HIT, whereas skew deviation is defined as the most specific but non-sensitive sign for PCS. Video-oculography-based HIT (vHIT) may have an additional power in making the differentiation. If vHIT is undertaken, then both gain and gain asymmetry should be taken into account as anterior inferior cerebellar artery (AICA) strokes are at risk of being misclassified based on VOR gain alone. Further refinement in video technology, increased operator proficiency and incorporation with saccade analysis will increase the sensitivity of vHIT for PCS diagnosis. For the time being, clinical examination seems adequate in frontline diagnostic evaluation of AVS.

  3. Second-order periodic problem with Phi-Laplacian and impulses

    Czech Academy of Sciences Publication Activity Database

    Rachůnková, I.; Tvrdý, Milan

    2005-01-01

    Roč. 63, 5-7/Sp.Is/ (2005), e257-e266 ISSN 0362-546X. [Invited Talks from the Fourth World Congress of Nonlinear Analysts (WCNA 2004). Orlando , 30.7.2004-7.8.2004] R&D Projects: GA ČR(CZ) GA201/04/1077 Institutional research plan: CEZ:AV0Z1019905 Keywords : Laplacian * impulses * lower/upper functions Subject RIV: BA - General Mathematics Impact factor: 0.519, year: 2005 www.elsevier.com/locate/na

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

    Czech Academy of Sciences Publication Activity Database

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

    2017-01-01

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

  5. Exponential stability of delayed and impulsive cellular neural networks with partially Lipschitz continuous activation functions.

    Science.gov (United States)

    Song, Xueli; Xin, Xing; Huang, Wenpo

    2012-05-01

    The paper discusses exponential stability of distributed delayed and impulsive cellular neural networks with partially Lipschitz continuous activation functions. By relative nonlinear measure method, some novel criteria are obtained for the uniqueness and exponential stability of the equilibrium point. Our method abandons usual assumptions on global Lipschitz continuity, boundedness and monotonicity of activation functions. Our results are generalization and improvement of some existing ones. Finally, two examples and their simulations are presented to illustrate the correctness of our analysis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Linear ordinary differential equations with constant coefficients. Revisiting the impulsive response method using factorization

    Science.gov (United States)

    Camporesi, Roberto

    2011-06-01

    We present an approach to the impulsive response method for solving linear constant-coefficient ordinary differential equations based on the factorization of the differential operator. The approach is elementary, we only assume a basic knowledge of calculus and linear algebra. In particular, we avoid the use of distribution theory, as well as of the other more advanced approaches: Laplace transform, linear systems, the general theory of linear equations with variable coefficients and the variation of constants method. The approach presented here can be used in a first course on differential equations for science and engineering majors.

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

    Czech Academy of Sciences Publication Activity Database

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

    2017-01-01

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

  8. The Impact of Visual Merchandising on Consumer Impulse Buying Behavior

    Directory of Open Access Journals (Sweden)

    Khurram L. Bhatti

    2014-05-01

    Full Text Available In present Post-Modern Era, the competitive situation in the business is characterized by a cut throat competition, which subsequently results in companies and retailers to pay almost anything for undifferentiated merchandising. This merchandising tool is being used by today’s retailer to distinguish him from other competitors, to be prominent in the market and become a source of attraction for the customers. A few researchers contribute in this field by exploring the reasons which causes the customers impulsive buying, but still there is more to be determined. Purpose of this study is to identify the relation between the consumer impulsive buying and visual merchandising on buying behavior of customers. This study was based on primary data in the form of a questioner. A total of 350 questioners were floated in different consumer outlets (super marts and self-service stores of Rawalpindi, Pakistan out of which 344 questioners were completed and received. Defined four hypotheses were window display, forum display, floor merchandising and shop brand name. These hypotheses were tested for regression analysis by using Statistical Packages for Social Sciences (SPSS software. It was found that window display, forum display, floor merchandising and shop brand name (independent variables are significantly associated to consumer impulse buying behavior (dependent variable. Hence, forum display is negatively related to consumer impulse buying and window display; however, floor merchandising and shop brand name are positively related to consumer impulse buying behavior.

  9. Dysfunctional inhibitory control and impulsivity in Internet addiction.

    Science.gov (United States)

    Choi, Jung-Seok; Park, Su Mi; Roh, Myoung-Sun; Lee, Jun-Young; Park, Chan-Bin; Hwang, Jae Yeon; Gwak, Ah Reum; Jung, Hee Yeon

    2014-02-28

    The purpose of this study was to explore a psychological profile of Internet addiction (IA) considering impulsivity as a key personality trait and as a key component of neuropsychological functioning. Twenty three subjects with IA (Young's Internet Addiction Test scores=70 or more) and 24 sex-, age-, and intelligence-matched healthy controls were enrolled. Participants filled out a questionnaire about trait impulsivity, the Trait Characteristic Inventory, depression, and anxiety. Next, we administered traditional neuropsychological tests including the Stroop et al. and computerized neuropsychological tests using the Cambridge Neuropsychological Test Automated Battery. The IA group exhibited more trait impulsivity than the healthy control group. They also scored higher for novelty seeking and harm avoidance. The IA group performed more poorly than the healthy control group in a computerized stop signal test, a test for inhibitory function and impulsivity; no group differences appeared for other neuropsychological tests. The IA group also scored higher for depression and anxiety, and lower for self-directedness and cooperativeness. In conclusion, individuals with IA exhibited impulsivity as a core personality trait and in their neuropsychological functioning. © 2013 Published by Elsevier Ireland Ltd.

  10. Suppression of radiating harmonics Electro-Impulse Deicing (EIDI) systems

    Science.gov (United States)

    Zieve, Peter; Ng, James; Fiedberg, Robert

    1991-10-01

    The electromagnetic compatibility (EMC) of two different configurations of electromagnetic deicing systems is discussed. Both Electro-Impulse Deicing (EIDI) and Eddy Current Repulsion Deicing Strip (EDS) are investigated. With EIDI, rigid coils are mounted behind the wing; while with EDS, the impulse coils are built thin and flexible with printed circuit board technology. An important consideration in the certification of electromagnetic impulse deicing systems is electromagnetic compatibility (EMC). When the capacitor bank discharges, a large current pulse travels down a transmission line to the coil. The coil is one source of radiation. Another source is the cabling and connections to the coil. In work conducted for the FAA in 1988, it was found that excessive electromagnetic emissions resulted from the operation of a Low Voltage Electro-Impulse Deicer (LVEID) in conjunction with a composite wing. The goal of this project was to investigate and develop techniques for controlling emissions without the benefit of shielding. In this study it was determined that both EIDI and EDS could be brought within the RTCA/DO-160B standards through proper shielding and termination of the pulse power cable. An alternative topology of EDS with the impulse coil on the wing exterior surface did not meet the standard.

  11. Modulating presence and impulsiveness by external stimulation of the brain

    Directory of Open Access Journals (Sweden)

    Baumgartner Thomas

    2008-08-01

    Full Text Available Abstract Background "The feeling of being there" is one possible way to describe the phenomenon of feeling present in a virtual environment and to act as if this environment is real. One brain area, which is hypothesized to be critically involved in modulating this feeling (also called presence is the dorso-lateral prefrontal cortex (dlPFC, an area also associated with the control of impulsive behavior. Methods In our experiment we applied transcranial direct current stimulation (tDCS to the right dlPFC in order to modulate the experience of presence while watching a virtual roller coaster ride. During the ride we also registered electro-dermal activity. Subjects also performed a test measuring impulsiveness and answered a questionnaire about their presence feeling while they were exposed to the virtual roller coaster scenario. Results Application of cathodal tDCS to the right dlPFC while subjects were exposed to a virtual roller coaster scenario modulates the electrodermal response to the virtual reality stimulus. In addition, measures reflecting impulsiveness were also modulated by application of cathodal tDCS to the right dlPFC. Conclusion Modulating the activation with the right dlPFC results in substantial changes in responses of the vegetative nervous system and changed impulsiveness. The effects can be explained by theories discussing the top-down influence of the right dlPFC on the "impulsive system".

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

    Directory of Open Access Journals (Sweden)

    Jeakwan Kim

    2016-01-01

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

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

    Science.gov (United States)

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

    2018-04-01

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

  14. Impulsivity and apathy in Parkinson’s disease

    Science.gov (United States)

    Sinha, Nihal; Manohar, Sanjay; Husain, Masud

    2013-01-01

    Impulse control disorders (ICDs) and apathy are recognized as two important neuropsychiatric syndromes associated with Parkinson’s disease (PD), but as yet we understand very little about the cognitive mechanisms underlying them. Here, we review emerging findings, from both human and animal studies, that suggest that impulsivity and apathy are opposite extremes of a dopamine-dependent spectrum of motivated decision making. We first argue that there is strong support for a hypodopaminergic state in PD patients with apathy, as well as for an association between dopamine therapy and development of ICDs. However, there is little evidence for a clear dose-response relationship, and great heterogeneity of findings. We argue that dopaminergic state on its own is an insufficient explanation, and suggest instead that there is now substantial evidence that both apathy and impulsivity are in fact multi-dimensional syndromes, with separate, dissociable mechanisms underlying their ‘surface’ manifestations. Some of these mechanisms might be dopamine-dependent. According to this view, individuals diagnosed as impulsive or apathetic may have very different mechanisms underlying their clinical states. We propose that impulsivity and apathy can arise from dissociable deficits in option generation, option selection, action initiation or inhibition and learning. Review of the behavioural and neurobiological evidence leads us to a new conceptual framework that might help understand the variety of functional deficits seen in PD. PMID:23621377

  15. Frontotemporal correlates of impulsivity and machine learning in retired professional athletes with a history of multiple concussions.

    Science.gov (United States)

    Goswami, R; Dufort, P; Tartaglia, M C; Green, R E; Crawley, A; Tator, C H; Wennberg, R; Mikulis, D J; Keightley, M; Davis, Karen D

    2016-05-01

    The frontotemporal cortical network is associated with behaviours such as impulsivity and aggression. The health of the uncinate fasciculus (UF) that connects the orbitofrontal cortex (OFC) with the anterior temporal lobe (ATL) may be a crucial determinant of behavioural regulation. Behavioural changes can emerge after repeated concussion and thus we used MRI to examine the UF and connected gray matter as it relates to impulsivity and aggression in retired professional football players who had sustained multiple concussions. Behaviourally, athletes had faster reaction times and an increased error rate on a go/no-go task, and increased aggression and mania compared to controls. MRI revealed that the athletes had (1) cortical thinning of the ATL, (2) negative correlations of OFC thickness with aggression and task errors, indicative of impulsivity, (3) negative correlations of UF axial diffusivity with error rates and aggression, and (4) elevated resting-state functional connectivity between the ATL and OFC. Using machine learning, we found that UF diffusion imaging differentiates athletes from healthy controls with significant classifiers based on UF mean and radial diffusivity showing 79-84 % sensitivity and specificity, and 0.8 areas under the ROC curves. The spatial pattern of classifier weights revealed hot spots at the orbitofrontal and temporal ends of the UF. These data implicate the UF system in the pathological outcomes of repeated concussion as they relate to impulsive behaviour. Furthermore, a support vector machine has potential utility in the general assessment and diagnosis of brain abnormalities following concussion.

  16. New hybrid technique for impulsive noise suppression in OFDM systems

    International Nuclear Information System (INIS)

    Mirza, A.; Zeb, A.; Sheikh, S.A.

    2017-01-01

    In this paper, a new hybrid technique employing RS (Reed Solomon) coding and adaptive filter for impulsive noise suppression in OFDM (Orthogonal Frequency Division Multiplexing) systems is presented. Adaptive filter creates a more accurate estimate of the original OFDM signal after impulsive noise cancellation. The residual impulsive noise is further mitigated by RS decoder in the second stage of proposed technique. Three members of adaptive filters family i.e. NLMS (Normalized Least Mean Square) algorithm, RLS (Recursive Least Square) algorithm and Bhagyashri algorithm are tested with RS decoder in the proposed hybrid technique. Furthermore, the results in terms of steady state MSE (Mean Square Error) reduction, BER (Bit Error Rate) improvement and SNR (Signal to Noise Ratio) enhancement confirm the effectiveness of the proposed dual faceted technique when compared with the recently reported techniques in literature. (author)

  17. Spatial impulse response of a rectangular double curved transducer

    DEFF Research Database (Denmark)

    Bæk, David; Jensen, Jørgen Arendt; Willatzen, Morten

    2012-01-01

    Calculation of the pressure field from transducers having both a convex and a concave surface geometry is a complicated assignment that often is accomplished by subdividing the transducer surface into smaller flat elements of which the spatial impulse response is known. This method is often seen...... applied to curved transducers because an analytical solution is un-known. In this work a semi-analytical algorithm for the exact solution to a first order in diffraction effect of the spatial impulse response of rectangular shaped double curved transducers is presented. The algorithm and an approximation...... approximations ranging from 0.03 % to 0.8 % relative to a numerical solution for the spatial impulse response. It is shown that the presented algorithm gives consistent results with Field II for a linear flat, a linear focused, and a convex non-focused element. Best solution was found to be 0.01 % with a three...

  18. Simulation Analysis of DC and Switching Impulse Superposition Circuit

    Science.gov (United States)

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

    2018-03-01

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

  19. Impulse-induced localized control of chaos in starlike networks

    Science.gov (United States)

    Chacón, Ricardo; Palmero, Faustino; Cuevas-Maraver, Jesús

    2016-06-01

    Locally decreasing the impulse transmitted by periodic pulses is shown to be a reliable method of taming chaos in starlike networks of dissipative nonlinear oscillators, leading to both synchronous periodic states and equilibria (oscillation death). Specifically, the paradigmatic model of damped kicked rotators is studied in which it is assumed that when the rotators are driven synchronously, i.e., all driving pulses transmit the same impulse, the networks display chaotic dynamics. It is found that the taming effect of decreasing the impulse transmitted by the pulses acting on particular nodes strongly depends on their number and degree of connectivity. A theoretical analysis is given explaining the basic physical mechanism as well as the main features of the chaos-control scenario.

  20. Astrocytes promote myelination in response to electrical impulses.

    Science.gov (United States)

    Ishibashi, Tomoko; Dakin, Kelly A; Stevens, Beth; Lee, Philip R; Kozlov, Serguei V; Stewart, Colin L; Fields, R Douglas

    2006-03-16

    Myelin, the insulating layers of membrane wrapped around axons by oligodendrocytes, is essential for normal impulse conduction. It forms during late stages of fetal development but continues into early adult life. Myelination correlates with cognitive development and can be regulated by impulse activity through unknown molecular mechanisms. Astrocytes do not form myelin, but these nonneuronal cells can promote myelination in ways that are not understood. Here, we identify a link between myelination, astrocytes, and electrical impulse activity in axons that is mediated by the cytokine leukemia inhibitory factor (LIF). These findings show that LIF is released by astrocytes in response to ATP liberated from axons firing action potentials, and LIF promotes myelination by mature oligodendrocytes. This activity-dependent mechanism promoting myelination could regulate myelination according to functional activity or environmental experience and may offer new approaches to treating demyelinating diseases.

  1. Nonlinear resonant interaction between acoustic impulse and electrons in superconductors

    International Nuclear Information System (INIS)

    Bratus, E.N.; Shumeiko, V.S.

    1985-01-01

    The problem of inelastic electron interaction in a perfectly pure superconductor with a longitudinal sound impulse is considered. It is shown that the problem reduces to the equivalent one of elastic scattering by the static potential, and the sound absorption is expressed in terms of the reflection coefficient of this scattering. The classical and quantum properties of the scattering are studied and the phase region in which new excitations are created is indicated. A formula is derived that expresses the density matrix of the excitations created in terms of the exact scattering matrix of an impulse. The quasiclassical creation of excitations by a smooth-shaped impulse is investigated with regard to both overbarrier and underbarrier processes

  2. THz impulse radar for biomedical sensing: nonlinear system behavior

    Science.gov (United States)

    Brown, E. R.; Sung, Shijun; Grundfest, W. S.; Taylor, Z. D.

    2014-03-01

    The THz impulse radar is an "RF-inspired" sensor system that has performed remarkably well since its initial development nearly six years ago. It was developed for ex vivo skin-burn imaging, and has since shown great promise in the sensitive detection of hydration levels in soft tissues of several types, such as in vivo corneal and burn samples. An intriguing aspect of the impulse radar is its hybrid architecture which combines the high-peak-power of photoconductive switches with the high-responsivity and -bandwidth (RF and video) of Schottky-diode rectifiers. The result is a very sensitive sensor system in which the post-detection signal-to-noise ratio depends super-linearly on average signal power up to a point where the diode is "turned on" in the forward direction, and then behaves quasi-linearly beyond that point. This paper reports the first nonlinear systems analysis done on the impulse radar using MATLAB.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

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

    Science.gov (United States)

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

    2016-07-01

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

  5. Adolescent Exposure to Methylphenidate Increases Impulsive Choice Later in Life

    Directory of Open Access Journals (Sweden)

    Zarish Abbas

    2017-10-01

    Full Text Available Background: The psychostimulant methylphenidate (MPH is known to temporarily reduce impulsive choice and promote self-control. What is not sufficiently understood is how repeated treatment with MPH affects impulsive choice in the long run, and whether any such effect is contingent on exposure at certain developmental stages.Methods: Using an animal model for impulsive choice, we examined first whether giving MPH through early adolescence alters delay discounting, an operational measure of impulsive choice, later in adulthood. We then tested whether equivalent long-term effects are observed if exposure to the drug occurred during adulthood. Starting on postnatal day 25 or postnatal day 60, male rats received one of a range of doses of MPH for 10 consecutive days. Twenty-six days later, all rats were trained to choose between a lever that produced a small immediate reward and a lever that produced a large reward after a range of delays.Results: Rats showed a long-term decrease in the selection of the delayed larger reward when treated with moderate doses of MPH during early adolescence, but not when treated with the lower or higher doses. In contrast, no differences were observed in the selection of the delayed larger reward in animals that were treated with various doses of MPH during adulthood.Conclusions: Our findings suggest effects of MPH on impulsive choice that are contingent on dosage and on the developmental period of exposure. When administered during adolescence, moderate doses of MPH increase impulsive choice long after the end of treatment, whereas these same doses administered during adulthood were without effect

  6. Impulsive-reflective cognitive style, metacognition, and emotion in adolescence.

    Science.gov (United States)

    Palladino, P; Poli, P; Masi, G; Marcheschi, M

    1997-02-01

    The study investigated the relationship between reflective or impulsive cognitive style, metacognitive functioning, and depression in young adolescents. Metacognitive functioning (metacognitive knowledge about reading and memory, monitoring of text comprehension) and self-reported depressive feelings were analyzed in a group of subjects who showed a Reflective or Impulsive cognitive style. The sample consisted of 56 junior high-school students (Grades 6, 7, and 8) selected from a larger original group of 61 subjects. We excluded from the original group those with an IQ below 75 on both the Verbal and Performance subscales on the short form of the WISC-R, those reported by teachers to have a severe learning disability, and those that did not complete the test battery due to long absences from school. The reflective-impulsive cognitive style was identified with the Matching Familiar Figures Test-20. Using the median of the distribution for both Latency (17 sec. per item) and Errors (9 errors) on this task, the sample was divided in four partially overlapping subgroups: 16 with Impulsive cognitive style (Latency below the median, Errors above the median), 13 with Reflective cognitive style (Latency above the median, Error below the median), 4 fast and accurate (both scores below the median), and 11 slow and inaccurate (both scores above the median). Twelve subjects with one or both scores coinciding with the critical value (median) were excluded. Analysis showed that subjects with Impulsive cognitive style had significantly lower scores than those with Reflective cognitive style in monitoring of comprehension of text. No differences were found on monitoring by eighth graders, irrespective of cognitive style. No differences between the two groups were found in metacognitive knowledge. Subjects with Impulsive cognitive style had significantly higher scores than subjects with Reflective cognitive style on a self-rating scale for childhood depression, the Children

  7. [Biological function of trophology and the pathogenesis of metabolic syndrome--syndrome of overeating. Phylogenetically theory of general pathology, role of leptin and adiponectin].

    Science.gov (United States)

    Titov, V N

    2014-01-01

    Metabolic syndrome (overeating) is a phylogenetically-determined succession of symptoms with the same pathogenesis. There is only one etiological factor, namely, increased consumption of physiologically optimal food. Enterocytes and omental fat cells are a phylogenetically early paracrine-regulated cell community that realizes the biological reactions of exo- and endotrophy. Visceral obesity, high levels of unesterified fatty acids (FA), formation of a pool of micellar FA in the blood, integration of these FA into endothelial cell plasma membrane and enlargement of adipocytes are the causes of hydrodynamic pressure elevation. Toll-like receptors recognize the associates between albumin and greater than physiological number of FA as "foreing" and initiate inflammatory response. "Endoplasm stress" develops in lipid-overloaded cells, protein synthesis (folding) in them is impaired and apoptosis-like cell death is activated. Visceral fat is a phylogenetically early depot of FA to fulfill the biological function of homeostasis, trophology, endoecology and adaptation; it is regulated at the level of paracrine communities and is anatomically limited. The subcutaneous fat depot fulfills the phylogenetically late function of locomotion; the depot size is not anatomically limited. Visceral fat cells have no receptors for phylogenetically late insulin (INS); specialized adipocyes bearing INS and GLUT4 receptors are cells that form the subcutaneous depot. These cells are regulated by phylogenetically late humoral factors at the entire body level. Leptin is an initiator of humoral hypothalamic regulation of in vivo number of ontogenetically programmed number of visceral INS-insensitive fat cells. It prevents "endoplasm stress" and apoptosis, being designed to regulate the amount of consumed food. Leptin initiates storage of FA from visceral pool into subcutaneous pool. Adiponectin is a phylogenetically late humoral hypothalamic regulatory factor that controls optimal number of

  8. Motor impulsivity differentiates between psychiatric inpatients with multiple versus single lifetime suicide attempts.

    Science.gov (United States)

    Colborn, Victoria A; LaCroix, Jessica M; Neely, Laura L; Tucker, Jennifer; Perera, Kanchana; Daruwala, Samantha E; Grammer, Geoffrey; Weaver, Jennifer; Ghahramanlou-Holloway, Marjan

    2017-07-01

    A history of multiple suicide attempts conveys greater risk for suicide than a single attempt. Impulsivity may partially explain the association between multiple attempts and increased risk. We examined trait impulsivity, ability to engage in goal-directed behaviors, and impulse control among psychiatrically hospitalized United States military personnel and their dependents. Individuals with a history of multiple versus single attempts had significantly higher motor impulsivity, indicating spur of the moment action. Providers are encouraged to directly assess and treat motor impulsivity among suicidal individuals. Further research should explore whether motor impulsivity is a mechanism of change in psychosocial suicide prevention interventions. Copyright © 2017. Published by Elsevier B.V.

  9. Subthalamic nucleus stimulation, dopaminergic treatment and impulsivity in Parkinson's disease.

    Science.gov (United States)

    Fluchère, Frédérique; Burle, Borís; Vidal, Franck; van den Wildenberg, Wery; Witjas, Tatiana; Eusebio, Alexandre; Azulay, Jean-Philippe; Hasbroucq, Thierry

    2018-02-16

    Deep brain stimulation of the subthalamic nucleus (STN DBS) is known to increase response speed and lower response accuracy in Parkinson's disease (PD) patients. It has been proposed that this speed-accuracy tradeoff is due to enhanced sensitivity of the motor system to sensory information. An alternative possibility is that this effect is due to weakened suppressive processes. The two alternative interpretations can be tested by analyzing the electromyographic activity (EMG) of the response agonists when the patients perform conflict reaction time tasks. In those tasks, fast subthreshold muscle impulses often occur in the agonist of the incorrect response. These impulses are partial errors that are suppressed before being behaviourally committed. Here we analyzed the EMG of the response agonists recorded while sixteen PD patients performed a Simon task that elicits prepotent response tendencies so as to decipher (i) whether STN DBS affects the expression and/or suppression of subthreshold muscle impulses that are critical for action control and (ii) the interaction between dopaminergic treatment and STN DBS. The patients were tested On and Off STN DBS and On and Off dopaminergic medication in a full factorial design. STN DBS not only impaired the proficiency to suppress subliminal action impulses (p = 0.01) but also favoured the muscular expression of fast incorrect impulses (p<0.001). Dopaminergic treatment only affected the action impulses suppression (p = 0.02) and did not change the effect of STN DBS on impulsive action control. Contrary to a recent proposal, STN DBS impaired rather than improved action control by weakening erroneous impulse suppression, whether the patients were On or Off their usual medication. These findings are discussed in light of a recent proposal (Servant M, White C, Montagnini A, Burle B, 2015) that reconciles partial errors with accumulation-to-bound models of decision making. Our results suggest that medication specifically lowers

  10. Impulsivity traits and addiction-related behaviors in youth

    DEFF Research Database (Denmark)

    Rømer Thomsen, Kristine; Callesen, Mette Buhl; Hesse, Morten

    2018-01-01

    Background and aims Impulsivity is a risk factor for addictive behaviors. The UPPS-P impulsivity model has been associated with substance addiction and gambling disorder, but its role in other non-substance addiction-related behaviors is less understood. We sought to examine associations between...... problems to achieve a broad distribution of involvement in addiction-related behaviors. Participants completed the UPPS-P Questionnaire and standardized questionnaires assessing problematic use of substances (alcohol, cannabis, and other drugs) and non-substances (Internet gaming, pornography, and food...

  11. Reduced rank adaptive filtering in impulsive noise environments

    KAUST Repository

    Soury, Hamza

    2014-11-01

    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. The reduced rank adaptive filter is presented in this environment by using two methods for rank reduction, while the minimized objective function is defined using the Lp norm. The results are presented and the efficiency of each method is discussed. © 2014 IEEE.

  12. A comparative study of integrated pest management strategies based on impulsive control.

    Science.gov (United States)

    Páez Chávez, Joseph; Jungmann, Dirk; Siegmund, Stefan

    2018-12-01

    The paper presents a comprehensive numerical study of mathematical models used to describe complex biological systems in the framework of integrated pest management. Our study considers two specific ecosystems that describe the application of control mechanisms based on pesticides and natural enemies, implemented in an impulsive and periodic manner, due to which the considered models belong to the class of impulsive differential equations. The present work proposes a numerical approach to study such type of models in detail, via the application of path-following (continuation) techniques for nonsmooth dynamical systems, via the novel continuation platform COCO (Dankowicz and Schilder). In this way, a detailed study focusing on the influence of selected system parameters on the effectiveness of the pest control scheme is carried out for both ecological scenarios. Furthermore, a comparative study is presented, with special emphasis on the mechanisms upon which a pest outbreak can occur in the considered ecosystems. Our study reveals that such outbreaks are determined by the presence of a branching point found during the continuation analysis. The numerical investigation concludes with an in-depth study of the state-dependent pesticide mortality considered in one of the ecological scenarios.

  13. Aggression-impulsivity, mental pain, and communication difficulties in medically serious and medically non-serious suicide attempters.

    Science.gov (United States)

    Gvion, Yari; Horresh, Netta; Levi-Belz, Yossi; Fischel, Tsvi; Treves, Ilan; Weiser, Mark; David, Haim Shem; Stein-Reizer, Orit; Apter, Alan

    2014-01-01

    Unbearable mental pain, depression, and hopelessness have been associated with suicidal behavior in general, while difficulties with social communication and loneliness have been associated with highly lethal suicide attempts in particular. The literature also links aggression and impulsivity with suicidal behavior but raises questions about their influence on the lethality and outcome of the suicide attempt. To evaluate the relative effects of aggression and impulsivity on the lethality of suicide attempts we hypothesized that impulsivity and aggression differentiate between suicide attempters and non-attempters and between medically serious and medically non-serious suicide attempters. The study group included 196 participants divided into four groups: 43 medically serious suicide attempters; 49 medically non-serious suicide attempters, 47 psychiatric patients who had never attempted suicide; and 57 healthy control subjects. Data on sociodemographic parameters, clinical history, and details of the suicide attempts were collected. Participants completed a battery of instruments for assessment of aggression-impulsivity, mental pain, and communication difficulties. The medically serious and medically non-serious suicide attempters scored significantly higher than both control groups on mental pain, depression, and hopelessness (pcommunication variables with suicide lethality yielded significant correlations for self-disclosure, schizoid tendency, and loneliness. The interaction between mental pain and schizoid traits explained some of the variance in suicide lethality, over and above the contribution of each component alone. Aggression-impulsivity and mental pain are risk factors for suicide attempts. However, only difficulties in communication differentiate medically serious from medically non-serious suicide attempters. The combination of unbearable mental pain and difficulties in communication has a magnifying effect on the risk of lethal suicidal behavior.

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

    Science.gov (United States)

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

    2018-02-07

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

  15. High-intensity drying processes: Impulse drying. Progress report on furnish evaluations for impulse drying commercialization demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Orloff, D.I.; Phelan, P.M.; Rudman, I.

    1995-02-01

    Laboratory and pilot scale experiments were performed to identify potential furnishes and operating parameters for upcoming high-speed pilot scale trials and commercial demonstration of impulse drying of heavy weight grades of paper. Results indicate that hydrodynamic specific surface is highly dependent on sheet formation and prehandling. Mill refined pulp and machine paper were comparable to laboratory prepared samples in regards to permeability and impulse drying. Process variables such as platen surface coating, felt type, felt moisture, and presteaming temperature profiles were investigated. Substantial improvements in sheet smoothness were achieved.

  16. An On-Campus Botanical Tour to Promote Student Satisfaction and Learning in a University Level Biodiversity or General Biology Course

    Directory of Open Access Journals (Sweden)

    Harish H. Ratnayaka

    2017-01-01

    Full Text Available Outdoor, hands-on and experiential learning, as opposed to instruction-based learning in classroom, increases student satisfaction and motivation leading to a deeper understanding of the subject. However, the use of outdoor exercises in undergraduate biology courses is declining due to a variety of constraints. Thus, the goal of this paper is to describe a convenient, no-cost and flexible exercise using an on-campus botanical tour for strengthening specific knowledge areas of major plant groups. Its assessment on conduct and coverage, and student-perceived and actual knowledge gain is also described. Data presented derived from traditional biology undergraduates in sophomore year over nine fall and three spring semesters. Conduct and coverage was assessed using a summative survey including open-ended questions administered to 198 students. A pre- and post-exercise survey addressing 10 knowledge categories was administered to 139 students to evaluate student-perceived knowledge gain. Quiz grades from the on-campus tour exercise were compared with average quiz grades from two in-class plant-related labs of 234 students to assess actual knowledge gain. Each student reporting on the conduct and coverage indicated either one or a combination of outcomes of the exercise as positive engagement, experiential learning, or of interest. Student-perceived improvement was evident in all ten knowledge categories with a greater improvement in categories learned anew during exercise compared to subjects reviewed. Quiz grades from the exercise were >11% greater than quiz grades from the two in-class plant-related labs. Active learning with interest likely contributed to the increased perceived and actual knowledge gains. Suggestions for adoption of the exercise in different settings are presented based on both student comments and instructor’s experience.

  17. What is Impulse Buying? An analytical network processing framework for prioritizing factors affecting impulse buying

    Directory of Open Access Journals (Sweden)

    Javad Siahkali Moradi

    2012-08-01

    Full Text Available One of the most important issues affecting profitability is to determine the impact of different factors influencing purchasing activities. In this paper, we perform an extensive literature survey to detect different purchasing factors influencing customers' behavior. The factors are categorized in three different groups and they are ranked using analytical network process. The results of our survey indicate that three factors of personal, product and situational play important roles in purchasing impulse. The personal item includes different factors where demographic characteristic factors receive the highest ranking (35% followed by other factors are feelings, excitement and fun, self identify, education and novelty. There are also three sub-factors associated with demographic characteristics including gender, age and race and the weights are 0.46748, 0.42668 and 0.10584, respectively, which means gender is the most important factor followed by age and race. Finally, the other factor is associated with situational factors' group, which includes presence of others, culture, design of store, time available, local market condition, sales staff and self service with the relative importance of 0.04296, 0.08733, 0.12130, 0.22217, 0.05643, 0.15346 and 0.31635, respectively.

  18. Marine biology

    International Nuclear Information System (INIS)

    Thurman, H.V.; Webber, H.H.

    1984-01-01

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index

  19. Aggression and aspects of impulsivity in wild-type rats

    NARCIS (Netherlands)

    Coppens, Caroline M.; de Boer, Sietse F.; Buwalda, Bauke; Koolhaas, Jaap M.

    2014-01-01

    Aggression is closely related to impulsive behavior both in humans and in animals. To avoid potential negative consequences, aggressive behavior is kept in control by strong inhibitory mechanisms. Failure of these inhibitory mechanisms results in violent behavior. In the present experiments, we

  20. 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.

  1. Impulse Force Balance for Ultrashort Duration Hypersonic Test Facilities

    Directory of Open Access Journals (Sweden)

    P. Singh

    2015-01-01

    Full Text Available This paper presents the measurement of side force, pitching, and yawing moments on a model, using an accelerometer force balance, in a short duration hypersonic shock tunnel. The test model is a blunt-nosed, flapped delta wing, mounted on a support sting through a force balance. The flexible rubber bushes constituting the balance allow the model to float freely on the sting during the test. The accelerometers were located in the model to record accelerations in the directions of interest. The model was tested in shock tunnel at Mach 8 at different angles of incidence with the freestream. Dynamic calibration of the test assembly was carried out for the acquisition of impulse response functions for the above components of force and moments, using an impulse hammer. The convolution technique was applied to derive the impulse response functions. The accelerometer outputs from the model in the hypersonic freestream were processed using the respective impulse response functions to derive the unknown aerodynamic force and moments. The newly adopted convolution technique has been found very effective for data reduction from accelerometer force balances developed for shock tunnel applications.

  2. Impulsivity influences betting under stress in laboratory gambling

    NARCIS (Netherlands)

    Canale, Natale; Rubaltelli, Enrico; Vieno, Alessio; Pittarello, Andrea; Billieux, Joël

    2017-01-01

    Although recent research suggests that acute stress influences subsequent decision-making under ambiguity, less is known about the role of personality variables in this relationship. This study tested whether impulsivity traits and acute stress differentially influence the way in which a prior

  3. Experimental Characterization of Extremely Broadband THz Impulse Radio Communication Systems

    DEFF Research Database (Denmark)

    Yu, Xianbin; Vidal, Borja; Galili, Michael

    2015-01-01

    We experimentally characterize a ultrabroadband terahertz (THz) impulse radio system with up to 10 GHz repetition rate. THz generation and radiation are realized in an antenna-integrated uni-traveling-carrier photodiode (UTC-PD), and THz reception is implemented based on photoconductive sampling...

  4. 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.

  5. Impulsivity, gambling cognitions, and the gambler's fallacy in university students.

    Science.gov (United States)

    Marmurek, Harvey H C; Switzer, Jessica; D'Alvise, Joshua

    2015-03-01

    The present study explored the associations among impulsivity, gambling cognitions, and behavioral adherence to the gambler's fallacy in university students (N = 142). Both impulsivity and gambling cognitions were significant predictors of non-problem and problem gambler categories as defined the Problem Gambling Severity Index. A logistic regression analysis showed that the independent contribution of cognition was statistically significant but that the contribution of impulsivity was not. A behavioral measure of gambling was obtained by asking participants to play an online game of roulette for a maximum of 15 min. Only outside bets were permitted whereby participants were to bet on the color of the winning number. Adherence to the gambler's fallacy was indexed by the likelihood of betting on an alternation in the color of the winning number as the number of consecutive outcomes of the other color increased. Gambling cognitions and gender, but not impulsivity, were associated with adherence to the gambler's fallacy. Tracing the sources of specific influences on gambling behavior may benefit from a framework that distinguishes between "hot" (emotional) and "cold" (non-emotional) mechanisms that promote problem gambling.

  6. 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

  7. Model Predictive Control based on Finite Impulse Response Models

    DEFF Research Database (Denmark)

    Prasath, Guru; Jørgensen, John Bagterp

    2008-01-01

    We develop a regularized l2 finite impulse response (FIR) predictive controller with input and input-rate constraints. Feedback is based on a simple constant output disturbance filter. The performance of the predictive controller in the face of plant-model mismatch is investigated by simulations ...

  8. Impulse Based Scheme for Crystal-less ULP Radios

    NARCIS (Netherlands)

    Drago, S.; Sebastiano, Fabio; Breems, Lucien J.; Leenaerts, Domine M.W.; Makinwa, Kofi A.A.; Nauta, Bram

    2009-01-01

    Abstract—This study describes a method of implementing a fully integrated ultra-low-power (ULP) radio for wireless sensor networks (WSNs). This is achieved using an ad hoc modulation scheme (impulse radio), with a bandwidth of 17.7 MHz in the 2.4 GHz—ISM band and a specific medium access control

  9. Planar elliptically shaped dipole antenna for UWB Impulse Radio

    NARCIS (Netherlands)

    Vorobyov, A.V.

    2008-01-01

    The goal of this thesis was to develop design concepts of the UWB antenna with improved characteristics for impulse radio applications. To reach this goal a number of theoretical and experimental investigations were carried out. The major result of the thesis is a number of novel concepts for UWB

  10. 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 ...

  11. Role of local presence in online impulse buying

    NARCIS (Netherlands)

    Vonkeman, Charlotte; Verhagen, Tibert; van Dolen, Willemijn

    2017-01-01

    This paper proposes and tests a model to explain how consumers’ perceptions of product presentation technologies may affect online impulse buying. Data from a laboratory experiment (N = 212), which were analyzed using a structural equation modeling approach, showed that vividness and interactivity

  12. 'IMPULSES' Okechukwu Nwafor The willingness of artists to ...

    African Journals Online (AJOL)

    Ike Odimegwu

    The willingness of artists to challenge the meanings of art provides the platform of power and dynamism upon which art thrives today. In this little piece I address Krydz Ikwuemesi's Impulses by showing that his art is premised on an alternative historicity of both modernism and traditionalism and also possesses certain.

  13. 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

  14. Effects of mood state on impulsivity in pathological buying.

    Science.gov (United States)

    Nicolai, Jennifer; Darancó, Stefaniá; Moshagen, Morten

    2016-10-30

    Pathological buying is characterized by irrepressible buying behaviour and its negative consequences. A possible mechanism contributing to its development and maintenance is that buying episodes act as a maladaptive strategy to cope with negative emotions. Accordingly, pathological buying has been repeatedly associated with impulsivity, in particular with the tendency to experience strong reactions under negative affect. Relying on an experimental mood induction procedure, the present study tested in a sample of 100 individuals (a) whether individuals with pathological buying symptoms respond more impulsively in the Go/No-Go Task (as a measure of the behavioural inhibition aspect of impulsivity) and (b) whether this association is more pronounced in a negative mood. While controlling for comorbidities, the results show that pathological buying is associated with faster responses and a larger number of commission errors. Moreover, a significant interaction indicated that the association between pathological buying and performance the Go/No-Go Task was stronger in the negative mood condition. The present study thus shows that pathological buying is associated with deficits in the behavioural inhibition component of impulsivity. These deficits are most pronounced when mood is negative; in turn, this provides an explanation for the occurrence of excessive buying episodes following negative affect. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Cavitation and bubble dynamics: the Kelvin impulse and its applications.

    Science.gov (United States)

    Blake, John R; Leppinen, David M; Wang, Qianxi

    2015-10-06

    Cavitation and bubble dynamics have a wide range of practical applications in a range of disciplines, including hydraulic, mechanical and naval engineering, oil exploration, clinical medicine and sonochemistry. However, this paper focuses on how a fundamental concept, the Kelvin impulse, can provide practical insights into engineering and industrial design problems. The pathway is provided through physical insight, idealized experiments and enhancing the accuracy and interpretation of the computation. In 1966, Benjamin and Ellis made a number of important statements relating to the use of the Kelvin impulse in cavitation and bubble dynamics, one of these being 'One should always reason in terms of the Kelvin impulse, not in terms of the fluid momentum…'. We revisit part of this paper, developing the Kelvin impulse from first principles, using it, not only as a check on advanced computations (for which it was first used!), but also to provide greater physical insights into cavitation bubble dynamics near boundaries (rigid, potential free surface, two-fluid interface, flexible surface and axisymmetric stagnation point flow) and to provide predictions on different types of bubble collapse behaviour, later compared against experiments. The paper concludes with two recent studies involving (i) the direction of the jet formation in a cavitation bubble close to a rigid boundary in the presence of high-intensity ultrasound propagated parallel to the surface and (ii) the study of a 'paradigm bubble model' for the collapse of a translating spherical bubble, sometimes leading to a constant velocity high-speed jet, known as the Longuet-Higgins jet.

  16. Unsteady Viscous Flow Past an Impulsively Started Porous Vertical ...

    African Journals Online (AJOL)

    This paper presents a new numerical approach for solving unsteady two dimensional boundary layer flow past an infinite vertical porous surface with the flow generated by Newtonian heating and impulsive motion in the presence of viscous dissipation and temperature dependent viscosity. The viscosity of the fluid under ...

  17. The relationship between impulsivity and craving in alcohol dependent patients

    NARCIS (Netherlands)

    Joos, L.; Goudriaan, A. E.; Schmaal, L.; de Witte, N. A. J.; van den Brink, W.; Sabbe, B. G. C.; Dom, G.

    2013-01-01

    Impulsivity and craving are both associated with higher relapse rates and a worse prognosis in patients with a substance use disorder, but the relationship between these two phenomena has been largely ignored in the field of alcohol use disorders. The primary aim of this study was to investigate the

  18. The relationship between impulsivity and craving in alcohol dependent patients

    NARCIS (Netherlands)

    Joos, L.; Goudriaan, A.E.; Schmaal, L.; De Witte, N.A.J.; van den Brink, W.; Sabbe, B.G.C.; Dom, G.

    2013-01-01

    Rationale: Impulsivity and craving are both associated with higher relapse rates and a worse prognosis in patients with a substance use disorder, but the relationship between these two phenomena has been largely ignored in the field of alcohol use disorders. Objectives: The primary aim of this study

  19. Existence of solutions to singular fractional differential systems with impulses

    Directory of Open Access Journals (Sweden)

    Xingyuan Liu

    2012-11-01

    Full Text Available By constructing a weighted Banach space and a completely continuous operator, we establish the existence of solutions for singular fractional differential systems with impulses. Our results are proved using the Leray-Schauder nonlinear alternative, and are illustrated with examples.

  20. Mindfulness, emotional dysregulation, impulsivity, and stress proneness among hypersexual patients

    OpenAIRE

    Reid, RC; Bramen, JE; Anderson, A; Cohen, MS

    2014-01-01

    Objective: The current study explores relationships between mindfulness, emotional regulation, impulsivity, and stress proneness in a sample of participants recruited in a Diagnostic and Statistical Manual of Mental Disorder Fifth Edition Field Trial for Hypersexual Disorder and healthy controls to assess whether mindfulness attenuates symptoms of hypersexuality. Method: Hierarchal regression analysis was used to assess whether significant relationships between mindfulness and hypersexuality ...