Impulse Profile Research Articles

Pornography use, problematic pornography use, impulsivity, and sensation seeking: a meta-analysis.

While some individuals engage in recreational pornography use (PU), others may develop an uncontrolled pattern of use termed problematic pornography use (PPU). PPU is characterized by persistent, excessive, or compulsive engagement with pornographic content, despite distress and adverse consequences. Impulsivity has been identified as a factor associated with PU and PPU. The present meta-analysis aims to sum up the existing research on the relationship between impulsivity and PU/PPU and investigate whether age and gender could moderate this relationship. A keyword-based systematic literature search was performed to identify articles that assessed PU/PPU and impulsivity. Extracted correlations were converted into Fisher's Z. Meta-regression analyses were also performed. Publication bias was assessed by Egger's regression intercept. Outcomes included general impulsivity and its dimensions (ie, negative and positive urgency, lack of premeditation and perseverance), sensation seeking, PU, and PPU. Meta-analytic results of the random effects model showed a significant positive correlation between impulsivity as total score and PU (n = 1504, k = 4, Fisher's Z = 0.21, P < .001) and PPU (n = 20174, k = 13, Fisher's Z = 0.17, P < .001). Significant and positive associations were also found between sensation seeking and PU (n = 11707, k = 11, Fisher's Z = 0.14, P < .001) and PPU (n = 20152, k = 9, Fisher's Z = 0.06, P < .001). Concerning the relationship between PPU and different dimensions of impulsivity, almost all the associations were significant and positive. The dimension of positive urgency and attentional and nonplanning impulsivity showed the strongest association. Age (β = -0.50, Q = 101.26, df = 11, P < .001) and gender (female = 1; β = -0.46, Q = 102.54, df = 12, P < .001) moderated the association between general impulsivity and PPU. No risk of publication bias emerged. Prevention programs of PPU should focus on impulsivity and certain key dimensions (eg, positive urgency, attentional and nonplanning impulsivity) and be tailored to individual impulsivity profiles, considering age and gender differences. The primary strength of this meta-analysis is that it considers various conceptualizations of impulsivity. However, the results are to be interpreted with caution since >30% of relevant studies had to be excluded because information could not be gathered from the study authors. These results suggest that general impulsivity is linked to PU and PPU and that specific dimensions of impulsivity (ie, attentional impulsivity, nonplanning impulsivity, and positive urgency) can serve as risk factors for PPU.

Distinct impulsivity profiles in subtypes of violence among community-dwelling patients with severe mental disorders: a longitudinal study

BackgroundAlthough only a few patients with severe mental disorders (SMD) can commit violent behaviour in the community, violent behaviour aggravates the stigma towards patients with SMD. Understanding the subtypes of violent behaviour may be beneficial for preventing violent behaviour among patients with SMD, but it has rarely been studied.MethodsThis longitudinal study investigated 1914 patients with SMD in the community at baseline, and the follow-up period ranged from February 2021 to August 2021. The Barratt Impulsiveness Scale Version-11, the Buss-Perry Aggression Questionnaire, the Impulsive/Premeditated Aggression Scale, the Personality Diagnostic Questionnaire and the MacArthur Community Violence Instrument were used at baseline. The Modified Overt Aggression Scale was used to assess the occurrence of violent behaviour (outcome) during the follow-up period. Cox regression models were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs). Latent class analysis was used to characterise the subtypes of patients with SMD who engaged in violent behaviour at follow-up.ResultsWe found that 7.2% of patients with SMD presented violent behaviour within six months in the community. Younger age (OR = 0.98, 95% CI = 0.96-1.00, p = 0.016) and no economic source (OR = 1.60, 95% CI = 1.10–2.33, p = 0.014) were risk factors for violent behaviour. Patients with SMD who engaged in violent behaviour could be classified into three subtypes: one class characterised by a history of violence and impulsivity, another class characterised by high levels of aggression and motor impulsivity, and the last class characterised by median cognitive impulsivity.ConclusionsSocio-demographic factors were risk factors for violent behaviour among patients with SMD, which could eliminate the discrimination toward this group. Impulsivity played a vital role in identifying the three subtypes of patients with SMD who engaged in violent behaviour. These findings may be helpful for the development of a personalised violence risk management plan for patients with SMD who commit violent behaviour in the community.

Blast Wave Simulator for Laminated Glass Panels Experimental Evaluation

The study of blast loads on structures is important due to the potential of significant consequences in various scenarios. From terrorist attacks to industrial accidents, comprehending how structures respond to blast waves is critical for ensuring public safety and designing resilient structures. Studying these effects typically involves two main methods: free-field tests with live explosives and shock tube tests. Although shock tube testing offers certain advantages, both approaches are costly and demand significant space. This research aims to develop a cost-effective and straightforward technique for generating stress waves that closely replicate the progressive and spatial characteristics of free-field or shock tube blast waves. This method was designed to evaluate the dynamic response of laminated glass panels. The stress wave was generated by impacting a piston on the fluid inside a tube, which was connected to a fluid chamber. This setup produced impulsive loads that were distributed across a laminated glass test panel. Moreover, it was used to simulate the shock near filed explosions for a certain part of a structure. High-speed cameras were utilized to analyze the initial velocity of flying glass fragments. The apparatus successfully produced various blast waves and impulsive profiles for different drop weight heights. The initial velocities of randomly selected flying shards ranged from 3 m/s to 4 m/s.

The mediating effect of dispositional mindfulness on the association between UPPS-P impulsivity traits and gaming disorder among Asia-Pacific young adults

BackgroundLittle evidence is available to verify the mediating effect of dispositional mindfulness on the association between gaming disorder and various impulsivity traits. The present study aimed to investigate the mediating effect of dispositional mindfulness on the association between the five UPPS-P impulsivity traits and the risk of gaming disorder among young adults.MethodsIt was an inter-regional cross-sectional study using online survey in Australia, Japan, The Philippines and China. Impulsivity measured by the UPPS-P Impulsive Behavior Scale–Short version; dispositional mindfulness measured by the Mindfulness Attention Awareness Scale; and the risk of gaming disorder measured by the Internet Gaming Disorder Scale were collected in the focal regions. Structural equation modeling was performed by SPSS AMOS version 26 to verify the study hypotheses. Bootstrapped 95% confidence interval was reported. Statistical significance was indicated by the p-value below 0.05.ResultsAmong the 1,134 returned questionnaires, about 40% of them aged 18–20 years and 21–23 years, respectively. 53.8% were male. 40.7% had been playing digital and video games for over 10 years. The prevalence of gaming disorder was 4.32%. The model fitness indices reflected that the constructed model had an acceptable model fit (χ2(118) = 558.994, p < 0.001; χ2/df = 4.737; CFI = 0.924; TLI = 0.890; GFI = 0.948; RMSEA = 0.058; SRMR = 0.0487). Dispositional mindfulness fully mediated the effect of positive urgency and negative urgency on the risk of gaming disorder. The effect of lack of premeditation on the risk of gaming disorder was partially mediated by dispositional mindfulness. However, dispositional mindfulness did not mediate the effect of sensation seeking on the risk of gaming disorder.ConclusionsThe varied associations between dispositional mindfulness and the five impulsivity traits hints that improving some impulsive traits may increase dispositional mindfulness and so lower the risk of gaming disorder. Despite further studies are needed to verify the present findings, it sheds light on the need to apply interventions on gamers based on their impulsivity profile. Interventions targeting at emotion regulation and self-control such as mindfulness-based interventions seem to be effective to help gamers with dominant features of urgency and lack of premeditation only. Other interventions shall be considered for gamers with high sensation seeking tendency to enhance the effectiveness of gaming disorder prevention.

Impulsivity profiles across five harmonized longitudinal childhood preventive interventions and associations with adult outcomes.

This study aimed to parse between-person heterogeneity in growth of impulsivity across childhood and adolescence among participants enrolled in five childhood preventive intervention trials targeting conduct problems. In addition, we aimed to test profile membership in relation to adult psychopathologies. Measurement items representing impulsive behavior across grades 2, 4, 5, 7, 8, and 10, and aggression, substance use, suicidal ideation/attempts, and anxiety/depression in adulthood were integrated from the five trials (N = 4,975). We applied latent class growth analysis to this sample, as well as samples separated into nonintervention (n = 2,492) and intervention (n = 2,483) participants. Across all samples, profiles were characterized by high, moderate, low, and low-increasing impulsive levels. Regarding adult outcomes, in all samples, the high, moderate, and low profiles endorsed greater levels of aggression compared to the low-increasing profile. There were nuanced differences across samples and profiles on suicidal ideation/attempts and anxiety/depression. Across samples, there were no significant differences between profiles on substance use. Overall, our study helps to inform understanding of the developmental course and prognosis of impulsivity, as well as adding to collaborative efforts linking data across multiple studies to better inform understanding of developmental processes.

Impulsivity profile analysis and it’s potential role in the differential diagnostics of adult Attention Deficit Hyperactivity Disorder and Borderline Personality Disorder

IntroductionImpulsivity is a complex construct, having at least three factors: 1) impulsivity as a personality trait, 2) ismpulsive action – waiting and stopping impulsivity and 3) choice impulsivity. Impulsive symptoms are present in Attention Deficit Hyperactivity Disorder (ADHD) and Borderline Personality Disorder (BPD) as well, eventhough impulsvity profile significantly differs.ObjectivesOur aim is to describe the impulsivity profile in adult ADHD (aADHD) and BPD in comparison with the control group, and describe a characteristic pattern, which associates with these disorders.Methods aADHD (n=100) and BPD Patients (n=63) were included, based on DSM-5 diagnostic criteria. Healthy control subjects (n=100) were screened using the Derogatis Symptom Checklist (SCL-90). Comorbid psychiatric disorders were assessed by structured clinical interviews and those who have both aADHD and BPD were excluded from the study. Participants were further investigated with online questionnaires: e.g. Barratt Impulsiveness Scale (BIS-11) Difficulties in Emotion Regulation Scale (DERS) and neuropsychological tests, like CANTAB Rapid Visual Processing, Stop Signal Task, and the Rogers’ decision-making test.Results Based ont the BIS-11 results, significantly higher attentional impulsivity was present in adult ADHD compared to BPD (p&lt;.001) and healthy controls (p&lt;.001). Emotional regulation difficulties, measured by DERS were significantly higher in BPD (p&lt;.001) than aADHD, but the impulse control problems were more pronounced in the aADHD group, compared to BPD (p&lt;.001). Using CANTAB neuropsychological test battery, strategy formulation difficulties (p=0.16) and stopping impulsivity (p&lt;.001) were only present in aADHD compared to HC. BPD patients did not differ significantly from the control group in strategy formulation and in Stop Signal Reaction Time, a measure of stopping impulsivity. The significantly higher level of total false alarms, reflecting on waiting impulsivity were present both in aADHD and BPD.ConclusionsAccording to our results these two disorders have different impulsivity profile characteristics, which can be useful in differentiating these two disorders, and in buiding treatment plans. Stopping impulsivity, measured by SST was found in aADHD, but not in BPD. In BPD impulsive behavior is more likely attached to emotional dysregulation, a trait rooted in childhood traumatization.This study was supported by the National Research, Development and Innovation Office grant K 129195 and K 135437.Disclosure of InterestNone Declared

Comparative Analysis of Impulsivity Profiles in Children and Young Patients with Anorexia Nervosa Restrictive Type, Anorexia Nervosa Binge Eating/Purging Type, Bulimia Nervosa, and Binge Eating Disorder

IntroductionHigh levels of impulsivity are associated with individuals suffering from eating disorders. Impulsivity is a complex and multidimensional construct, with elevated impulsivity traits posing a specific risk in relation to binge-eating and purging disorders when compared to restrictive types eating disorders.ObjectivesOur aim was to identify the difference in impulsivity profile in children and young patients with eating disorders, including anorexia nervosa restrictive type (ANR), anorexia nervosa binge eating/purging type (ANP), bulimia nervosa (BN) and binge-eating disorder (BED).MethodsPatients aged 21 years or younger, meeting the DSM-V criteria for ANR (n=125), ANP (n=48), BN (n=38), and BED (n=37) were enrolled in the study. The participants had an average age of 16.3 ± 2.15 years. Data collection involved the administration of the UPPS Impulsiveness Scale (UPPS). Bilateral Student’s t-tests were conducted to evaluate potential statistically significant differences among the diagnostic groups.ResultsOur results indicated statistically significant differences in total impulsivity between patients diagnosed with ANR and each of the other eating disorders including ANP (T-Stud -2,19 p &lt; .02), BN (T-Stud -2.17p &lt; .03), and BED (T-Stud -2,68 p &lt; .008) (Figure 1). However, no significant differences were observed among the other eating disorder groups. Nevertheless, it is noteworthy that heightened impulsivity traits, particularly sensation-seeking tendencies, were a common feature among all subtypes of eating disorders, regardless of their specific diagnostic category. Impulsivity and age also exhibited a statistically significant negative correlation (r = -0.13, p = .03) (Figure 2).Image:Image 2:ConclusionsImpulsivity in individuals with restrictive and binge/purgative eating disorders differ significantly, with lower levels of impulsivity in ANR (Figure 1), except for sensation-seeking tendencies. This suggests that both groups may share a similar inclination for seeking intense emotions or engaging in emotionally arousing behaviors. As individuals age from adolescence to young adulthood, there is a tendency for impulsivity levels to decrease (Figure 2).Disclosure of InterestNone Declared

Effects of material strain rate, impulse profile on damage evolution of steel plates subjected to repeated pressures

This study deals with a numerical estimation of the damage evolution of steel plates used in ships and offshore structures due to repeated slamming-induced pressures. The numerical analysis model was developed using finite element ABAQUS software. Subsequently, the validated model was extended to investigate the effects of material strain rate and impulse profile on the damage evolution of plates having actual scantlings. Different strain rate models were used, and several types of impulse profiles that can be used to simplify the actual slamming pressure were adopted. In the simulation, the material strain hardening was defined for the plate model, and the impulsive pressures were applied uniformly over the plate while it was fully clamped at four edges. The results showed that a large effect of the material strain rate on the damage evolution of the plate was noticed for only several first impacts, while the effect of the impulse profile is remarkable for whole impact events. The occurrence of the pseudo-shakedown phenomenon of steel plates was examined accordingly. The results can be useful for the design of ships and offshore structures against slamming.

On the role of unsteadiness in impulsive-flow-driven shear instabilities: precursors of fragmentation

Shear instabilities at the interface of two fluids, such as classical Kelvin–Helmholtz instability (KHI), is the precursor of interface destabilization, leading to fluid fragmentation critical in a wide range of applications. While many insights into such instabilities are derived for steady background forcing flow, unsteady impulse flows are ubiquitous in environmental and physiological processes. Yet, little is understood on how unsteadiness shapes the initial interface amplification necessary for the onset of its topological change enabling subsequent fragmentation. In this combined theoretical, numerical and experimental study, we focus on an air-on-liquid interface exposed to canonical unsteady shear flow profiles. Evolution of the perturbed interface is formulated theoretically as an impulse-driven initial value problem using both linearized potential flow and nonlinear boundary integral methods. We show that the unsteady airflow forcing can amplify the interface's inherent gravity–capillary wave, up to wave-breaking transition, even if the configuration is classically KH stable. For impulses much shorter than the gravity–capillary wave period, it is the cumulative action, akin to total energy, that determines amplification, independent of the details of the impulse profile. However, for longer impulses, the details of the impulse profile become important. In this limit, akin to a resonance, it is the entangled history of the interaction of the forcing, i.e. the impulse, that changes rapidly in amplitude, and the response of the oscillating interface that matters. The insights gained are discussed and experimentally illustrated in the context of interface distortion and destabilization relevant for upper respiratory mucosalivary fluid fragmentation in violent exhalations.

From non-problematic smartphone use to smartphone addiction: Impulsivity-based profiles.

Problematic smartphone use (PSU) is an uncontrollable behavior that impedes the ability to stop using it despite potential negative consequences. This excessive behavior has been considered in the research field as a behavioral addiction, as literature has shown common characteristics with behavioral addictions, including its impulsivity-driven factor. However, impulsivity is a multidimensional construct whose specific traits lead differently to each addiction. Hence, the present study aimed to address the different existent PSU profiles depending on their individual impulsivity personality traits. To this end, N=412 adults (average age 31.91, SD=11.70, including 108 men and 304 women) were recruited to explore their daily smartphone usage, level of smartphone addiction (SAS-SV) and impulsivity profile across the five impulsivity personality traits (UPPS-P). Cluster analysis revealed the existence of three different profiles: one without PSU; one showing an excessive impulsively but almost no addictive smartphone use, expressing only a loss of control symptomatology; and one showing excessive impulsively but also addictive smartphone patterns, driven mainly by the impulsivity personality traits of negative urgency, positive urgency and lack of premeditation. Therefore, this study showed the impulsivity personality traits that differentiate excessive from addictive smartphone use, which is valuable information for the development of more precise prevention and interventions programs.

Impulsivity profile and cocaine abuse in polysubstance abusers receiving Opioid Maintenance Treatment

Impulsivity profile and cocaine abuse in polysubstance abusers receiving Opioid Maintenance Treatment

Comparative analysis of impulsivity profiles in adult Attention Deficit Hyperactivity Disorder and Borderline Personality Disorder

IntroductionHigh levels of impulsive behavior represent a core symptom of different psychiatric conditions, such as Attention Deficit Hyperactivity Disorder (ADHD), Borderline Personality Disorder (BPD), impulse control and conduct disorders, bulimia nervosa, substance use disorders, and other maladaptive behaviors. Impulsivity is a multidimensional construct, having at least three factors.ObjectivesOur aim was to describe the impulsivity profile in adult ADHD and BPD patients in comparison with a healthy control group, taking into consideration the different impulsivity factors.MethodsaADHD (n=80) and BPD Patients (n=60) were recruited, based on the DSM-5 criteria. Control subjects (n=80) were screened using Derogatis Symptom Checklist (SCL-90). Comorbidities were assessed by structured clinical interviews. Participants were further investigated with online questionnaires including the Barratt Impulsiveness Scale (BIS-11), Difficulties in Emotion Regulation Scale (DERS), and neuropsychological tests, like Rogers’ decision-making test.ResultsBased ont the BIS-11 and DERS results, significantly higher levels of impulsivity (motor, attentional, non-planning) and difficulties in emotion regulation were present both in the aADHD and BPD groups, compared to the control group. Impulsivity factors were more characteristic to aADHD, emotion dysregulation was more specific to BPD. In the Rogers test, aADHD group was significantly slower in decision-making, while in BPD decision quality and risk-taking were affected.ConclusionsImpulsivity profiles of the two disorders are different, which leads to the assumption of potentially altered pathway of developing impulsive behavior. As a neuropsychiatric condition, impulsivity in aADHD is related to neurobiological dysinhibition, in BPD impulsive behavior is attached to emotionally involving situations, and emotional dysregulation rooted in childhood adverse events.DisclosureNo significant relationships.

Impulsivity and entrepreneurial perseverance: toward an empirical account and entrepreneurship-prone profile

PurposeAlthough emerging research has linked impulsivity with the decision to start a business, scholars have yet to draw implications for later-stage entrepreneurial outcomes. Furthermore, the authors have still to derive a parsimonious profile of the multidimensional impulsivity construct which can be positively linked to the entrepreneurial context. This paper proposes and tests a model to explain how impulsivity may relate to entrepreneurial perseverance—a construct typically regarded as a pivotal later-stage entrepreneurial outcome.Design/methodology/approachData were collected from 807 owner-managers using an online survey and augmented with the novel use of longitudinal data from the central registrar of companies in South Africa. Covariance-based structural equation modeling and a D2 indexing approach for forming an entrepreneurship-prone impulsivity profile were employed.FindingsResults show that multidimensional impulsivity is significantly, but differentially, related to entrepreneurial perseverance; the perceived desirability of entrepreneurship mediates this effect for two of the four impulsivity dimensions. In particular, the authors find evidence that insufficiency of deliberation enhances, while urgency hinders, perseverance—reflected behaviorally through the filing of annual returns over a three-year period. Furthermore, the authors derive a new entrepreneurship-prone impulsivity profile which begins to suggest an intraindividual profile of impulsivity traits which may be beneficial to the entrepreneurial context.Originality/valueBy demonstrating how impulsivity impacts entrepreneurial perseverance over time, this paper advances emerging research on the relationship between impulsivity and entrepreneurship, while contributing to explaining why the perseverance decision is not simply a matter of venture pecuniary benefits and feasibility.

Can Gravitational Waves Halt the Expansion of the Universe?

We numerically investigate the propagation of plane gravitational waves in the form of an initial boundary value problem with de Sitter initial data. The full non-linear Einstein equations with positive cosmological constant λ are written in the Friedrich–Nagy gauge which yields a wellposed system. The propagation of a single wave and the collision of two with colinear polarization are studied and contrasted with their Minkowskian analogues. Unlike with λ=0, critical behaviours are found with λ&gt;0 and are based on the relationship between the wave profile and λ. We find that choosing boundary data close to one of these bifurcations results in a “false” steady state which violates the constraints. Simulations containing (approximate) impulsive wave profiles are run and general features are discussed. Analytic results of Tsamis and Woodard, which describe how gravitational waves could affect an expansion rate at an initial instance of time, are explored and generalized to the entire space–time. Finally we put forward boundary conditions that, at least locally, slow down the expansion considerably for a time.

Trait impulsivity and health risk behaviors: A latent profile analysis

Substance use and risky sexual behavior are negative health outcomes associated with the heterogeneous construct of impulsivity and emerging adulthood. The present study appears to be the first to examine how different facets of impulsive personality may be used to depict various profiles that differentially predict engagement in substance use and risky sexual behavior. Specifically, this study extends previous research by providing a comprehensive examination of impulsivity profiles in relation to various health risk outcomes via negative urgency, lack of premeditation, lack of perseverance, sensation seeking, and positive urgency. Participants (N = 599) completed the Short Urgency, Premeditation, Perseverance, Sensation Seeking, and Positive Urgency Scale (SUPPS-P), the Youth Risk Behavior Survey (YRBS), and the Student Sexual Risks Scale (SSRS). Impulsivity profiles were examined using latent profile analysis in which varying degrees of the SUPPS-P facets were grouped together based on participant response patterns. Results of latent profile analyses indicated an optimal 5-profile solution (low total impulsivity, moderate total impulsivity, high lack of premeditation/lack of perseverance facets, moderate positive urgency/negative urgency/sensation seeking facets, high positive urgency/negative urgency/sensation seeking facets).

Abnormal organization of inhibitory control functional networks in future binge drinkers

Background and aimsAdolescent Binge drinking has become an increasing health and social concern, which cause several detrimental consequences for brain integrity. However, research on neurophysiological traits of vulnerability for binge drinking predisposition is limited at this time. In this work, we conducted a two-year longitudinal study with magnetoencephalography (MEG) over a cohort of initially alcohol-naive adolescents with the purpose of characterize inhibitory cortical networks’ anomalies prior to alcohol consumption onset in those youths who will transit into binge drinkers years later. MethodsSixty-seven participant’s inhibitory functional networks, and dysexecutive/impulsivity traits were measured by means of inhibitory task (go/no-go) and questionnaires battery. After a follow-up period of two years, we evaluated their alcohol consumption habits, sub-dividing them in two groups according to their alcohol intake patterns: future binge drinkers (fBD): n = 22; future Light/non-drinkers (fLD): n = 17. We evaluated whole-brain and seed-based functional connectivity profiles, as well as its correlation with impulsive and dysexecutive behaviours, searching for early abnormalities before consumption onset. ResultsFor the first time, abnormalities in MEG functional networks and higher dysexecutive and impulsivity profiles were detected in alcohol-naïve adolescents who two years later became binge drinkers. Concretely, fBD exhibit a distinctive pattern of beta band hyperconnectivity among crucial regions of inhibitory control networks, positively correlated with behavioral traits and future alcohol intake rate. ConclusionsThese findings strongly support the idea of early neurobiological vulnerabilities for substances consumption initiation, with inhibitory functional networks’ abnormalities as a relevant neurophysiological marker of subjects at risk— we hypothesize this profile is due to neurodevelopmental and neurobiological differences involving cognitive control networks and neurotransmission pathways.

Pulsed-jet propulsion via shape deformation of an axisymmetric swimmer

By using an axisymmetric immersed-boundary model, we numerically investigate the thrust generation of a deformable body via pulsed jetting. We focus on a single discharging process resulting from the deflation of the body as inspired by the jetting mechanism of cephalopods, such as squids. We examine three jet velocity profiles, namely, impulsive, half-cosine, and cosine, in the relatively low Reynolds number regime. For the impulsive profile, we demonstrate via wake visualization that the leading vortex ring does not pinch off from the trailing jet although its circulation stops growing after a critical formation number (hereby, the formation number is defined as the ratio between the length and diameter of the jet plug) of 6–7. The exact value of the critical formation number depends on the jet velocity profile, suggesting that jet acceleration and viscous dissipation play significant roles in vortex ring evolution. In terms of thrust generation, our results indicate that besides the jet momentum flux, an important source of thrust generation is jet acceleration. The implication is that the jet velocity profile is a key factor in determining the propulsive performance.

Impulsivity and physical activity: A T-Pattern detection of motor behavior profiles

The relation between impulsivity and physical activity has been scantly investigated. Actually, during physical activity, several goals are achieved on the basis of a certain dose of impulsiveness. This study detects motor and interactive behavior profiles from athletes with traits of impulsiveness, moderate impulsiveness and non-impulsiveness, performing open motor tasks concerning material, space and interaction behaviors. A specific test was administered to assess the impulsivity profiles of athletes; then the Observational System of Motor Skills, Space, Time and Interaction (OSMOSTI), was used to observe and detect movement sequences patterns throughout T-Pattern detection and analysis (TPA). Recent researches have shown that TPA is a suitable approach to study physical activity in different contexts related, for instance, to sport, dance or exergames.Results of TPA revealed that open motor situations enhance motor behavior profiles especially by comparing participants with different impulsiveness. T-Patterns of non-impulsiveness and moderate impulsiveness traits emphasized much more the executive functions of response inhibition, working memory and mental shifting. In this study we pointed out on how impulsiveness, as a candent trait, traditionally considered that leads to a precipitation, unplanned and risky actions could enhance adequate responses to goal achievements if we consider it far to be a disorder on sport and similar subjects. The tool OSMOSTI and TPA used to observe diverse degrees of impulsivity have evidenced objectively the aim of the study.

5-HT1A and α2 adrenergic receptor levels are associated with high anxiety-like patterns and impulsivity in selectively bred Long Evans rats

Impulsivity and anxiety are psychological traits involved in many aspects of the drug addiction cycle. However, few preclinical models exist for examining both impulsive and anxiety patterns. In the current study, we investigated whether 6th generation rats selectively bred for high anxiety (HAn)-like behavior would display amphetamine (AMPH) hyperactivity. In the same generational line, we also determined if HAn animals would display impulsivity in an operant task. Filial 5 male Long Evans rats phenotyped as HAn and low anxiety (LAn) were tested on the elevated plus maze (EPM) and in locomotor chambers following a low dose of AMPH (0.5 mg/kg, IP). Next, a separate group of F5 animals was exposed to a differential reinforcement of low rate of responding (DRL: 30 s) operant schedule to assess impulsivity. Postmortem, 5-HT1A and α2 adrenergic receptor protein levels were measured in the medial prefrontal cortex (mPFC), nucleus accumbens (NAc) core and shell, and α2 adrenergic counts were assessed in the locus coeruleus (LC), and the paraventricular nucleus (PVN) of the hypothalamus. F5 outbred HAn rats had decreased percent open arm time and entries on the EPM and elevated AMPH-induced locomotion. In the DRL, HAn rats displayed an impulsive profile, they attained fewer total rewards, had more inter-response times, and showed greater burst ratios. We found that HAn rats had a higher number of 5-HT1A receptor immunostained cells in the mPFC but were not different than LAn in NAc core or shell. By contrast, levels of the α2 adrenergic receptor protein were no different in the mPFC while HAn rats had greater levels in the LC and lower levels in the PVN. Overall, these data further validate our outbred trait anxiety rats: HAn males show anxiety-like behavior, AMPH hypersensitivity, greater impulsivity, and varying levels of limbic and midbrain 5-HT1A and α2 adrenergic receptor proteins.

Stochastic response analysis of elastic and inelastic systems with uncertain parameters under random impulse loading

Response analysis of structural systems under impulse loading is extremely important for appropriate design against accidental loads such as blast. Herein, the response of elastic and inelastic single degree of freedom (SDOF) systems with uncertain parameters under random impulse loadings is investigated. Four different types of impulse loading profiles (rectangular-, half-sine wave-, and two triangular-shaped), having same duration and impulse, are applied to the SDOF systems with varying fundamental periods of vibration. Non-sampling stochastic simulation procedure based on the generalized polynomial chaos (gPC) expansion technique is used to model the dynamic response of the SDOF systems duly considering the uncertainties. Effects of uncertainty levels in the input parameters on the peak response and sensitivity of the peak response to the uncertain input parameters are investigated in detail. It is concluded that the propagation of uncertainties from the inputs to the response quantities is more prominent in stiffer systems. Amongst the impulse profiles considered, those pulses with sudden rise in force lead to higher deviations in response of the systems for a given uncertainty scenario. Further, it is observed that the shock response spectra of all the impulse loads are more sensitive to the uncertainties when time periods are less than or close to the loading duration. Furthermore, the gPC expansion-based simulation technique is observed to be an efficient alternative to computationally demanding conventional Monte Carlo (MC) simulation for quantifying the uncertainties.