An Assessment of Treatment Integrity in Behavioral Intervention Studies Conducted with Persons with Mental Retardation

ERIC Educational Resources Information Center

Wheeler, John J.; Mayton, Michael R.; Carter, Stacy L.; Chitiyo, Morgan; Menendez, Anthony L.; Huang, Ann

2009-01-01

The purpose of this study was to assess the degree to which behavioral intervention studies conducted with persons with mental retardation operationally defined the independent variables and evaluated and reported measures of treatment integrity. The study expands the previous work in this area reported by Gresham, Gansle, and Noell (1993) and…

Cancer survivors' perspectives and experiences regarding behavioral determinants of return to work and continuation of work.

PubMed

Duijts, Saskia F A; van Egmond, Martine P; Gits, Maxime; van der Beek, Allard J; Bleiker, Eveline M

2017-10-01

Supportive interventions to enhance return to work (RTW) in cancer survivors hardly showed positive effects so far. Behavioral determinants might have to be considered in the development of interventions to achieve sustained employability. This study aimed to explore cancer survivors' perspectives and experiences regarding behavioral determinants of RTW and continuation of work. In this qualitative study, semi-structured telephone interviews were held with 28 cancer survivors. All participants were at working age, 1-2 years after diagnosis and employed at time of diagnosis. Thematic content analysis was performed. Work turned out to be a meaningful aspect of cancer survivors' life, and most participants reported a positive attitude towards their job. Social support to RTW or to continue working was mainly received from family and friends, but pressure to RTW from the occupational physician was also experienced. Changes in expectations regarding work ability from negative to positive during the treatment process were observed. Those who applied active coping mechanisms felt equipped to deal with difficulties regarding work. Behavioral determinants should be taken into account in the development of future interventions to support cancer survivors' RTW. However, the causal relationship still has to be determined. Implications for rehabilitation Factors influencing occupational motivation among cancer survivors need to be understood in more detail. Previous studies in non-cancer populations have demonstrated that behavioral determinants, such as a positive attitude towards work, high social support and self-efficacy may increase return to work rates or shorten the time to return to work. Addressing behavioral determinants in future development of work-related interventions for cancer survivors is essential in achieving sustained employability.

Communication-related affective, behavioral, and cognitive reactions in speakers with spasmodic dysphonia.

PubMed

Watts, Christopher R; Vanryckeghem, Martine

2017-12-01

To investigate the self-perceived affective, behavioral, and cognitive reactions associated with communication of speakers with spasmodic dysphonia as a function of employment status. Prospective cross-sectional investigation. 148 Participants with spasmodic dysphonia (SD) completed an adapted version of the Behavior Assessment Battery (BAB-Voice), a multidimensional assessment of self-perceived reactions to communication. The BAB-Voice consisted of four subtests: the Speech Situation Checklist for A) Emotional Reaction (SSC-ER) and B) Speech Disruption (SSC-SD), C) the Behavior Checklist (BCL), and D) the Communication Attitude Test for Adults (BigCAT). Participants were assigned to groups based on employment status (working versus retired). Descriptive comparison of the BAB-Voice in speakers with SD to previously published non-dysphonic speaker data revealed substantially higher scores associated with SD across all four subtests. Multivariate Analysis of Variance (MANOVA) revealed no significantly different BAB-Voice subtest scores as a function of SD group status (working vs. retired). BAB-Voice scores revealed that speakers with SD experienced substantial impact of their voice disorder on communication attitude, coping behaviors, and affective reactions in speaking situations as reflected in their high BAB scores. These impacts do not appear to be influenced by work status, as speakers with SD who were employed or retired experienced similar levels of affective and behavioral reactions in various speaking situations and cognitive responses. These findings are consistent with previously published pilot data. The specificity of items assessed by means of the BAB-Voice may inform the clinician of valid patient-centered treatment goals which target the impairment extended beyond the physiological dimension. 2b.

Testing and extending the group engagement model: linkages between social identity, procedural justice, economic outcomes, and extrarole behavior.

PubMed

Blader, Steven L; Tyler, Tom R

2009-03-01

Two field studies tested and extended the group engagement model (Tyler & Blader, 2000, Tyler & Blader, 2003) by examining the model with regard to employee extrarole behavior. Consistent with the group engagement model's predictions, results of these studies indicate that the social identities employees form around their work groups and their organizations are strongly related to whether employees engage in extrarole behaviors. Moreover, the studies demonstrated that social identity explains the impact of other factors that have previously been linked to extrarole behavior. In particular, the findings indicate that social identity mediates the effect of procedural justice judgments and economic outcomes on supervisor ratings of extrarole behavior. Overall, these studies provide compelling indication that social identity is an important determinant of behavior within work organizations and provide strong support for the application of the group engagement model in organizational settings. (c) 2009 APA, all rights reserved.

Perspectives of Pre-Service Teachers on Students with Emotional Disabilities

ERIC Educational Resources Information Center

Beam, Andrea P.; Yocum, Russell G.; Pinkie, Elyse C.

2016-01-01

Perceptions of working with students of emotional disabilities or who are considered Emotionally/Behaviorally Disturbed (E/BD) is varied across the spectrum. However, one constant that does hold true is that all pre-service teachers have some hesitation in working with such students, especially if they lack any previous exposure to students with…

Training and Transfer Effects of Executive Functions in Preschool Children

ERIC Educational Resources Information Center

Thorell, Lisa B.; Lindqvist, Sofia; Nutley, Sissela Bergman; Bohlin, Gunilla; Klingberg, Torkel

2009-01-01

Executive functions, including working memory and inhibition, are of central importance to much of human behavior. Interventions intended to improve executive functions might therefore serve an important purpose. Previous studies show that working memory can be improved by training, but it is unknown if this also holds for inhibition, and whether…

The neural bases of the effects of item-nonspecific proactive interference in working memory

PubMed Central

POSTLE, BRADLEY R.; BRUSH, LAUREN N.

2005-01-01

We reanalyzed the behavioral and fMRI data from seven previously published studies of working memory in order to assess the behavioral and neural effects of item-nonspecific proactive interference (PI; attributable to the accrual of antecedent information independent of the repetition of particular items). We hypothesized that item-nonspecific PI, implicated in age-related declines in working memory performance, is mediated by the same mechanism(s) that mediate item-specific PI (occurring when an invalid memory probe matches a memorandum from the previous trial). Reaction time increased across trials as a function of position within the block, a trend that reversed across the duration of each multiblock experiment. The fMRI analyses revealed sensitivity to item-nonspecific PI during the probe epoch in the left anterior inferior frontal gyrus and the left dorsolateral prefrontal cortex (PFC). They also revealed a negative trend, across trials, in the transient probe-evoked component of the global signal. A common PFC-based mechanism may mediate many forms of PI. PMID:15535173

The neural bases of the effects of item-nonspecific proactive interference in working memory.

PubMed

Postle, Bradley R; Brush, Lauren N

2004-09-01

We reanalyzed the behavioral and fMRI data from seven previously published studies of working memory in order to assess the behavioral and neural effects of item-nonspecific proactive interference (PI; attributable to the accrual of antecedent information independent of the repetition of particular items). We hypothesized that item-nonspecific PI, implicated in age-related declines in working memory performance, is mediated by the same mechanism(s) that mediate item-specific PI (occurring when an invalid memory probe matches a memorandum from the previous trial). Reaction time increased across trials as a function of position within the block, a trend that reversed across the duration of each multiblock experiment. The fMRI analyses revealed sensitivity to item-nonspecific PI during the probe epoch in the left anterior inferior frontal gyrus and the left dorsolateral prefrontal cortex(PFC). They also revealed a negative trend, across trials, in the transient probe-evoked component of the global signal. A common PFC-based mechanism may mediate many forms of PI.

Positive and Negative Reinforcement Effects on Behavior in a Three-Person Microsociety.

DTIC Science & Technology

1983-12-01

Per-hour earning potential uas roughly equivalent among the groups. Prdr The consequences of ompletlng a work trip were varied to assess the effects ...31 abandoned his previously established pattern. These effects are attributable, at least In part, to the style of alternating work that the... working under aversive control. These effects suggest that the functional properties of work (C-.h. oonsequences) were far more significant to the group

"Aprender a Convivir." A Prevention Program for Improving Social Competence in Three-to Seven-Year-Olds

ERIC Educational Resources Information Center

Alba, Guadalupe; Justicia-Arraez, Ana; Pichardo, M. Carmen; Justicia-Justicia, Fernando

2013-01-01

Behavior problems are often observed in classrooms. The age at which problems appears is increasingly younger, and there are no interventions that ensure a reduction in such behavior problems among school age children. Research and previous evidence show the importance of social competence in this kind of prevention. Working with preschool and…

Relationships of job hazards, lack of knowledge, alcohol use, health status and risk taking behavior to work injury of coal miners: a case-control study in India.

PubMed

Kunar, Bijay Mihir; Bhattacherjee, Ashis; Chau, Nearkasen

2008-01-01

Objective is to assess the relationships of job hazards, individual characteristics, and risk taking behavior to occupational injuries of coal miners. This case-control study compared 245 male underground coal miners with injury during the previous two-year period with 330 matched controls without injury during the previous five years. Data were collected via face-to-face interview and analyzed using the conditional logistic model. Handling material, poor environmental/working conditions, and geological/strata control- related hazards were the main risk factors: adjusted ORs 5.15 (95% CI 2.42-10.9), 2.40 (95% CI 1.29-4.47), and 2.25 (95% CI 1.24-4.07) respectively. Their roles were higher among the face-workers than among the non-face-workers. No formal education, alcohol consumption, disease, big-family, and risk-taking behavior were associated with injuries (2.36

Ghosts in the Machine II: Neural Correlates of Memory Interference from the Previous Trial.

PubMed

Papadimitriou, Charalampos; White, Robert L; Snyder, Lawrence H

2017-04-01

Previous memoranda interfere with working memory. For example, spatial memories are biased toward locations memorized on the previous trial. We predicted, based on attractor network models of memory, that activity in the frontal eye fields (FEFs) encoding a previous target location can persist into the subsequent trial and that this ghost will then bias the readout of the current target. Contrary to this prediction, we find that FEF memory representations appear biased away from (not toward) the previous target location. The behavioral and neural data can be reconciled by a model in which receptive fields of memory neurons converge toward remembered locations, much as receptive fields converge toward attended locations. Convergence increases the resources available to encode the relevant memoranda and decreases overall error in the network, but the residual convergence from the previous trial can give rise to an attractive behavioral bias on the next trial. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Communication‐related affective, behavioral, and cognitive reactions in speakers with spasmodic dysphonia

PubMed Central

Vanryckeghem, Martine

2017-01-01

Objectives To investigate the self‐perceived affective, behavioral, and cognitive reactions associated with communication of speakers with spasmodic dysphonia as a function of employment status. Study Design Prospective cross‐sectional investigation Methods 148 Participants with spasmodic dysphonia (SD) completed an adapted version of the Behavior Assessment Battery (BAB‐Voice), a multidimensional assessment of self‐perceived reactions to communication. The BAB‐Voice consisted of four subtests: the Speech Situation Checklist for A) Emotional Reaction (SSC‐ER) and B) Speech Disruption (SSC‐SD), C) the Behavior Checklist (BCL), and D) the Communication Attitude Test for Adults (BigCAT). Participants were assigned to groups based on employment status (working versus retired). Results Descriptive comparison of the BAB‐Voice in speakers with SD to previously published non‐dysphonic speaker data revealed substantially higher scores associated with SD across all four subtests. Multivariate Analysis of Variance (MANOVA) revealed no significantly different BAB‐Voice subtest scores as a function of SD group status (working vs. retired). Conclusions BAB‐Voice scores revealed that speakers with SD experienced substantial impact of their voice disorder on communication attitude, coping behaviors, and affective reactions in speaking situations as reflected in their high BAB scores. These impacts do not appear to be influenced by work status, as speakers with SD who were employed or retired experienced similar levels of affective and behavioral reactions in various speaking situations and cognitive responses. These findings are consistent with previously published pilot data. The specificity of items assessed by means of the BAB‐Voice may inform the clinician of valid patient‐centered treatment goals which target the impairment extended beyond the physiological dimension. Level of Evidence 2b PMID:29299525

Smoking and (Not) Voting: The Negative Relationship Between a Health-Risk Behavior and Political Participation in Colorado.

PubMed

Albright, Karen; Hood, Nancy; Ma, Ming; Levinson, Arnold H

2016-03-01

Considerable evidence suggests that cigarette smokers are an increasingly marginalized population, involved in fewer organizations and activities and with less interpersonal trust than their nonsmoking counterparts. However, only two previous studies, both among Swedish populations, have investigated smokers' attitudes toward political systems and institutions. The current, cross-sectional study examines smoking in relation to voting, a direct behavioral measure of civic and political engagement that at least partly reflects trust in formal political institutions. Secondary analyses were conducted of interview data from 11 626 respondents in the Colorado Tobacco Attitudes and Behaviors Survey. Data were collected via telephone between October 2005 and mid-April 2006 and included respondents' reported voting behavior in the 2004 national election; the participation rate was 89.7%. Balanced multiple logistic regression was used to examine associations between smoking and voting while controlling for other covariates known to be associated with both variables. In the final model, daily smokers were less than half as likely as nonsmokers to report having voted in the election. The results suggest possible consonance with previous work linking smoking with political mistrust. Possible causal mechanisms are discussed. This study is the first to link a health-risk behavior with electoral participation, and provides initial evidence that smoking is negatively associated with political participation. Future research should investigate how public health might enhance tobacco control efforts by taking nonvoting behavior into consideration, or creatively combining smoking cessation interventions with voter registration and other civic engagement work, particularly among socioeconomically disadvantaged populations. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

A Meta-Analysis of the Relationship between Trait Mindfulness and Substance Use Behaviors

PubMed Central

Karyadi, Kenny A.; VanderVeen, J. Davis; Cyders, Melissa A.

2014-01-01

Background The relationship between trait mindfulness and substance use behaviors has been inconsistent across studies. The current study is a meta-analysis aimed at quantifying the magnitude of this relationship, and at determining how this relationship varies in context of (1) mindfulness facets, (2) substance type, (3) sample characteristics, and (4) substance use severity. Methods A literature search was conducted using electronic databases. The literature search yielded 303 articles, but only 39 articles met inclusion criteria to be included in this meta-analysis. The relationship was quantified as a Pearson's r correlation coefficient for all studies. Results Findings indicated a small, negative, and significant relationship between trait mindfulness and substance use behaviors (r = -0.13). This relationship varied across substance type, clinical status of the sample, and substance use severity. Although not significant, relationship sizes showed different patterns across mindfulness facets. Conclusions This meta-analysis quantified the relationship between trait mindfulness and substance use behaviors, which can be used as future effect size estimates. Findings also clarify inconsistency in previous work by indicating that the trait mindfulness-substance use behaviors relationship was more robust: (1) for alcohol use and tobacco use behaviors; (2) for problematic substance use behaviors; and (3) with inpatient clinical samples. Further work should continue to examine if acting with awareness, non-judgment, and non-reactivity mindfulness facets are more robustly associated with substance use behaviors. Failure to consider these factors, or collapsing across these factors, could explain the smaller or inconsistently reported associations across previous studies. PMID:25113434

Interspecific interaction between Telenomus remus (Hymenoptera: Platygastridae) and Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) on Spodoptera frugiperda (Lepidoptera: Noctuidae) eggs.

PubMed

Carneiro, Tatiana R; Fernandes, Odair A

2012-12-01

This work aims to evaluate the interspecific interaction between Trichogramma pretiosum and Telenomus remus, two biological control agents of fall armyworm (Spodoptera frugiperda) eggs. Eggs of Spodoptera frugiperda previously parasitized by Telenomus remus were offered to Trichogramma pretiosum, and those parasitized by Trichogramma pretiosum were offered to Telenomus remus. The previously parasitized eggs were tested at different embryonic development stages for each parasitoid. In addition, to evaluate the competition between species, Spodoptera frugiperda eggs were offered to the parasitoids simultaneously. The behavior of the insects was recorded under a stereomicroscope. When Spodoptera frugiperda eggs were previously exposed to either parasitoid, there was no emergence of the other parasitoid. When the Telenomus remus and Trichogramma pretiosum females were placed together with Spodoptera frugiperda eggs, Telenomus remus had a greater parasitism rate. Except searching time, all Trichogramma pretiosum behaviors took a longer time than Telenomus remus behaviors. Thus, despite belonging to different families, each of these parasitoids is able to recognize host eggs previously parasitized by the other. So, this suggests that the recognition mechanism involved is not exclusively specific.

Mechanisms of Percept-Percept and Image-Percept Integration in Vision: Behavioral and Electrophysiological Evidence

ERIC Educational Resources Information Center

Dalvit, Silvia; Eimer, Martin

2011-01-01

Previous research has shown that the detection of a visual target can be guided not only by the temporal integration of two percepts, but also by integrating a percept and an image held in working memory. Behavioral and event-related brain potential (ERP) measures were obtained in a target detection task that required temporal integration of 2…

Behavior of an epoxy-polysulfide adhesive in wood joints exposed to moisture content changes

Treesearch

Gordon P. Krueger

1965-01-01

The mechanical behavior of a flexible epoxy-resin adhesive system was observed in joints of plywood to lumber. The joints were subjected to internal swelling stresses caused by an increase in moisture content. Previous experimental work at the U.S. Forest Products Laboratory has shown that this adhesive system acts as a strain-absorbing cushion and thus has a...

Cognitive Reflection and the Diligent Worker: An Experimental Study of Millennials

PubMed Central

Corgnet, Brice; Hernán Gonzalez, Roberto; Mateo, Ricardo

2015-01-01

Recent studies have shown that despite crucially needing the creative talent of millennials (people born after 1980) organizations have been reluctant to hire young workers because of their supposed lack of diligence. We propose to help resolve this dilemma by studying the determinants of task performance and shirking behaviors of millennials in a laboratory work environment. We find that cognitive ability is a good predictor of task performance in line with previous literature. In contrast with previous research, personality traits do not consistently predict either task performance or shirking behaviors. Shirking behaviors, as measured by the time participants spent browsing the internet for non-work purposes (Cyberloafing), were only explained by the performance on the Cognitive Reflection Test (CRT). This finding echoes recent research in cognitive psychology according to which conventional measures of cognitive ability only assess a narrow concept of rational thinking (the algorithmic mind) that fails to capture individuals’ capacity to reflect and control their impulses. Our findings suggest that hiring diligent millennials relies on the use of novel cognitive measures such as CRT in lieu of standard personality and intelligence tests. PMID:26545244

Cognitive Reflection and the Diligent Worker: An Experimental Study of Millennials.

PubMed

Corgnet, Brice; Hernán Gonzalez, Roberto; Mateo, Ricardo

2015-01-01

Recent studies have shown that despite crucially needing the creative talent of millennials (people born after 1980) organizations have been reluctant to hire young workers because of their supposed lack of diligence. We propose to help resolve this dilemma by studying the determinants of task performance and shirking behaviors of millennials in a laboratory work environment. We find that cognitive ability is a good predictor of task performance in line with previous literature. In contrast with previous research, personality traits do not consistently predict either task performance or shirking behaviors. Shirking behaviors, as measured by the time participants spent browsing the internet for non-work purposes (Cyberloafing), were only explained by the performance on the Cognitive Reflection Test (CRT). This finding echoes recent research in cognitive psychology according to which conventional measures of cognitive ability only assess a narrow concept of rational thinking (the algorithmic mind) that fails to capture individuals' capacity to reflect and control their impulses. Our findings suggest that hiring diligent millennials relies on the use of novel cognitive measures such as CRT in lieu of standard personality and intelligence tests.

Spike-Timing Dependent Plasticity in Unipolar Silicon Oxide RRAM Devices

PubMed Central

Zarudnyi, Konstantin; Mehonic, Adnan; Montesi, Luca; Buckwell, Mark; Hudziak, Stephen; Kenyon, Anthony J.

2018-01-01

Resistance switching, or Resistive RAM (RRAM) devices show considerable potential for application in hardware spiking neural networks (neuro-inspired computing) by mimicking some of the behavior of biological synapses, and hence enabling non-von Neumann computer architectures. Spike-timing dependent plasticity (STDP) is one such behavior, and one example of several classes of plasticity that are being examined with the aim of finding suitable algorithms for application in many computing tasks such as coincidence detection, classification and image recognition. In previous work we have demonstrated that the neuromorphic capabilities of silicon-rich silicon oxide (SiOx) resistance switching devices extend beyond plasticity to include thresholding, spiking, and integration. We previously demonstrated such behaviors in devices operated in the unipolar mode, opening up the question of whether we could add plasticity to the list of features exhibited by our devices. Here we demonstrate clear STDP in unipolar devices. Significantly, we show that the response of our devices is broadly similar to that of biological synapses. This work further reinforces the potential of simple two-terminal RRAM devices to mimic neuronal functionality in hardware spiking neural networks. PMID:29472837

Comprehensive behavioral analysis of pituitary adenylate cyclase-activating polypeptide (PACAP) knockout mice

PubMed Central

Hattori, Satoko; Takao, Keizo; Tanda, Koichi; Toyama, Keiko; Shintani, Norihito; Baba, Akemichi; Hashimoto, Hitoshi; Miyakawa, Tsuyoshi

2012-01-01

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide acting as a neurotransmitter, neuromodulator, or neurotrophic factor. PACAP is widely expressed throughout the brain and exerts its functions through the PACAP-specific receptor (PAC1). Recent studies reveal that genetic variants of the PACAP and PAC1 genes are associated with mental disorders, and several behavioral abnormalities of PACAP knockout (KO) mice are reported. However, an insufficient number of backcrosses was made using PACAP KO mice on the C57BL/6J background due to their postnatal mortality. To elucidate the effects of PACAP on neuropsychiatric function, the PACAP gene was knocked out in F1 hybrid mice (C57BL/6J × 129SvEv) for appropriate control of the genetic background. The PACAP KO mice were then subjected to a behavioral test battery. PACAP deficiency had no significant effects on neurological screen. As shown previously, the mice exhibited significantly increased locomotor activity in a novel environment and abnormal anxiety-like behavior, while no obvious differences between genotypes were shown in home cage (HC) activity. In contrast to previous reports, the PACAP KO mice showed normal prepulse inhibition (PPI) and slightly decreased depression-like behavior. Previous study demonstrates that the social interaction (SI) in a resident-intruder test was decreased in PACAP KO mice. On the other hand, we showed that PACAP KO mice exhibited increased SI in Crawley's three-chamber social approach test, although PACAP KO had no significant impact on SI in a HC. PACAP KO mice also exhibited mild performance deficit in working memory in an eight-arm radial maze (RM) and the T-maze (TM), while they did not show any significant abnormalities in the left-right discrimination task in the TM. These results suggest that PACAP has an important role in the regulation of locomotor activity, social behavior, anxiety-like behavior and, potentially, working memory. PMID:23060763

Maternal work and children's diet, activity, and obesity.

PubMed

Datar, Ashlesha; Nicosia, Nancy; Shier, Victoria

2014-04-01

Mothers' work hours are likely to affect their time allocation towards activities related to children's diet, activity and well-being. For example, mothers who work more may be more reliant on processed foods, foods prepared away from home and school meal programs for their children's meals. A greater number of work hours may also lead to more unsupervised time for children that may, in turn, allow for an increase in unhealthy behaviors among their children such as snacking and sedentary activities such as TV watching. Using data on a national cohort of children, we examine the relationship between mothers' average weekly work hours during their children's school years on children's dietary and activity behaviors, BMI and obesity in 5th and 8th grade. Our results are consistent with findings from the literature that maternal work hours are positively associated with children's BMI and obesity especially among children with higher socioeconomic status. Unlike previous papers, our detailed data on children's behaviors allow us to speak directly to affected behaviors that may contribute to the increased BMI. We show that children whose mothers work more consume more unhealthy foods (e.g. soda, fast food) and less healthy foods (e.g. fruits, vegetables, milk) and watch more television. Although they report being slightly more physically active, likely due to organized physical activities, the BMI and obesity results suggest that the deterioration in diet and increase in sedentary behaviors dominate. Copyright © 2014 Elsevier Ltd. All rights reserved.

Maternal Work and Children’s Diet, Activity, and Obesity

PubMed Central

Datar, Ashlesha; Nicosia, Nancy; Shier, Victoria

2014-01-01

Mothers’ work hours are likely to affect their time allocation towards activities related to children’s diet, activity and well-being. For example, mothers who work more may be more reliant on processed foods, foods prepared away from home and school meal programs for their children’s meals. A greater number of work hours may also lead to more unsupervised time for children that may, in turn, allow for an increase in unhealthy behaviors among their children such as snacking and sedentary activities such as TV watching. Using data on a national cohort of children, we examine the relationship between mothers’ average weekly work hours during their children’s school years on children’s dietary and activity behaviors, BMI and obesity in 5th and 8th grade. Our results are consistent with findings from the literature that maternal work hours are positively associated with children’s BMI and obesity especially among children with higher socioeconomic status. Unlike previous papers, our detailed data on children’s behaviors allow us to speak directly to affected behaviors that may contribute to the increased BMI. We show that children whose mothers work more consume more unhealthy foods (e.g. soda, fast food) and less healthy foods (e.g. fruits, vegetables, milk) and watch more television. Although they report being slightly more physically active, likely due to organized physical activities, the BMI and obesity results suggest that the deterioration in diet and increase in sedentary behaviors dominate. PMID:24491828

Transgender women and the sex work industry: roots in systemic, institutional, and interpersonal discrimination.

PubMed

Nadal, Kevin L; Davidoff, Kristin C; Fujii-Doe, Whitney

2014-01-01

Because transgender people face discrimination on systemic, institutional, and interpersonal levels, the previous literature has supported that many transgender women view the sex work industry as their only viable career option. The current article reviews the literature on discrimination against transgender people, explores how discrimination influences their participation in sex work, and discusses how institutional discrimination against transgender women manifests within the criminal justice system. Furthermore, recommendations are provided for advocating for the rights of transgender people while promoting healthy behaviors and higher quality of life. Throughout the article, quotes from previous qualitative research are used to illustrate the experiences of transgender women through their own voices and perspectives.

Relating retinal nerve fiber thickness to behavioral sensitivity in patients with glaucoma: application of a linear model.

PubMed

Hood, Donald C

2007-05-01

Glaucoma causes damage to the retinal ganglion cells and their axons, and this damage can be detected with both structural and functional tests. The purpose of this study was to better understand the relationship between a structural measure of retinal nerve fiber layer (RNFL) and the most common functional test, behavioral sensitivity with static automated perimetry (SAP). First, a linear model, previously shown to describe the relationship between local visual evoked potentials and SAP sensitivity, was modified to predict the change in RNFL as measured by optical coherence tomography. Second, previous work by others was shown to be consistent with this model.

Driving behaviors and on-duty road accidents: a French case-control study.

PubMed

Fort, Emmanuel; Chiron, Mireille; Davezies, Philippe; Bergeret, Alain; Charbotel, Barbara

2013-01-01

A case-control study was carried out to identify driving behaviors associated with the risk of on-duty road accident and to compare driving behaviors according to the type of journey (on duty, commuting, and private) for on-duty road accident victims. Cases were recruited from the Rhône Road Trauma Registry between January 2004 and October 2005 and were on duty at the time of the accident. Control subjects were recruited from the electoral rolls of the case subjects' constituencies of residence. Cases' and controls' driving behavior data were collected by self-administered questionnaire. A logistic regression was performed to identify behavioral risk factors for on-duty road accidents, taking into account age, sex, place of residence, road accident risk exposure, socio-occupational category, and type of road user. A second analysis focused specifically on the case subjects, comparing their self-assessed usual behaviors according to the type of journey. Significant factors for multivariate analysis of on-duty road accidents were female gender, history of on-duty road accidents during the previous 10 years, severe time pressure at work, and driving a vehicle not belonging to the driver. On-duty road accident victims reported behavioral risk factors more frequently in relation to driving for work than driving for private reasons or commuting: nonsystematic seat belt use, cell phone use at least once daily while driving, and history of accidents with injury during the previous 10 years. This study provides knowledge on behavioral risk factors for on-duty road accidents and differences in behavior according to the type of journey for subjects who have been on-duty road accident victims. These results will be useful for the design of on-duty road risk prevention.

Safety behavior: Job demands, job resources, and perceived management commitment to safety.

PubMed

Hansez, Isabelle; Chmiel, Nik

2010-07-01

The job demands-resources model posits that job demands and resources influence outcomes through job strain and work engagement processes. We test whether the model can be extended to effort-related "routine" safety violations and "situational" safety violations provoked by the organization. In addition we test more directly the involvement of job strain than previous studies which have used burnout measures. Structural equation modeling provided, for the first time, evidence of predicted relationships between job strain and "routine" violations and work engagement with "routine" and "situational" violations, thereby supporting the extension of the job demands-resources model to safety behaviors. In addition our results showed that a key safety-specific construct 'perceived management commitment to safety' added to the explanatory power of the job demands-resources model. A predicted path from job resources to perceived management commitment to safety was highly significant, supporting the view that job resources can influence safety behavior through both general motivational involvement in work (work engagement) and through safety-specific processes.

Automated Generation of Fault Management Artifacts from a Simple System Model

NASA Technical Reports Server (NTRS)

Kennedy, Andrew K.; Day, John C.

2013-01-01

Our understanding of off-nominal behavior - failure modes and fault propagation - in complex systems is often based purely on engineering intuition; specific cases are assessed in an ad hoc fashion as a (fallible) fault management engineer sees fit. This work is an attempt to provide a more rigorous approach to this understanding and assessment by automating the creation of a fault management artifact, the Failure Modes and Effects Analysis (FMEA) through querying a representation of the system in a SysML model. This work builds off the previous development of an off-nominal behavior model for the upcoming Soil Moisture Active-Passive (SMAP) mission at the Jet Propulsion Laboratory. We further developed the previous system model to more fully incorporate the ideas of State Analysis, and it was restructured in an organizational hierarchy that models the system as layers of control systems while also incorporating the concept of "design authority". We present software that was developed to traverse the elements and relationships in this model to automatically construct an FMEA spreadsheet. We further discuss extending this model to automatically generate other typical fault management artifacts, such as Fault Trees, to efficiently portray system behavior, and depend less on the intuition of fault management engineers to ensure complete examination of off-nominal behavior.

Profile of female sex workers in a Chinese county: Does it differ by where they came from and where they work?

PubMed Central

Fang, Xiaoyi; Li, Xiaoming; Yang, Hongmei; Hong, Yan; Zhao, Ran; Dong, Baiqing; Liu, Wei; Zhou, Yuejiao; Liang, Shaoling; Stanton, Bonita

2007-01-01

Since the 1980s, informal or clandestine sex work in the service or entertainment industry has spread from municipalities to small towns in most areas of China. Despite recognition of the important role of female sex workers in HIV and STD epidemics in China, limited data are available regarding their individual characteristics and social and environmental context of their work. Furthermore, most existing studies on commercial sex in China have been conducted in large cities or tourist attractions. Using data from 454 female sex workers in a rural Chinese county, the current study was designed to explore the individual profile of commercial sex workers and to examine whether the profile and sexual risk behavior differ by where the female sex workers came from and where they work. The sample in the current study was different from previous studies in a number of key individual characteristics. However, similar to previous studies, the sample in the current study were driven into commercial sex by poverty or limited employment opportunities, lived in a stressful life, were subject to sexual harassment and related violence, and engaged in a number of health-compromising behaviors including behaviors that put them at risk of HIV/STD infection and depression. The findings of the current study underscore the urgent needs for effective HIV/STD prevention intervention and mental health promotion program among female sex workers in China. The data in the current study suggest a strong association of individual profile with the economic conditions of work sites and residence status (in-province residency versus out-province residence) which suggests that such efforts must take the social and cultural contextual factors of their working environment (and sexual risks) into consideration. PMID:18270499

Proportion of Dermatitis Attributed to Work Exposures in the Working Population, United States, 2011 Behavioral Risk Factor Surveillance System

PubMed Central

Ehrlich, Emily; Bunn, Terry; Kanotra, Sarojini; Fussman, Chris; Rosenman, Kenneth D.

2016-01-01

Background The US employer-based surveillance system for work-related health conditions underestimates the prevalence of work-related dermatitis. Objective The authors sought to utilize information from workers to improve the accuracy of prevalence estimates for work-related dermatitis. Methods Three state health departments included questions in the 2011 Behavioral Risk Factor Surveillance System survey designed to ascertain the prevalence of dermatitis in the working population, as well as healthcare experiences, personal perceptions of work-relatedness, and job changes associated with dermatitis. Results The percentage of working respondents who reported receiving a clinician’s opinion that their dermatitis was work-related was between 3.8% and 10.2%. When patients’ perceptions were considered, the work-related dermatitis prevalence estimate increased to between 12.9% and 17.6%. Conclusions Including patients’ perceptions of work-relatedness produced a larger prevalence estimate for work-related dermatitis than the previously published estimate of 5.6%, which included only those cases of dermatitis attributed to work by healthcare professionals. PMID:24619601

The relation between indicators of low employment quality and attendance behavior in countries of the European Union.

PubMed

Janssens, Heidi; Braeckman, Lutgart; De Clercq, Bart; De Bacquer, Dirk; Clays, Els

2017-12-01

Previous research demonstrated an association between low employment quality and lower sickness absence, which may be explained by presenteeism. Therefore, this study aimed exploring the relation between three indicators of employment quality (long working hours, precarious employment, job insecurity) and attendance behavior. The association between employment quality and attendance behavior was investigated in 28.999 workers (mean age: 40.0 years, 53% males) of the fifth wave of the European Working Conditions Survey, using multilevel multinomial logistic regression analysis. Attendance behavior was operationalized as different combinations of sickness absence and presenteeism. Those working >48 h/week, had a higher risk to report presenteeism (with or without sickness absence). They had a lower risk to report sickness absence without presenteeism. Workers with a precarious contract had a lower risk to report absenteeism without presenteeism and the combination of both presenteeism and absenteeism. Finally, for workers perceiving job insecurity, the risk for presenteeism without sickness absence was significantly higher. Several indicators of low employment quality were associated with attendance behavior, suggesting a complex behavioral mechanism in workers facing low job quality employment. Therefore, policy makers are recommended to re-establish the indefinite contractual employment as the standard, avoiding long working hours. © The Author 2016. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Linear modeling of steady-state behavioral dynamics.

PubMed Central

Palya, William L; Walter, Donald; Kessel, Robert; Lucke, Robert

2002-01-01

The observed steady-state behavioral dynamics supported by unsignaled periods of reinforcement within repeating 2,000-s trials were modeled with a linear transfer function. These experiments employed improved schedule forms and analytical methods to improve the precision of the measured transfer function, compared to previous work. The refinements include both the use of multiple reinforcement periods that improve spectral coverage and averaging of independently determined transfer functions. A linear analysis was then used to predict behavior observed for three different test schedules. The fidelity of these predictions was determined. PMID:11831782

Clarifying the Behavioral Economics of Social Anxiety Disorder: Effects of Interpersonal Problems and Symptom Severity on Generosity.

PubMed

Rodebaugh, Thomas L; Heimberg, Richard G; Taylor, Kristin P; Lenze, Eric J

2016-01-01

Social anxiety disorder is associated with lower interpersonal warmth, possibly explaining its associated interpersonal impairment. Across two samples, we attempted to replicate previous findings that the disorder's constraint of interpersonal warmth can be detected via behavioral economic tasks. We also tested the test-retest stability of task indices. Results indicated that factors associated with social anxiety disorder (and not the disorder itself), such as the severity of social anxiety and more extreme interpersonal problems, lead to less generous behavior on the economic task examined. Results were clearest regarding fine-grained indices derived from latent trajectories. Unexpectedly, the combination of generalized anxiety disorder and higher depression also restricted generosity. Two of three indices showed acceptable test-retest stability. Maladaptive giving behavior may be a treatment target to improve interpersonal functioning in psychiatric disorders; therefore, future work should more precisely characterize behavioral economic tasks, including basic psychometric work (i.e., tests of reliability and validity).

Clarifying the Behavioral Economics of Social Anxiety Disorder: Effects of Interpersonal Problems and Symptom Severity on Generosity

PubMed Central

Rodebaugh, Thomas L.; Heimberg, Richard G.; Taylor, Kristin P.; Lenze, Eric J.

2015-01-01

Social anxiety disorder is associated with lower interpersonal warmth, possibly explaining its associated interpersonal impairment. Across two samples, we attempted to replicate previous findings that the disorder’s constraint of interpersonal warmth can be detected via behavioral economic tasks. We also tested the test-retest stability of task indices. Results indicated that factors associated with social anxiety disorder (and not the disorder itself), such as the severity of social anxiety and more extreme interpersonal problems, lead to less generous behavior on the economic task examined. Results were clearest regarding fine-grained indices derived from latent trajectories. Unexpectedly, the combination of generalized anxiety disorder and higher depression also restricted generosity. Two of three indices showed acceptable test-retest stability. Maladaptive giving behavior may be a treatment target to improve interpersonal functioning in psychiatric disorders; therefore, future work should more precisely characterize behavioral economic tasks, including basic psychometric work (i.e., tests of reliability and validity). PMID:27034911

Computer modeling of batteries from nonlinear circuit elements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waaben, S.; Dyer, C.K.; Federico, J.

1985-06-01

Circuit analogs for a single battery cell have previously been composed of resistors, capacitors, and inductors. This work introduces a nonlinear circuit model for cell behavior. The circuit is configured around the PIN junction diode, whose charge-storage behavior has features similar to those of electrochemical cells. A user-friendly integrated circuit simulation computer program has reproduced a variety of complex cell responses including electrica isolation effects causing capacity loss, as well as potentiodynamic peaks and discharge phenomena hitherto thought to be thermodynamic in origin. However, in this work, they are shown to be simply due to spatial distribution of stored chargemore » within a practical electrode.« less

Dorsal and ventral working memory-related brain areas support distinct processes in contextual cueing.

PubMed

Manginelli, Angela A; Baumgartner, Florian; Pollmann, Stefan

2013-02-15

Behavioral evidence suggests that the use of implicitly learned spatial contexts for improved visual search may depend on visual working memory resources. Working memory may be involved in contextual cueing in different ways: (1) for keeping implicitly learned working memory contents available during search or (2) for the capture of attention by contexts retrieved from memory. We mapped brain areas that were modulated by working memory capacity. Within these areas, activation was modulated by contextual cueing along the descending segment of the intraparietal sulcus, an area that has previously been related to maintenance of explicit memories. Increased activation for learned displays, but not modulated by the size of contextual cueing, was observed in the temporo-parietal junction area, previously associated with the capture of attention by explicitly retrieved memory items, and in the ventral visual cortex. This pattern of activation extends previous research on dorsal versus ventral stream functions in memory guidance of attention to the realm of attentional guidance by implicit memory. Copyright © 2012 Elsevier Inc. All rights reserved.

Altered Error-Related Activity in Patients with Schizophrenia

ERIC Educational Resources Information Center

Koch, Kathrin; Wagner, Gerd; Schultz, Christoph; Schachtzabel, Claudia; Nenadic, Igor; Axer, Martina; Reichenbach, Jurgen R.; Sauer, Heinrich; Schlosser, Ralf G. M.

2009-01-01

Deficits in working memory (WM) and executive cognitive control are core features of schizophrenia. However, findings regarding functional activation strengths are heterogeneous, partly due to differences in task demands and behavioral performance. Previous investigators proposed integrating these heterogeneous findings into a comprehensive model…

Numerical Simulation of the Diffusion Processes in Nanoelectrode Arrays Using an Axial Neighbor Symmetry Approximation.

PubMed

Peinetti, Ana Sol; Gilardoni, Rodrigo S; Mizrahi, Martín; Requejo, Felix G; González, Graciela A; Battaglini, Fernando

2016-06-07

Nanoelectrode arrays have introduced a complete new battery of devices with fascinating electrocatalytic, sensitivity, and selectivity properties. To understand and predict the electrochemical response of these arrays, a theoretical framework is needed. Cyclic voltammetry is a well-fitted experimental technique to understand the undergoing diffusion and kinetics processes. Previous works describing microelectrode arrays have exploited the interelectrode distance to simulate its behavior as the summation of individual electrodes. This approach becomes limited when the size of the electrodes decreases to the nanometer scale due to their strong radial effect with the consequent overlapping of the diffusional fields. In this work, we present a computational model able to simulate the electrochemical behavior of arrays working either as the summation of individual electrodes or being affected by the overlapping of the diffusional fields without previous considerations. Our computational model relays in dividing a regular electrode array in cells. In each of them, there is a central electrode surrounded by neighbor electrodes; these neighbor electrodes are transformed in a ring maintaining the same active electrode area than the summation of the closest neighbor electrodes. Using this axial neighbor symmetry approximation, the problem acquires a cylindrical symmetry, being applicable to any diffusion pattern. The model is validated against micro- and nanoelectrode arrays showing its ability to predict their behavior and therefore to be used as a designing tool.

Restoration of fMRI Decodability Does Not Imply Latent Working Memory States

PubMed Central

Schneegans, Sebastian; Bays, Paul M.

2018-01-01

Recent imaging studies have challenged the prevailing view that working memory is mediated by sustained neural activity. Using machine learning methods to reconstruct memory content, these studies found that previously diminished representations can be restored by retrospective cueing or other forms of stimulation. These findings have been interpreted as evidence for an activity-silent working memory state that can be reactivated dependent on task demands. Here, we test the validity of this conclusion by formulating a neural process model of working memory based on sustained activity and using this model to emulate a spatial recall task with retrocueing. The simulation reproduces both behavioral and fMRI results previously taken as evidence for latent states, in particular the restoration of spatial reconstruction quality following an informative cue. Our results demonstrate that recovery of the decodability of an imaging signal does not provide compelling evidence for an activity-silent working memory state. PMID:28820674

Simulation of the mechanical behavior of a HIP implant. Implant fixed to bone by cementation under arbitrary load

NASA Astrophysics Data System (ADS)

Oldani, C. R.; Dominguez, A. A.

2007-11-01

In a previous work a finite elements model was constructed to simulate a fatigue assay according to the norm IRAM 9422-3. Three materials were studied, two of them are the most used in this type of implant (Stainless steel 3161 and alloy T16A14V) and the third was a new developed titanium alloy (Ti35Nb7Zr5Ta). Static loads were applied to the model according to the highest requirements of the norm and the stress - strain distribution were determined. In this study a simplified analysis of the material's fatigue was done according to the previous work. The best behavior of the titanium alloys vs. the stainless steel was evident. With the objective of studying the behavior of both: the implant and the femur bone, new finite elements models were realized, in which the presence of the bone was considered. Inside the bone, the femoral component of the implant was placed in a similar way of a cemented prosthesis in a total hip arthroplasty. The advantage of the titanium implant related to the stainless steel one, was very clear.

Settling behavior of unpurified Cryptosporidium oocysts in laboratory settling columns.

PubMed

Young, Pamela L; Komisar, Simeon J

2005-04-15

The settling behavior of fresh and aged unpurified oocysts was examined in settling column suspensions with varied ionic strengths and concentrations of calcium and magnesium. Independent measurements of the size and density of unpurified oocysts were performed to determine a theoretical settling velocity for the test populations. Viability of the oocysts was assessed using a dye permeability assay. Latex microspheres were included to provide a standard by which to assess the settling conditions in the columns. Mean settling velocities for viable oocysts measured in this work were faster than predicted and faster than measured for purified oocysts in other work: 1.31 (+/-0.21) microm/s for viable oocysts from populations having a low percentage of viable oocysts and 1.05 (+/-0.20) microm/s for viable oocysts from populations with a high percentage of viable oocysts. Results were attributed to the higher than previously reported densities measured for oocysts in this study and the presence of fecal material, which allowed opportunity for particle agglomeration. Settling velocity of oocysts was significantly related to the viability of the population, particle concentration, ionic strength, and presence of calcium and magnesium in the suspending medium. Behavior of the latex microspheres was not entirely predictive of the behavior of the oocysts under the test conditions. Viable oocysts may have a greater probability of settling than previously assumed; however, nonviable, and especially nonintact, oocysts have the potential to be significantly transported in water. This work underscores the importance of assessing the viability of oocysts to predict their response to environmental and experimental conditions.

The evolution of honest communication: integrating social and physiological costs of ornamentation.

PubMed

Tibbetts, Elizabeth A

2014-10-01

Much research on animal communication has addressed how costs such as social costs or physiological costs favor the accuracy of signals. Previous work has largely considered these costs separately, but we may be missing essential connections by studying costs in isolation. After all, social interactions produce rapid changes in hormone titers which can then affect individual behavior and physiology. As a result, social costs are likely to have widespread physiological consequences. Here, I present a new perspective on the factors that maintain honest signals by describing how the interplay between social costs and physiological costs may maintain an accurate link between an animal's abilities and ornament elaboration. I outline three specific mechanisms by which the interaction between social behavior and hormones could favor honest signals and present specific predictions for each of the three models. Then, I review how ornaments alter agonistic behavior, agonistic behavior influences hormones, and how these hormonal effects influence fitness. I also describe the few previous studies that have directly tested how ornaments influence hormones. Finally, opportunities for future work are discussed. Considering the interaction between social behavior and physiology may address some challenges associated with both social and physiological models of costs. Understanding the dynamic feedbacks between physiology and social costs has potential to transform our understanding of the stability of animals' communication systems. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Innovative approach to the design and evaluation of treatment adherence interventions for drug-resistant TB.

PubMed

Alegria-Flores, K; Weiner, B J; Wiesen, C A; Lich, K L H; Van Rie, A; Paul, J E; Tovar, M A

2017-11-01

Drug-resistant tuberculosis (DR-TB) treatment is expensive, lengthy, and can cause severe side effects. Patients face socio-economic, psychosocial, and systemic barriers to adherence; poor adherence results in poor treatment outcomes. To estimate the effects of the components of the information-motivation-behavioral skills model on DR-TB treatment adherence. We recruited 326 adults receiving DR-TB treatment and 86 of their health care service providers from 40 health centers in Lima, Peru. The main outcome was adherence (i.e., the proportion of prescribed doses taken by a patient). Exposure measures were adherence information, motivation, and behavioral skills; loss to follow-up during previous TB treatment(s); providers' work engagement; and patient-perceived support from his/her social network. Structural equation modeling revealed that adherence information and motivation had positive effects on adherence, but only if mediated through behavioral skills (β = 0.02, P < 0.01 and β = 0.07, P < 0.001, respectively). Behavioral skills had a direct positive effect on adherence (β = 0.27, P < 0.001). Loss to follow-up during previous treatment had a direct negative effect, providers' work engagement had a direct positive effect, and perceived support had indirect positive effects on adherence. The model's overall R2 was 0.76. The components of the information-motivation-behavioral skills model were associated with adherence and could be used to design, monitor, and evaluate interventions targeting adherence to DR-TB treatment.

Institutionalization and indiscriminate social behavior: Differential-susceptibility versus diathesis-stress models for the 5-HTTLPR and BDNF genotypes.

PubMed

Mesquita, A R; Belsky, J; Li, Z; Baptista, J; Carvalho-Correia, E; Maciel, P; Soares, I

2015-12-01

Institutionalization adversely impacts children's emotional functioning, proving related to attachment disorders, perhaps most notably that involving indiscriminate behavior, the subject of this report. In seeking to extend work in this area, this research on gene X environment (GXE) interplay investigated whether the serotonin transporter (5-HTTLPR) and val66met Brain-Derived Neurotrophic Factor (BDNF) polymorphisms moderated the effect of institutional care on indiscriminate behavior in preschoolers. Eighty-five institutionalized and 135 home-reared Portuguese children were assessed using Disturbances of Attachment Interview (DAI). GXE results indicated that s/s homozygotes of the 5-HTTLPR gene displayed significantly higher levels of indiscriminate behavior than all other children if institutionalized, something not true of such children when family reared. These findings proved consistent with the diathesis-stress rather than differential-susceptibility model of person×environment interaction. BDNF proved unrelated to indiscriminate behavior. Results are discussed in relation to previous work on this subject of indiscriminate behavior, institutionalization and GXE interaction. Copyright © 2015 Elsevier Inc. All rights reserved.

Alcohol dependence and criminal behavior: preliminary results of an association study of environmental and genetic factors in an Italian male population.

PubMed

Terranova, Claudio; Tucci, Marianna; Sartore, Daniela; Cavarzeran, Fabiano; Barzon, Luisa; Palù, Giorgio; Ferrara, Santo D

2012-09-01

The aim of this study is to propose an innovative approach evaluating the connection between alcohol use disorders and criminal behavior. The research, structured as a case-control study, was based on the analysis of environmental (social variables) and genetic factors (single nucleotide polymorphisms of glutamic acid decarboxylase) in a population (N = 173) of Italian alcohol-dependent men. Group 1 (N = 47, convicted subjects) was compared with Group 2 (N = 126, no previous criminal conduct). Grade repetition, work problems, and drug problems were statistically associated with criminal behavior. Having daily family meals together and having children were inversely related to convictions. The genotype distribution of the two groups was similar. The association between environmental factors and antisocial behavior confirms previous findings in the literature. The lack of genetic association does not exclude the role of the gamma-aminobutyric acid (GABA) system in determining antisocial behavior; further studies with larger samples are needed, together with investigation of other components of the GABA pathway. © 2012 American Academy of Forensic Sciences.

Tart cherries improve working memory in aged rats

USDA-ARS?s Scientific Manuscript database

Aged rats show impaired performance on cognitive tasks that require the use of spatial learning and memory. In previous studies, we have shown the beneficial effects of various dark-colored berry fruits (blueberries, strawberries, and blackberries) in reversing age-related deficits in behavioral and...

The Constructivist Concept: Primacy of the Obscure.

ERIC Educational Resources Information Center

Thoresen, Carl E.

1988-01-01

Responds to Mahoney and Lyddon's review of constructivism in previous article by raising questions about how the conceptual framework of constructivism can be further examined or challenged scientifically, how a constructivist orientation can be used in clinical and counseling work, and what role behavior plays. (NB)

CARDIOVASCULAR AND THERMOREGULATORY RESPONSE TO ORAL TOLUENE IN THE RAT.

EPA Science Inventory

Toluene and other volatile organic compounds have often been shown to affect behavior in animals when given by inhalation, and less effective when given orally. Previous work showed that toluene increased heart rate (HR) and motor activity (MA), and reduced core temperature (Tc) ...

Transient Mobility on Submonolayer Island Growth: An Exploration of Asymptotic Effects in Modeling

NASA Astrophysics Data System (ADS)

Morales-Cifuentes, Josue; Einstein, Theodore L.; Pimpinelli, Alberto

In studies of epitaxial growth, modeling of the smallest stable cluster (i+1 monomers, with i the critical nucleus size), is paramount in understanding growth dynamics. Our previous work has tackled submonolayer growth by modeling the effect of ballistic monomers, hot-precursors, on diffusive dynamics. Different scaling regimes and energies were predicted, with initial confirmation by applying to para-hexaphenyl submonolayer studies. Lingering questions about the applicability and behavior of the model are addressed. First, we show how an asymptotic approximation based on the growth exponent, α (N Fα) allows for robustness of modeling to experimental data; second, we answer questions about non-monotonicity by exploring the behavior of the growth exponent across realizable parameter spaces; third, we revisit our previous para-hexaphenyl work and examine relevant physical parameters, namely the speed of the hot-monomers. We conclude with an exploration of how the new asymptotic approximation can be used to strengthen the application of our model to other physical systems.

Expanding the role of striatal cholinergic interneurons and the midbrain dopamine system in appetitive instrumental conditioning.

PubMed

Crossley, Matthew J; Horvitz, Jon C; Balsam, Peter D; Ashby, F Gregory

2016-01-01

The basal ganglia are a collection of subcortical nuclei thought to underlie a wide variety of vertebrate behavior. Although a great deal is known about the functional and physiological properties of the basal ganglia, relatively few models have been formally developed that have been tested against both behavioral and physiological data. Our previous work (Ashby FG, Crossley MJ. J Cogn Neurosci 23: 1549-1566, 2011) showed that a model grounded in the neurobiology of the basal ganglia could account for basic single-neuron recording data, as well as behavioral phenomena such as fast reacquisition that constrain models of conditioning. In this article we show that this same model accounts for a variety of appetitive instrumental conditioning phenomena, including the partial reinforcement extinction (PRE) effect, rapid and slowed reacquisition following extinction, and renewal of previously extinguished instrumental responses by environmental context cues. Copyright © 2016 the American Physiological Society.

An experimental and numerical approach to understand the effect of the IPMC composition on its sensing and energy harvesting behavior

NASA Astrophysics Data System (ADS)

Akle, Barbar; Khairallah, Reef; Challita, Elio

2014-03-01

Ionic Polymer Metal Composite (IPMC) is an Electo-Active Polymer (EAP) that is well-known for its actuation and sensing behavior. It has been shown that in charge sensing mode an IPMC generates one order of magnitude larger current as compared to piezoelectric materials. However the voltage generated is on the order of couple millivolts, making it less attractive as a sensor and energy harvester. Previous numerical work by the author, demonstrated that increasing the ionic concentration of the ionomer will increase the current and voltage generated by an IPMC. Conversely, the previous study showed that the electrode composition and architecture had minimal effects. This paper will present an experimental investigation of the effect of changing the composition of the ionomer, the membrane thickness, and electrode architecture on the sensing and energy harvesting behavior. The response of all IPMC transducers is analyzed and compared to numerical simulations.

Item generation and pilot testing of the Comprehensive Professional Behaviours Development Log.

PubMed

Bartlett, Doreen J; Lucy, S Deborah; Bisbee, Leslie

2006-01-01

The purpose of this project was to generate and refine criteria for professional behaviors previously identified to be important for physical therapy practice and to develop and pilot test a new instrument, which we have called the Comprehensive Professional Behaviours Development Log (CPBDL). Items were generated from our previous work, the work of Warren May and his colleagues, a competency profile for entry-level physical therapists, our regulatory code of ethics, and an evaluation of clinical performance. A group of eight people, including recent graduates, clinical instructors and professional practice leaders, and faculty members, refined the items in two iterations using the Delphi process. The CPBDL contains nine key professional behaviors with a range of nine to 23 specific behavioral criteria for individuals to reflect on and to indicate the consistency of performance from a selection of "not at all," "sometimes," and "always" response options. Pilot testing with a group of 42 students in the final year of our entry-to-practice curriculum indicated that the criteria were clear, the measure was feasible to complete in a reasonable time frame, and there were no ceiling or floor effects. We believe that others, including health care educators and practicing professionals, might be interested in adapting the CPBDL in their own settings to enhance the professional behaviors of either students in preparation for entry to practice or clinicians wishing to demonstrate continuing competency to professional regulatory bodies.

Changes in the Influence of Alcohol-Paired Stimuli on Alcohol Seeking across Extended Training

PubMed Central

Corbit, Laura H.; Janak, Patricia H.

2016-01-01

Previous work has demonstrated that goal-directed control of alcohol-seeking and other drug-related behaviors is reduced following extended self-administration and drug exposure. Here, we examined how the magnitude of stimulus influences on responding changes across similar training and drug exposure. Rats self-administered alcohol or sucrose for 2 or 8 weeks. Previous work has shown that 8 weeks, but not 2 weeks of self-administration produces habitual alcohol seeking. Next, all animals received equivalent Pavlovian conditioning sessions where a discrete stimulus predicted the delivery of alcohol or sucrose. Finally, the impact of the stimuli on ongoing instrumental responding was examined in a Pavlovian–instrumental transfer (PIT) test. While a significant PIT effect was observed following 2 weeks of either alcohol or sucrose self-administration, the magnitude of this effect was greater following 8 weeks of training. The specificity of the PIT effect appeared unchanged by extended training. While it is well established that evaluation of the outcome of responding contributes less to behavioral control following extended training and/or drug exposure, our data indicate that reward–predictive stimuli have a stronger contribution to responding after extended training. Together, these findings provide insight into the factors that control behavior after extended drug use, which will be important for developing effective methods for controlling and ideally reducing these behaviors. PMID:27777560

Spatiotemporal encoding of search strategies by prefrontal neurons.

PubMed

Chiang, Feng-Kuei; Wallis, Joni D

2018-05-08

Working memory is capacity-limited. In everyday life we rarely notice this limitation, in part because we develop behavioral strategies that help mitigate the capacity limitation. How behavioral strategies are mediated at the neural level is unclear, but a likely locus is lateral prefrontal cortex (LPFC). Neurons in LPFC play a prominent role in working memory and have been shown to encode behavioral strategies. To examine the role of LPFC in overcoming working-memory limitations, we recorded the activity of LPFC neurons in animals trained to perform a serial self-ordered search task. This task measured the ability to prospectively plan the selection of unchosen spatial search targets while retrospectively tracking which targets were previously visited. We found that individual LPFC neurons encoded the spatial location of the current search target but also encoded the spatial location of targets up to several steps away in the search sequence. Neurons were more likely to encode prospective than retrospective targets. When subjects used a behavioral strategy of stereotyped target selection, mitigating the working-memory requirements of the task, not only did the number of selection errors decrease but there was a significant reduction in the strength of spatial encoding in LFPC. These results show that LPFC neurons have spatiotemporal mnemonic fields, in that their firing rates are modulated both by the spatial location of future selection behaviors and the temporal organization of that behavior. Furthermore, the strength of this tuning can be dynamically modulated by the demands of the task.

An Experimental and Computational Analysis of Primary Cilia Deflection Under Fluid Flow

PubMed Central

Downs, Matthew E.; Nguyen, An M.; Herzog, Florian A.; Hoey, David A.; Jacobs, Christopher R.

2013-01-01

In this work we have developed a novel model of the deflection of primary cilia experiencing fluid flow accounting for phenomena not previously considered. Specifically, we developed a large rotation formulation that accounts for rotation at the base of the cilium, the initial shape of the cilium and fluid drag at high deflection angles. We utilized this model to analyze full three dimensional datasets of primary cilia deflecting under fluid flow acquired with high-speed confocal microscopy. We found a wide variety of previously unreported bending shapes and behaviors. We also analyzed post-flow relaxation patterns. Results from our combined experimental and theoretical approach suggest that the average flexural rigidity of primary cilia might be higher than previously reported (Schwartz et al. 1997). In addition our findings indicate the mechanics of primary cilia are richly varied and mechanisms may exist to alter their mechanical behavior. PMID:22452422

Children's Syntactic-Priming Magnitude: Lexical Factors and Participant Characteristics

ERIC Educational Resources Information Center

Foltz, Anouschka; Thiele, Kristina; Kahsnitz, Dunja; Stenneken, Prisca

2015-01-01

This study examines whether lexical repetition, syntactic skills, and working memory (WM) affect children's syntactic-priming behavior, i.e. their tendency to adopt previously encountered syntactic structures. Children with Specific Language Impairment (SLI) and typically developing (TD) children were primed with prenominal (e.g. "the yellow…

Decoupling Object Detection and Categorization

ERIC Educational Resources Information Center

Mack, Michael L.; Palmeri, Thomas J.

2010-01-01

We investigated whether there exists a behavioral dependency between object detection and categorization. Previous work (Grill-Spector & Kanwisher, 2005) suggests that object detection and basic-level categorization may be the very same perceptual mechanism: As objects are parsed from the background they are categorized at the basic level. In…

Evolution of the Deformation Behavior of Sn-Rich Solders during Cyclic Fatigue

NASA Astrophysics Data System (ADS)

Wentlent, Luke Arthur

Continuous developments in the electronics industry have provided a critical need for a quantitative, fundamental understanding of the behavior of SnAgCu (SAC) solders in both isothermal and thermal fatigue conditions. This study examines the damage behavior of Sn-based solders in a constant amplitude and variable amplitude environment. In addition, damage properties are correlated with crystal orientation and slip behavior. Select solder joints were continuously characterized and tested repeatedly in order to eliminate the joint to joint variation due to the anisotropy of beta-Sn. Characterization was partitioned into three different categories: effective properties and slip behavior, creep mechanisms and crystal morphology development, and atomic behavior and evolution. Active slip systems were correlated with measured properties. Characterization of the mechanical behavior was performed by the calculation and extrapolation of the elastic modulus, work, effective stiffness, Schmid factors, and time-dependent plasticity (creep). Electron microscopy based characterization methods included Scanning Electron Microscopy (SEM), Electron Backscattering Diffraction (EBSD), and Transmission Electron Microscopy (TEM). Testing showed a clear evolution of the steady-state creep mechanism when the cycling amplitudes were varied, from dislocation controlled to diffusion controlled creep. Dislocation behavior was examined and shown to evolve differently in single amplitude vs. variable amplitude testing. Finally, the mechanism of the recrystallization behavior of the beta-Sn was observed. This work fills a gap in the literature, providing a systematic study which identifies how the damage behavior in Sn-alloys depends upon the previous damage. A link is made between the observed creep behavior and the dislocation observations, providing a unified picture. Information developed in this work lays a stepping stone to future fundamental analyses as well as clarifying aspects of the mechanistic behavior of Sn and Sn-based alloys.

Attention and working memory deficits in a perinatal nicotine exposure mouse model.

PubMed

Zhang, Lin; Spencer, Thomas J; Biederman, Joseph; Bhide, Pradeep G

2018-01-01

Cigarette smoking by pregnant women is associated with a significant increase in the risk for cognitive disorders in their children. Preclinical models confirm this risk by showing that exposure of the developing brain to nicotine produces adverse behavioral outcomes. Here we describe behavioral phenotypes resulting from perinatal nicotine exposure in a mouse model, and discuss our findings in the context of findings from previously published studies using preclinical models of developmental nicotine exposure. Female C57Bl/6 mice received drinking water containing nicotine (100μg/ml) + saccharin (2%) starting 3 weeks prior to breeding and continuing throughout pregnancy, and until 3 weeks postpartum. Over the same period, female mice in two control groups received drinking water containing saccharin (2%) or plain drinking water. Offspring from each group were weaned at 3-weeks of age and subjected to behavioral analyses at 3 months of age. We examined spontaneous locomotor activity, anxiety-like behavior, spatial working memory, object based attention, recognition memory and impulsive-like behavior. We found significant deficits in attention and working memory only in male mice, and no significant changes in the other behavioral phenotypes in male or female mice. Exposure to saccharin alone did not produce significant changes in either sex. The perinatal nicotine exposure produced significant deficits in attention and working memory in a sex-dependent manner in that the male but not female offspring displayed these behaviors. These behavioral phenotypes are associated with attention deficit hyperactivity disorder (ADHD) and have been reported in other studies that used pre- or perinatal nicotine exposure. Therefore, we suggest that preclinical models of developmental nicotine exposure could be useful tools for modeling ADHD and related disorders.

Androgen-primed castrate males are sufficient for methamphetamine-facilitated increases in proceptive behavior in female rats

PubMed Central

Rudzinskas, Sarah A.; Mong, Jessica A.

2015-01-01

Methamphetamine (MA) is a psychomotor stimulant associated with increases in sex drive in both men and women. Women, however, are far more likely to face social disadvantages as a consequence of MA use, and their increased sexual motivation poses additional health concerns such as unplanned pregnancies. To better understand the mechanisms underlying MA-facilitated sexual motivation in females, we previously established a rodent model where a ‘binge”-type administration paradigm of MA to sexually receptive female rats significantly increases proceptive behavior in the presence of a sexually active, gonadally-intact male. Our previous work with this model has led us to consider whether the increases in proceptive behavior are truly indicative of increased sexual motivation, or instead a consequence of heightened motor responsivity. Here, we test whether MA-induced increases in proceptive behaviors are specific to a sexually relevant stimulus. Females’ sexual, social, exploratory behaviors, and interaction times were scored during the exposure to stimulus males, including castrates, and dihydrotestosterone (DHT)-treated castrates. MA-treated females demonstrated significant increases in proceptive behaviors toward DHT-treated castrate males but not toward castrate males. While the non-MA-treated females did display proceptive behavior, there was no significant difference between behaviors elicited by DHT-CX males compared to CX males. Our results support the hypothesis that MA facilitates proceptive behavior only in response to specific, androgen mediated sexually-relevant cues. PMID:26497407

The choice to text and drive in younger drivers: behavior may shape attitude.

PubMed

Atchley, Paul; Atwood, Stephanie; Boulton, Aaron

2011-01-01

Following a previous study that reported a large number of young adult drivers text and drive, the current study investigated this behavior by looking at patterns of use and driver assessment of the risk of the behavior. The data from the current study converge with and extended the previous work showing 70% of the 348 young adult drivers surveyed report initiating texts while driving while higher numbers reply to texts (81%) and read texts (92%) while driving. Additional drivers also report doing these behaviors, but only while stopped in traffic, showing only 2% never text and drive under any circumstances. The drivers indicated that they perceived these behaviors to be very risky and riskier than talking on a cell phone while driving, but perception of risk was a very weak predictor of behavior (for initiating texts) or had no effect on texting (for replying or reading texts while driving). In addition, a factor analysis of the perception of road conditions while texting revealed that making the choice to engage in texting (initiating) led drivers to perceive road conditions as being safer than if they replied to a text or read a text, suggesting that choosing to engage in the behavior itself changes attitudes toward risk. Copyright © 2010 Elsevier Ltd. All rights reserved.

Value-Based Standards Guide Sexism Inferences for Self and Others.

PubMed

Mitamura, Chelsea; Erickson, Lynnsey; Devine, Patricia G

2017-09-01

People often disagree about what constitutes sexism, and these disagreements can be both socially and legally consequential. It is unclear, however, why or how people come to different conclusions about whether something or someone is sexist. Previous research on judgments about sexism has focused on the perceiver's gender and attitudes, but neither of these variables identifies comparative standards that people use to determine whether any given behavior (or person) is sexist. Extending Devine and colleagues' values framework (Devine, Monteith, Zuwerink, & Elliot, 1991; Plant & Devine, 1998), we argue that, when evaluating others' behavior, perceivers rely on the morally-prescriptive values that guide their own behavior toward women. In a series of 3 studies we demonstrate that (1) people's personal standards for sexism in their own and others' behavior are each related to their values regarding sexism, (2) these values predict how much behavioral evidence people need to infer sexism, and (3) people with stringent, but not lenient, value-based standards get angry and try to regulate a sexist perpetrator's behavior to reduce sexism. Furthermore, these personal values are related to all outcomes in the present work above and beyond other person characteristics previously used to predict sexism inferences. We discuss the implications of differing value-based standards for explaining and reconciling disputes over what constitutes sexist behavior.

Real-time fMRI training-induced changes in regional connectivity mediating verbal working memory behavioral performance.

PubMed

Shen, J; Zhang, G; Yao, L; Zhao, X

2015-03-19

Working memory refers to the ability to temporarily store and manipulate information that is necessary for complex cognition activities. Previous studies have demonstrated that working memory capacity can be improved by behavioral training, and brain activities in the frontal and parietal cortices and the connections between these regions are also altered by training. Our recent neurofeedback training has proven that the regulation of the left dorsal lateral prefrontal cortex (DLPFC) activity using real-time functional magnetic resonance imaging (rtfMRI) can improve working memory performance. However, how working memory training promotes interaction between brain regions and whether this promotion correlates with performance improvement remain unclear. In this study, we employed structural equation modeling (SEM) to calculate the interactions between the regions within the working memory network during neurofeedback training. The results revealed that the direct effect of the frontoparietal connection in the left hemisphere was enhanced by the rtfMRI training. Specifically, the increase in the path from the left DLPFC to the left inferior parietal lobule (IPL) was positively correlated with improved performance in verbal working memory. These findings demonstrate the important role of the frontoparietal connection in working memory training and suggest that increases in frontoparietal connectivity might be a key factor associated with behavioral improvement. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Variables involved in the perception of psychological harassment in the nursing work environment.

PubMed

Fontes, Kátia Biagio; Carvalho, Maria Dalva de Barros

2012-01-01

This is a descriptive-exploratory study with a quantitative approach, with the objective of identifying how nurses perceive psychological harassment at work, the behaviors experienced and the variables involved. In collecting data, two questionnaires were used: one socio-professional and another for identifying the behaviors involving psychological harassment experienced by the subjects in the previous twelve months, along with the duration and frequency of the behaviors. At the end of the questionnaire, a dichotomous question was added, which addressed nurses' perceptions in relation to feeling victimized by psychological harassment at work. Both the questionnaires were applied in electronic and print format between May and September 2010. The data was analyzed through descriptive statistics. The results showed that some of the subjects felt that they were victims of psychological harassment. Only the variables related to characterization of the psychological harassment presented significant association. The following were highlighted among the most-referred-to behaviors: "They question your decisions" and "You receive verbal attacks criticizing work you have done". It's important to open spaces for discussing violence at work, so that managers may establish strategic measures for preventing and containing this type of violence, so as to ensure health, dignity and well-being at work. It is also important to discuss this issue in the academic space, so as to give the theme greater visibility, such that future nurses will be able to identify and appropriately confront this type of violence.

Decomposing Bias in Different Types of Simple Decisions

ERIC Educational Resources Information Center

White, Corey N.; Poldrack, Russell A.

2014-01-01

The ability to adjust bias, or preference for an option, allows for great behavioral flexibility. Decision bias is also important for understanding cognition as it can provide useful information about underlying cognitive processes. Previous work suggests that bias can be adjusted in 2 primary ways: by adjusting how the stimulus under…

Quantization of the damped harmonic oscillator revisited

NASA Astrophysics Data System (ADS)

Baldiotti, M. C.; Fresneda, R.; Gitman, D. M.

2011-04-01

We return to the description of the damped harmonic oscillator with an assessment of previous works, in particular the Bateman-Caldirola-Kanai model and a new model proposed by one of the authors. We argue the latter has better high energy behavior and is connected to existing open-systems approaches.

Atrazine Does Not Induce Pica Behavior at Doses that Increase Hypothalamic-Pituitary-Adrenal Axis Activation and Cause Conditioned Taste Avoidance.

EPA Science Inventory

Previous work has shown that a single oral administration of atrazine (ATR), a chlorotriazine herbicide, induces dose-dependent increases in plasma adrenocorticotropic hormone (ACTH), serum corticosterone (CORT) and progesterone. The mechanism for these effects is unknown. To tes...

A Longitudinal Examination of Parenting Behaviors and Perceived Discrimination Predicting Latino Adolescents' Ethnic Identity

ERIC Educational Resources Information Center

Umana-Taylor, Adriana J.; Guimond, Amy B.

2010-01-01

Characteristics of the familial and societal context were examined as predictors of Latino adolescents' (N = 323; 49.5% female) ethnic identity. Consistent with previous work, familial ethnic socialization significantly predicted future levels of ethnic identity exploration, resolution, and affirmation for both male adolescents and female…

Predictions of Children's Experiences with Latina Family Child Care Providers

ERIC Educational Resources Information Center

Zuniga, Stephen A.; Howes, Carollee

2009-01-01

Research Findings: Relatively little is known about the pre-academic experiences of Latino/a children in family child care. In this work we tested the extent to which previously established relations among provider characteristics, scaffolding and responsive behaviors, total quality (Family Day Care Rating Scale), and children's engagement in…

Functional Analytic Psychotherapy with Juveniles Who Have Committed Sexual Offenses

ERIC Educational Resources Information Center

Newring, Kirk A. B.; Wheeler, Jennifer G.

2012-01-01

We have previously discussed the application of Functional Analytic Psychotherapy (FAP) with adults who have committed sexual offense behaviors (Newring & Wheeler, 2010). The present entry borrows heavily from the foundation presented in that chapter, and extends this approach to working with adolescents, youth, and juveniles with sexual offense…

Epidemics on adaptive networks with geometric constraints

NASA Astrophysics Data System (ADS)

Shaw, Leah; Schwartz, Ira

2008-03-01

When a population is faced with an epidemic outbreak, individuals may modify their social behavior to avoid exposure to the disease. Recent work has considered models in which the contact network is rewired dynamically so that susceptibles avoid contact with infectives. We consider extensions in which the rewiring is subject to constraints that preserve key properties of the social network structure. Constraining to a fixed degree distribution destroys previously observed bistable behavior. The most effective rewiring strategy is found to depend on the spreading rate.

Death on the digital landscape: a preliminary investigation into the grief process and motivations behind participation in the online memoriam.

PubMed

Egnoto, Michael J; Sirianni, Joseph M; Ortega, Christopher R; Stefanone, Michael

2014-01-01

Increasingly, individuals are bonding and maintaining relationships online. These digital representations of ourselves allow us to connect with others in ways previously not possible. One behavior that is growing in online presentations of self is grieving after the death of an individual in our social network. This work investigates the outcomes of online grieving from a transcorporeal communication model perspective, and draws conclusions on the outcomes of online grief behaviors.

Learning to use working memory: a reinforcement learning gating model of rule acquisition in rats

PubMed Central

Lloyd, Kevin; Becker, Nadine; Jones, Matthew W.; Bogacz, Rafal

2012-01-01

Learning to form appropriate, task-relevant working memory representations is a complex process central to cognition. Gating models frame working memory as a collection of past observations and use reinforcement learning (RL) to solve the problem of when to update these observations. Investigation of how gating models relate to brain and behavior remains, however, at an early stage. The current study sought to explore the ability of simple RL gating models to replicate rule learning behavior in rats. Rats were trained in a maze-based spatial learning task that required animals to make trial-by-trial choices contingent upon their previous experience. Using an abstract version of this task, we tested the ability of two gating algorithms, one based on the Actor-Critic and the other on the State-Action-Reward-State-Action (SARSA) algorithm, to generate behavior consistent with the rats'. Both models produced rule-acquisition behavior consistent with the experimental data, though only the SARSA gating model mirrored faster learning following rule reversal. We also found that both gating models learned multiple strategies in solving the initial task, a property which highlights the multi-agent nature of such models and which is of importance in considering the neural basis of individual differences in behavior. PMID:23115551

When does transformational leadership enhance employee proactive behavior? The role of autonomy and role breadth self-efficacy.

PubMed

Den Hartog, Deanne N; Belschak, Frank D

2012-01-01

Two multisource studies address the interactive effects of personal and contextual variables on employees' proactive behavior. In line with previous work, we find positive main effects of transformational leadership, role breadth self-efficacy, and job autonomy on employee proactive behavior (personal initiative in Study 1 and prosocial proactive behavior in Study 2). As expected, a 3-way interaction qualifies these main effects: In situations of high autonomy, transformational leadership relates positively to proactive behavior for individuals high (but not low) on self-efficacy. Vice versa, in situations low on job autonomy, transformational leadership relates positively to proactive behavior for individuals low (but not high) on self-efficacy. This pattern is found both for self-ratings and peer-ratings of employees' proactive behavior in Study 1 and for supervisor ratings of such behavior in Study 2.

Modulating oscillatory brain activity correlates of behavioral inhibition using transcranial direct current stimulation.

PubMed

Jacobson, Liron; Ezra, Adi; Berger, Uri; Lavidor, Michal

2012-05-01

Studies have mainly documented behavioral changes induced by transcranial direct current stimulation (tDCS), but recently cortical modulations of tDCS have also been investigated. Our previous work revealed behavioral inhibition modulation by anodal tDCS over the right inferior frontal gyrus (rIFG); however, the electrophysiological correlates underlying this stimulation montage have yet to be established. The current work aimed to evaluate the distribution of neuronal oscillations changes following anodal tDCS over rIFG coupled with cathodal tDCS over left orbitofrontal cortex (lOFC) using spectral power analysis. Healthy subjects underwent sham and real tDCS (15 min, 1.5 mA, anodal rIFG; cathodal lOFC) stimulation conditions in a single-blind, placebo-controlled cross-over trial. Following tDCS session, resting EEG recordings were collected during 15 min. Analysis showed a significant and selective diminution of the power of theta band. The theta diminution was observed in the rIFG area (represented the anode electrode), and was not found in the lOFC area (represented the cathode electrode). A significant effect was observed only in the theta but not in other bands. These results are the first demonstration of modulating oscillatory activity as measured by EEG with tDCS over rIFG in general, and documenting theta band reduction with this montage in particular. Our results may explain the improvement in behavioral inhibition reported in our previous work, and although this study was conducted with healthy subjects, the findings suggest that tDCS may also modulate electrophysiological changes among ADHD patients, where decreasing theta activity is the target of neuro-feedback methods aimed to improve cognitive control. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Long Term Degradation of Resin for High Temperature Composites

NASA Technical Reports Server (NTRS)

Patekar, Kaustubh A.

2000-01-01

The durability of polymer matrix composites exposed to harsh environments is a major concern. Surface degradation and damage are observed in polyimide composites used in air at 125 to 300 C. It is believed that diffusion of oxygen into the material and oxidative chemical reactions in the matrix are responsible. Previous work has characterized and modeled diffusion behavior, and thermogravimetric analyses (TGAs) have been carried out in nitrogen, air, and oxygen to provide quantitative information on thermal and oxidative reactions. However, the model developed using these data was not able to capture behavior seen in isothermal tests, especially those of long duration. A test program that focuses on lower temperatures and makes use of isothermal tests was undertaken to achieve a better understanding of the degradation reactions under use conditions. A new low-cost technique was developed to collect chemical degradation data for isothermal tests lasting over 200 hr in the temperature range 125 to 300 C. Results indicate complex behavior not captured by the previous TGA tests, including the presence of weight-adding reactions. Weight gain reactions dominated in the 125 to 225 C temperature range, while weight loss reactions dominated beyond 225 C. The data obtained from isothermal tests was used to develop a new model of the material behavior. This model was able to fully capture the behavior seen in the tests up to 275 C. Correlation of the current model with both isothermal data at 300 C and high rate TGA test data is mediocre. At 300 C and above, the reaction mechanisms appear to change. Attempts (which failed) to measure non-oxidative degradation indicate that oxidative reactions dominate the degradation at low temperatures. Based on this work, long term isothermal testing in an oxidative atmosphere is recommended for studying the degradation behavior of this class of materials.

Design Criteria for Deflection Capacity of conventionally Reinforced Concrete Slabs. Phase I. State-of-the-Art Report.

DTIC Science & Technology

1980-10-01

Previous Investigations 9 3.2 Ockleston’s Work 9 3.3 Wood’s Work 11 3.3.1 Experimental Investigation 11 3.3.2 Analytical investigation 13 3.3.3 Load...Deflection Relationship 16 3.4 Sawczuck’s Work 17 3.5 Park’s Work on Compressive Membrane Action 19 3.5.1 Experimental Investigation 19 3.5.2 Analysis of...DEFLECTION CAPACITY 104 8.1 Idealized Load-Deflection Behavior of a Restrained Strip 104 8.2 A Comparison with Experimental Results 110 9. DEVELOPMENT OF

A retrospective and prospective look at strategies to increase adolescent HPV vaccine uptake in the United States.

PubMed

Head, Katharine J; Biederman, Erika; Sturm, Lynne A; Zimet, Gregory D

2018-01-23

The HPV vaccine debuted more than ten years ago in the United States and many strategies have been evaluated to increase HPV vaccination rates, which include not only improving current vaccination behaviors but also sustaining these behaviors. Researchers and practitioners from a variety of backgrounds have engaged in this work, which has included efforts directed at public health and government policies, health education and health promotion programs, and clinical and patient-provider approaches, as well as work aimed to respond to and combat anti-HPV vaccination movements in society. Using a previously developed conceptual model to organize and summarize each of these areas, this paper also highlights the need for future HPV vaccine promotion work to adopt a multi-level and, when possible, integrated approach in order to maximize impact on vaccination rates.

Simulating Activities: Relating Motives, Deliberation and Attentive Coordination

NASA Technical Reports Server (NTRS)

Clancey, William J.; Clancy, Daniel (Technical Monitor)

2002-01-01

Activities are located behaviors, taking time, conceived as socially meaningful, and usually involving interaction with tools and the environment. In modeling human cognition as a form of problem solving (goal-directed search and operator sequencing), cognitive science researchers have not adequately studied "off-task" activities (e.g., waiting), non-intellectual motives (e.g., hunger), sustaining a goal state (e.g., playful interaction), and coupled perceptual-motor dynamics (e.g., following someone). These aspects of human behavior have been considered in bits and pieces in past research, identified as scripts, human factors, behavior settings, ensemble, flow experience, and situated action. More broadly, activity theory provides a comprehensive framework relating motives, goals, and operations. This paper ties these ideas together, using examples from work life in a Canadian High Arctic research station. The emphasis is on simulating human behavior as it naturally occurs, such that "working" is understood as an aspect of living. The result is a synthesis of previously unrelated analytic perspectives and a broader appreciation of the nature of human cognition. Simulating activities in this comprehensive way is useful for understanding work practice, promoting learning, and designing better tools, including human-robot systems.

Neural circuit basis of visuo-spatial working memory precision: a computational and behavioral study.

PubMed

Almeida, Rita; Barbosa, João; Compte, Albert

2015-09-01

The amount of information that can be retained in working memory (WM) is limited. Limitations of WM capacity have been the subject of intense research, especially in trying to specify algorithmic models for WM. Comparatively, neural circuit perspectives have barely been used to test WM limitations in behavioral experiments. Here we used a neuronal microcircuit model for visuo-spatial WM (vsWM) to investigate memory of several items. The model assumes that there is a topographic organization of the circuit responsible for spatial memory retention. This assumption leads to specific predictions, which we tested in behavioral experiments. According to the model, nearby locations should be recalled with a bias, as if the two memory traces showed attraction or repulsion during the delay period depending on distance. Another prediction is that the previously reported loss of memory precision for an increasing number of memory items (memory load) should vanish when the distances between items are controlled for. Both predictions were confirmed experimentally. Taken together, our findings provide support for a topographic neural circuit organization of vsWM, they suggest that interference between similar memories underlies some WM limitations, and they put forward a circuit-based explanation that reconciles previous conflicting results on the dependence of WM precision with load. Copyright © 2015 the American Physiological Society.

Humidity-activated shape memory effect on plasticized starch-based biomaterials.

PubMed

Sessini, Valentina; Arrieta, Marina P; Fernández-Torres, Alberto; Peponi, Laura

2018-01-01

Humidity-activated shape memory behavior of plasticized starch-based films reinforced with the innovative combination of starch nanocrystals (SNCs) and catechin as antioxidant were studied. In a previous work, we reported the processing of gelatinized starch-based films filled with SNCs and catechin as antioxidant agent, and we observed that this novel combination leads to starch-based film with enhanced thermal and mechanical performance. In this work, the humidity-activated shape memory behavior of the previous developed starch-based films was characterized. The moisture loss as well as the moisture absorption were studied since they are essential parameters in humidity-activated shape memory polymers to fix the temporary shape and to recover the original shape, respectively. Therefore, the effect of the incorporation of SNCs and catechin on the humidity-activated shape memory properties of plasticized starch was also studied. Moreover, the effectiveness of catechin to increase the polymer stability under oxidative atmosphere and the thermo-mechanical relaxation of all the starch-based materials were studied. The combination of plasticized starch matrix loaded with both, SNCs and catechin, leads to a multifunctional starch-based films with increased hydrophilicity and with excellent humidity-activated shape memory behavior with interest for potential biomedical applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

Is outcome responsibility at work emotionally exhausting? Investigating employee proactivity as a moderator.

PubMed

Schmitt, Antje; Den Hartog, Deanne N; Belschak, Frank D

2015-10-01

This study investigates the relationship between outcome responsibility and employees' well-being in terms of emotional exhaustion. Outcome responsibility is a job demand implying that employees' decisions at work have high material and/or nonmaterial consequences. Previous research indicates that outcome responsibility can have both positive and negative effects on employee well-being. Based on the person-job fit approach we hypothesize that whether or not outcome responsibility is positively or negatively related to emotional exhaustion depends on whether employees' behavioral style fits with this job demand. We investigate the role of proactive behavior as a personal resource that fits with high responsibility. We test our hypothesis in a multisource study among 138 employee-colleague dyads. Results of hierarchical moderated regression analysis reveal that peer-rated proactive behavior moderates the relationship between outcome responsibility and emotional exhaustion, such that the relationship is negative for employees showing high and nonsignificant for employees showing low proactivity. This finding holds also when controlling for trait positive and negative affect. The current study contributes to previous research on job design, proactivity, and occupational well-being and offers practical implications in terms of selection and training of employees for jobs high in outcome responsibility. (c) 2015 APA, all rights reserved).

Molecular Dynamics Investigation of Each Bubble Behavior in Coarsening of Cavitation Bubbles in a Finite Space

NASA Astrophysics Data System (ADS)

Tsuda, Shin-Ichi; Nakano, Yuta; Watanabe, Satoshi

2017-11-01

Recently, several studies using Molecular Dynamics (MD) simulation have been conducted for investigation of Ostwald ripening of cavitation bubbles in a finite space. The previous studies focused a characteristic length of bubbles as one of the spatially-averaged quantities, but each bubble behavior was not been investigated in detail. The objective of this study is clarification of the characteristics of each bubble behavior in Ostwald ripening, and we conducted MD simulation of a Lennard-Jones fluid in a semi-confined space. As a result, the time dependency of the characteristic length of bubbles as a spatially-averaged quantity suggested that the driving force of the Ostwald ripening is Evaporation/Condensation (EC) across liquid-vapor surface, which is the same result as the previous works. The radius change of the relatively larger bubbles also showed the same tendency to a classical EC model. However, the sufficiently smaller bubbles than the critical size, e.g., the bubbles just before collapsing, showed a different characteristic from the classical EC model. Those smaller bubbles has a tendency to be limited by mechanical non-equilibrium in which viscosity of liquid is dominant rather than by EC across liquid-vapor surface. This work was supported by JSPS KAKENHI Grant Number JP16K06085.

Active Listening in a Bat Cocktail Party: Adaptive Echolocation and Flight Behaviors of Big Brown Bats, Eptesicus fuscus, Foraging in a Cluttered Acoustic Environment.

PubMed

Warnecke, Michaela; Chiu, Chen; Engelberg, Jonathan; Moss, Cynthia F

2015-09-01

In their natural environment, big brown bats forage for small insects in open spaces, as well as in vegetation and in the presence of acoustic clutter. While searching and hunting for prey, bats experience sonar interference, not only from densely cluttered environments, but also from calls of conspecifics foraging in close proximity. Previous work has shown that when two bats compete for a single prey item in a relatively open environment, one of the bats may go silent for extended periods of time, which can serve to minimize sonar interference between conspecifics. Additionally, pairs of big brown bats have been shown to adjust frequency characteristics of their vocalizations to avoid acoustic interference in echo processing. In this study, we extended previous work by examining how the presence of conspecifics and environmental clutter influence the bat's echolocation behavior. By recording multichannel audio and video data of bats engaged in insect capture in open and cluttered spaces, we quantified the bats' vocal and flight behaviors. Big brown bats flew individually and in pairs in an open and cluttered room, and the results of this study shed light on the different strategies that this species employs to negotiate a complex and dynamic environment. © 2015 S. Karger AG, Basel.

Universality of nonthermal behavior in spinor Bose condensates

NASA Astrophysics Data System (ADS)

Patil, Yogesh Sharad; Cheung, Hil F. H.; Shaffer, Airlia; Chen, Huiyao Y.; Vengalattore, Mukund

2016-05-01

Spinor Bose condensates exhibit a rich phase diagram with varied magnetic ordering and topological defects because of the close competition between their spin and charge dependent interactions. Quenching such a spinor condensate into a ferromagnetic state realizes robust non-equilibrium and prethermalized states whose macroscopic behavior differs from thermodynamic predictions. In previous work, we have identified the microscopic origin of prethermalization in Rubidium spinor gases as being the disparate energy scales of the phonon and magnon excitations in this gas. This identification of the microscopic origin enables us to broaden the scope of our studies to address fundamental questions regarding the equilibration of isolated quantum systems. We will discuss our recent results that suggest the universality of this coarsening behavior and evidence that this system can be mapped on to a non-thermal fixed point studied in high energy field theories. This work is supported by the ARO MURI on non-equilibrium dynamics.

Avian Models for Human Cognitive Neuroscience: A Proposal.

PubMed

Clayton, Nicola S; Emery, Nathan J

2015-06-17

Research on avian cognitive neuroscience over the past two decades has revealed the avian brain to be a better model for understanding human cognition than previously thought, despite differences in the neuroarchitecture of avian and mammalian brains. The brain, behavior, and cognition of songbirds have provided an excellent model of human cognition in one domain, namely learning human language and the production of speech. There are other important behavioral candidates of avian cognition, however, notably the capacity of corvids to remember the past and plan for the future, as well as their ability to think about another's perspective, and physical reasoning. We review this work and assess the evidence that the corvid brain can support such a cognitive architecture. We propose potential applications of these behavioral paradigms for cognitive neuroscience, including recent work on single-cell recordings and neuroimaging in corvids. Finally, we discuss their impact on understanding human developmental cognition. Copyright © 2015 Elsevier Inc. All rights reserved.

Correlating Resolving Power, Resolution, and Collision Cross Section: Unifying Cross-Platform Assessment of Separation Efficiency in Ion Mobility Spectrometry.

PubMed

Dodds, James N; May, Jody C; McLean, John A

2017-11-21

Here we examine the relationship among resolving power (R p ), resolution (R pp ), and collision cross section (CCS) for compounds analyzed in previous ion mobility (IM) experiments representing a wide variety of instrument platforms and IM techniques. Our previous work indicated these three variables effectively describe and predict separation efficiency for drift tube ion mobility spectrometry experiments. In this work, we seek to determine if our previous findings are a general reflection of IM behavior that can be applied to various instrument platforms and mobility techniques. Results suggest IM distributions are well characterized by a Gaussian model and separation efficiency can be predicted on the basis of the empirical difference in the gas-phase CCS and a CCS-based resolving power definition (CCS/ΔCCS). Notably traveling wave (TWIMS) was found to operate at resolutions substantially higher than a single-peak resolving power suggested. When a CCS-based R p definition was utilized, TWIMS was found to operate at a resolving power between 40 and 50, confirming the previous observations by Giles and co-workers. After the separation axis (and corresponding resolving power) is converted to cross section space, it is possible to effectively predict separation behavior for all mobility techniques evaluated (i.e., uniform field, trapped ion mobility, traveling wave, cyclic, and overtone instruments) using the equations described in this work. Finally, we are able to establish for the first time that the current state-of-the-art ion mobility separations benchmark at a CCS-based resolving power of >300 that is sufficient to differentiate analyte ions with CCS differences as small as 0.5%.

A single exposure to immobilization causes long-lasting pituitary-adrenal and behavioral sensitization to mild stressors.

PubMed

Belda, Xavier; Fuentes, Silvia; Nadal, Roser; Armario, Antonio

2008-11-01

We have previously reported that a single exposure to immobilization (IMO) in rats causes a long-term desensitization of the hypothalamic-pituitary-adrenal (HPA) response to the same (homotypic) stressor. Since there are reports showing that a single exposure to other stressors causes sensitization of the HPA response to heterotypic stressors and increases anxiety-like behavior, we studied in the present work the long-term effects of IMO on behavioral and HPA response to mild superimposed stressors. In Experiments 1 and 2, adult male Sprague-Dawley rats were subjected to 2 h of IMO and then exposed for 5 min to the elevated plus-maze (EPM) at 1, 3 or 7 days after IMO. Blood samples were taken at 15 min after initial exposure to the EPM. Increases in anxiety-like behavior and HPA responsiveness to the EPM were found at all times post-IMO. Changes in the resting levels of HPA hormones did not explain the enhanced HPA responsiveness to the EPM (Experiment 3). In Experiments 4 and 5, we studied the effects of a single exposure to a shorter session of IMO (1 h) on behavioral and HPA responses to a brief and mild session of foot-shocks done 10 days after IMO. Neither previous IMO nor exposure to shocks in control rats modified behavior in the EPM. However, a brief session of shocks in previously IMO-exposed rats dramatically increased anxiety in the EPM. HPA and freezing responses to shocks were similar in control and previous IMO groups. Therefore, a single exposure to IMO appears to induce long-lasting HPA and behavioral sensitization to mild superimposed stressors, although the two responses are likely to be at least partially independent. Long-term effects of IMO on the susceptibility to stress-induced endocrine and emotional disturbances may be relevant to the characterization of animal models of post-traumatic stress.

Effects of Thermomechanical History on the Tensile Behavior of Nitinol Ribbon

NASA Technical Reports Server (NTRS)

Lach, Cynthia L.; Turner, Travis L.; Taminger, Karen M.; Shenoy, Ravi N.

2002-01-01

Shape memory alloys (SMAs) have enormous potential for a wide variety of applications. A large body of work exists on the characterization of the microstructure and stress-strain behavior of these alloys, Nitinol (NiTi) in particular. However, many attributes of these materials are yet to be fully understood. Previous work at NASA Langley Research Center (LaRC) has included fabrication of hybrid composite specimens with embedded Nitinol actuators and modeling of their thermomechanical behavior. An intensive characterization effort has been undertaken to facilitate fundamental understanding of this alloy and to promote implementation of Nitinol in aerospace applications. Previous work revealed attributes of the Nitinol ribbon that were not easily rationalized with existing data in the literature. In particular, tensile behavior at ambient temperature showed significant dependence on the thermomechanical history prior to testing. The present work is focused on characterizing differences in the microstructure of Nitinol ribbons exposed to four different thermomechanical histories and correlation of the microstructure with tensile properties. Differential scanning calorimetry (DSC) and x-ray diffraction (XRD) analysis were employed to rationalize the microstructures present after exposure to various thermomechanical histories. Three of the Nitinol ribbon conditions were reversible upon heating (in the DSC) through the reverse transformation temperature (A(sub f) to transform the microstructure to austenite. However, the prior thermomechanical conditioning for the Nitinol ribbon that reflected the entire fabrication procedure (4% thermal cycle condition) was found to have an irreversible effect on the microstructure, as it remained unchanged after repeated complete thermal cycles. Tensile tests were conducted to determine the effect of prior thermomechancal conditioning on both the tensile behavior of the Nitinol ribbons and the stress state of the microstructure. The stress-strain behavior of the Nitinol actuators appears to be governed by the interplay between two major variables: namely, microstructural constituents such as the R-phase and the martensite; and the stress state of these constituents (whether twinned with low residual stresses, or detwinned with high residual stresses). The most significant difference in the stress-strain behavior of the four conditions, the critical stress required to achieve an initial stress plateau, was found to depend on both the amount and stress state (twinned or detwinned) of R-phase present in the initial microstructure. Thus, the effect of prior thermomechanical processing is critical to the resulting tensile behavior of the Nitinol actuator. For numerical modeling inputs one must take into account the entire fabrication process on the Nitinol actuator.

A mechanistic explanation of popularity: genes, rule breaking, and evocative gene-environment correlations.

PubMed

Burt, Alexandra

2009-04-01

Previous work has suggested that the serotonergic system plays a key role in "popularity" or likeability. A polymorphism within the 5HT-sub(2A) serotonin receptor gene (-G1438A) has also been associated with popularity, suggesting that genes may predispose individuals to particular social experiences. However, because genes cannot code directly for others' reactions, any legitimate association should be mediated via the individual's behavior (i.e., genes-->behaviors-->social consequences), a phenomenon referred to as an evocative gene-environment correlation (rGE). The current study aimed to identify one such mediating behavior. The author focused on rule breaking given its prior links to both the serotonergic system and to increased popularity during adolescence. Two samples of previously unacquainted late-adolescent boys completed a peer-based interaction paradigm designed to assess their popularity. Analyses revealed that rule breaking partially mediated the genetic effect on popularity, thereby furthering our understanding of the biological mechanisms that underlie popularity. Moreover, the present results represent the first meaningfully explicated evidence that genes predispose individuals not only to particular behaviors but also to the social consequences of those behaviors. (c) 2009 APA, all rights reserved.

Activation of kappa opioid receptors in the dorsal raphe have sex dependent effects on social behavior in California mice.

PubMed

Wright, Emily C; Parks, Tiffany V; Alexander, Jonathon O; Supra, Rajesh; Trainor, Brian C

2018-06-06

Kappa opioid receptor activation has been linked to stress and anxiety behavior, thus leading to kappa antagonists being popularized in research as potential anxiolytics. However, while these findings may hold true in standard models, the neuromodulatory effects of social defeat may change the behavioral outcome of kappa opioid receptor activation. Previous research has shown that social defeat can lead to hyperactivity of serotonergic neurons in the dorsal raphe nucleus, and that inhibition of this increase blocks the social deficits caused by defeat. Kappa opioid receptor activation in the dorsal raphe nucleus works to decrease serotonergic activity. We injected the kappa opioid receptor U50,488 directly into the dorsal raphe nucleus of male and female, defeat and control adult California mice. Here we show evidence that U50,488 induces anxiety behavior in control male California mice, but helps relieve it in defeated males. Consistent with previous literature, we find little effect in females adding evidence that there are marked and important sex differences in the kappa opioid system. Copyright © 2018 Elsevier B.V. All rights reserved.

Moving target, distributed, real-time simulation using Ada

NASA Technical Reports Server (NTRS)

Collins, W. R.; Feyock, S.; King, L. A.; Morell, L. J.

1985-01-01

Research on a precompiler solution is described for the moving target compiler problem encountered when trying to run parallel simulation algorithms on several microcomputers. The precompiler is under development at NASA-Lewis for simulating jet engines. Since the behavior of any component of a jet engine, e.g., the fan inlet, rear duct, forward sensor, etc., depends on the previous behaviors and not the current behaviors of other components, the behaviors can be modeled on different processors provided the outputs of the processors reach other processors in appropriate time intervals. The simulator works in compute and transfer modes. The Ada procedure sets for the behaviors of different components are divided up and routed by the precompiler, which essentially receives a multitasking program. The subroutines are synchronized after each computation cycle.

Factors Influencing Female Registered Nurses' Work Behavior

PubMed Central

Brewer, Carol S; Kovner, Christine T; Wu, Yow-Wu; Greene, William; Liu, Yu; Reimers, Cordelia W

2006-01-01

Objective To analyze factors that are related to whether registered nurses (RNs) work (WK) or do not work (NW) in nursing; and if the RN works, whether she works full- (FT) or part-time (PT). Data Sources Secondary data from National Sample Survey of Registered Nurses 2000 (NSSRN), the InterStudy Competitive Edge Part III Regional Market Analysis (2001), and the Area Resource File (2002). Study Design Using a cross-sectional design we tested the relationship between WK or NW and FT or PT; and demographic, job-related, and metropolitan statistical area (MSA)-level variables. Data Collection/Extraction Methods We combined the data sources noted above to produce the analytic sample of 25,471 female RNs. Principal Findings Working in nursing is not independent of working FT or PT. Age (55 and older), other family income, and prior other work experience in health care are negatively related to working as an RN. The wage is not related to working as an RN, but negatively influences FT work. Age, children, minority status, student status, employment status, other income, and some job settings have a negative impact on working FT. Previous health care work has a positive effect on whether married RNs worked. Married RNs who are more dissatisfied are less likely to work FT. A greater number of market-level factors influence FT/PT than WK/NW behavior. Conclusions An important contribution of this study is demonstrating that MSA-level variables influence RN work behavior. The market environment seems to have little effect on whether a nurse works, but is influential on how much the nurse works, and has differential effects on married versus single nurses. PMID:16704517

New leads in speculative behavior

NASA Astrophysics Data System (ADS)

Kindler, A.; Bourgeois-Gironde, S.; Lefebvre, G.; Solomon, S.

2017-02-01

The Kiyotaki and Wright (1989) (henceforth KW) model of money emergence as a medium of exchange has been studied from various perspectives in recent papers. In the present work we propose a minimalistic model for the behavior of agents in the KW framework, which may either reproduce the theoretical predictions of Kiyotaki and Wright (1989) on the emerging Nash equilibria, or (less closely) the empirical results of Brown (1996), Duffy and Ochs (1999) and our own, introduced in a first part of the present paper. The main import is the systematic computer scanning of speculative monetary equilibria under drastic bounded rationality of agents, based on behavior previously observed in the lab.

Association between Pap smear screening and job stress in Taiwanese nurses.

PubMed

Su, Shiang-Yuan; Chiou, Shu-Ti; Huang, Nicole; Huang, Chiu-Mieh; Chiang, Jen-Huai; Chien, Li-Yin

2016-02-01

Nursing is a professional job characterized by high stress. Stress could be associated with less practice of health promoting behaviors; however, no study has investigated the relationship between job stress and health screening behaviors among nurses. This study aimed to describe the rate of Pap smears in hospital nurses and examine the effects of job stress on receiving a Pap smear. This study was a cross-sectional survey. The study participants were 30,681 full-time female nurses who were at least 30 years of age working in 100 hospitals across Taiwan. The study participants filled out an anonymous structured questionnaire from May to July, 2011. The outcome variable was having a Pap test during the previous 3 years. The level of stress was measured by a 19-item scale, with higher scores indicating higher stress levels. About 62.4% of the nurses had a Pap smear during the previous three years. Each point increase in the stress score decreased the likelihood of Pap smears (OR = .997, 95% CI: .995-.999), after adjustment for participant characteristics, health status, health behaviors, and hospital characteristics. Despite more knowledge and higher accessibility, nurses were less likely to have Pap smear screening than the general population. A higher level of job stress was associated with a lower likelihood of having a Pap smear. Hospital administrators could help decrease work-related stress and improve stress adaption among nurses in order to improve their health screening behaviors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Infant-Feeding Intentions and Practices of Internal Medicine Physicians.

PubMed

Sattari, Maryam; Serwint, Janet R; Shuster, Jonathan J; Levine, David M

2016-05-01

Personal breastfeeding behavior of physician mothers is associated with their clinical breastfeeding advocacy, which in turn impacts patients' breastfeeding behavior. Internists can play an important role in breastfeeding advocacy as they usually come in contact with mothers longitudinally. To explore the personal infant-feeding decisions and behavior of physician mothers in internal medicine (IM). Physicians with current or previous IM training were isolated from our "Breastfeeding Among Physicians" database. The data in the database were gathered from cross-sectional surveys of 130 physician volunteers, mainly affiliated with the Johns Hopkins University School of Medicine (Baltimore, MD) and the University of Florida College of Medicine (Gainesville, FL). Seventy-two mothers reported current or previous IM training and had 196 infants. Breastfeeding rates were 96% at birth, 77% at 6 months, and 40% at 12 months. Exclusive breastfeeding rates were 78% at birth, 67% at 3 months, and 30% at 6 months. While maternal goal for breastfeeding duration correlated with duration of both exclusive and any breastfeeding, there was a consistent and appreciable disparity between maternal duration goal and actual breastfeeding duration. The participants reported work-related reasons for early supplementation and breastfeeding cessation. We have described for the first time in the literature the personal infant-feeding intentions and behavior of a cohort of IM physician mothers. Workplace interventions to enable internists to maintain breastfeeding after return to work and to achieve their breastfeeding goals might improve the health of these mothers and their infants and positively impact their clinical breastfeeding advocacy.

Stochastic model predicts evolving preferences in the Iowa gambling task

PubMed Central

Fuentes, Miguel A.; Lavín, Claudio; Contreras-Huerta, L. Sebastián; Miguel, Hernan; Rosales Jubal, Eduardo

2014-01-01

Learning under uncertainty is a common task that people face in their daily life. This process relies on the cognitive ability to adjust behavior to environmental demands. Although the biological underpinnings of those cognitive processes have been extensively studied, there has been little work in formal models seeking to capture the fundamental dynamic of learning under uncertainty. In the present work, we aimed to understand the basic cognitive mechanisms of outcome processing involved in decisions under uncertainty and to evaluate the relevance of previous experiences in enhancing learning processes within such uncertain context. We propose a formal model that emulates the behavior of people playing a well established paradigm (Iowa Gambling Task - IGT) and compare its outcome with a behavioral experiment. We further explored whether it was possible to emulate maladaptive behavior observed in clinical samples by modifying the model parameter which controls the update of expected outcomes distributions. Results showed that the performance of the model resembles the observed participant performance as well as IGT performance by healthy subjects described in the literature. Interestingly, the model converges faster than some subjects on the decks with higher net expected outcome. Furthermore, the modified version of the model replicated the trend observed in clinical samples performing the task. We argue that the basic cognitive component underlying learning under uncertainty can be represented as a differential equation that considers the outcomes of previous decisions for guiding the agent to an adaptive strategy. PMID:25566043

Stochastic model predicts evolving preferences in the Iowa gambling task.

PubMed

Fuentes, Miguel A; Lavín, Claudio; Contreras-Huerta, L Sebastián; Miguel, Hernan; Rosales Jubal, Eduardo

2014-01-01

Learning under uncertainty is a common task that people face in their daily life. This process relies on the cognitive ability to adjust behavior to environmental demands. Although the biological underpinnings of those cognitive processes have been extensively studied, there has been little work in formal models seeking to capture the fundamental dynamic of learning under uncertainty. In the present work, we aimed to understand the basic cognitive mechanisms of outcome processing involved in decisions under uncertainty and to evaluate the relevance of previous experiences in enhancing learning processes within such uncertain context. We propose a formal model that emulates the behavior of people playing a well established paradigm (Iowa Gambling Task - IGT) and compare its outcome with a behavioral experiment. We further explored whether it was possible to emulate maladaptive behavior observed in clinical samples by modifying the model parameter which controls the update of expected outcomes distributions. Results showed that the performance of the model resembles the observed participant performance as well as IGT performance by healthy subjects described in the literature. Interestingly, the model converges faster than some subjects on the decks with higher net expected outcome. Furthermore, the modified version of the model replicated the trend observed in clinical samples performing the task. We argue that the basic cognitive component underlying learning under uncertainty can be represented as a differential equation that considers the outcomes of previous decisions for guiding the agent to an adaptive strategy.

Evaluation of an intact, an ACL-deficient, and a reconstructed human knee joint finite element model.

PubMed

Vairis, Achilles; Stefanoudakis, George; Petousis, Markos; Vidakis, Nectarios; Tsainis, Andreas-Marios; Kandyla, Betina

2016-02-01

The human knee joint has a three-dimensional geometry with multiple body articulations that produce complex mechanical responses under loads that occur in everyday life and sports activities. Understanding the complex mechanical interactions of these load-bearing structures is of use when the treatment of relevant diseases is evaluated and assisting devices are designed. The anterior cruciate ligament (ACL) in the knee is one of four main ligaments that connects the femur to the tibia and is often torn during sudden twisting motions, resulting in knee instability. The objective of this work is to study the mechanical behavior of the human knee joint and evaluate the differences in its response for three different states, i.e., intact, ACL-deficient, and surgically treated (reconstructed) knee. The finite element models corresponding to these states were developed. For the reconstructed model, a novel repair device was developed and patented by the author in previous work. Static load cases were applied, as have already been presented in a previous work, in order to compare the calculated results produced by the two models the ACL-deficient and the surgically reconstructed knee joint, under the exact same loading conditions. Displacements were calculated in different directions for the load cases studied and were found to be very close to those from previous modeling work and were in good agreement with experimental data presented in literature. The developed finite element model for both the intact and the ACL-deficient human knee joint is a reliable tool to study the kinematics of the human knee, as results of this study show. In addition, the reconstructed human knee joint model had kinematic behavior similar to the intact knee joint, showing that such reconstruction devices can restore human knee stability to an adequate extent.

Special Education Disabilities and Juvenile Delinquency: A Unique Challenge for School Social Work

ERIC Educational Resources Information Center

Mallett, Christopher A.; Stoddard-Dare, Patricia; Workman-Crewnshaw, Lisa

2011-01-01

In pursuit of their mission to augment the educational process, school social workers provide service to special education students and to youths at risk for juvenile delinquency. This paper builds on previous literature that has looked at the relationship between special education disabilities and youths offending behaviors and delinquency. In…

Regulatory Fit and Systematic Exploration in a Dynamic Decision-Making Environment

ERIC Educational Resources Information Center

Otto, A. Ross; Markman, Arthur B.; Gureckis, Todd M.; Love, Bradley C.

2010-01-01

This work explores the influence of motivation on choice behavior in a dynamic decision-making environment, where the payoffs from each choice depend on one's recent choice history. Previous research reveals that participants in a regulatory fit exhibit increased levels of exploratory choice and flexible use of multiple strategies over the course…

Response of seedlings of two hypogeal brush species to CO2 enrichment

Treesearch

Charles R. Tischler; Justin D. Derner; H. Wayne Polley; Hyrum B. Johnson

2007-01-01

Previous work has demonstrated that epigeal woody invasive plants (with expanding, photosynthetic cotyledons), such as honey mesquite (Prosopis glandulosa L.), respond positively to elevated atmospheric CO2 concentrations in as little as 3 days after emergence. No research has addressed the behavior of larger seeded, hypogeal invasive plants (common...

Affective decision-making predictive of Chinese adolescent drinking behaviors

PubMed Central

XIAO, LIN; BECHARA, ANTOINE; GRENARD, L. JERRY; STACY, W. ALAN; PALMER, PAULA; WEI, YONGLAN; JIA, YONG; FU, XIAOLU; JOHNSON, C. ANDERSON

2013-01-01

The goal of the current investigation was to address whether affective decision making would serve as a unique neuropsychological marker to predict drinking behaviors among adolescents. We conducted a longitudinal study of 181 Chinese adolescents in Chengdu city, China. In their 10th grade (ages 15–16), these adolescents were tested for their affective decision-making ability using the Iowa Gambling Task (IGT) and working memory capacity using the Self-Ordered Pointing Test. Self-report questionnaires were used to assess academic performance and drinking behaviors. At 1-year follow-up, questionnaires were completed to assess drinking behaviors, and the UPPS Impulsive Behavior Scale was used to examine four dimensions of impulsivity: urgency, lack of premeditation, lack of perseverance, and sensation seeking. Results indicated that those adolescents who progressed to binge drinking or exhibited consistent binge drinking not only performed poorly on the IGT but also scored significantly higher in urgency compared to those who never or occasionally drank. Moreover, better IGT scores predicted fewer drinking problems and fewer drinks 1 year later after controlling for demographic variables, the previous drinking behaviors, working memory, and impulsivity. These findings suggest that deficits in affective decision making may be important independent determinants of compulsive drinking and potentially addictive behavior in adolescents. PMID:19573273

Dog Breed Differences in Visual Communication with Humans.

PubMed

Konno, Akitsugu; Romero, Teresa; Inoue-Murayama, Miho; Saito, Atsuko; Hasegawa, Toshikazu

2016-01-01

Domestic dogs (Canis familiaris) have developed a close relationship with humans through the process of domestication. In human-dog interactions, eye contact is a key element of relationship initiation and maintenance. Previous studies have suggested that canine ability to produce human-directed communicative signals is influenced by domestication history, from wolves to dogs, as well as by recent breed selection for particular working purposes. To test the genetic basis for such abilities in purebred dogs, we examined gazing behavior towards humans using two types of behavioral experiments: the 'visual contact task' and the 'unsolvable task'. A total of 125 dogs participated in the study. Based on the genetic relatedness among breeds subjects were classified into five breed groups: Ancient, Herding, Hunting, Retriever-Mastiff and Working). We found that it took longer time for Ancient breeds to make an eye-contact with humans, and that they gazed at humans for shorter periods of time than any other breed group in the unsolvable situation. Our findings suggest that spontaneous gaze behavior towards humans is associated with genetic similarity to wolves rather than with recent selective pressure to create particular working breeds.

SOC Strategies and Organizational Citizenship Behaviors toward the Benefits of Co-workers: A Multi-Source Study.

PubMed

Müller, Andreas; Weigl, Matthias

2017-01-01

Background: Individuals' behavioral strategies like selection, optimization, and compensation (SOC) contribute to efficient use of available resources. In the work context, previous studies revealed positive associations between employees' SOC use and favorable individual outcomes, like engagement and job performance. However, the social implications of self-directed behaviors like SOC that are favorable for the employee but may imply consequences for coworkers have not been investigated yet in an interpersonal work context. Objective: This study aimed to assess associations between employees' use of SOC behaviors at work and their organizational citizenship behaviors (OCB) toward the benefits of co-workers rated by their peers at work. We further sought to identify age-specific associations between SOC use and OCB. Design and Method: A cross-sectional design combining multi-source data was applied in primary school teachers (age range: 23-58 years) who frequently teach in dyads. N = 114 dyads were finally included. Teachers reported on their SOC strategies at work. Their peer colleagues evaluated teachers' OCB. Control variables were gender, workload, working hours, and perceived proximity of relationship between the dyads. Results: We observed a positive effect of loss-based selection behaviors on peer-rated OCB. Moreover, there was a significant two-way interaction effect between the use of compensation strategies and age on OCB, such that there was a positive association for older employees and a negative association for younger employees. There were no significant main and age-related interaction effects of elective selection, optimization, and of overall SOC strategies on OCB. Conclusion: Our study suggests that high use of loss-based selection and high use of compensation strategies in older employees is positively related with OCB as perceived by their colleagues. However, high use of compensation strategies in younger employees is perceived negatively related with OCB. Our findings contribute to a better understanding of the age-differentiated interpersonal effects of successful aging strategies in terms of SOC in organizations.

SOC Strategies and Organizational Citizenship Behaviors toward the Benefits of Co-workers: A Multi-Source Study

PubMed Central

Müller, Andreas; Weigl, Matthias

2017-01-01

Background: Individuals’ behavioral strategies like selection, optimization, and compensation (SOC) contribute to efficient use of available resources. In the work context, previous studies revealed positive associations between employees’ SOC use and favorable individual outcomes, like engagement and job performance. However, the social implications of self-directed behaviors like SOC that are favorable for the employee but may imply consequences for coworkers have not been investigated yet in an interpersonal work context. Objective: This study aimed to assess associations between employees’ use of SOC behaviors at work and their organizational citizenship behaviors (OCB) toward the benefits of co-workers rated by their peers at work. We further sought to identify age-specific associations between SOC use and OCB. Design and Method: A cross-sectional design combining multi-source data was applied in primary school teachers (age range: 23–58 years) who frequently teach in dyads. N = 114 dyads were finally included. Teachers reported on their SOC strategies at work. Their peer colleagues evaluated teachers’ OCB. Control variables were gender, workload, working hours, and perceived proximity of relationship between the dyads. Results: We observed a positive effect of loss-based selection behaviors on peer-rated OCB. Moreover, there was a significant two-way interaction effect between the use of compensation strategies and age on OCB, such that there was a positive association for older employees and a negative association for younger employees. There were no significant main and age-related interaction effects of elective selection, optimization, and of overall SOC strategies on OCB. Conclusion: Our study suggests that high use of loss-based selection and high use of compensation strategies in older employees is positively related with OCB as perceived by their colleagues. However, high use of compensation strategies in younger employees is perceived negatively related with OCB. Our findings contribute to a better understanding of the age-differentiated interpersonal effects of successful aging strategies in terms of SOC in organizations. PMID:29085315

Application of synchrotron radiation phase-contrast microtomography with iodine staining to Rhodnius prolixus head during ecdysis period

NASA Astrophysics Data System (ADS)

Sena, G.; Nogueira, L. P.; Braz, D.; Colaço, M. V.; Azambuja, P.; Gonzalez, M. S.; Tromba, G.; Mantuano, A.; Costa, F. N.; Barroso, R. C.

2018-05-01

Synchrotron radiation phase-contrast microtomography (SR-PHC-CT) has become an important tool in studies of insects, mainly Rhodinius prolixus, the insect vector of Chagas disease. A previous work has shown that SR-PHC-CT is an excellent technique in studies about the ecdysis process of R.prolixus head. The term ecdysis refers to the set of behaviors by which an insect extracts itself from an old exoskeleton. The exoskeleton formation is indispensable for the evolutionary success of insect species, so failure to complete ecdysis will, in most cases result in death, making this process an excellent target in the search for new insect pest management strategies. Understanding the behavior of the ecdysis process is fundamental for the non-proliferation of Chagas disease. Despite it has been possible to identify the moulting process in the first work, main structures of the R.prolixus head could not be identified. In this work, it was developed a staining protocol which enabled the identification of these important structures using Iodine at SYRMEP beamline of ELETTRA. In the 3D images, it was possible to segment essential structures in the process of ecdysis. These structures have never been presented previously in the moulting period with SR-PHC-CT.

Evidence that NMDA-dependent limbic neural plasticity in the right hemisphere mediates pharmacological stressor (FG-7142)-induced lasting increases in anxiety-like behavior: study 3--the effects on amygdala efferent physiology of block of NMDA receptors prior to injection of FG-7142 and its relationship to behavioral change.

PubMed

Adamec, R E

1998-01-01

The findings of this study support the hypothesis that N-methyl-D-aspartate (NMDA) receptors mediate the initiation of long-term potentiation (LTP) and behavioral changes induced by the anxiogenic beta-carboline, FG-7142. Unlike previous work, this study examined the effects of FG-7142 on LTP of amygdala efferents in both hemispheres. 7-amino-phosphono-heptanoic acid (AP7), a competitive NMDA receptor blocker, given prior to administration of FG-7142, prevented LTP in amygdala efferent transmission to the medial hypothalamus and periacqueductal gray (PAG). When given FG-7142 alone, cats showed lasting behavioral changes accompanied by LTP in all pathways studied. Duration of LTP, and its relationship to behavioral change, depended on the pathway and the hemisphere of the pathway. Correlation and covariance analyses indicate that LTP in the left amygdalo-ventromedial hypothalamic pathway mediates initiation, but not maintenance, of increased defensiveness. This finding replicates previous work. A new finding is that increased local excitability in the right basal amygdala (reduced threshold for evoked response), and LTP in the right amygdalo-PAG pathway, may be important for maintenance of increases in defensive behavior. Furthermore, the effects of flumazenil, a benzodiazepine receptor antagonist, on behavior and physiology single out the importance of right amygdalo-PAG LTP as a critical mediator of increased defensiveness. Flumazenil reversed the increase in defensiveness produced by FG-7142 in a drug-dependent manner as described in Adamec (1998a). Moreover, flumazenil reversed LTP only in the right amygdalo-PAG pathway. The findings of the present study suggest that response to FG-7142 may be a useful model of the effects of traumatic stressors on limbic system function in anxiety, especially in view of the recent data in humans implicating right hemispheric function in persisting negative affective states.

A Process and Outcomes Evaluation of the International AIDS Conference: Who Attends? Who Benefits Most?

PubMed Central

Lalonde, Bernadette; Wolvaardt, Jacqueline E.; Webb, Elize M; Tournas-Hardt, Amy

2007-01-01

The objective of the study was to conduct a process and outcomes evaluation of the International AIDS Conference (IAC). Reaction evaluation data are presented from a delegate survey distributed at the 2004 IAC held in Thailand. Input and output data from the Thailand IAC are compared to data from previous IACs to ascertain attendance and reaction trends, which delegates benefit most, and host country effects. Outcomes effectiveness data were collected via a survey and intercept interviews. Data suggest that the host country may significantly affect the number and quality of basic science IAC presentations, who attends, and who benefits most. Intended and executed HIV work-related behavior change was assessed under 9 classifications. Delegates who attended 1 previous IAC were more likely to report behavior changes than attendees who attended more than 1 previous IAC. The conference needs to be continually evaluated to elicit the required data to plan effective future IACs. PMID:17435615

Selection of behavioral tasks and development of software for evaluation of rhesus monkey behavior during spaceflight

NASA Technical Reports Server (NTRS)

Rumbaugh, Duane M.; Washburn, David A.

1993-01-01

The results of several experiments were disseminated professionally during this semiannual period. These peer-reviewed papers that were accepted for publication represent the growth of our research areas, as follow-up experiments to previously published work in cognition and enrichment have been completed and are being published. The presentations not only reflect the latest interesting results that we have obtained, but also serve as a testament to the intense interest that is being expressed for our test system and findings.

Formal behavioral evaluation of enrichment programs on a zookeeper's schedule: a case study with a polar bear (Ursus Maritimus) at the Bronx Zoo.

PubMed

Canino, Wendy; Powell, David

2010-01-01

We conducted a brief study of the effectiveness of environmental enrichment for a polar bear at the Bronx Zoo with two objectives in mind. First we wanted to determine if a novel method of collecting data that easily fits into a zookeeper's work routine would produce usable data and if so, we wanted to evaluate the effectiveness of some new items that had been purchased for enriching the polar bear in reducing his pacing behavior. Observations were recorded for 119 days over a period of 5 months from April 2007 through August 2007. Five new items and eight previously used items were rotated and presented to the polar bear in the morning and afternoon. We recorded the bear's behavior five times per day as we passed by his exhibit during our regular work routine. Predictably, we found that the newer enrichment items were more effective at increasing play and decreasing pacing, as well as other more subtle effects on his behavior that helped us to design a better enrichment routine. More importantly, we found that this method of "multi-point scan sampling" was effective at producing ample and reliable data that could be used to analyze the bear's behavior without adding significant work to the keepers' daily routine. (c) 2009 Wiley-Liss, Inc.

Electrokinesis is a microbial behavior that requires extracellular electron transport

PubMed Central

Harris, H. W.; El-Naggar, M. Y.; Bretschger, O.; Ward, M. J.; Romine, M. F.; Obraztsova, A. Y.; Nealson, K. H.

2009-01-01

We report a previously undescribed bacterial behavior termed electrokinesis. This behavior was initially observed as a dramatic increase in cell swimming speed during reduction of solid MnO2 particles by the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1. The same behavioral response was observed when cells were exposed to small positive applied potentials at the working electrode of a microelectrochemical cell and could be tuned by adjusting the potential on the working electrode. Electrokinesis was found to be different from both chemotaxis and galvanotaxis but was absent in mutants defective in electron transport to solid metal oxides. Using in situ video microscopy and cell tracking algorithms, we have quantified the response for different strains of Shewanella and shown that the response correlates with current-generating capacity in microbial fuel cells. The electrokinetic response was only exhibited by a subpopulation of cells closest to the MnO2 particles or electrodes. In contrast, the addition of 1 mM 9,10-anthraquinone-2,6-disulfonic acid, a soluble electron shuttle, led to increases in motility in the entire population. Electrokinesis is defined as a behavioral response that requires functional extracellular electron transport and that is observed as an increase in cell swimming speeds and lengthened paths of motion that occur in the proximity of a redox active mineral surface or the working electrode of an electrochemical cell. PMID:20018675

Property and Microstructural Characterization of Diboride Composites for High Temperature Aerospace Applications

NASA Technical Reports Server (NTRS)

Gusman, Michael I.; Stackpoole, Mairead; Ellerby, Donald T.; Johnson, Sylvia M.; Arnold, Jim (Technical Monitor)

2001-01-01

Previous work on refractory diboride composites has shown these systems to have potential for use in high temperature leading edge applications for reusable reentry vehicles. These composites, based on compositions of HfB2 or ZrB2 with SiC particulate reinforcements, have shown good oxidation resistance in reentry environments. In this work we are investigating the effects of composition and microstructure on properties. Preliminary studies of composite mechanical properties and oxidation behavior will be discussed.

Aggressive behavior and employment histories in patients from an internal medicine outpatient clinic.

PubMed

Sansone, Randy A; Leung, Justin S; Wiederman, Michael W

2013-01-01

A number of studies have examined the relationships between aggression and various facets of the work environment. However, to our knowledge, the relationship between self-reported aggressive behaviors and corresponding employment histories has never been previously explored. Using a cross-sectional approach and a self-report survey methodology in a consecutive sample of 325 internal medicine outpatients, we examined lifetime histories of 21 aggressive behaviors and 4 employment variables. In both men and women, a higher number of aggressive behaviors correlated with a greater number of different jobs held, greater likelihood of being paid "under the table," and a greater number of firings. However, only in men was the number of aggressive behaviors related to the percentage of time employed as an adult. According to findings, a history of aggressive behavior appears to be associated with compromised employment viability in adulthood. Copyright © 2013 Elsevier Inc. All rights reserved.

Caregiver Protective Behavior, Toddler Fear and Sadness, and Toddler Cortisol Reactivity in Novel Contexts

PubMed Central

Hutt, Rachel L.; Buss, Kristin A.; Kiel, Elizabeth J.

2012-01-01

Previous research has shown that caregiver protective behavior may exacerbate toddler distress in specific contexts. The current study sought to extend this work to examine associations between these variables and toddler cortisol reactivity. Ninety-three 24-month-old toddlers were observed across six novel contexts designed to elicit distress. Toddlers were asked to give saliva samples at the beginning and end of the laboratory procedure. Toddler sadness, toddler fear, and caregiver protective behavior were coded. Results indicate that caregiver protective behavior accounted for the association between toddler sadness and cortisol reactivity where higher levels of protective behavior were associated with higher cortisol reactivity. The current study showed that caregiver protective behavior, which functions to prevent a child from interacting with a novel stimulus, is an important mechanism to consider when understanding toddler stress responses during novel contexts. PMID:24659922

Input dependent cell assembly dynamics in a model of the striatal medium spiny neuron network.

PubMed

Ponzi, Adam; Wickens, Jeff

2012-01-01

The striatal medium spiny neuron (MSN) network is sparsely connected with fairly weak GABAergic collaterals receiving an excitatory glutamatergic cortical projection. Peri-stimulus time histograms (PSTH) of MSN population response investigated in various experimental studies display strong firing rate modulations distributed throughout behavioral task epochs. In previous work we have shown by numerical simulation that sparse random networks of inhibitory spiking neurons with characteristics appropriate for UP state MSNs form cell assemblies which fire together coherently in sequences on long behaviorally relevant timescales when the network receives a fixed pattern of constant input excitation. Here we first extend that model to the case where cortical excitation is composed of many independent noisy Poisson processes and demonstrate that cell assembly dynamics is still observed when the input is sufficiently weak. However if cortical excitation strength is increased more regularly firing and completely quiescent cells are found, which depend on the cortical stimulation. Subsequently we further extend previous work to consider what happens when the excitatory input varies as it would when the animal is engaged in behavior. We investigate how sudden switches in excitation interact with network generated patterned activity. We show that sequences of cell assembly activations can be locked to the excitatory input sequence and outline the range of parameters where this behavior is shown. Model cell population PSTH display both stimulus and temporal specificity, with large population firing rate modulations locked to elapsed time from task events. Thus the random network can generate a large diversity of temporally evolving stimulus dependent responses even though the input is fixed between switches. We suggest the MSN network is well suited to the generation of such slow coherent task dependent response which could be utilized by the animal in behavior.

Input Dependent Cell Assembly Dynamics in a Model of the Striatal Medium Spiny Neuron Network

PubMed Central

Ponzi, Adam; Wickens, Jeff

2012-01-01

The striatal medium spiny neuron (MSN) network is sparsely connected with fairly weak GABAergic collaterals receiving an excitatory glutamatergic cortical projection. Peri-stimulus time histograms (PSTH) of MSN population response investigated in various experimental studies display strong firing rate modulations distributed throughout behavioral task epochs. In previous work we have shown by numerical simulation that sparse random networks of inhibitory spiking neurons with characteristics appropriate for UP state MSNs form cell assemblies which fire together coherently in sequences on long behaviorally relevant timescales when the network receives a fixed pattern of constant input excitation. Here we first extend that model to the case where cortical excitation is composed of many independent noisy Poisson processes and demonstrate that cell assembly dynamics is still observed when the input is sufficiently weak. However if cortical excitation strength is increased more regularly firing and completely quiescent cells are found, which depend on the cortical stimulation. Subsequently we further extend previous work to consider what happens when the excitatory input varies as it would when the animal is engaged in behavior. We investigate how sudden switches in excitation interact with network generated patterned activity. We show that sequences of cell assembly activations can be locked to the excitatory input sequence and outline the range of parameters where this behavior is shown. Model cell population PSTH display both stimulus and temporal specificity, with large population firing rate modulations locked to elapsed time from task events. Thus the random network can generate a large diversity of temporally evolving stimulus dependent responses even though the input is fixed between switches. We suggest the MSN network is well suited to the generation of such slow coherent task dependent response which could be utilized by the animal in behavior. PMID:22438838

Sickness-induced changes in physiology do not affect fecundity or same-sex behavior.

PubMed

Sylvia, Kristyn E; Báez Ramos, Patricia; Demas, Gregory E

2018-02-01

Previous work in our lab has shown that early-life infection affects female reproductive physiology and function (i.e., smaller ovaries, abnormal estrous cycles) and alters investigation and aggression towards male conspecifics in a reproductive context. Although many studies have investigated the effects of postnatal immune challenge on physiological and behavioral development, fewer studies have examined whether these changes have ultimate effects on reproduction. In the current study, we paired Siberian hamsters (Phodopus sungorus) and simulated a bacterial infection in early life by administering lipopolysaccharide (LPS) to male and female pups on pnd3 and pnd5. In adulthood, hamsters were paired with novel individuals of the same sex, and we scored an array of social behaviors (e.g., investigation, aggression). We then paired animals with individuals of the opposite sex for 5 consecutive nights, providing them with the opportunity to mate. We found that females exhibited impaired reproductive physiology and function in adulthood (i.e., smaller ovaries and abnormal estrous cycles), similar to our previous work. However, both LPS-treated males and females exhibited similar same-sex social behavior when compared with saline-treated controls, they successfully mated, and there were no significant changes in fecundity. These data suggest that the physiological changes in response to neonatal immune challenge may not have long-term effects on reproductive success in a controlled environment. Collectively, the results of this study are particularly important when investigating the relationships between physiology and behavior within an ultimate context. Animals exposed to early-life stress may in fact be capable of compensating for changes in physiology in order to survive and reproduce in some contexts. Copyright © 2017 Elsevier Inc. All rights reserved.

Modeling choice and reaction time during arbitrary visuomotor learning through the coordination of adaptive working memory and reinforcement learning

PubMed Central

Viejo, Guillaume; Khamassi, Mehdi; Brovelli, Andrea; Girard, Benoît

2015-01-01

Current learning theory provides a comprehensive description of how humans and other animals learn, and places behavioral flexibility and automaticity at heart of adaptive behaviors. However, the computations supporting the interactions between goal-directed and habitual decision-making systems are still poorly understood. Previous functional magnetic resonance imaging (fMRI) results suggest that the brain hosts complementary computations that may differentially support goal-directed and habitual processes in the form of a dynamical interplay rather than a serial recruitment of strategies. To better elucidate the computations underlying flexible behavior, we develop a dual-system computational model that can predict both performance (i.e., participants' choices) and modulations in reaction times during learning of a stimulus–response association task. The habitual system is modeled with a simple Q-Learning algorithm (QL). For the goal-directed system, we propose a new Bayesian Working Memory (BWM) model that searches for information in the history of previous trials in order to minimize Shannon entropy. We propose a model for QL and BWM coordination such that the expensive memory manipulation is under control of, among others, the level of convergence of the habitual learning. We test the ability of QL or BWM alone to explain human behavior, and compare them with the performance of model combinations, to highlight the need for such combinations to explain behavior. Two of the tested combination models are derived from the literature, and the latter being our new proposal. In conclusion, all subjects were better explained by model combinations, and the majority of them are explained by our new coordination proposal. PMID:26379518

Living up to safety values in health care: the effect of leader behavioral integrity on occupational safety.

PubMed

Halbesleben, Jonathon R B; Leroy, Hannes; Dierynck, Bart; Simons, Tony; Savage, Grant T; McCaughey, Deirdre; Leon, Matthew R

2013-10-01

While previous research has identified that leaders' safety expectations and safety actions are important in fostering occupational safety, research has yet to demonstrate the importance of leader alignment between safety expectations and actions for improving occupational safety. We build on safety climate literature and theory on behavioral integrity to better understand the relationship between the leader's behavioral integrity regarding safety and work-related injuries. In a time-lagged study of 658 nurses, we find that behavioral integrity for high safety values is positively associated with greater reporting of fewer and less severe occupational injuries. The effects of behavioral integrity regarding safety can be better understood through the mediating mechanisms of safety compliance and psychological safety toward one's supervisor. We discuss the implications of our findings for future research on safety climate.

Aggressive Behaviors in Young Siblings: Associations with Executive Functions and Maternal Characteristics.

PubMed

Spann, Catherine A; Gagne, Jeffrey R

2016-04-01

Aggressive behaviors in early childhood are associated with multiple undesirable outcomes, including juvenile delinquency, academic failure, and substance abuse. This investigation employed a family study design to examine child, mother and sibling predictors of early-emerging aggressive behaviors. These predictors included several indices of executive functioning within children, depression symptoms and education level of mothers, and inhibitory control (IC) of siblings. The sample consisted of 95 families (191 children; boys = 100) with at least two, typically developing children between 30 and 66 months of age (M(age) = 45.93 months, SD = 12.40). Measures included laboratory-assessed working memory and IC, parent-reported aggressive behaviors, as well as self-reported maternal depression symptoms and education. Results revealed that children showed substantial sibling similarity in aggressive behaviors. Using multilevel regression analyses, low child IC and greater maternal depression symptoms were associated with increased child aggressive behaviors. Child working memory, maternal education, and sibling IC did not uniquely predict child aggressive behaviors. Moderation analyses revealed an interaction between maternal depression symptoms and maternal education, such that the effect of depression symptoms on child aggressive behaviors was particularly evident amongst highly educated mothers. The current analysis moved beyond a main effects model of maternal depression and extended previous findings on the importance of child IC to aggressive behaviors by using a multiple-child-per-family framework. A promising direction for future research includes assessing whether efforts to increase child IC are successful in reducing child aggressive behaviors.

Investigating the relative permeability behavior of microporosity-rich carbonates and tight sandstones with multiscale pore network models

NASA Astrophysics Data System (ADS)

Bultreys, Tom; Stappen, Jeroen Van; Kock, Tim De; Boever, Wesley De; Boone, Marijn A.; Hoorebeke, Luc Van; Cnudde, Veerle

2016-11-01

The relative permeability behavior of rocks with wide ranges of pore sizes is in many cases still poorly understood and is difficult to model at the pore scale. In this work, we investigate the capillary pressure and relative permeability behavior of three outcrop carbonates and two tight reservoir sandstones with wide, multimodal pore size distributions. To examine how the drainage and imbibition properties of these complex rock types are influenced by the connectivity of macropores to each other and to zones with unresolved small-scale porosity, we apply a previously presented microcomputed-tomography-based multiscale pore network model to these samples. The sensitivity to the properties of the small-scale porosity is studied by performing simulations with different artificial sphere-packing-based networks as a proxy for these pores. Finally, the mixed-wet water-flooding behavior of the samples is investigated, assuming different wettability distributions for the microporosity and macroporosity. While this work is not an attempt to perform predictive modeling, it seeks to qualitatively explain the behavior of the investigated samples and illustrates some of the most recent developments in multiscale pore network modeling.

Emerging role for corticotropin releasing factor signaling in the bed nucleus of the stria terminalis at the intersection of stress and reward.

PubMed

Silberman, Yuval; Winder, Danny G

2013-01-01

Stress and anxiety play an important role in the development and maintenance of drug and alcohol addiction. The bed nucleus of the stria terminalis (BNST), a brain region involved in the production of long-term stress-related behaviors, plays an important role in animal models of relapse, such as reinstatement to previously extinguished drug-seeking behaviors. While a number of neurotransmitter systems have been suggested to play a role in these behaviors, recent evidence points to the neuropeptide corticotropin releasing factor (CRF) as being critically important in BNST-mediated reinstatement behaviors. Although numerous studies indicate that the BNST is a complex brain region with multiple afferent and efferent systems and a variety of cell types, there has only been limited work to determine how CRF modulates this complex neuronal system at the circuit level. Recent work from our lab and others have begun to unravel these BNST neurocircuits and explore their roles in CRF-related reinstatement behaviors. This review will examine the role of CRF signaling in drug addiction and reinstatement with an emphasis on critical neurocircuitry within the BNST that may offer new insights into treatments for addiction.

Phase Transition Behavior in a Neutral Evolution Model

NASA Astrophysics Data System (ADS)

King, Dawn; Scott, Adam; Maric, Nevena; Bahar, Sonya

2014-03-01

The complexity of interactions among individuals and between individuals and the environment make agent based modeling ideal for studying emergent speciation. This is a dynamically complex problem that can be characterized via the critical behavior of a continuous phase transition. Concomitant with the main tenets of natural selection, we allow organisms to reproduce, mutate, and die within a neutral phenotype space. Previous work has shown phase transition behavior in an assortative mating model with variable fitness landscapes as the maximum mutation size (μ) was varied (Dees and Bahar, 2010). Similarly, this behavior was recently presented in the work of Scott et al. (2013), even on a completely neutral landscape, for bacterial-like fission as well as for assortative mating. Here we present another neutral model to investigate the `critical' phase transition behavior of three mating types - assortative, bacterial, and random - in a phenotype space as a function of the percentage of random death. Results show two types of phase transitions occurring for the parameters of the population size and the number of clusters (an analogue of species), indicating different evolutionary dynamics for system survival and clustering. This research was supported by funding from: University of Missouri Research Board and James S. McDonnell Foundation.

Prediction of the Possibility a Right-Turn Driving Behavior at Intersection Leads to an Accident by Detecting Deviation of the Situation from Usual when the Behavior is Observed

NASA Astrophysics Data System (ADS)

Hayashi, Toshinori; Yamada, Keiichi

Deviation of driving behavior from usual could be a sign of human error that increases the risk of traffic accidents. This paper proposes a novel method for predicting the possibility a driving behavior leads to an accident from the information on the driving behavior and the situation. In a previous work, a method of predicting the possibility by detecting the deviation of driving behavior from usual one in that situation has been proposed. In contrast, the method proposed in this paper predicts the possibility by detecting the deviation of the situation from usual one when the behavior is observed. An advantage of the proposed method is the number of the required models is independent of the variety of the situations. The method was applied to a problem of predicting accidents by right-turn driving behavior at an intersection, and the performance of the method was evaluated by experiments on a driving simulator.

Maternal management behaviors for young children with type 1 diabetes.

PubMed

Sullivan-Bolyai, Susan; Knafl, Kathleen; Deatrick, Janet; Grey, Margaret

2003-01-01

To describe the process that mothers raising young (0-4 years old) children who are newly diagnosed with type 1 diabetes move through to attain the necessary skills to care for their children. A mixed methods design was used, including qualitative interviews with 28 mothers of young children with type 1 diabetes. Principles of naturalistic inquiry were used to guide the data collection process, management, and analysis of the qualitative findings. The process paralleled two of three management approaches and associated behaviors previously described by Gallo and Knafl. Strict adherence behaviors included rigidly following the team recommendations and avoiding strange environments outside the home. Flexible adherence behaviors strove to bring spontaneity back into family life. Selective adherence was not used by this population. Nurses working with these mothers can provide information and support to help them transition from using strict adherence to the more user-friendly flexible adherence, while avoiding the pitfalls of the possibly harmful third approach of selective adherence. Nurses need to remember to praise the parents' efforts at managing their children's diabetes, for our acknowledgment of their work is empowering and affirming.

Morphology and proteome characterization of the salivary glands of the western chinch bug, Blissus occiduus (Hemiptera: Blissidae)

USDA-ARS?s Scientific Manuscript database

The western chinch bug, Blissus occiduus Barber, is a serious pest of buffalograss due to physical and chemical damage caused during the feeding process. Although previous work has investigated the feeding behaviors of chinch bugs in the Blissus complex, no study to date has explored salivary gland ...

The Role of Passion for Teaching in Intrapersonal and Interpersonal Outcomes

ERIC Educational Resources Information Center

Carbonneau, Noemie; Vallerand, Robert J.; Fernet, Claude; Guay, Frederic

2008-01-01

The purpose of this study was to determine the role of passion in teachers' burnout symptoms, work satisfaction, and perceptions of positive student classroom behaviors. The dualistic model of passion (Vallerand et al., 2003) proposes 2 types of passion: harmonious and obsessive. In previous studies, harmonious passion has been shown to lead to…

Relations among Grade 4 Students' Perceptions of Autonomy, Engagement in Science, and Reading Motivation

ERIC Educational Resources Information Center

Taboada Barber, Ana; Buehl, Michelle M.

2013-01-01

The authors extend previous work on students' perceptions of teachers' autonomy-enhancing and autonomy-suppressing behaviors in relation to students' engagement to a more situated context (i.e., two Grade 4 science instructional conditions instead of school in general) and a linguistically diverse population (i.e., Hispanic students). They also…

ACUTE AND REPEATED INHALATION OF TOLUENE BY RATS PERFORMING A SIGNAL DETECTION TASK LEADS TO BEHAVIORAL TOLERANCE ON SOME PERFORMANCE MEASURES.

EPA Science Inventory

Previous work showed that trichloroethylene (TCE) impairs accuracy and latency in a signal detection task (SDT) in rats, and that these effects abate during repeated exposures if rats inhale TCE during SDT testing. The present experiment compared the effects of acute and repeated...

Molecular dynamics analysis of the influence of Coulomb and van der Waals interactions on the work of adhesion at the solid-liquid interface

NASA Astrophysics Data System (ADS)

Surblys, Donatas; Leroy, Frédéric; Yamaguchi, Yasutaka; Müller-Plathe, Florian

2018-04-01

We investigated the solid-liquid work of adhesion of water on a model silica surface by molecular dynamics simulations, where a methodology previously developed to determine the work of adhesion through thermodynamic integration was extended to a system with long-range electrostatic interactions between solid and liquid. In agreement with previous studies, the work of adhesion increased when the magnitude of the surface polarity was increased. On the other hand, we found that when comparing two systems with and without solid-liquid electrostatic interactions, which were set to have approximately the same total solid-liquid interfacial energy, former had a significantly smaller work of adhesion and a broader distribution in the interfacial energies, which has not been previously reported in detail. This was explained by the entropy contribution to the adhesion free energy; i.e., the former with a broader energy distribution had a larger interfacial entropy than the latter. While the entropy contribution to the work of adhesion has already been known, as a work of adhesion itself is free energy, these results indicate that, contrary to common belief, wetting behavior such as the contact angle is not only governed by the interfacial energy but also significantly affected by the interfacial entropy. Finally, a new interpretation of interfacial entropy in the context of solid-liquid energy variance was offered, from which a fast way to qualitatively estimate the work of adhesion was also presented.

Characterizing neurocognitive late effects in childhood leukemia survivors using a combination of neuropsychological and cognitive neuroscience measures.

PubMed

Van Der Plas, Ellen; Erdman, Lauren; Nieman, Brian J; Weksberg, Rosanna; Butcher, Darci T; O'connor, Deborah L; Aufreiter, Susanne; Hitzler, Johann; Guger, Sharon L; Schachar, Russell J; Ito, Shinya; Spiegler, Brenda J

2017-10-10

Knowledge about cognitive late effects in survivors of childhood acute lymphoblastic leukemia (ALL) is largely based on standardized neuropsychological measures and parent reports. To examine whether cognitive neuroscience paradigms provided additional insights into neurocognitive and behavioral late effects in ALL survivors, we assessed cognition and behavior using a selection of cognitive neuroscience tasks and standardized measures probing domains previously demonstrated to be affected by chemotherapy. 130 ALL survivors and 158 control subjects, between 8 and 18 years old at time of testing, completed the n-back (working memory) and stop-signal (response inhibition) tasks. ALL survivors also completed standardized measures of intelligence (Wechsler Intelligence Scales [WISC-IV]), motor skills (Grooved Pegboard), math abilities (WIAT-III), and executive functions (Delis-Kaplan Executive Function System). Parents completed behavioral measures of executive functions (Behavior Rating Inventory of Executive Function [BRIEF]) and attention (Conners-3). ALL survivors exhibited deficiencies in working memory and response inhibition compared with controls. ALL survivors also exhibited deficits on WISC-IV working memory and processing speed, Grooved Pegboard, WIAT-III addition and subtraction fluency, and numerical operations, as well as DKEFS number-letter switching. Parent reports suggested more attention deficits (Conners-3) and behavioral difficulties (BRIEF) in ALL survivors compared with referenced norms. Low correspondence between standardized and experimental measures of working memory and response inhibition was noted. The use of cognitive neuroscience paradigms complements our understanding of the cognitive deficits evident after treatment of ALL. These measures could further delineate cognitive processes involved in neurocognitive late effects, providing opportunities to explore their underlying mechanisms.

5HT2A receptor blockade in dorsomedial striatum reduces repetitive behaviors in BTBR mice.

PubMed

Amodeo, D A; Rivera, E; Cook, E H; Sweeney, J A; Ragozzino, M E

2017-03-01

Restricted and repetitive behaviors are a defining feature of autism, which can be expressed as a cognitive flexibility deficit or stereotyped, motor behaviors. There is limited knowledge about the underlying neuropathophysiology contributing to these behaviors. Previous findings suggest that central 5HT 2A receptor activity is altered in autism, while recent work indicates that systemic 5HT 2A receptor antagonist treatment reduces repetitive behaviors in an idiopathic model of autism. 5HT 2A receptors are expressed in the orbitofrontal cortex and striatum. These two regions have been shown to be altered in autism. The present study investigated whether 5HT 2A receptor blockade in the dorsomedial striatum or orbitofrontal cortex in the BTBR mouse strain, an idiopathic model of autism, affects the phenotype related to restricted and repetitive behaviors. Microinfusion of the 5HT 2A receptor antagonist, M100907 into the dorsomedial striatum alleviated a reversal learning impairment and attenuated grooming behavior. M100907 infusion into the orbitofrontal cortex increased perseveration during reversal learning and potentiated grooming. These findings suggest that increased 5HT 2A receptor activity in the dorsomedial striatum may contribute to behavioral inflexibility and stereotyped behaviors in the BTBR mouse. 5HT 2A receptor signaling in the orbitofrontal cortex may be critical for inhibiting a previously learned response during reversal learning and expression of stereotyped behavior. The present results suggest which brain areas exhibit abnormalities underlying repetitive behaviors in an idiopathic mouse model of autism, as well as which brain areas systemic treatment with M100907 may principally act on in BTBR mice to attenuate repetitive behaviors. © 2016 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Modulating the neural bases of persuasion: why/how, gain/loss, and users/non-users

PubMed Central

Katzman, Perri L.; Ames, Daniel L.; Falk, Emily B.; Lieberman, Matthew D.

2017-01-01

Abstract Designing persuasive content is challenging, in part because people can be poor predictors of their actions. Medial prefrontal cortex (MPFC) activation during message exposure reliably predicts downstream behavior, but past work has been largely atheoretical. We replicated past results on this relationship and tested two additional framing effects known to alter message receptivity. First, we examined gain- vs. loss-framed reasons for a health behavior (sunscreen use). Consistent with predictions from prospect theory, we observed greater MPFC activity to gain- vs. loss-framed messages, and this activity was associated with behavior. This relationship was stronger for those who were not previously sunscreen users. Second, building on theories of action planning, we compared neural activity during messages regarding how vs. why to enact the behavior. We observed rostral inferior parietal lobule and posterior inferior frontal gyrus activity during action planning (“how” messages), and this activity was associated with behavior; this is in contrast to the relationship between MPFC activity during the “why” (i.e., gain and loss) messages and behavior. These results reinforce that persuasion occurs in part via self-value integration—seeing value and incorporating persuasive messages into one's self-concept—and extend this work to demonstrate how message framing and action planning may influence this process. PMID:27521303

Discrepancy-based and anticipated emotions in behavioral self-regulation.

PubMed

Brown, Christina M; McConnell, Allen R

2011-10-01

Discrepancies between one's current and desired states evoke negative emotions, which presumably guide self-regulation. In the current work we evaluated the function of discrepancy-based emotions in behavioral self-regulation. Contrary to classic theories of self-regulation, discrepancy-based emotions did not predict the degree to which people engaged in self-regulatory behavior. Instead, expectations about how future self-discrepancies would make one feel (i.e., anticipated emotions) predicted self-regulation. However, anticipated emotions were influenced by previous discrepancy-based emotional experiences, suggesting that the latter do not directly motivate self-regulation but rather guide expectations. These findings are consistent with the perspective that emotions do not necessarily direct immediate behavior, but rather have an indirect effect by guiding expectations, which in turn predict goal-directed action.

A theory for the evolution of other-regard integrating proximate and ultimate perspectives.

PubMed

Akçay, Erol; Van Cleve, Jeremy; Feldman, Marcus W; Roughgarden, Joan

2009-11-10

Although much previous work describes evolutionary mechanisms that promote or stabilize different social behaviors, we still have little understanding of the factors that drive animal behavior proximately. Here we present a modeling approach to answer this question. Our model rests on motivations to achieve objectives as the proximate determinants of behavior. We develop a two-tiered framework by first modeling the dynamics of a social interaction at the behavioral time scale and then find the evolutionarily stable objectives that result from the outcomes these dynamics produce. We use this framework to ask whether "other-regarding" motivations, which result from a kind of nonselfish objective, can evolve when individuals are engaged in a social interaction that entails a conflict between their material payoffs. We find that, at the evolutionarily stable state, individuals can be other-regarding in that they are motivated to increase their partners' payoff as well as their own. In contrast to previous theories, we find that such motivations can evolve because of their direct effect on fitness and do not require kin selection or a special group structure. We also derive general conditions for the evolutionary stability of other-regarding motivations. Our conditions indicate that other-regarding motivations are more likely to evolve when social interactions and behavioral objectives are both synergistic.

Neural mechanisms of cue-approach training

PubMed Central

Bakkour, Akram; Lewis-Peacock, Jarrod A.; Poldrack, Russell A.; Schonberg, Tom

2016-01-01

Biasing choices may prove a useful way to implement behavior change. Previous work has shown that a simple training task (the cue-approach task), which does not rely on external reinforcement, can robustly influence choice behavior by biasing choice toward items that were targeted during training. In the current study, we replicate previous behavioral findings and explore the neural mechanisms underlying the shift in preferences following cue-approach training. Given recent successes in the development and application of machine learning techniques to task-based fMRI data, which have advanced understanding of the neural substrates of cognition, we sought to leverage the power of these techniques to better understand neural changes during cue-approach training that subsequently led to a shift in choice behavior. Contrary to our expectations, we found that machine learning techniques applied to fMRI data during non-reinforced training were unsuccessful in elucidating the neural mechanism underlying the behavioral effect. However, univariate analyses during training revealed that the relationship between BOLD and choices for Go items increases as training progresses compared to choices of NoGo items primarily in lateral prefrontal cortical areas. This new imaging finding suggests that preferences are shifted via differential engagement of task control networks that interact with value networks during cue-approach training. PMID:27677231

Infant-Feeding Intentions and Practices of Internal Medicine Physicians

PubMed Central

Serwint, Janet R.; Shuster, Jonathan J.; Levine, David M.

2016-01-01

Abstract Background: Personal breastfeeding behavior of physician mothers is associated with their clinical breastfeeding advocacy, which in turn impacts patients' breastfeeding behavior. Internists can play an important role in breastfeeding advocacy as they usually come in contact with mothers longitudinally. Objective: To explore the personal infant-feeding decisions and behavior of physician mothers in internal medicine (IM). Materials and Methods: Physicians with current or previous IM training were isolated from our “Breastfeeding Among Physicians” database. The data in the database were gathered from cross-sectional surveys of 130 physician volunteers, mainly affiliated with the Johns Hopkins University School of Medicine (Baltimore, MD) and the University of Florida College of Medicine (Gainesville, FL). Results: Seventy-two mothers reported current or previous IM training and had 196 infants. Breastfeeding rates were 96% at birth, 77% at 6 months, and 40% at 12 months. Exclusive breastfeeding rates were 78% at birth, 67% at 3 months, and 30% at 6 months. While maternal goal for breastfeeding duration correlated with duration of both exclusive and any breastfeeding, there was a consistent and appreciable disparity between maternal duration goal and actual breastfeeding duration. The participants reported work-related reasons for early supplementation and breastfeeding cessation. Conclusions: We have described for the first time in the literature the personal infant-feeding intentions and behavior of a cohort of IM physician mothers. Workplace interventions to enable internists to maintain breastfeeding after return to work and to achieve their breastfeeding goals might improve the health of these mothers and their infants and positively impact their clinical breastfeeding advocacy. PMID:26918534

Exploring Expressive Vocabulary Variability in Two-Year-Olds: The Role of Working Memory.

PubMed

Newbury, Jayne; Klee, Thomas; Stokes, Stephanie F; Moran, Catherine

2015-12-01

This study explored whether measures of working memory ability contribute to the wide variation in 2-year-olds' expressive vocabulary skills. Seventy-nine children (aged 24-30 months) were assessed by using standardized tests of vocabulary and visual cognition, a processing speed measure, and behavioral measures of verbal working memory and phonological short-term memory. Strong correlations were observed between phonological short-term memory, verbal working memory, and expressive vocabulary. Speed of spoken word recognition showed a moderate significant correlation with expressive vocabulary. In a multivariate regression model for expressive vocabulary, the most powerful predictor was a measure of phonological short-term memory (accounting for 66% unique variance), followed by verbal working memory (6%), sex (2%), and age (1%). Processing speed did not add significant unique variance. These findings confirm previous research positing a strong role for phonological short-term memory in early expressive vocabulary acquisition. They also extend previous research in two ways. First, a unique association between verbal working memory and expressive vocabulary in 2-year-olds was observed. Second, processing speed was not a unique predictor of variance in expressive vocabulary when included alongside measures of working memory.

Lack of Association between Human Plasma Oxytocin and Interpersonal Trust in a Prisoner’s Dilemma Paradigm

PubMed Central

Christensen, James C.; Shiyanov, Pavel A.; Estepp, Justin R.; Schlager, John J.

2014-01-01

Expanding interest in oxytocin, particularly the role of endogenous oxytocin in human social behavior, has created a pressing need for replication of results and verification of assay methods. In this study, we sought to replicate and extend previous results correlating plasma oxytocin with trust and trustworthy behavior. As a necessary first step, the two most commonly used commercial assays were compared in human plasma via the addition of a known quantity of exogenous oxytocin, with and without sample extraction. Plasma sample extraction was found to be critical in obtaining repeatable concentrations of oxytocin. In the subsequent trust experiment, twelve samples in duplicate, from each of 82 participants, were collected over approximately six hours during the performance of a Prisoner’s Dilemma task paradigm that stressed human interpersonal trust. We found no significant relationship between plasma oxytocin concentrations and trusting or trustworthy behavior. In light of these findings, previous published work that used oxytocin immunoassays without sample extraction should be reexamined and future research exploring links between endogenous human oxytocin and trust or social behavior should proceed with careful consideration of methods and appropriate biofluids for analysis. PMID:25549255

Repeated MDMA ("Ecstasy") exposure in adolescent male rats alters temperature regulation, spontaneous motor activity, attention, and serotonin transporter binding.

PubMed

Piper, Brian J; Fraiman, Joseph B; Meyer, Jerrold S

2005-09-01

Previous research in our laboratory found that repeated exposure of adolescent rats to 3,4-methylenedioxymethamphetamine (MDMA) impaired working memory and reduced anxiety. The present experiment extended these findings by investigating the physiological, behavioral, and neurotoxic effects of a modified MDMA treatment regimen. Male Sprague-Dawley rats received 5 mg/kg of MDMA hourly for a period of 4 hr on every fifth day from postnatal day 35-60. Acute effects of the MDMA treatment included hypothermia, serotonin syndrome behavior, and ejaculation. Body weight gain was attenuated by repeated drug administration. The animals completed anxiety and working memory tests beginning 4 days after the final MDMA dose. MDMA altered habituation to the open-field, increased locomotor activity in the elevated plus-maze, decreased attention in the novel object-recognition test, and reduced serotonin transporter binding in the neocortex. These results indicate that repeated exposure to a relatively moderate MDMA dose during adolescence produces later changes in behavior and neurochemistry. Copyright 2005 Wiley Periodicals, Inc

DRD2/CHRNA5 Interaction on Prefrontal Biology and Physiology during Working Memory

PubMed Central

Fazio, Leonardo; D'Ambrosio, Enrico; Gelao, Barbara; Tomasicchio, Aldo; Selvaggi, Pierluigi; Taurisano, Paolo; Quarto, Tiziana; Masellis, Rita; Rampino, Antonio; Caforio, Grazia; Popolizio, Teresa; Blasi, Giuseppe; Sadee, Wolfgang; Bertolino, Alessandro

2014-01-01

Background Prefrontal behavior and activity in humans are heritable. Studies in animals demonstrate an interaction between dopamine D2 receptors and nicotinic acetylcholine receptors on prefrontal behavior but evidence in humans is weak. Therefore, we hypothesize that genetic variation regulating dopamine D2 and nicotinic acetylcholine receptor signaling impact prefrontal cortex activity and related cognition. To test this hypothesis in humans, we explored the interaction between functional genetic variants in the D2 receptor gene (DRD2, rs1076560) and in the nicotinic receptor α5 gene (CHRNA5, rs16969968) on both dorsolateral prefrontal cortex mediated behavior and physiology during working memory and on prefrontal gray matter volume. Methods A large sample of healthy subjects was compared for genotypic differences for DRD2 rs1076560 (G>T) and CHNRA5 rs16969968 (G>A) on prefrontal phenotypes, including cognitive performance at the N-Back task, prefrontal physiology with BOLD fMRI during performance of the 2-Back working memory task, and prefrontal morphometry with structural MRI. Results We found that DRD2 rs1076560 and CHNRA5 rs16969968 interact to modulate cognitive function, prefrontal physiology during working memory, and prefrontal gray matter volume. More specifically, CHRNA5-AA/DRD2-GT subjects had greater behavioral performance, more efficient prefrontal cortex activity at 2Back working memory task, and greater prefrontal gray matter volume than the other genotype groups. Conclusions The present data extend previous studies in animals and enhance our understanding of dopamine and acetylcholine signaling in the human prefrontal cortex, demonstrating interactions elicited by working memory that are modulated by genetic variants in DRD2 and CHRNA5. PMID:24819610

DRD2/CHRNA5 interaction on prefrontal biology and physiology during working memory.

PubMed

Di Giorgio, Annabella; Smith, Ryan M; Fazio, Leonardo; D'Ambrosio, Enrico; Gelao, Barbara; Tomasicchio, Aldo; Selvaggi, Pierluigi; Taurisano, Paolo; Quarto, Tiziana; Masellis, Rita; Rampino, Antonio; Caforio, Grazia; Popolizio, Teresa; Blasi, Giuseppe; Sadee, Wolfgang; Bertolino, Alessandro

2014-01-01

Prefrontal behavior and activity in humans are heritable. Studies in animals demonstrate an interaction between dopamine D2 receptors and nicotinic acetylcholine receptors on prefrontal behavior but evidence in humans is weak. Therefore, we hypothesize that genetic variation regulating dopamine D2 and nicotinic acetylcholine receptor signaling impact prefrontal cortex activity and related cognition. To test this hypothesis in humans, we explored the interaction between functional genetic variants in the D2 receptor gene (DRD2, rs1076560) and in the nicotinic receptor α5 gene (CHRNA5, rs16969968) on both dorsolateral prefrontal cortex mediated behavior and physiology during working memory and on prefrontal gray matter volume. A large sample of healthy subjects was compared for genotypic differences for DRD2 rs1076560 (G>T) and CHNRA5 rs16969968 (G>A) on prefrontal phenotypes, including cognitive performance at the N-Back task, prefrontal physiology with BOLD fMRI during performance of the 2-Back working memory task, and prefrontal morphometry with structural MRI. We found that DRD2 rs1076560 and CHNRA5 rs16969968 interact to modulate cognitive function, prefrontal physiology during working memory, and prefrontal gray matter volume. More specifically, CHRNA5-AA/DRD2-GT subjects had greater behavioral performance, more efficient prefrontal cortex activity at 2Back working memory task, and greater prefrontal gray matter volume than the other genotype groups. The present data extend previous studies in animals and enhance our understanding of dopamine and acetylcholine signaling in the human prefrontal cortex, demonstrating interactions elicited by working memory that are modulated by genetic variants in DRD2 and CHRNA5.

Disentangling and modeling interactions in fish with burst-and-coast swimming reveal distinct alignment and attraction behaviors

PubMed Central

Calovi, Daniel S.; Litchinko, Alexandra; Lopez, Ugo; Chaté, Hugues; Sire, Clément

2018-01-01

The development of tracking methods for automatically quantifying individual behavior and social interactions in animal groups has open up new perspectives for building quantitative and predictive models of collective behavior. In this work, we combine extensive data analyses with a modeling approach to measure, disentangle, and reconstruct the actual functional form of interactions involved in the coordination of swimming in Rummy-nose tetra (Hemigrammus rhodostomus). This species of fish performs burst-and-coast swimming behavior that consists of sudden heading changes combined with brief accelerations followed by quasi-passive, straight decelerations. We quantify the spontaneous stochastic behavior of a fish and the interactions that govern wall avoidance and the reaction to a neighboring fish, the latter by exploiting general symmetry constraints for the interactions. In contrast with previous experimental works, we find that both attraction and alignment behaviors control the reaction of fish to a neighbor. We then exploit these results to build a model of spontaneous burst-and-coast swimming and interactions of fish, with all parameters being estimated or directly measured from experiments. This model quantitatively reproduces the key features of the motion and spatial distributions observed in experiments with a single fish and with two fish. This demonstrates the power of our method that exploits large amounts of data for disentangling and fully characterizing the interactions that govern collective behaviors in animals groups. PMID:29324853

The impact of leadership and team behavior on standard of care delivered during human patient simulation: a pilot study for undergraduate medical students.

PubMed

Carlson, Jim; Min, Elana; Bridges, Diane

2009-01-01

Methodology to train team behavior during simulation has received increased attention, but standard performance measures are lacking, especially at the undergraduate level. Our purposes were to develop a reliable team behavior measurement tool and explore the relationship between team behavior and the delivery of an appropriate standard of care specific to the simulated case. Authors developed a unique team measurement tool based on previous work. Trainees participated in a simulated event involving the presentation of acute dyspnea. Performance was rated by separate raters using the team behavior measurement tool. Interrater reliability was assessed. The relationship between team behavior and the standard of care delivered was explored. The instrument proved to be reliable for this case and group of raters. Team behaviors had a positive relationship with the standard of medical care delivered specific to the simulated case. The methods used provide a possible method for training and assessing team performance during simulation.

Perceived Work Conditions and Turnover Intentions: The Mediating Role of Meaning of Work

PubMed Central

Arnoux-Nicolas, Caroline; Sovet, Laurent; Lhotellier, Lin; Di Fabio, Annamaria; Bernaud, Jean-Luc

2016-01-01

Perceived working conditions lead to various negative outcomes for employee behaviors, including turnover intentions. Although potential mediators for these relationships were previously identified, the importance of meaning of work has not yet been investigated. This study examines the role of this psychological resource as a mediator for the relationships between perceived working conditions and turnover intentions in a sample of 336 French workers from different job contexts. Results show that adverse working conditions were positively and significantly associated with turnover intentions. Meaning of work is negatively related to both perceived working conditions and turnover intentions. Mediation analyses for meaning of work demonstrated indirect effects of several adverse working conditions on turnover intentions. The role of meaning of work as a psychological resource for employees facing adverse working conditions is discussed, especially regarding its implications for research and practice within organizational contexts. PMID:27242616

Perceived Work Conditions and Turnover Intentions: The Mediating Role of Meaning of Work.

PubMed

Arnoux-Nicolas, Caroline; Sovet, Laurent; Lhotellier, Lin; Di Fabio, Annamaria; Bernaud, Jean-Luc

2016-01-01

Perceived working conditions lead to various negative outcomes for employee behaviors, including turnover intentions. Although potential mediators for these relationships were previously identified, the importance of meaning of work has not yet been investigated. This study examines the role of this psychological resource as a mediator for the relationships between perceived working conditions and turnover intentions in a sample of 336 French workers from different job contexts. Results show that adverse working conditions were positively and significantly associated with turnover intentions. Meaning of work is negatively related to both perceived working conditions and turnover intentions. Mediation analyses for meaning of work demonstrated indirect effects of several adverse working conditions on turnover intentions. The role of meaning of work as a psychological resource for employees facing adverse working conditions is discussed, especially regarding its implications for research and practice within organizational contexts.

Predicting the ash behavior during biomass combustion in FBC conditions by combining advanced fuel analyses with thermodynamic multicomponent equilibrium calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skrifvars, B.J.; Blomquist, J.P.; Hupa, M.

1998-12-31

Previous work at Aabo Akademi University has focused on identification and quantification of various sintering mechanisms which are relevant for problematic ash behavior during biomass combustion in fluidized bed combustion conditions, and on multi-component multi-phase thermodynamic phase equilibrium calculations of ash chemistry in these conditions. In both areas new information has been developed and useful modeling capabilities have been created. Based on the previous work, the authors now present a novel approach of using a combination of an advanced fuel analysis method and thermodynamic phase equilibrium calculations to predict the chemical and thermal behavior of the ash when firing biomass.more » Four different fuels [coal, forest residues, wood chips, and a mixture of forest residue and wood chips] were analyzed using the chemical fractionation analysis technique. Based on the results from these analyses, the authors formed two different ash fractions, (1) one fine sized fraction consisting of those elements found in the water and weak acid leach, and (2) a coarse ash particle fraction consisting of those elements found in the strong acid leach and non-leachable rest. The small sized ash fraction was then assumed to be carried up with the flue gases and consequently formed the base for any ash related problems in the flue gas channel. This fraction was therefore analyzed on its chemical and thermal behavior using multi-component multi-phase equilibrium calculations, by which the composition and the melting behavior was estimated as a function of the temperature. The amount of melt, which has earlier been found to be strongly related to problematic ash behavior, was finally expressed as a function of the temperature for the fraction. The coarse fraction was treated separately. Here the authors estimate the composition only. The paper discusses the results and their relevance to full scale combustion.« less

Contributions of Medial Temporal Lobe and Striatal Memory Systems to Learning and Retrieving Overlapping Spatial Memories

PubMed Central

Brown, Thackery I.; Stern, Chantal E.

2014-01-01

Many life experiences share information with other memories. In order to make decisions based on overlapping memories, we need to distinguish between experiences to determine the appropriate behavior for the current situation. Previous work suggests that the medial temporal lobe (MTL) and medial caudate interact to support the retrieval of overlapping navigational memories in different contexts. The present study used functional magnetic resonance imaging (fMRI) in humans to test the prediction that the MTL and medial caudate play complementary roles in learning novel mazes that cross paths with, and must be distinguished from, previously learned routes. During fMRI scanning, participants navigated virtual routes that were well learned from prior training while also learning new mazes. Critically, some routes learned during scanning shared hallways with those learned during pre-scan training. Overlap between mazes required participants to use contextual cues to select between alternative behaviors. Results demonstrated parahippocampal cortex activity specific for novel spatial cues that distinguish between overlapping routes. The hippocampus and medial caudate were active for learning overlapping spatial memories, and increased their activity for previously learned routes when they became context dependent. Our findings provide novel evidence that the MTL and medial caudate play complementary roles in the learning, updating, and execution of context-dependent navigational behaviors. PMID:23448868

Affect and Subsequent Physical Activity: An Ambulatory Assessment Study Examining the Affect-Activity Association in a Real-Life Context.

PubMed

Niermann, Christina Y N; Herrmann, Christian; von Haaren, Birte; van Kann, Dave; Woll, Alexander

2016-01-01

Traditionally, cognitive, motivational, and volitional determinants have been used to explain and predict health behaviors such as physical activity. Recently, the role of affect in influencing and regulating health behaviors received more attention. Affects as internal cues may automatically activate unconscious processes of behavior regulation. The aim of our study was to examine the association between affect and physical activity in daily life. In addition, we studied the influence of the habit of being physically active on this relationship. An ambulatory assessment study in 89 persons (33.7% male, 25 to 65 years, M = 45.2, SD = 8.1) was conducted. Affect was assessed in the afternoon on 5 weekdays using smartphones. Physical activity was measured continuously objectively using accelerometers and subjectively using smartphones in the evening. Habit strength was assessed at the beginning of the diary period. The outcomes were objectively and subjectively measured moderate-to-vigorous physical activity (MVPA) performed after work. Multilevel regression models were used to analyze the association between affect and after work MVPA. In addition, the cross-level interaction of habit strength and affect on after work MVPA was tested. Positive affect was positively related to objectively measured and self-reported after work MVPA: the greater the positive affect the more time persons subsequently spent on MVPA. An inverse relationship was found for negative affect: the greater the negative affect the less time persons spent on MVPA. The cross-level interaction effect was significant only for objectively measured MVPA. A strong habit seems to strengthen both the positive influence of positive affect and the negative influence of negative affect. The results of this study confirm previous results and indicate that affect plays an important role for the regulation of physical activity behavior in daily life. The results for positive affect were consistent. However, in contrast to previous reports of no or an inverse association, negative affect decreased subsequent MVPA. These inconsistencies may be-in part-explained by the different measurements of affect in our and other studies. Therefore, further research is warranted to gain more insight into the association between affect and physical activity.

Domains of unprofessional behavior during medical school associated with future disciplinary action by a state medical board.

PubMed

Teherani, Arianne; Hodgson, Carol S; Banach, Mary; Papadakis, Maxine A

2005-10-01

In a previous study, we showed that unprofessional behavior in medical school was associated with subsequent disciplinary action. This study expands on that work by identifying the domains of unprofessional behavior that are most problematic. In this retrospective case-control study, negative comments were extracted from student files for 68 case (disciplined) and 196 matched control (nondisciplined) physicians. Comments were analyzed qualitatively and subsequently quantified. The relationship between domains of behavior and disciplinary action was established through chi-square tests and multivariate analysis of variance. Three domains of unprofessional behavior emerged that were related significantly to later disciplinary outcome: (1) poor reliability and responsibility, (2) lack of self-improvement and adaptability, and (3) poor initiative and motivation. Three critical domains of professionalism associated with future disciplinary action have been defined. These findings could lead to focused remediation strategies and policy decisions.

Mapping Sub-Second Structure in Mouse Behavior

PubMed Central

Wiltschko, Alexander B.; Johnson, Matthew J.; Iurilli, Giuliano; Peterson, Ralph E.; Katon, Jesse M.; Pashkovski, Stan L.; Abraira, Victoria E.; Adams, Ryan P.; Datta, Sandeep Robert

2015-01-01

Summary Complex animal behaviors are likely built from simpler modules, but their systematic identification in mammals remains a significant challenge. Here we use depth imaging to show that three-dimensional (3D) mouse pose dynamics are structured at the sub-second timescale. Computational modeling of these fast dynamics effectively describes mouse behavior as a series of reused and stereotyped modules with defined transition probabilities. We demonstrate this combined 3D imaging and machine learning method can be used to unmask potential strategies employed by the brain to adapt to the environment, to capture both predicted and previously-hidden phenotypes caused by genetic or neural manipulations, and to systematically expose the global structure of behavior within an experiment. This work reveals that mouse body language is built from identifiable components and is organized in a predictable fashion; deciphering this language establishes an objective framework for characterizing the influence of environmental cues, genes and neural activity on behavior. PMID:26687221

Understanding the Implications of Neural Population Activity on Behavior

NASA Astrophysics Data System (ADS)

Briguglio, John

Learning how neural activity in the brain leads to the behavior we exhibit is one of the fundamental questions in Neuroscience. In this dissertation, several lines of work are presented to that use principles of neural coding to understand behavior. In one line of work, we formulate the efficient coding hypothesis in a non-traditional manner in order to test human perceptual sensitivity to complex visual textures. We find a striking agreement between how variable a particular texture signal is and how sensitive humans are to its presence. This reveals that the efficient coding hypothesis is still a guiding principle for neural organization beyond the sensory periphery, and that the nature of cortical constraints differs from the peripheral counterpart. In another line of work, we relate frequency discrimination acuity to neural responses from auditory cortex in mice. It has been previously observed that optogenetic manipulation of auditory cortex, in addition to changing neural responses, evokes changes in behavioral frequency discrimination. We are able to account for changes in frequency discrimination acuity on an individual basis by examining the Fisher information from the neural population with and without optogenetic manipulation. In the third line of work, we address the question of what a neural population should encode given that its inputs are responses from another group of neurons. Drawing inspiration from techniques in machine learning, we train Deep Belief Networks on fake retinal data and show the emergence of Garbor-like filters, reminiscent of responses in primary visual cortex. In the last line of work, we model the state of a cortical excitatory-inhibitory network during complex adaptive stimuli. Using a rate model with Wilson-Cowan dynamics, we demonstrate that simple non-linearities in the signal transferred from inhibitory to excitatory neurons can account for real neural recordings taken from auditory cortex. This work establishes and tests a variety of hypotheses that will be useful in helping to understand the relationship between neural activity and behavior as recorded neural populations continue to grow.

Passive vs. Active Control of Rhythmic Ball Bouncing: The Role of Visual Information

ERIC Educational Resources Information Center

Siegler, Isabelle A.; Bardy, Benoit G.; Warren, William H.

2010-01-01

The simple task of bouncing a ball on a racket offers a model system for studying how human actors exploit the physics and information of the environment to control their behavior. Previous work shows that people take advantage of a passively stable solution for ball bouncing but can also use perceptual information to actively stabilize bouncing.…

Achieving Affective and Behavioral Outcomes in Culture Learning: The Case for Ethnographic Interviews

ERIC Educational Resources Information Center

Bateman, Blair E.

2004-01-01

This study sought to extend previous research on ethnographic interviews as a method of culture learning in foreign language classes by employing a qualitative case study methodology. Fifty-four university students in a first-year Spanish course worked in pairs to conduct a series of three ethnographic interviews with a native speaker of Spanish.…

The Relationship between Parental Knowledge and Monitoring and Child and Adolescent Conduct Problems: A 10-Year Update

ERIC Educational Resources Information Center

Racz, Sarah Jensen; McMahon, Robert J.

2011-01-01

Inadequate parental monitoring is widely recognized as a risk factor for the development of child and adolescent conduct problems. However, previous studies examining parental monitoring have largely measured parental knowledge and not the active methods used by parents to track the activities and behavior of their children. The seminal work of…

Working Memory Effects of Gap-Predictions in Normal Adults: An Event-Related Potentials Study

ERIC Educational Resources Information Center

Hestvik, Arild; Bradley, Evan; Bradley, Catherine

2012-01-01

The current study examined the relationship between verbal memory span and the latency with which a filler-gap dependency is constructed. A previous behavioral study found that low span listeners did not exhibit antecedent reactivation at gap sites in relative clauses, in comparison to high verbal memory span subjects (Roberts et al. in "J…

Time to Tenure: Does Tenure Reform Affect Teacher Absence Behavior and Mobility? Working Paper 172

ERIC Educational Resources Information Center

Goldhaber, Dan; Hansen, Michael; Walch, Joe

2016-01-01

We rely on natural experiments in North Carolina and Washington State, which previously extended time to tenure by one year, to estimate models that assess the relationship between the extended probationary period and absence and attrition outcomes for teachers affected by the new tenure laws. Across both states we find evidence of decreases in…

Encouraging Survey Participation among Individuals Seeking HIV Prevention Services: Does a Community Identity Match Help or Hurt?

ERIC Educational Resources Information Center

Crowley, Jocelyn Elise; Roff, Brian H.; Lynch, Jeneve

2007-01-01

Understanding the behaviors and attitudes of at-risk populations is fundamental to controlling the spread of HIV, the virus that causes AIDS. The problem of nonresponse among these populations, however, plagues survey research designed to address these issues. Previous work undertaken to map out the dynamics of nonresponse--both noncontacts and…

Faking Bad: Do High-Ability Elementary Students Intentionally Underachieve When Their Work Is Peer-Reviewed?

ERIC Educational Resources Information Center

Black, Kasey M. K.

2012-01-01

While faking bad, or the intentional distortion of assessment results, has been studied extensively with self-report measures (Lim & Butcher, 1996; Roskes, 2009), the possible presence of this behavior on direct measures has only just begun to be examined. Previous studies of faking bad on academic measures have been limited to students at the…

Dog Breed Differences in Visual Communication with Humans

PubMed Central

Konno, Akitsugu; Romero, Teresa; Inoue-Murayama, Miho; Saito, Atsuko; Hasegawa, Toshikazu

2016-01-01

Domestic dogs (Canis familiaris) have developed a close relationship with humans through the process of domestication. In human-dog interactions, eye contact is a key element of relationship initiation and maintenance. Previous studies have suggested that canine ability to produce human-directed communicative signals is influenced by domestication history, from wolves to dogs, as well as by recent breed selection for particular working purposes. To test the genetic basis for such abilities in purebred dogs, we examined gazing behavior towards humans using two types of behavioral experiments: the ‘visual contact task’ and the ‘unsolvable task’. A total of 125 dogs participated in the study. Based on the genetic relatedness among breeds subjects were classified into five breed groups: Ancient, Herding, Hunting, Retriever-Mastiff and Working). We found that it took longer time for Ancient breeds to make an eye-contact with humans, and that they gazed at humans for shorter periods of time than any other breed group in the unsolvable situation. Our findings suggest that spontaneous gaze behavior towards humans is associated with genetic similarity to wolves rather than with recent selective pressure to create particular working breeds. PMID:27736990

Fatigue Crack Growth Behavior Evaluation of Grainex Mar-M 247 for NASA's High Temperature, High Speed Turbine Seal Test Rig

NASA Technical Reports Server (NTRS)

Delgado, Irebert R.; Steinetz, Bruce M.; Rimnac, Clare M.; Lewandowski, John J.

2008-01-01

The fatigue crack growth behavior of Grainex Mar-M 247 is evaluated for NASA s Turbine Seal Test Facility. The facility is used to test air-to-air seals primarily for use in advanced jet engine applications. Because of extreme seal test conditions of temperature, pressure, and surface speeds, surface cracks may develop over time in the disk bolt holes. An inspection interval is developed to preclude catastrophic disk failure by using experimental fatigue crack growth data. By combining current fatigue crack growth results with previous fatigue strain-life experimental work, an inspection interval is determined for the test disk. The fatigue crack growth life of the NASA disk bolt holes is found to be 367 cycles at a crack depth of 0.501 mm using a factor of 2 on life at maximum operating conditions. Combining this result with previous fatigue strain-life experimental work gives a total fatigue life of 1032 cycles at a crack depth of 0.501 mm. Eddy-current inspections are suggested starting at 665 cycles since eddy current detection thresholds are currently at 0.381 mm. Inspection intervals are recommended every 50 cycles when operated at maximum operating conditions.

A biologically inspired meta-control navigation system for the Psikharpax rat robot.

PubMed

Caluwaerts, K; Staffa, M; N'Guyen, S; Grand, C; Dollé, L; Favre-Félix, A; Girard, B; Khamassi, M

2012-06-01

A biologically inspired navigation system for the mobile rat-like robot named Psikharpax is presented, allowing for self-localization and autonomous navigation in an initially unknown environment. The ability of parts of the model (e.g. the strategy selection mechanism) to reproduce rat behavioral data in various maze tasks has been validated before in simulations. But the capacity of the model to work on a real robot platform had not been tested. This paper presents our work on the implementation on the Psikharpax robot of two independent navigation strategies (a place-based planning strategy and a cue-guided taxon strategy) and a strategy selection meta-controller. We show how our robot can memorize which was the optimal strategy in each situation, by means of a reinforcement learning algorithm. Moreover, a context detector enables the controller to quickly adapt to changes in the environment-recognized as new contexts-and to restore previously acquired strategy preferences when a previously experienced context is recognized. This produces adaptivity closer to rat behavioral performance and constitutes a computational proposition of the role of the rat prefrontal cortex in strategy shifting. Moreover, such a brain-inspired meta-controller may provide an advancement for learning architectures in robotics.

Assessing Homework Problems in Children with ADHD: Validation of a Parent-Report Measure and Evaluation of Homework Performance Patterns.

PubMed

Langberg, Joshua M; Arnold, L Eugene; Flowers, Amanda M; Altaye, Mekibib; Epstein, Jeff N; Molina, Brooke S G

2010-03-01

The factor structure of a parent-report measure of child homework problems, the Homework Problems Checklist, was examined in a geographically and ethnically diverse sample of children with Attention-Deficit/Hyperactivity Disorder (ADHD). This measure was completed by the parents of 579 children ages 7.0-9.9 diagnosed with ADHD Combined Type as part of the Multimodal Treatment Study of Children with ADHD (MTA). Results replicated previous work showing two salient factors that measure homework completion behaviors (Factor I) and homework management behaviors (Factor II). This two-factor solution remained consistent when examined across child sex and ethnicity subgroups. Analysis of patterns revealed that homework problems are greater for children in higher grades and that children with ADHD and comorbid Learning Disabilities experience significantly more homework problems than children with ADHD alone. This study also replicated previous work showing that homework problems and ADHD inattentive symptoms are highly correlated whereas correlations between homework problems and hyperactivity and impulsivity are low to moderate. Implications of the findings for the assessment of homework problems in children with ADHD and for intervention are discussed.

Assessing Homework Problems in Children with ADHD: Validation of a Parent-Report Measure and Evaluation of Homework Performance Patterns

PubMed Central

Langberg, Joshua M.; Arnold, L. Eugene; Flowers, Amanda M.; Altaye, Mekibib; Epstein, Jeff N.; Molina, Brooke S.G.

2011-01-01

The factor structure of a parent-report measure of child homework problems, the Homework Problems Checklist, was examined in a geographically and ethnically diverse sample of children with Attention-Deficit/Hyperactivity Disorder (ADHD). This measure was completed by the parents of 579 children ages 7.0-9.9 diagnosed with ADHD Combined Type as part of the Multimodal Treatment Study of Children with ADHD (MTA). Results replicated previous work showing two salient factors that measure homework completion behaviors (Factor I) and homework management behaviors (Factor II). This two-factor solution remained consistent when examined across child sex and ethnicity subgroups. Analysis of patterns revealed that homework problems are greater for children in higher grades and that children with ADHD and comorbid Learning Disabilities experience significantly more homework problems than children with ADHD alone. This study also replicated previous work showing that homework problems and ADHD inattentive symptoms are highly correlated whereas correlations between homework problems and hyperactivity and impulsivity are low to moderate. Implications of the findings for the assessment of homework problems in children with ADHD and for intervention are discussed. PMID:21544228

How does the past of a soccer match influence its future? Concepts and statistical analysis.

PubMed

Heuer, Andreas; Rubner, Oliver

2012-01-01

Scoring goals in a soccer match can be interpreted as a stochastic process. In the most simple description of a soccer match one assumes that scoring goals follows from independent rate processes of both teams. This would imply simple Poissonian and Markovian behavior. Deviations from this behavior would imply that the previous course of the match has an impact on the present match behavior. Here a general framework for the identification of deviations from this behavior is presented. For this endeavor it is essential to formulate an a priori estimate of the expected number of goals per team in a specific match. This can be done based on our previous work on the estimation of team strengths. Furthermore, the well-known general increase of the number of the goals in the course of a soccer match has to be removed by appropriate normalization. In general, three different types of deviations from a simple rate process can exist. First, the goal rate may depend on the exact time of the previous goals. Second, it may be influenced by the time passed since the previous goal and, third, it may reflect the present score. We show that the Poissonian scenario is fulfilled quite well for the German Bundesliga. However, a detailed analysis reveals significant deviations for the second and third aspect. Dramatic effects are observed if the away team leads by one or two goals in the final part of the match. This analysis allows one to identify generic features about soccer matches and to learn about the hidden complexities behind scoring goals. Among others the reason for the fact that the number of draws is larger than statistically expected can be identified.

How Does the Past of a Soccer Match Influence Its Future? Concepts and Statistical Analysis

PubMed Central

Heuer, Andreas; Rubner, Oliver

2012-01-01

Scoring goals in a soccer match can be interpreted as a stochastic process. In the most simple description of a soccer match one assumes that scoring goals follows from independent rate processes of both teams. This would imply simple Poissonian and Markovian behavior. Deviations from this behavior would imply that the previous course of the match has an impact on the present match behavior. Here a general framework for the identification of deviations from this behavior is presented. For this endeavor it is essential to formulate an a priori estimate of the expected number of goals per team in a specific match. This can be done based on our previous work on the estimation of team strengths. Furthermore, the well-known general increase of the number of the goals in the course of a soccer match has to be removed by appropriate normalization. In general, three different types of deviations from a simple rate process can exist. First, the goal rate may depend on the exact time of the previous goals. Second, it may be influenced by the time passed since the previous goal and, third, it may reflect the present score. We show that the Poissonian scenario is fulfilled quite well for the German Bundesliga. However, a detailed analysis reveals significant deviations for the second and third aspect. Dramatic effects are observed if the away team leads by one or two goals in the final part of the match. This analysis allows one to identify generic features about soccer matches and to learn about the hidden complexities behind scoring goals. Among others the reason for the fact that the number of draws is larger than statistically expected can be identified. PMID:23226200

The Physics of Protoplanetesimal Dust Agglomerates. VII. The Low-velocity Collision Behavior of Large Dust Agglomerates

NASA Astrophysics Data System (ADS)

Schräpler, Rainer; Blum, Jürgen; Seizinger, Alexander; Kley, Wilhelm

2012-10-01

We performed micro-gravity collision experiments in our laboratory drop tower using 5 cm sized dust agglomerates with volume filling factors of 0.3 and 0.4, respectively. This work is an extension of our previous experiments reported in Beitz et al. to aggregates of more than one order of magnitude higher masses. The dust aggregates consisted of micrometer-sized silica particles and were macroscopically homogeneous. We measured the coefficient of restitution for collision velocities ranging from 1 cm s-1 to 0.5 m s-1, and determined the fragmentation velocity. For low velocities, the coefficient of restitution decreases with increasing impact velocity, in contrast to findings by Beitz et al. At higher velocities, the value of the coefficient of restitution becomes constant, before the aggregates break at the onset of fragmentation. We interpret the qualitative change in the coefficient of restitution as the transition from a solid-body-dominated to a granular-medium-dominated behavior. We complement our experiments by molecular-dynamics simulations of porous aggregates and obtain a reasonable match to the experimental data. We discuss the importance of our experiments for protoplanetary disks, debris disks, and planetary rings. This work is an extension to the previous work of our group and gives new insight into the velocity dependency of the coefficient of restitution due to improved measurements, better statistics, and a theoretical approach.

Re-Evaluation of the Lower San Fernando Dam. Report 3. The Behavior of Undrained Contractive Sand and Its Effect on Seismic Liquefaction Flow Failures of Earth Structures

DTIC Science & Technology

1989-09-01

34 nrn. 4th World Crnf. n 7rthquake Engr., Vol 2, Santiago , Chile , pp. 1-11. 137. Seed, H.B., Lee, K.L. and Idriss, I.M. (1969): "An Analysis of...391 Fig. 8.10. Approximate Sections Through Large Slide Area Near Lake Rinihue, Chile (after Seed, 1967) . . . 392 Fig. 8.11. Cross Section of...to clarify the fundamental behavior of these soils. Previous work on contractive sands concentrated on steady-state or residual strength

A comparison of methods for teaching receptive language to toddlers with autism.

PubMed

Vedora, Joseph; Grandelski, Katrina

2015-01-01

The use of a simple-conditional discrimination training procedure, in which stimuli are initially taught in isolation with no other comparison stimuli, is common in early intensive behavioral intervention programs. Researchers have suggested that this procedure may encourage the development of faulty stimulus control during training. The current study replicated previous work that compared the simple-conditional and the conditional-only methods to teach receptive labeling of pictures to young children with autism spectrum disorder. Both methods were effective, but the conditional-only method required fewer sessions to mastery. © Society for the Experimental Analysis of Behavior.

What scientists want from their research ethics committee.

PubMed

Keith-Spiegel, Patricia; Tabachnick, Barbara

2006-03-01

Whereas investigators have directed considerable criticism against Institutional Review Boards (IRBs), the desirable characteristics of IRBs have not previously been empirically determined. A sample of 886 experienced biomedical and social and behavioral scientists rated 45 descriptors of IRB actions and functions as to their importance. Predictions derived from organizational justice research findings in other work settings were generally borne out. Investigators place high value on the fairness and respectful consideration of their IRBs. Expected differences between biomedical and social behavioral researchers and other variables were unfounded. Recommendations are offered for educating IRBs to accord researchers greater respect and fair treatment.

Spermidine boosts autophagy to protect from synapse aging.

PubMed

Bhukel, Anuradha; Madeo, Frank; Sigrist, Stephan J

2017-02-01

All animals form memories to adapt their behavior in a context-dependent manner. With increasing age, however, forming new memories becomes less efficient. While synaptic plasticity promotes memory formation, the etiology of age-induced memory formation remained enigmatic. Previous work showed that simple feeding of polyamine spermidine protects from age-induced memory impairment in Drosophila. Most recent work now shows that spermidine operates directly at synapses, allowing for an autophagy-dependent homeostatic regulation of presynaptic specializations. How exactly autophagic regulations intersect with synaptic plasticity should be an interesting subject for future research.

Mental models of safety: do managers and employees see eye to eye?

PubMed

Prussia, Gregory E; Brown, Karen A; Willis, P Geoff

2003-01-01

Disagreements between managers and employees about the causes of accidents and unsafe work behaviors can lead to serious workplace conflicts and distract organizations from the important work of establishing positive safety climate and reducing the incidence of accidents. In this study, the authors examine a model for predicting safe work behaviors and establish the model's consistency across managers and employees in a steel plant setting. Using the model previously described by Brown, Willis, and Prussia (2000), the authors found that when variables influencing safety are considered within a framework of safe work behaviors, managers and employees share a similar mental model. The study then contrasts employees' and managers' specific attributional perceptions. Findings from these more fine-grained analyses suggest the two groups differ in several respects about individual constructs. Most notable were contrasts in attributions based on their perceptions of safety climate. When perceived climate is poor, managers believe employees are responsible and employees believe managers are responsible for workplace safety. However, as perceived safety climate improves, managers and employees converge in their perceptions of who is responsible for safety. It can be concluded from this study that in a highly interdependent work environment, such as a steel mill, where high system reliability is essential and members possess substantial experience working together, managers and employees will share general mental models about the factors that contribute to unsafe behaviors, and, ultimately, to workplace accidents. It is possible that organizations not as tightly coupled as steel mills can use such organizations as benchmarks, seeking ways to create a shared understanding of factors that contribute to a safe work environment. Part of this improvement effort should focus on advancing organizational safety climate. As climate improves, managers and employees are likely to agree more about the causes of safe/unsafe behaviors and workplace accidents, ultimately increasing their ability to work in unison to prevent accidents and to respond appropriately when they do occur. Finally, the survey items included in this study may be useful to organizations wishing to conduct self-assessments.

Perception of partner sexual history: Effects on safe-sex intentions.

PubMed

Cornelius, Talea; Kershaw, Trace

2017-07-01

Sexual intercourse is a dyadic activity, and intentions to engage in safe sex vary across partners. Because pregnant and newly parenting adolescents and young adults are at high risk for sexually transmitted infections (STIs), it is important to understand sexual decision-making in this population. This cross-sectional study examined how participants' own risk behavior and their partners' risk behavior influence perceptions of partner risk, and the impact of risk perceptions on condom use intentions and monogamy intentions in 296 pregnant adolescent and young adult couples (MAgeFemale = 18.71 years; MAgeMale = 21.33 years). Participants' behavior and their partners' behavior both related to increased perceptions of partner risk. Male participants' perceptions were more strongly influenced by female partners' behavior than participants' own behavior. Perceiving a partner as having a history of more risk behaviors trended toward a negative relationship with condom use intentions and monogamy intentions. For females, more previous sex partners related negatively to condom use intentions and positively to monogamy intentions. Having a male partner with more previous sex partners related positively to condom use intentions and monogamy intentions. Perceptions of partner risk did not significantly relate to condom use intentions and monogamy intentions, however, trends suggest that risk perception could reflect similarity bias and ongoing risk engagement. Differences in partner perception by gender suggest that females may communicate more openly about risks. Interventions to reduce STI transmission in couples should work to interrupt trajectories of risky behavior and enhance risk communication. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Revisiting the relationship between jet position, forced response, and annular mode variability in the southern midlatitudes

NASA Astrophysics Data System (ADS)

Simpson, Isla R.; Polvani, Lorenzo M.

2016-03-01

Climate models exhibit a wide range in latitudinal position of the Southern Hemisphere westerly jet. Previous work has demonstrated, in the annual mean, that models with lower latitude jets, exhibit greater poleward jet shifts under climate forcings. It has been argued that this behavior is due to stronger eddy/mean flow feedbacks in models with lower latitude jets, as inferred from the timescale of the Southern Annular Mode (SAM). Here we revisit this question with a focus on seasonality. Using a larger set of models and forcing scenarios from the Coupled Model Intercomparison Project, phase 5, we find that the jet position/jet shift relationship is strong in winter but insignificant in summer, whereas the model spread in SAM timescales arises primarily in summer, with winter timescales similar across models. The results, therefore, question previous interpretations and motivate an improved understanding of the spread in model behavior.

Hybrid value foraging: How the value of targets shapes human foraging behavior.

PubMed

Wolfe, Jeremy M; Cain, Matthew S; Alaoui-Soce, Abla

2018-04-01

In hybrid foraging, observers search visual displays for multiple instances of multiple target types. In previous hybrid foraging experiments, although there were multiple types of target, all instances of all targets had the same value. Under such conditions, behavior was well described by the marginal value theorem (MVT). Foragers left the current "patch" for the next patch when the instantaneous rate of collection dropped below their average rate of collection. An observer's specific target selections were shaped by previous target selections. Observers were biased toward picking another instance of the same target. In the present work, observers forage for instances of four target types whose value and prevalence can vary. If value is kept constant and prevalence manipulated, participants consistently show a preference for the most common targets. Patch-leaving behavior follows MVT. When value is manipulated, observers favor more valuable targets, though individual foraging strategies become more diverse, with some observers favoring the most valuable target types very strongly, sometimes moving to the next patch without collecting any of the less valuable targets.

The effects of environmental resource and security on aggressive behavior.

PubMed

Ng, Henry Kin Shing; Chow, Tak Sang

2017-05-01

Exposure to different environments has been reported to change aggressive behavior, but previous research did not consider the underlying elements that caused such an effect. Based on previous work on environmental perception, we examined the role of environmental resource and security in altering aggression level. In three experiments, participants were exposed to environments that varied in resource (High vs. Low) and security (High vs. Low) levels, after which aggression was measured. The environments were presented through visual priming (Experiments 1-2) and a first-person gameplay (Experiment 3). We observed a consistent resource-security interaction effect on aggression, operationalized as the level of noise blast (Experiment 1) and number of unpleasant pictures (Experiments 2-3) delivered to strangers by the participants. High resource levels associated with higher aggression in insecure conditions, but lower aggression in secure conditions. The findings suggest that the adaptive value of aggression varies under different environmental constraints. Implications are discussed in terms of the effects of adverse environments on aggression, and the nature's effects on social behavior. Aggr. Behav. 43:304-314, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Exploration of the short-term and long-term effects of parental illness on children's educational and behavioral functioning using a large Taiwanese sample.

PubMed

Chen, Yung-Chi

2014-05-01

This study used data from Waves I and II of the Taiwan Educational Panel Survey (TEPS) to explore the potential short-term and long-term effects of parental illness and health condition on children's behavioral and educational functioning. A sample of 11,018 junior high school students and their parents and teachers in Taiwan were included in this present study. The results supported previous work that parental illness may place children at slight risk for poor psychosocial adjustment and behavioral problems. Parental illness was associated with lower adaptive skills and more behavioral problems in children. Children of ill parents showed resilience in their educational functioning in the event of parental illness as children's academic achievement and learning skills were not related to parental illness/health condition.

Losing our humanity: the self-dehumanizing consequences of social ostracism.

PubMed

Bastian, Brock; Jetten, Jolanda; Chen, Hannah; Radke, Helena R M; Harding, Jessica F; Fasoli, Fabio

2013-02-01

People not only dehumanize others, they also dehumanize the self in response to their own harmful behavior. We examine this self-dehumanization effect across four studies. Studies 1 and 2 show that when participants are perpetrators of social ostracism, they view themselves as less human compared with when they engage in nonaversive interpersonal interactions. Perceived immorality of their behavior mediated this effect. Studies 3 and 4 highlight the behavioral consequences of self-dehumanization. The extent to which participants saw themselves as less human after perpetrating social ostracism predicted subsequent prosocial behavior. Studies 2 to 4 also demonstrate that consequences of self-dehumanization occur independently of any effects of self-esteem or mood. The findings are discussed in relation to previous work on dehumanization and self-perception. We conclude that in the context of immoral actions (self) dehumanization may be functional.

Online monitoring of corrosion behavior in molten metal using laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Zeng, Qiang; Pan, Congyuan; Li, Chaoyang; Fei, Teng; Ding, Xiaokang; Du, Xuewei; Wang, Qiuping

2018-04-01

The corrosion behavior of structure materials in direct contact with molten metals is widespread in metallurgical industry. The corrosion of casting equipment by molten metals is detrimental to the production process, and the corroded materials can also contaminate the metals being produced. Conventional methods for studying the corrosion behavior by molten metal are offline. This work explored the application of laser-induced breakdown spectroscopy (LIBS) for online monitoring of the corrosion behavior of molten metal. The compositional changes of molten aluminum in crucibles made of 304 stainless steel were obtained online at 1000 °C. Several offline techniques were combined to determine the corrosion mechanism, which was highly consistent with previous studies. Results proved that LIBS was an efficient method to study the corrosion mechanism of solid materials in molten metal.

The Neural Correlates of Race

PubMed Central

Ito, Tiffany A.; Bartholow, Bruce D.

2009-01-01

Behavioral analyses are a natural choice for understanding the wide-ranging behavioral consequences of racial stereotyping and prejudice. However, neuroimaging and electrophysiological research has recently considered the neural mechanisms that underlie racial categorization and the activation and application of racial stereotypes and prejudice, revealing exciting new insights. Work reviewed here points to the importance of neural structures previously associated with face processing, semantic knowledge activation, evaluation, and self-regulatory behavioral control, allowing for the specification of a neural model of race processing. We show how research on the neural correlates of race can serve to link otherwise disparate lines of evidence on the neural underpinnings of a broad array of social-cognitive phenomena, and consider implications for effecting change in race relations. PMID:19896410

Family Meals and Child Academic and Behavioral Outcomes

PubMed Central

Miller, Daniel P.; Waldfogel, Jane; Han, Wen-Jui

2012-01-01

This study investigates the link between the frequency of family breakfasts and dinners and child academic and behavioral outcomes in a panel sample of 21,400 children aged 5–15. It complements previous work by examining younger and older children separately and by using information on a large number of controls and rigorous analytic methods to discern whether there is causal relation between family meal frequency (FMF) and child outcomes. In child fixed effects models, which controlled for unchanging aspects of children and their families, there were no significant (p<.05) relations between FMF and either academic or behavioral outcomes, a novel finding. These results were robust to various specifications of the FMF variables and did not differ by child age. PMID:22880815

Narrative and framing: a test of an integrated message strategy in the exercise context.

PubMed

Gray, Jennifer B; Harrington, Nancy G

2011-03-01

Health communication interventions encouraging exercise may aid in mitigating the obesity crisis in the United States. Although much research has investigated behavioral predictors of exercise, little work has explored message characteristics most persuasive in the exercise context. The purpose of this study, therefore, was to test a message strategy drawing on previous work in health behavior theory combined with persuasion theories (exemplification theory and prospect theory) to encourage positive exercise attitudes, control beliefs, and intentions. The authors report the results of a controlled experiment testing messages using gain or loss frames and narrative or statistical evidence. Results indicate that gain-framed messages are significantly more successful in promoting positive exercise variables and are perceived as more effective than are loss-framed or control messages. The authors discuss the implications of the results for future research.

Contributions of participatory ergonomics to the improvement of safety culture in an industrial context.

PubMed

Lallemand, Carine

2012-01-01

This paper presents the results of an ergonomic intervention conducted within a blast furnace plant. As part of its risk prevention program, the company decided to set up an action plan, in a participatory manner, by setting up working groups to solve health & safety issues. This field mission involved 230 employees, 80 of whom participated actively by being incorporated into working groups. After four months of intervention, a questionnaire survey has been conducted among employees to study the effects of participation on the safety climate. The results seem promising and show that the benefits of participation are numerous: a more positive safety climate associated to safer attitudes and behaviors. However, rather than just participation, it seems to be the employee involvement in the working groups and the satisfaction they derive from their participation that guarantee these positive results. Hence, participatory ergonomics seems to be an effective way to decrease the number of unsafe behaviors at work, provided that the type of participation has been previously well defined and organized according to the specific context of each organization.

Bullying among radiation therapists: effects on job performance and work environment.

PubMed

Trad, Megan; Johnson, Jordan

2014-01-01

To identify the effects of workplace bullying in the radiation therapy department on job performance and explore the environment and morale of individuals who work with a bully. A quantitative research study was designed to assess the prevalence and effects of bullying in the radiation therapy workplace. A total of 308 radiation therapists participated in the study for a return rate of 46%. Of those, 194 indicated that workplace bullying was present either in their current workplace or in a previous radiation therapy environment and that it negatively affected job performance and satisfaction. Findings of this study indicate a need for evaluation of the radiation therapy workplace, education on how to identify and prevent bullying behavior, and better communication among members of the radiation therapy environment. Participants indicated that working in a hostile environment led to forgetfulness, ineffective communication, and perceived discrepancies in promotion and treatment by management. Any bullying behavior contributes to an overall toxic work environment, which is unhealthy and unsafe for patients and therapists. Those who manage therapists should promote a culture of safety and embrace their staff's independence.

Gender differences in Reasons for Sickness Presenteeism - a study among GPs in a Swedish health care organization.

PubMed

Gustafsson Sendén, Marie; Schenck-Gustafsson, Karin; Fridner, Ann

2016-01-01

It is common that physicians go to work while sick and therefore it is important to understand the reasons behind. Previous research has shown that women and men differ in health and health related behavior. In this study, we examine gender differences among general practitioners who work while sick. General practitioners (GP's) working in outpatient care in a Swedish city participated in the study (n = 283; women = 63 %; response rate = 41 %). Data were obtained from a large web-based questionnaire about health and organization within primary care. Two questions about sickness presenteeism (going to work while sick) were included; life-long and during the past 12 months, and five questions about reasons. We controlled for general health, work-family conflict and demographic variables. Female physicians reported sickness presenteeism more often than male physicians. Work-family conflict mediated the association between gender and sickness presenteeism. Women reported reasons related with "concern for others" and "workload" more strongly than men. Men reported reasons related with "capacity" and "money" more strongly than women. These differences are likely effects of gender stereotyping and different family-responsibilities. Gender socialization and gender stereotypes may influence work and health-related behavior. Because sickness presenteeism is related with negative effects both on individuals and at organizational levels, it is important that managers of health organizations understand the reasons for this, and how gender roles may influence the prevalence of sickness presenteeism and the reasons that female and male GPs give for their behavior.

Human Behavior and Performance Support for ISS Operations and Astronaut Selections: NASA Operational Psychology for Six-Crew Operations

NASA Technical Reports Server (NTRS)

VanderArk, Steve; Sipes, Walter; Holland, Albert; Cockrell, Gabrielle

2010-01-01

The Behavioral Health and Performance group at NASA Johnson Space Center provides psychological support services and behavioral health monitoring for ISS astronauts and their families. The ISS began as an austere outpost with minimal comforts of home and minimal communication capabilities with family, friends, and colleagues outside of the Mission Control Center. Since 1998, the work of international partners involved in the Space Flight Human Behavior and Performance Working Group has prepared high-level requirements for behavioral monitoring and support. The "buffet" of services from which crewmembers can choose has increased substantially. Through the process of development, implementation, reviewing effectiveness and modifying as needed, the NASA and Wyle team have proven successful in managing the psychological health and well being of the crews and families with which they work. Increasing the crew size from three to six brought additional challenges. For the first time, all partners had to collaborate at the planning and implementation level, and the U.S. served as mentor to extrapolate their experiences to the others. Parity in available resources, upmass, and stowage had to be worked out. Steady progress was made in improving off-hours living and making provisions for new technologies within a system that has difficulty moving quickly on certifications. In some respect, the BHP support team fell victim to its previous successes. With increasing numbers of crewmembers in training, requests to engage our services spiraled upward. With finite people and funds, a cap had to placed on many services to ensure that parity could be maintained. The evolution of NASA BHP services as the ISS progressed from three- to six-crew composition will be reviewed, and future challenges that may be encountered as the ISS matures in its assembly-complete state will be discussed.

Combining dispositions and evaluations of vocation and job to account for counterproductive work behavior in adolescent job apprentices.

PubMed

Marcus, Bernd; Wagner, Uwe

2007-04-01

In the present research, we investigated the joint impact of selected antecedents of counterproductive work behavior (CWB). A sample of German apprentices reported on their CWB and completed measures of situational evaluations (vocational preference, level and constructiveness of job satisfaction) believed to trigger CWB and of dispositional motivators (measured by integrity test subscales) and controls (self-control and another subset of integrity scales) of CWB. All predictors investigated showed the expected bivariate relationships with CWB. Multivariate analyses revealed that the triggering effect of an unfavorable vocational choice on CWB was fully mediated by job satisfaction. When predictors were aggregated, a composite of dispositional control variables had the largest effect on CWB and moderated the effects of motivational dispositions and situational evaluations. These results extend the knowledge on antecedents of CWB by investigating previously overlooked variables and samples and partially replicate recent findings on the joint impact of dispositions and work-related evaluations on CWB. Copyright (c) 2007 APA, all rights reserved.

Predicting fruit consumption: the role of habits, previous behavior and mediation effects

PubMed Central

2014-01-01

Background This study assessed the role of habits and previous behavior in predicting fruit consumption as well as their additional predictive contribution besides socio-demographic and motivational factors. In the literature, habits are proposed as a stable construct that needs to be controlled for in longitudinal analyses that predict behavior. The aim of this study is to provide empirical evidence for the inclusion of either previous behavior or habits. Methods A random sample of 806 Dutch adults (>18 years) was invited by an online survey panel of a private research company to participate in an online study on fruit consumption. A longitudinal design (N = 574) was used with assessments at baseline and after one (T2) and two months (T3). Multivariate linear regression analysis was used to assess the differential value of habit and previous behavior in the prediction of fruit consumption. Results Eighty percent of habit strength could be explained by habit strength one month earlier, and 64% of fruit consumption could be explained by fruit consumption one month earlier. Regression analyses revealed that the model with motivational constructs explained 41% of the behavioral variance at T2 and 38% at T3. The addition of previous behavior and habit increased the explained variance up to 66% at T2 and to 59% at T3. Inclusion of these factors resulted in non-significant contributions of the motivational constructs. Furthermore, our findings showed that the effect of habit strength on future behavior was to a large extent mediated by previous behavior. Conclusions Both habit and previous behavior are important as predictors of future behavior, and as educational objectives for behavior change programs. Our results revealed less stability for the constructs over time than expected. Habit strength was to a large extent mediated by previous behavior and our results do not strongly suggest a need for the inclusion of both constructs. Future research needs to assess the conditions that determine direct influences of both previous behavior and habit, since these influences may differ per type of health behavior, per context stability in which the behavior is performed, and per time frame used for predicting future behavior. PMID:25037859

mlCAF: Multi-Level Cross-Domain Semantic Context Fusioning for Behavior Identification.

PubMed

Razzaq, Muhammad Asif; Villalonga, Claudia; Lee, Sungyoung; Akhtar, Usman; Ali, Maqbool; Kim, Eun-Soo; Khattak, Asad Masood; Seung, Hyonwoo; Hur, Taeho; Bang, Jaehun; Kim, Dohyeong; Ali Khan, Wajahat

2017-10-24

The emerging research on automatic identification of user's contexts from the cross-domain environment in ubiquitous and pervasive computing systems has proved to be successful. Monitoring the diversified user's contexts and behaviors can help in controlling lifestyle associated to chronic diseases using context-aware applications. However, availability of cross-domain heterogeneous contexts provides a challenging opportunity for their fusion to obtain abstract information for further analysis. This work demonstrates extension of our previous work from a single domain (i.e., physical activity) to multiple domains (physical activity, nutrition and clinical) for context-awareness. We propose multi-level Context-aware Framework (mlCAF), which fuses the multi-level cross-domain contexts in order to arbitrate richer behavioral contexts. This work explicitly focuses on key challenges linked to multi-level context modeling, reasoning and fusioning based on the mlCAF open-source ontology. More specifically, it addresses the interpretation of contexts from three different domains, their fusioning conforming to richer contextual information. This paper contributes in terms of ontology evolution with additional domains, context definitions, rules and inclusion of semantic queries. For the framework evaluation, multi-level cross-domain contexts collected from 20 users were used to ascertain abstract contexts, which served as basis for behavior modeling and lifestyle identification. The experimental results indicate a context recognition average accuracy of around 92.65% for the collected cross-domain contexts.

mlCAF: Multi-Level Cross-Domain Semantic Context Fusioning for Behavior Identification

PubMed Central

Villalonga, Claudia; Lee, Sungyoung; Akhtar, Usman; Ali, Maqbool; Kim, Eun-Soo; Khattak, Asad Masood; Seung, Hyonwoo; Hur, Taeho; Kim, Dohyeong; Ali Khan, Wajahat

2017-01-01

The emerging research on automatic identification of user’s contexts from the cross-domain environment in ubiquitous and pervasive computing systems has proved to be successful. Monitoring the diversified user’s contexts and behaviors can help in controlling lifestyle associated to chronic diseases using context-aware applications. However, availability of cross-domain heterogeneous contexts provides a challenging opportunity for their fusion to obtain abstract information for further analysis. This work demonstrates extension of our previous work from a single domain (i.e., physical activity) to multiple domains (physical activity, nutrition and clinical) for context-awareness. We propose multi-level Context-aware Framework (mlCAF), which fuses the multi-level cross-domain contexts in order to arbitrate richer behavioral contexts. This work explicitly focuses on key challenges linked to multi-level context modeling, reasoning and fusioning based on the mlCAF open-source ontology. More specifically, it addresses the interpretation of contexts from three different domains, their fusioning conforming to richer contextual information. This paper contributes in terms of ontology evolution with additional domains, context definitions, rules and inclusion of semantic queries. For the framework evaluation, multi-level cross-domain contexts collected from 20 users were used to ascertain abstract contexts, which served as basis for behavior modeling and lifestyle identification. The experimental results indicate a context recognition average accuracy of around 92.65% for the collected cross-domain contexts. PMID:29064459

Factors influencing unsafe behaviors and accidents on construction sites: a review.

PubMed

Khosravi, Yahya; Asilian-Mahabadi, Hassan; Hajizadeh, Ebrahim; Hassanzadeh-Rangi, Narmin; Bastani, Hamid; Behzadan, Amir H

2014-01-01

Construction is a hazardous occupation due to the unique nature of activities involved and the repetitiveness of several field behaviors. The aim of this methodological and theoretical review is to explore the empirical factors influencing unsafe behaviors and accidents on construction sites. In this work, results and findings from 56 related previous studies were investigated. These studies were categorized based on their design, type, methods of data collection, analytical methods, variables, and key findings. A qualitative content analysis procedure was used to extract variables, themes, and factors. In addition, all studies were reviewed to determine the quality rating and to evaluate the strength of provided evidence. The content analysis identified 8 main categories: (a) society, (b) organization, (c) project management, (d) supervision, (e) contractor, (f) site condition, (g) work group, and (h) individual characteristics. The review highlighted the importance of more distal factors, e.g., society and organization, and project management, that may contribute to reducing the likelihood of unsafe behaviors and accidents through the promotion of site condition and individual features (as proximal factors). Further research is necessary to provide a better understanding of the links between unsafe behavior theories and empirical findings, challenge theoretical assumptions, develop new applied theories, and make stronger recommendations.

Thinking like a trader selectively reduces individuals' loss aversion

PubMed Central

Sokol-Hessner, Peter; Hsu, Ming; Curley, Nina G.; Delgado, Mauricio R.; Camerer, Colin F.; Phelps, Elizabeth A.

2009-01-01

Research on emotion regulation has focused upon observers' ability to regulate their emotional reaction to stimuli such as affective pictures, but many other aspects of our affective experience are also potentially amenable to intentional cognitive regulation. In the domain of decision-making, recent work has demonstrated a role for emotions in choice, although such work has generally remained agnostic about the specific role of emotion. Combining psychologically-derived cognitive strategies, physiological measurements of arousal, and an economic model of behavior, this study examined changes in choices (specifically, loss aversion) and physiological correlates of behavior as the result of an intentional cognitive regulation strategy. Participants were on average more aroused per dollar to losses relative to gains, as measured with skin conductance response, and the difference in arousal to losses versus gains correlated with behavioral loss aversion across subjects. These results suggest a specific role for arousal responses in loss aversion. Most importantly, the intentional cognitive regulation strategy, which emphasized “perspective-taking,” uniquely reduced both behavioral loss aversion and arousal to losses relative to gains, largely by influencing arousal to losses. Our results confirm previous research demonstrating loss aversion while providing new evidence characterizing individual differences and arousal correlates and illustrating the effectiveness of intentional regulation strategies in reducing loss aversion both behaviorally and physiologically. PMID:19289824

Evolutionary dynamics under interactive diversity

NASA Astrophysics Data System (ADS)

Su, Qi; Li, Aming; Wang, Long

2017-10-01

As evidenced by many cases in human societies, individuals often make different behavior decisions in different interactions, and adaptively adjust their behavior in changeable interactive scenarios. However, up to now, how such diverse interactive behavior affects cooperation dynamics has still remained unknown. Here we develop a general framework of interactive diversity, which models individuals’ separated behavior against distinct opponents and their adaptive adjustment in response to opponents’ strategies, to explore the evolution of cooperation. We find that interactive diversity enables individuals to reciprocate every single opponent, and thus sustains large-scale reciprocal interactions. Our work witnesses an impressive boost of cooperation for a notably extensive range of parameters and for all pairwise games. These results are robust against well-mixed and various networked populations, and against degree-normalized and cumulative payoff patterns. From the perspective of network dynamics, distinguished from individuals competing for nodes in most previous work, in this paper, the system evolves in the form of behavior disseminating along edges. We propose a theoretical method based on evolution of edges, which predicts well both the frequency of cooperation and the compact cooperation clusters. Our thorough investigation clarifies the positive role of interactive diversity in resolving social dilemmas and highlights the significance of understanding evolutionary dynamics from the viewpoint of edge dynamics.

Associations of fatigue to work-related stress, mental and physical health in an employed community sample.

PubMed

Rose, D M; Seidler, A; Nübling, M; Latza, U; Brähler, E; Klein, E M; Wiltink, J; Michal, M; Nickels, S; Wild, P S; König, J; Claus, M; Letzel, S; Beutel, M E

2017-05-05

While work-related fatigue has become an issue of concern among European employees, the relationship between fatigue, depression and work-related stressors is far from clear. The purposes of this study were (1) to determine the associations of fatigue with work-related stressors, severe medical disease, health behavior and depression in the working population and (2) to determine the unique impact of work-related stressors on fatigue. We used cross-sectional data of N = 7,930 working participants enrolled in the Gutenberg Health Study (GHS) from 2007 to 2012 filled out the Personal Burnout Scale (PBS) of the Copenhagen Psychosocial Questionnaire (COPSOQ), the PHQ-9, and a list of work-related stressors. A total of 27.5% reported increased fatigue, esp. women, younger persons with a lower social status and income, smokers, severely medically ill, previously and currently depressed participants. Fatigue was consistently associated with severe medical disease, health behavior and depression, which need to be taken into account as potential confounders when analyzing its relationship to work-related strains. Depression was consistently associated with work-related stressors. However, after statistically partialling out depression, fatigue was still significantly associated with work-related stress. Fatigue as an indicator of allostatic load is consistently associated with work-related stressors such as work overload after controlling for depression. The brief Personal Burn-out Scale is suitable for assessing work-related fatigue in the general population.

Challenges of implementing routine health behavior change support in a children's hospital setting.

PubMed

Elwell, Laura; Powell, Jane; Wordsworth, Sharon; Cummins, Carole

2014-07-01

Evidence indicates that health behavior change initiatives are often not implemented successfully. This qualitative study aims to understand the barriers and facilitators to implementation of health behavior change brief advice into routine practice in an acute children's hospital setting. Semi-structured interviews were conducted with health professionals working at a UK children's hospital (n=33). Participants were purposively sampled to incorporate a range of specialties, job roles and training. An inductive thematic framework analysis identified two emergent themes. These capture the challenges of implementing routine health behavior change support in a children's hospital setting: (1) 'health professional knowledge, beliefs and behaviors' and (2) 'patient and family related challenges'. This study enhances findings from previous research by outlining the challenges pediatric health professionals face in relation to supporting health behavior change. Challenges include failure to assume responsibility, low confidence, prioritization of the health provider relationship with patients and families, health provider and patient knowledge, and low patient and family motivation. Skills-based behavior change training is needed for pediatric health professionals to effectively support health behavior change. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Portraying the Contribution of Individual Behaviors to Team Cohesion and Performance

NASA Technical Reports Server (NTRS)

Parke, Bonny; Orasanu, Judith

2012-01-01

Behaviors of individuals in teams both contribute to and are molded by team dynamics. How they do so has been the subject of much research. A method of portraying individuals' behaviors in teams, the Team Diagramming Method (TDM) is presented. Behaviors are rated by other team members on three important dimensions: positivity/negativity, dominant/submissive, and task-orientedness/expressiveness. A study of 5-person teams engaging in a 3-day moon simulation task demonstrated that measures of these perceived behaviors as well as the variances of these behaviors correlated with cohesion measures and performance. The method shows strengths and weaknesses of particular teams and, by comparison with high-performing teams, suggests interventions based on individual as well as team behaviors. The primary goal of this study was to determine the extent to which these team level variables, derived from all team members' rated behaviors, were associated with previous methods of measuring cohesion and with performance. A secondary goal was to determine the stability of TDM measures over time by comparing team level variables based on ratings early and later in the team s work together.

Exposure to bullying behaviors as a predictor of mental health problems among Norwegian nurses: results from the prospective SUSSH-survey.

PubMed

Reknes, Iselin; Pallesen, Ståle; Magerøy, Nils; Moen, Bente Elisabeth; Bjorvatn, Bjørn; Einarsen, Ståle

2014-03-01

The relationship between workplace bullying and mental health problems are well documented in previous cross-sectional studies, but knowledge on how this relationship develops over time is still scarce. The aim of this study was to explore the prospective relationship between exposure to bullying behaviors at baseline, and increased symptoms of mental health problems (anxiety, depression, fatigue) one year later. Furthermore, the reverse relationship was investigated. This is a prospective longitudinal study, where members of the Norwegian Nurses Organization answered identical questions regarding workplace bullying and mental health problems, at baseline (2008-2009) and follow-up (2010). Altogether, 1582 nurses completed both questionnaires. Hierarchical regression analyses indicated that exposure to bullying behaviors at baseline predicted subsequent increased symptoms of anxiety and fatigue, after adjusting for baseline symptoms of anxiety and fatigue respectively, age, gender, night work and job demands. Moreover, symptoms of anxiety, depression and fatigue at baseline predicted increased exposure to bullying behaviors one year later, after adjusting for exposure to bullying behaviors at baseline, age, gender, night work and job demands. In this study we find support for a reciprocal relationship between exposure to bullying behaviors and symptoms of anxiety and fatigue, respectively. Thus, the results may indicate a vicious circle where workplace bullying and mental health problems mutually affect each other negatively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Modulating the neural bases of persuasion: why/how, gain/loss, and users/non-users.

PubMed

Vezich, I Stephanie; Katzman, Perri L; Ames, Daniel L; Falk, Emily B; Lieberman, Matthew D

2017-02-01

Designing persuasive content is challenging, in part because people can be poor predictors of their actions. Medial prefrontal cortex (MPFC) activation during message exposure reliably predicts downstream behavior, but past work has been largely atheoretical. We replicated past results on this relationship and tested two additional framing effects known to alter message receptivity. First, we examined gain- vs. loss-framed reasons for a health behavior (sunscreen use). Consistent with predictions from prospect theory, we observed greater MPFC activity to gain- vs. loss-framed messages, and this activity was associated with behavior. This relationship was stronger for those who were not previously sunscreen users. Second, building on theories of action planning, we compared neural activity during messages regarding how vs. why to enact the behavior. We observed rostral inferior parietal lobule and posterior inferior frontal gyrus activity during action planning ("how" messages), and this activity was associated with behavior; this is in contrast to the relationship between MPFC activity during the "why" (i.e., gain and loss) messages and behavior. These results reinforce that persuasion occurs in part via self-value integration-seeing value and incorporating persuasive messages into one's self-concept-and extend this work to demonstrate how message framing and action planning may influence this process. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Factors associated with nurses' reporting of patients' aggressive behavior: a cross-sectional survey.

PubMed

Sato, Kana; Wakabayashi, Takeko; Kiyoshi-Teo, Hiroko; Fukahori, Hiroki

2013-10-01

Aggressive behavior and violence directed by patients at nurses are increasing worldwide. Aggressive behavior against nurses in their workplace can result in personal problems, such as impairment of physical and mental well-being, and, consequently, in organizational problems. Underreporting of patients' aggressive behavior is prevalent among nurses. Although underreporting might lead to inefficient attention to strategies for preventing aggressive behavior, the reasons for such behavior not being reported frequently have not been well examined. To explore the frequency of nurses' reporting to their managers of patients' aggressive behavior by type and degree of impact suffered by the nurses, to examine the association between reporting of aggressive behavior and demographic factors, and to determine the reasons for underreporting. A questionnaire-based cross-sectional survey. Six acute care hospitals in two regions in Japan. A total of 1953 nurses working at general acute care hospitals participated. Data were collected through a questionnaire seeking sociodemographic information, information on experience of aggressive behavior from patients, and the frequency with which they had reported such behavior in the previous month. The questionnaire also contained items assessing barriers to reporting of patients' aggressive behavior. The association between the possible influencing factors and reporting behavior was assessed using multiple logistic regression analyses. Of the 1953 questionnaires distributed, 1498 (76.7%) were returned, and 1385 (70.9%) fully completed questionnaires were analyzed. More than one-third of the respondents had experienced the mildest assessed level of impact from patients' aggressive behavior, and 70% of those hardly reported any incidents. The milder the impact was, the less the nurse victims tended to report the incident. Nurse's tendency to feel that aggressive behavior was mitigated by the situation, less work experience, and lack of confidence that management would defend staff nurses from patients' aggressive behavior were found to be negatively associated with reporting behavior. This study identified factors associated with nurses' reporting of patients' aggressive behavior. Underreporting was found to be associated with the level of impact, managerial attitudes, nurses' work experience, and nurses' perception that the behavior was mitigated by the situation. Improving education among nurses to promote reporting incidents and establishing an organized system is needed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Voluntary wheel running reduces voluntary consumption of ethanol in mice: identification of candidate genes through striatal gene expression profiling

PubMed Central

Darlington, Todd M; McCarthy, Riley D; Cox, Ryan J; Miyamoto-Ditmon, Jill; Gallego, Xavier; Ehringer, Marissa A

2016-01-01

Hedonic substitution, where wheel running reduces voluntary ethanol consumption has been observed in prior studies. Here we replicate and expand on previous work showing that mice decrease voluntary ethanol consumption and preference when given access to a running wheel. While earlier work has been limited mainly to behavioral studies, here we assess the underlying molecular mechanisms that may account for this interaction. From four groups of female C57BL/6J mice (control, access to two-bottle choice ethanol, access to a running wheel, and access to both two-bottle choice ethanol and a running wheel), mRNA-sequencing of the striatum identified differential gene expression. Many genes in ethanol preference quantitative trait loci were differentially expressed due to running. Furthermore, we conducted Weighted Gene Co-expression Network Analysis and identified gene networks corresponding to each effect behavioral group. Candidate genes for mediating the behavioral interaction between ethanol consumption and wheel running include multiple potassium channel genes, Oprm1, Prkcg, Stxbp1, Crhr1, Gabra3, Slc6a13, Stx1b, Pomc, Rassf5, Polr2a, and Camta2. After observing an overlap of many genes and functional groups previously identified in studies of initial sensitivity to ethanol, we hypothesized that wheel running may induce a change in sensitivity, thereby affecting ethanol consumption. A behavioral study examining Loss of Righting Reflex to ethanol following exercise trended toward supporting this hypothesis. These data provide a rich resource for future studies that may better characterize the observed transcriptional changes in gene networks in response to ethanol consumption and wheel running. PMID:27063791

Crafting in context: Exploring when job crafting is dysfunctional for performance effectiveness.

PubMed

Dierdorff, Erich C; Jensen, Jaclyn M

2018-05-01

Job crafting theory purports that the consequences of revising one's work role can be simultaneously beneficial and detrimental. Previous research, however, has almost exclusively emphasized the beneficial outcomes of job crafting. In the current study, we proposed dysfunctional consequences of crafting for performance-related outcomes in the form of a U-shaped relationship between job crafting and performance effectiveness (managerial ratings of job proficiency and peer ratings of citizenship behavior). We further predicted that elements of the task context (autonomy and ambiguity) and the social context (interdependence and social support) moderate these curvilinear relationships. Consistent with previous research, job crafting displayed positive and linear effects on work-related attitudes (job satisfaction and affective commitment). Consistent with our predictions, moderate levels of crafting were associated with dysfunctional performance-related outcomes and features of work context either exacerbated or dissipated these dysfunctional consequences of job crafting for individuals. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

New insight into the spawning behavior of lake trout, Salvelinus namaycush, from a recovering population in the Laurentian Great Lakes

USGS Publications Warehouse

Binder, Thomas R.; Thompson, Henry T.; Muir, Andrew M.; Riley, Stephen C.; Marsden, J. Ellen; Bronte, Charles R.; Krueger, Charles C.

2015-01-01

Spawning behavior of lake trout, Salvelinus namaycush, is poorly understood, relative to stream-dwelling salmonines. Underwater video records of spawning in a recovering population from the Drummond Island Refuge (Lake Huron) represent the first reported direct observations of lake trout spawning in the Laurentian Great Lakes. These observations provide new insight into lake trout spawning behavior and expand the current conceptual model. Lake trout spawning consisted of at least four distinct behaviors: hovering, traveling, sinking, and gamete release. Hovering is a new courtship behavior that has not been previously described. The apparent concentration of hovering near the margin of the spawning grounds suggests that courtship and mate selection might be isolated from the spawning act (i.e., traveling, sinking, and gamete release). Moreover, we interpret jockeying for position displayed by males during traveling as a unique form of male-male competition that likely evolved in concert with the switch from redd-building to itinerant spawning in lake trout. Unlike previous models, which suggested that intra-sexual competition and mate selection do not occur in lake trout, our model includes both and is therefore consistent with evolutionary theory, given that the sex ratio on spawning grounds is skewed heavily towards males. The model presented in this paper is intended as a working hypothesis, and further revision may become necessary as we gain a more complete understanding of lake trout spawning behavior.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayashinaka, Takahiro; Department of Physics, Graduate School of Science,The University of Tokyo, Bunkyo, Tokyo, 113-0033; Yokoyama, Jun’ichi

The covariant and gauge invariant calculation of the current expectation value in the homogeneous electric field in 1+3 dimensional de Sitter spacetime is shown. The result accords with previous work obtained by using adiabatic subtraction scheme. We therefore conclude the counterintuitive behaviors of the current in the infrared (IR) regime such as IR hyperconductivity and negative current are not artifacts of the renormalization scheme, but are real IR effects of the spacetime.

The Physician-Patient Working Alliance in Hemodialysis Treatment.

PubMed

Fuertes, Jairo N; Rubinstein, Sofia; Reyes, Mariela; Iampornpipopchai, Pichet; Mujeeb, Shanza; Smith, Carroll R; Toporovsky, Arielle

2017-01-01

Over the past 20 years, the role of psychological and social factors, including the physician-patient working alliance, have emerged as integral components of medical care for patients with a myriad of health conditions. The current study examines a model comprised of psychological-interpersonal factors and the extent to which it explains patient satisfaction with and adherence to hemodialysis treatment. One hundred and seven adults with end-stage renal disease who were receiving regular outpatient hemodialysis participated in the study. Path analyses show that the physician-patient working alliance indirectly predicts patient adherence through patient satisfaction and patients' outcome expectations. The working alliance directly predicts patients' quality of life. It is concluded that consistent with previous research, the physician-patient working alliance is a significant factor in predicting key patient behaviors in medical care.

Ghosts in the machine: memory interference from the previous trial.

PubMed

Papadimitriou, Charalampos; Ferdoash, Afreen; Snyder, Lawrence H

2015-01-15

Previous memoranda can interfere with the memorization or storage of new information, a concept known as proactive interference. Studies of proactive interference typically use categorical memoranda and match-to-sample tasks with categorical measures such as the proportion of correct to incorrect responses. In this study we instead train five macaques in a spatial memory task with continuous memoranda and responses, allowing us to more finely probe working memory circuits. We first ask whether the memoranda from the previous trial result in proactive interference in an oculomotor delayed response task. We then characterize the spatial and temporal profile of this interference and ask whether this profile can be predicted by an attractor network model of working memory. We find that memory in the current trial shows a bias toward the location of the memorandum of the previous trial. The magnitude of this bias increases with the duration of the memory period within which it is measured. Our simulations using standard attractor network models of working memory show that these models easily replicate the spatial profile of the bias. However, unlike the behavioral findings, these attractor models show an increase in bias with the duration of the previous rather than the current memory period. To model a bias that increases with current trial duration we posit two separate memory stores, a rapidly decaying visual store that resists proactive interference effects and a sustained memory store that is susceptible to proactive interference. Copyright © 2015 the American Physiological Society.

Ghosts in the machine: memory interference from the previous trial

PubMed Central

Ferdoash, Afreen; Snyder, Lawrence H.

2014-01-01

Previous memoranda can interfere with the memorization or storage of new information, a concept known as proactive interference. Studies of proactive interference typically use categorical memoranda and match-to-sample tasks with categorical measures such as the proportion of correct to incorrect responses. In this study we instead train five macaques in a spatial memory task with continuous memoranda and responses, allowing us to more finely probe working memory circuits. We first ask whether the memoranda from the previous trial result in proactive interference in an oculomotor delayed response task. We then characterize the spatial and temporal profile of this interference and ask whether this profile can be predicted by an attractor network model of working memory. We find that memory in the current trial shows a bias toward the location of the memorandum of the previous trial. The magnitude of this bias increases with the duration of the memory period within which it is measured. Our simulations using standard attractor network models of working memory show that these models easily replicate the spatial profile of the bias. However, unlike the behavioral findings, these attractor models show an increase in bias with the duration of the previous rather than the current memory period. To model a bias that increases with current trial duration we posit two separate memory stores, a rapidly decaying visual store that resists proactive interference effects and a sustained memory store that is susceptible to proactive interference. PMID:25376781

Relationships among supervisor feedback environment, work-related stressors, and employee deviance.

PubMed

Peng, Jei-Chen; Tseng, Mei-Man; Lee, Yin-Ling

2011-03-01

Previous research has demonstrated that the employee deviance imposes enormous costs on organizational performance and productivity. Similar research supports the positive effect of favorable supervisor feedback on employee job performance. In light of such, it is important to understand the interaction between supervisor feedback environment and employee deviant behavior to streamline organization operations. The purposes of this study were to explore how the supervisor feedback environment influences employee deviance and to examine the mediating role played by work-related stressors. Data were collected from 276 subordinate-supervisor dyads at a regional hospital in Yilan. Structural equation modeling analyses were conducted to test hypotheses. Structural equation modeling analysis results show that supervisor feedback environment negatively related to interpersonal and organizational deviance. Moreover, work-related stressors were found to partially mediate the relationship between supervisor feedback environment and employee deviance. Study findings suggest that when employees (nurses in this case) perceive an appropriate supervisor-provided feedback environment, their deviance is suppressed because of the related reduction in work-related stressors. Thus, to decrease deviant behavior, organizations may foster supervisor integration of disseminated knowledge such as (a) how to improve employees' actual performance, (b) how to effectively clarify expected performance, and (c) how to improve continuous performance feedback. If supervisors absorb this integrated feedback knowledge, they should be in a better position to enhance their own daily interactions with nurses and reduce nurses' work-related stress and, consequently, decrease deviant behavior.

Tensile Fracture Behavior of 316L Austenitic Stainless Steel Manufactured by Hot Isostatic Pressing

NASA Astrophysics Data System (ADS)

Cooper, A. J.; Brayshaw, W. J.; Sherry, A. H.

2018-02-01

Herein we investigate how the oxygen content in hot isostatically pressed (HIP'd) 316L stainless steel affects the mechanical properties and tensile fracture behavior. This work follows on from previous studies, which aimed to understand the effect of oxygen content on the Charpy impact toughness of HIP'd steel. We expand on the work by performing room-temperature tensile testing on different heats of 316L stainless steel, which contain different levels of interstitial elements (carbon and nitrogen) as well as oxygen in the bulk material. Throughout the work we repeat the experiments on conventionally forged 316L steel as a reference material. The analysis of the work indicates that oxygen does not contribute to a measureable solution strengthening mechanism, as is the case with carbon and nitrogen in austenitic stainless steels (Werner in Mater Sci Eng A 101:93-98, 1988). Neither does oxygen, in the form of oxide inclusions, contribute to precipitation hardening due to the size and spacing of particles. However, the oxide particles do influence fracture behavior; fractography of the failed tension test specimens indicates that the average ductile dimple size is related to the oxygen content in the bulk material, the results of which support an on-going hypothesis relating oxygen content in HIP'd steels to their fracture mechanisms by providing additional sites for the initiation of ductile damage in the form of voids.

Viral-mediated Zif268 expression in the prefrontal cortex protects against gonadectomy-induced working memory, long-term memory, and social interaction deficits in male rats.

PubMed

Dossat, Amanda M; Jourdi, Hussam; Wright, Katherine N; Strong, Caroline E; Sarkar, Ambalika; Kabbaj, Mohamed

2017-01-06

In humans, some males experience reductions in testosterone levels, as a natural consequence of aging or in the clinical condition termed hypogonadism, which are associated with impaired cognitive performance and mood disorder(s). Some of these behavioral deficits can be reversed by testosterone treatment. Our previous work in rats reported that sex differences in the expression of the transcription factor Zif268, a downstream target of testosterone, within the medial prefrontal cortex (mPFC) mediates sex differences in social interaction. In the present study, we aimed to examine the effects of gonadectomy (GNX) in male rats on mPFC Zif268 expression, mood and cognitive behaviors. We also examined whether reinstitution of Zif268 in GNX rats will correct some of the behavioral deficits observed following GNX. Our results show that GNX induced a downregulation of Zif268 protein in the mPFC, which was concomitant with impaired memory in the y-maze and spontaneous object recognition test, reduced social interaction time, and depression-like behaviors in the forced swim test. Reinstitution of mPFC Zif268, using a novel adeno-associated-viral (AAV) construct, abrogated GNX-induced working memory and long-term memory impairments, and reductions in social interaction time, but not GNX-induced depression-like behaviors. These findings suggest that mPFC Zif268 exerts beneficial effects on memory and social interaction, and could be a potential target for novel treatments for behavioral impairments observed in hypogonadal and aged men with declining levels of gonadal hormones. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

The association between long working hours and health: a systematic review of epidemiological evidence.

PubMed

Bannai, Akira; Tamakoshi, Akiko

2014-01-01

Many studies have investigated the association between long working hours and health. By focusing on differences in the definition of long working hours and the influence of shift work, we attempt to explain why the results of these studies remain inconclusive. We defined long working hours as working time greater than around 40 hours per week or 8 hours per day. Since previous studies have indicated that shift work is detrimental to health, we minimized the influence of shift work in the studies. We also placed importance on the existence of reference groups since this made the results clearer. Based on these points, we analyzed previous studies to clarify the epidemiological evidence regarding the association between long working hours and health. We established inclusion criteria and carried out a systematic search for articles published in the Medline and PsycINFO databases between 1995-2012. We identified a total of 17 articles and 19 studies (12 prospective cohort and 7 cross-sectional studies). The outcomes were all-cause mortality, circulatory disease, diabetes mellitus, metabolic syndrome, depressive state, anxiety, other psychological disorders, sleep condition, cognitive function, and health-related behavior. Long working hours had significant adverse effects on most health outcomes. We concluded that working long hours is associated with depressive state, anxiety, sleep condition, and coronary heart disease. However, further studies that appropriately deal with the definition of long working hours and shift work are needed.

A simulation analysis to characterize the dynamics of vaccinating behaviour on contact networks.

PubMed

Perisic, Ana; Bauch, Chris T

2009-05-28

Human behavior influences infectious disease transmission, and numerous "prevalence-behavior" models have analyzed this interplay. These previous analyses assumed homogeneously mixing populations without spatial or social structure. However, spatial and social heterogeneity are known to significantly impact transmission dynamics and are particularly relevant for certain diseases. Previous work has demonstrated that social contact structure can change the individual incentive to vaccinate, thus enabling eradication of a disease under a voluntary vaccination policy when the corresponding homogeneous mixing model predicts that eradication is impossible due to free rider effects. Here, we extend this work and characterize the range of possible behavior-prevalence dynamics on a network. We simulate transmission of a vaccine-preventable infection through a random, static contact network. Individuals choose whether or not to vaccinate on any given day according to perceived risks of vaccination and infection. We find three possible outcomes for behavior-prevalence dynamics on this type of network: small final number vaccinated and final epidemic size (due to rapid control through voluntary ring vaccination); large final number vaccinated and significant final epidemic size (due to imperfect voluntary ring vaccination), and little or no vaccination and large final epidemic size (corresponding to little or no voluntary ring vaccination). We also show that the social contact structure enables eradication under a broad range of assumptions, except when vaccine risk is sufficiently high, the disease risk is sufficiently low, or individuals vaccinate too late for the vaccine to be effective. For populations where infection can spread only through social contact network, relatively small differences in parameter values relating to perceived risk or vaccination behavior at the individual level can translate into large differences in population-level outcomes such as final size and final number vaccinated. The qualitative outcome of rational, self interested behaviour under a voluntary vaccination policy can vary substantially depending on interactions between social contact structure, perceived vaccine and disease risks, and the way that individual vaccination decision-making is modelled.

A simulation analysis to characterize the dynamics of vaccinating behaviour on contact networks

PubMed Central

2009-01-01

Background Human behavior influences infectious disease transmission, and numerous "prevalence-behavior" models have analyzed this interplay. These previous analyses assumed homogeneously mixing populations without spatial or social structure. However, spatial and social heterogeneity are known to significantly impact transmission dynamics and are particularly relevant for certain diseases. Previous work has demonstrated that social contact structure can change the individual incentive to vaccinate, thus enabling eradication of a disease under a voluntary vaccination policy when the corresponding homogeneous mixing model predicts that eradication is impossible due to free rider effects. Here, we extend this work and characterize the range of possible behavior-prevalence dynamics on a network. Methods We simulate transmission of a vaccine-prevetable infection through a random, static contact network. Individuals choose whether or not to vaccinate on any given day according to perceived risks of vaccination and infection. Results We find three possible outcomes for behavior-prevalence dynamics on this type of network: small final number vaccinated and final epidemic size (due to rapid control through voluntary ring vaccination); large final number vaccinated and significant final epidemic size (due to imperfect voluntary ring vaccination), and little or no vaccination and large final epidemic size (corresponding to little or no voluntary ring vaccination). We also show that the social contact structure enables eradication under a broad range of assumptions, except when vaccine risk is sufficiently high, the disease risk is sufficiently low, or individuals vaccinate too late for the vaccine to be effective. Conclusion For populations where infection can spread only through social contact network, relatively small differences in parameter values relating to perceived risk or vaccination behavior at the individual level can translate into large differences in population-level outcomes such as final size and final number vaccinated. The qualitative outcome of rational, self interested behaviour under a voluntary vaccination policy can vary substantially depending on interactions between social contact structure, perceived vaccine and disease risks, and the way that individual vaccination decision-making is modelled. PMID:19476616

μ-Opioid and 5-HT1A receptors in the dorsomedial hypothalamus interact for the regulation of panic-related defensive responses.

PubMed

Roncon, Camila Marroni; Yamashita, Paula Shimene de Melo; Frias, Alana Tercino; Audi, Elisabeth Aparecida; Graeff, Frederico Guilherme; Coimbra, Norberto Cysne; Zangrossi, Helio

2017-06-01

The dorsomedial hypothalamus (DMH) and the dorsal periaqueductal gray (DPAG) have been implicated in the genesis and regulation of panic-related defensive behaviors, such as escape. Previous results point to an interaction between serotonergic and opioidergic systems within the DPAG to inhibit escape, involving µ-opioid and 5-HT1A receptors (5-HT1AR). In the present study we explore this interaction in the DMH, using escape elicited by electrical stimulation of this area as a panic attack index. The obtained results show that intra-DMH administration of the non-selective opioid receptor antagonist naloxone (0.5 nmol) prevented the panicolytic-like effect of a local injection of serotonin (20 nmol). Pretreatment with the selective μ-opioid receptor (MOR) antagonist CTOP (1 nmol) blocked the panicolytic-like effect of the 5-HT1AR agonist 8-OHDPAT (8 nmol). Intra-DMH injection of the selective MOR agonist DAMGO (0.3 nmol) also inhibited escape behavior, and a previous injection of the 5-HT1AR antagonist WAY-100635 (0.37 nmol) counteracted this panicolytic-like effect. These results offer the first evidence that serotonergic and opioidergic systems work together within the DMH to inhibit panic-like behavior through an interaction between µ-opioid and 5-HT1A receptors, as previously described in the DPAG.

Neighborhood Deprivation Negatively Impacts Children’s Prosocial Behavior

PubMed Central

Safra, Lou; Tecu, Teodora; Lambert, Stéphane; Sheskin, Mark; Baumard, Nicolas; Chevallier, Coralie

2016-01-01

Children show stronger cooperative behavior in experimental settings as they get older, but little is known about how the environment of a child shapes this development. In adults, prosocial behavior toward strangers is markedly decreased in low socio-economic status (SES) neighborhoods, suggesting that environmental harshness has a negative impact on some prosocial behaviors. Similar results have been obtained with 9-year-olds recruited from low vs. high SES schools. In the current study, we investigate whether these findings generalize to a younger age group and a developing country. Specifically, we worked with a sample of thirty-nine 6- to 7-year-olds in two neighborhoods in a single city in Romania. Using a “Quality Dictator Game” that offers greater resolution than previous measures, we find that children living in the harsher neighborhood behave less prosocially toward a stranger than children living in the less harsh neighborhood. PMID:27895603

Exploring the zone of anisotropy and broken symmetries in DNA-mediated nanoparticle crystallization.

PubMed

O'Brien, Matthew N; Girard, Martin; Lin, Hai-Xin; Millan, Jaime A; Olvera de la Cruz, Monica; Lee, Byeongdu; Mirkin, Chad A

2016-09-20

In this work, we present a joint experimental and molecular dynamics simulations effort to understand and map the crystallization behavior of polyhedral nanoparticles assembled via the interaction of DNA surface ligands. In these systems, we systematically investigated the interplay between the effects of particle core (via the particle symmetry and particle size) and ligands (via the ligand length) on crystallization behavior. This investigation revealed rich phase diagrams, previously unobserved phase transitions in polyhedral crystallization behavior, and an unexpected symmetry breaking in the ligand distribution on a particle surface. To understand these results, we introduce the concept of a zone of anisotropy, or the portion of the phase space where the anisotropy of the particle is preserved in the crystallization behavior. Through comparison of the zone of anisotropy for each particle we develop a foundational roadmap to guide future investigations.

Integrating sensorimotor systems in a robot model of cricket behavior

NASA Astrophysics Data System (ADS)

Webb, Barbara H.; Harrison, Reid R.

2000-10-01

The mechanisms by which animals manage sensorimotor integration and coordination of different behaviors can be investigated in robot models. In previous work the first author has build a robot that localizes sound based on close modeling of the auditory and neural system in the cricket. It is known that the cricket combines its response to sound with other sensorimotor activities such as an optomotor reflex and reactions to mechanical stimulation for the antennae and cerci. Behavioral evidence suggests some ways these behaviors may be integrated. We have tested the addition of an optomotor response, using an analog VLSI circuit developed by the second author, to the sound localizing behavior and have shown that it can, as in the cricket, improve the directness of the robot's path to sound. In particular it substantially improves behavior when the robot is subject to a motor disturbance. Our aim is to better understand how the insect brain functions in controlling complex combinations of behavior, with the hope that this will also suggest novel mechanisms for sensory integration on robots.

Risky behavior and its effect on survival: snowshoe hare behavior under varying moonlight conditions

USGS Publications Warehouse

Gigliotti, Laura C.; Diefenbach, Duane R.

2018-01-01

Predation and predation risk can exert strong influences on the behavior of prey species. However, risk avoidance behaviors may vary among populations of the same species. We studied a population of snowshoe hares (Lepus americanus) near the southern edge of their range, in Pennsylvania. This population occupies different habitat types, experiences different environmental conditions, and are exposed to different predator species and densities than northern hare populations; therefore, they might exhibit differences in risk avoidance behaviors. We analyzed hare survival, movement rates, and habitat use under different levels of predation risk, as indexed by moonlight. Similar to previous work, we found snowshoe hare survival decreased with increased moon illumination during the winter, but we found differences in behavioral responses to increased predation risk. We found that snowshoe hares did not reduce movement rates during high‐risk nights, but instead found that hares selected areas with denser canopy cover, compared to low‐risk nights. We suggest that behavioral plasticity in response to predation risk allows populations of the same species to respond to localized conditions.

Comprehensive behavioral analysis of mice deficient in Rapgef2 and Rapgef6, a subfamily of guanine nucleotide exchange factors for Rap small GTPases possessing the Ras/Rap-associating domain.

PubMed

Maeta, Kazuhiro; Hattori, Satoko; Ikutomo, Junji; Edamatsu, Hironori; Bilasy, Shymaa E; Miyakawa, Tsuyoshi; Kataoka, Tohru

2018-05-10

Rapgef2 and Rapgef6 define a subfamily of guanine nucleotide exchange factors for Rap small GTPases, characterized by the possession of the Ras/Rap-associating domain. Previous genomic analyses suggested their possible involvement in the etiology of schizophrenia. We recently demonstrated the development of an ectopic cortical mass (ECM), which resembles the human subcortical band heterotopia, in the dorsal telencephalon-specific Rapgef2 conditional knockout (Rapgef2-cKO) brains. Additional knockout of Rapgef6 in Rapgef2-cKO mice resulted in gross enlargement of the ECM whereas knockout of Rapgef6 alone (Rapgef6-KO) had no discernible effect on the brain morphology. Here, we performed a battery of behavioral tests to examine the effects of Rapgef2 or Rapgef6 deficiency on higher brain functions. Rapgef2-cKO mice exhibited hyperlocomotion phenotypes. They showed decreased anxiety-like behavior in the elevated plus maze and the open-field tests as well as increased depression-like behavior in the Porsolt forced swim and tail suspension tests. They also exhibited increased sociability especially in novel environments. They showed defects in cognitive function as evidenced by reduced learning ability in the Barnes circular maze test and by impaired working memory in the T maze tests. In contrast, although Rapgef6 and Rapgef2 share similarities in biochemical roles, Rapgef6-KO mice exhibited mild behavioral abnormalities detected with a number of behavioral tests, such as hyperlocomotion phenotype in the open-field test and the social interaction test with a novel environment and working-memory defects in the T-maze test. In conclusion, although there were differences in their brain morphology and the magnitude of the behavioral abnormalities, Rapgef2-cKO mice and Rapgef6-KO mice exhibited hyperlocomotion phenotype and working-memory defect, both of which could be recognized as schizophrenia-like behavior.

Characterization of Atmospheric Aerosol Behavior and Climatic Effects by Analysis of SAGE 2 and Other Space, Air, and Ground Measurements

NASA Technical Reports Server (NTRS)

Livingston, John M.

1999-01-01

This report documents the research performed under NASA Ames Cooperative Agreement NCC 2-991, which covered the period 1 April 1997 through 31 March 1999. Previously, an interim technical report (Technical Report No. 1, 20 March 1998) summarized the work completed during the period 1 April 1997 through 31 March 1998. The objective of the proposed research was to advance our understanding of atmospheric aerosol behavior, aerosol-induced climatic effects, and the remote measurement and retrieval capabilities of spaceborne sensors such as SAGE II by combining and comparing data from these instruments and from airborne and ground-based instruments.

Chemotaxis in P. Aeruginosa Biofilm Formation

NASA Astrophysics Data System (ADS)

Bienvenu, Samuel; Strain, Shinji; Thatcher, Travis; Gordon, Vernita

2010-10-01

Pseudomonas biofilms form infections in the lungs of Cystic Fibrosis (CF) patients that damage lung tissue and lead to death. Previous work shows chemotaxis is important for Pseudomonas in CF lungs. The work studied swimming bacteria at high concentrations. In contrast, medically relevant biofilms initiate from sparse populations of surface-bound bacteria. The recent development of software techniques for automated, high-throughput bacteria tracking leaves us well-poised to quantitatively study these chemotactic conditions. We will develop experimental systems for such studies, focusing on L-Arginine (an amino acid), D-Galactose (a sugar present in lungs), and succinate and glucose (carbon sources for bacteria). This suite of chemoattractants will allow us to study how chemoattractant characteristics--size and diffusion behavior--change bacterial response; the interaction of competing chemoattractants; and, differences in bacterial behaviors, like motility modes, in response to different types of chemoattractions and varying neighbor cell density.

Rheological behavior and cryogenic properties of cyanate ester/epoxy insulation material for fusion superconducting magnet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Z. X.; Huang, C. J.; Li, L. F.

2014-01-27

In a Tokamak fusion reactor device like ITER, insulation materials for superconducting magnets are usually fabricated by a vacuum pressure impregnation (VPI) process. Thus these insulation materials must exhibit low viscosity, long working life as well as good radiation resistance. Previous studies have indicated that cyanate ester (CE) blended with epoxy has an excellent resistance against neutron irradiation which is expected to be a candidate insulation material for a fusion magnet. In this work, the rheological behavior of a CE/epoxy (CE/EP) blend containing 40% CE was investigated with non-isothermal and isothermal viscosity experiments. Furthermore, the cryogenic mechanical and electrical propertiesmore » of the composite were evaluated in terms of interlaminar shear strength and electrical breakdown strength. The results showed that CE/epoxy blend had a very low viscosity and an exceptionally long processing life of about 4 days at 60 °C.« less

The effects of workstation changes and behavioral interventions on safe typing postures in an office.

PubMed

Gravina, Nicole; Lindstrom-Hazel, Debra; Austin, John

2007-01-01

The purpose of the present study was to determine the effectiveness of an ergonomic and behavioral safety intervention for improving participants' safe typing postures in a library office setting. A single-subject multiple baseline design across five participants was employed to evaluate the effects of the four independent variables (workstation adjustment, equipment trial (rollermouse mouse alternative), peer observations, and graphic feedback). Six participant postures were observed repeatedly while participants worked at their workstations throughout the study. Each of the interventions resulted in improvements in safety for more than one posture compared to the previous phase. Results of the study indicate that a comprehensive ergonomic program that includes a workstation adjustment and a behavioral safety approach may be helpful to produce maximum improvements in employees' safe ergonomic postures.

Optimization of power utilization in multimobile robot foraging behavior inspired by honeybees system.

PubMed

Ahmad, Faisul Arif; Ramli, Abd Rahman; Samsudin, Khairulmizam; Hashim, Shaiful Jahari

2014-01-01

Deploying large numbers of mobile robots which can interact with each other produces swarm intelligent behavior. However, mobile robots are normally running with finite energy resource, supplied from finite battery. The limitation of energy resource required human intervention for recharging the batteries. The sharing information among the mobile robots would be one of the potentials to overcome the limitation on previously recharging system. A new approach is proposed based on integrated intelligent system inspired by foraging of honeybees applied to multimobile robot scenario. This integrated approach caters for both working and foraging stages for known/unknown power station locations. Swarm mobile robot inspired by honeybee is simulated to explore and identify the power station for battery recharging. The mobile robots will share the location information of the power station with each other. The result showed that mobile robots consume less energy and less time when they are cooperating with each other for foraging process. The optimizing of foraging behavior would result in the mobile robots spending more time to do real work.

Optimization of Power Utilization in Multimobile Robot Foraging Behavior Inspired by Honeybees System

PubMed Central

Ahmad, Faisul Arif; Ramli, Abd Rahman; Samsudin, Khairulmizam; Hashim, Shaiful Jahari

2014-01-01

Deploying large numbers of mobile robots which can interact with each other produces swarm intelligent behavior. However, mobile robots are normally running with finite energy resource, supplied from finite battery. The limitation of energy resource required human intervention for recharging the batteries. The sharing information among the mobile robots would be one of the potentials to overcome the limitation on previously recharging system. A new approach is proposed based on integrated intelligent system inspired by foraging of honeybees applied to multimobile robot scenario. This integrated approach caters for both working and foraging stages for known/unknown power station locations. Swarm mobile robot inspired by honeybee is simulated to explore and identify the power station for battery recharging. The mobile robots will share the location information of the power station with each other. The result showed that mobile robots consume less energy and less time when they are cooperating with each other for foraging process. The optimizing of foraging behavior would result in the mobile robots spending more time to do real work. PMID:24949491

Near-Threshold Ionization of Argon by Positron Impact

NASA Astrophysics Data System (ADS)

Babij, T. J.; Machacek, J. R.; Murtagh, D. J.; Buckman, S. J.; Sullivan, J. P.

2018-03-01

The direct single-ionization cross section for Ar by positron impact has been measured in the region above the first ionization threshold. These measurements are compared to semiclassical calculations which give rise to a power law variation of the cross section in the threshold region. The experimental results appear to be in disagreement with extensions to the Wannier theory applied to positron impact ionization, with a smaller exponent than that calculated by most previous works. In fact, in this work, we see no difference in threshold behavior between the positron and electron cases. Possible reasons for this discrepancy are discussed.

Beam wandering statistics of twin thin laser beam propagation under generalized atmospheric conditions.

PubMed

Pérez, Darío G; Funes, Gustavo

2012-12-03

Under the Geometrics Optics approximation is possible to estimate the covariance between the displacements of two thin beams after they have propagated through a turbulent medium. Previous works have concentrated in long propagation distances to provide models for the wandering statistics. These models are useful when the separation between beams is smaller than the propagation path-regardless of the characteristics scales of the turbulence. In this work we give a complete model for these covariances, behavior introducing absolute limits to the validity of former approximations. Moreover, these generalizations are established for non-Kolmogorov atmospheric models.

Creep, Fatigue and Environmental Interactions and Their Effect on Crack Growth in Superalloys

NASA Technical Reports Server (NTRS)

Telesman, J.; Gabb, T. P.; Ghosn, L. J.; Smith, T.

2017-01-01

Complex interactions of creep/fatigue/environment control dwell fatigue crack growth (DFCG) in superalloys. Crack tip stress relaxation during dwells significantly changes the crack driving force and influence DFCG. Linear Elastic Fracture Mechanics, Kmax, parameter unsuitable for correlating DFCG behavior due to extensive visco-plastic deformation. Magnitude of remaining crack tip axial stresses controls DFCG resistance due to the brittle-intergranular nature of the crack growth process. Proposed a new empirical parameter, Ksrf, which incorporates visco-plastic evolution of the magnitude of remaining crack tip stresses. Previous work performed at 704C, extend the work to 760C.

Orbitofrontal inactivation impairs reversal of Pavlovian learning by interfering with 'disinhibition' of responding for previously unrewarded cues.

PubMed

Burke, Kathryn A; Takahashi, Yuji K; Correll, Jessica; Brown, P Leon; Schoenbaum, Geoffrey

2009-11-01

Orbitofrontal cortex (OFC) is critical for reversal learning. Reversal deficits are typically demonstrated in complex settings that combine Pavlovian and instrumental learning. Yet recent work has implicated the OFC specifically in behaviors guided by cues and the features of the specific outcomes they predict. To test whether the OFC is important for reversing such Pavlovian associations in the absence of confounding instrumental requirements, we trained rats on a simple Pavlovian task in which two auditory cues were presented, one paired with a food pellet reward and the other presented without reward. After learning, we reversed the cue-outcome associations. For half the rats, OFC was inactivated prior to each reversal session. Inactivation of OFC impaired the ability of the rats to reverse conditioned responding. This deficit reflected the inability of inactivated rats to develop normal responding for the previously unrewarded cue; inactivation of OFC had no impact on the ability of the rats to inhibit responding to the previously rewarded cue. These data show that OFC is critical to reversal of Pavlovian responding, and that the role of OFC in this behavior cannot be explained as a simple deficit in response inhibition. Furthermore, the contrast between the normal inhibition of responding, reported here, and impaired inhibition of responding during Pavlovian over-expectation, reported previously, suggests the novel hypothesis that OFC may be particularly critical for learning (or behavior) when it requires the subject to generate predictions about outcomes by bringing together or integrating disparate pieces of associative information.

Employed and expecting in Germany: A qualitative investigation into pregnancy-related occupational stress and coping behavior.

PubMed

Lojewski, Julia; Flothow, Annegret; Harth, Volker; Mache, Stefanie

2018-01-01

Previous studies demonstrate a higher risk for pregnant women to experience stressors within the work context and therefore suggest a higher risk for occupational stress. However, the interaction between work and pregnancy in Germany is currently an area without much active research, even though it is a common occurrence. This qualitative study explores stressors, coping behaviors and related consequences for pregnant employees in Germany. Furthermore, the study researches intervention possibilities for the purpose to prevent the target group from negative health outcomes. Thirteen semi-standardized interviews with employed pregnant women living and working in Germany were conducted. The interviews were recorded and verbatim transcribed. Data was analyzed by Mayring's structuring qualitative content analysis. Compounding the results, the interviewed women noted most frequently stressors in relation to their employer/line manager due to their pregnant condition. Even though the women showed various adaptive coping behaviors, the identified negative consequences, mainly on their emotional wellbeing. Various intervention possibilities to improve the pregnant employee's situation were mentioned. This study was able to explore broad insights into the topic of pregnant employees in Germany. Therefore, this study underlines the actuality and relevance of the topic and is able to contribute to a scientific discussion about pregnancy at the workplace.

Videosensor for the Detection of Unsafe Driving Behavior in the Proximity of Black Spots

PubMed Central

Fuentes, Andres; Fuentes, Ricardo; Cabello, Enrique; Conde, Cristina; Martin, Isaac

2014-01-01

This paper discusses the overall design and implementation of a video sensor for the detection of risky behaviors of car drivers near previously identified and georeferenced black spots. The main goal is to provide the driver with a visual audio alert that informs of the proximity of an area of high incidence of highway accidents only if their driving behavior could result in a risky situation. It proposes a video sensor for detecting and supervising driver behavior, its main objective being manual distractions, so hand driver supervision is performed. A GPS signal is also considered, the GPS information is compared with a database of global positioning Black Spots to determine the relative proximity of a risky area. The outputs of the video sensor and GPS sensor are combined to evaluate a possible risky behavior. The results are promising in terms of risk analysis in order to be validated for use in the context of the automotive industry as future work. PMID:25347580

[Development and validation of a questionnaire about the main variables affecting the individual investor's behavior in the Stock Exchange].

PubMed

Pascual-Ezama, David; San Martín Castellanos, Rafael; Gil-Gómez de Liaño, Beatriz; Scandroglio, Bárbara

2010-11-01

Development and validation of a questionnaire about the main variables affecting the individual investor's behavior in the Stock Exchange. There is a considerable lack of information about the methodology usually used in most of the studies about individual investor's behavior. The studies reviewed do not show the method used in the selection of the items or the psychometric properties of the questionnaires. Because of the importance of investment in the Stock Exchange nowadays, it seems relevant to obtain a reliable instrument to understand individual investor's behavior in the Stock Exchange. Therefore, the goal of the present work is to validate a questionnaire about the main variables involved in individual investors' behavior in the Stock Exchange. Based on previous studies, we elaborated a questionnaire using the Delphi methodology with a group of experts. The internal consistency (Cronbach alpha=.934) and validity evidence of the questionnaire show that it may be an effective instrument and can be applied with some assurance.

Impulsive Choice in Mice Lacking Paternal Expression of Grb10 Suggests Intragenomic Conflict in Behavior

PubMed Central

Dent, Claire L.; Humby, Trevor; Lewis, Katie; Ward, Andrew; Fischer-Colbrie, Reiner; Wilkinson, Lawrence S.; Wilkins, Jon F.; Isles, Anthony R.

2018-01-01

Imprinted genes are expressed from one parental allele only as a consequence of epigenetic events that take place in the mammalian germ line and are thought to have evolved through intragenomic conflict between parental alleles. We demonstrate, for the first time, oppositional effects of imprinted genes on brain and behavior. Specifically, we show that mice lacking paternal Grb10 make fewer impulsive choices, with no dissociable effects on a separate measure of impulsive action. Taken together with previous work showing that mice lacking maternal Nesp55 make more impulsive choices, this suggests that impulsive choice behavior is a substrate for the action of genomic imprinting. Moreover, the contrasting effect of these two genes suggests that impulsive choices are subject to intragenomic conflict and that maternal and paternal interests pull this behavior in opposite directions. Finally, these data may also indicate that an imbalance in expression of imprinted genes contributes to pathological conditions such as gambling and drug addiction, where impulsive behavior becomes maladaptive. PMID:29563147

Speciation by Symbiosis: the Microbiome and Behavior

PubMed Central

Shropshire, J. Dylan

2016-01-01

ABSTRACT Species are fundamental units of comparison in biology. The newly discovered importance and ubiquity of host-associated microorganisms are now stimulating work on the roles that microbes can play in animal speciation. We previously synthesized the literature and advanced concepts of speciation by symbiosis with notable attention to hybrid sterility and lethality. Here, we review recent studies and relevant data on microbes as players in host behavior and behavioral isolation, emphasizing the patterns seen in these analyses and highlighting areas worthy of additional exploration. We conclude that the role of microbial symbionts in behavior and speciation is gaining exciting traction and that the holobiont and hologenome concepts afford an evolving intellectual framework to promote research and intellectual exchange between disciplines such as behavior, microbiology, genetics, symbiosis, and speciation. Given the increasing centrality of microbiology in macroscopic life, microbial symbiosis is arguably the most neglected aspect of animal and plant speciation, and studying it should yield a better understanding of the origin of species. PMID:27034284

Speciation by Symbiosis: the Microbiome and Behavior.

PubMed

Shropshire, J Dylan; Bordenstein, Seth R

2016-03-31

Species are fundamental units of comparison in biology. The newly discovered importance and ubiquity of host-associated microorganisms are now stimulating work on the roles that microbes can play in animal speciation. We previously synthesized the literature and advanced concepts of speciation by symbiosis with notable attention to hybrid sterility and lethality. Here, we review recent studies and relevant data on microbes as players in host behavior and behavioral isolation, emphasizing the patterns seen in these analyses and highlighting areas worthy of additional exploration. We conclude that the role of microbial symbionts in behavior and speciation is gaining exciting traction and that the holobiont and hologenome concepts afford an evolving intellectual framework to promote research and intellectual exchange between disciplines such as behavior, microbiology, genetics, symbiosis, and speciation. Given the increasing centrality of microbiology in macroscopic life, microbial symbiosis is arguably the most neglected aspect of animal and plant speciation, and studying it should yield a better understanding of the origin of species. Copyright © 2016 Shropshire and Bordenstein.

Videosensor for the detection of unsafe driving behavior in the proximity of black spots.

PubMed

Fuentes, Andres; Fuentes, Ricardo; Cabello, Enrique; Conde, Cristina; Martin, Isaac

2014-10-24

This paper discusses the overall design and implementation of a video sensor for the detection of risky behaviors of car drivers near previously identified and georeferenced black spots. The main goal is to provide the driver with a visual audio alert that informs of the proximity of an area of high incidence of highway accidents only if their driving behavior could result in a risky situation. It proposes a video sensor for detecting and supervising driver behavior, its main objective being manual distractions, so hand driver supervision is performed. A GPS signal is also considered, the GPS information is compared with a database of global positioning Black Spots to determine the relative proximity of a risky area. The outputs of the video sensor and GPS sensor are combined to evaluate a possible risky behavior. The results are promising in terms of risk analysis in order to be validated for use in the context of the automotive industry as future work.

Nursing theory and concept development: a theoretical model of clinical nurses' intentions to stay in their current positions.

PubMed

Cowden, Tracy L; Cummings, Greta G

2012-07-01

We describe a theoretical model of staff nurses' intentions to stay in their current positions. The global nursing shortage and high nursing turnover rate demand evidence-based retention strategies. Inconsistent study outcomes indicate a need for testable theoretical models of intent to stay that build on previously published models, are reflective of current empirical research and identify causal relationships between model concepts. Two systematic reviews of electronic databases of English language published articles between 1985-2011. This complex, testable model expands on previous models and includes nurses' affective and cognitive responses to work and their effects on nurses' intent to stay. The concepts of desire to stay, job satisfaction, joy at work, and moral distress are included in the model to capture the emotional response of nurses to their work environments. The influence of leadership is integrated within the model. A causal understanding of clinical nurses' intent to stay and the effects of leadership on the development of that intention will facilitate the development of effective retention strategies internationally. Testing theoretical models is necessary to confirm previous research outcomes and to identify plausible sequences of the development of behavioral intentions. Increased understanding of the causal influences on nurses' intent to stay should lead to strategies that may result in higher retention rates and numbers of nurses willing to work in the health sector. © 2012 Blackwell Publishing Ltd.

n-Type Conductivity of Cu2O Thin Film Prepared in Basic Aqueous Solution Under Hydrothermal Conditions

NASA Astrophysics Data System (ADS)

Ursu, Daniel; Miclau, Nicolae; Miclau, Marinela

2018-03-01

We report for the first time in situ hydrothermal synthesis of n-type Cu2O thin film using strong alkaline solution. The use of copper foil as substrate and precursor material, low synthesis temperature and short reaction time represent the arguments of a new, simple, inexpensive and high field synthesis method for the preparation of n-type Cu2O thin film. The donor concentration of n-type Cu2O thin film obtained at 2 h of reaction time has increased two orders of magnitude than previous reported values. We have demonstrated n-type conduction in Cu2O thin film prepared in strong alkaline solution, in the contradiction with the previous works. Based on experimental results, the synthesis mechanism and the origin of n-type photo-responsive behavior of Cu2O thin film were discussed. We have proposed that the unexpected n-type character could be explained by H doping of Cu2O thin film in during of the hydrothermal synthesis that caused the p-to-n conductivity-type conversion. Also, this work raises new questions about the origin of n-type conduction in Cu2O thin film, the influence of the synthesis method on the nature of the intrinsic defects and the electrical conduction behavior.

Portion Size: Latest Developments and Interventions.

PubMed

Steenhuis, Ingrid; Poelman, Maartje

2017-03-01

The aim of this review is to provide an overview of (1) underlying mechanisms of the effect of portion size on energy intake, (2) external factors explaining the portion size effect and (3) interventions and measurements aimed at food portion size. Previous studies have shown that portion sizes have increased in recent decades. Many experimental studies have been conducted to unravel the mechanisms underlying the portion-size effect on food intake (e.g. the appropriateness mechanism, the 'unit bias' mechanism, the 'previous experience/expectation' mechanism, the 'visual cue' mechanism and the 'bite size' mechanism). In addition, external factors have been found to drive food portion selection and consumption (e.g. value for money, mindless eating, levels of awareness, estimation bias. Research on several interventions (ranging from 'providing information' to 'eliminating choice') have been conducted, but remain scarce, especially intervention studies in which portion size is a key focus in weight loss. Moreover, only three new instruments with respect to portion control behavior have been developed. There is considerable evidence for the portion-size effect on energy intake. However, the work on interventions targeting portion size and measurements for portion control behavior are limited. Moreover, from the literature it is not yet clear what type of interventions work best, for whom and in what context.

Kinetic theory of pattern formation in mixtures of microtubules and molecular motors

NASA Astrophysics Data System (ADS)

Maryshev, Ivan; Marenduzzo, Davide; Goryachev, Andrew B.; Morozov, Alexander

2018-02-01

In this study we formulate a theoretical approach, based on a Boltzmann-like kinetic equation, to describe pattern formation in two-dimensional mixtures of microtubular filaments and molecular motors. Following the previous work by Aranson and Tsimring [Phys. Rev. E 74, 031915 (2006), 10.1103/PhysRevE.74.031915] we model the motor-induced reorientation of microtubules as collision rules, and devise a semianalytical method to calculate the corresponding interaction integrals. This procedure yields an infinite hierarchy of kinetic equations that we terminate by employing a well-established closure strategy, developed in the pattern-formation community and based on a power-counting argument. We thus arrive at a closed set of coupled equations for slowly varying local density and orientation of the microtubules, and study its behavior by performing a linear stability analysis and direct numerical simulations. By comparing our method with the work of Aranson and Tsimring, we assess the validity of the assumptions required to derive their and our theories. We demonstrate that our approximation-free evaluation of the interaction integrals and our choice of a systematic closure strategy result in a rather different dynamical behavior than was previously reported. Based on our theory, we discuss the ensuing phase diagram and the patterns observed.

Experimental Investigation into the Radar Anomalies on the Surface of Venus

NASA Technical Reports Server (NTRS)

Kohler, E.; Gavin, P.; Chevrier, V.; Johnson, Natasha M.

2012-01-01

Radar mapping of thc surface of Venus shows areas of high reflectivity (low emissivity) in the Venusian highlands at altitudes between 2.5-4.75 kilometers. The origin of the radar anomalies found in the Venusian highlands remains unclear. Most explanations of the potential causes for these radar anomalies come from theoretical work. Previous studies suggest increased surface roughness or materials with higher dielectric constants as well as surface atmospheric interactions. Several possible candidates of high-dielectric materials are tellurium) ferroelectric materials, and lead or bismuth sulfides. While previous studies have been influential in determining possible sources for the Venus anomalies, only a very few hypotheses have been verified via experimentation. This work intends to experimentally constrain the source of the radar anomalies on Venus. This study proposes to investigate four possible materials that could potentially cause the high reflectivities on the surface of Venus and tests their behavior under simulated Venusian conditions.

Inter-individual differences in decision-making, flexible and goal-directed behaviors: novel insights within the prefronto-striatal networks.

PubMed

Fitoussi, Aurélie; Renault, Prisca; Le Moine, Catherine; Coutureau, Etienne; Cador, Martine; Dellu-Hagedorn, Françoise

2018-03-01

Inflexible behavior is a hallmark of several decision-making-related disorders such as ADHD and addiction. As in humans, a subset of healthy rats makes poor decisions and prefers immediate larger rewards despite suffering large losses in a rat gambling task (RGT). They also display a combination of traits reminiscent of addiction, notably inflexible behavior and perseverative responses. The goal of the present work was twofold: (1) to elucidate if behavioral inflexibility of poor decision-makers could be related to a lower quality of goal-directed behavior (action-outcome associations); (2) to uncover the neural basis of inter-individual differences in goal-directed behavior. We specifically assessed inter-individual differences in decision-making in the RGT, flexibility in the RGT-reversed version and goal-directed behavior in a contingency degradation test, i.e., response adaptation when dissociating reward delivery from the animal's action. The contributions of the medial prefrontal cortex and the dorsal striatum to action-outcome associations were assessed using Zif268 immunodetection. Inflexible behavior was related to a lower sensitivity to contingency degradation in all poor decision-makers and only in a few good decision-makers. This poorer sensitivity was associated with a lower immunoreactivity in prelimbic and infralimbic cortices and a higher one in the dorsomedial and dorsolateral striatum. These findings suggest that an imbalanced prefronto-striatal activity could underlie inaccurate goal representation in changing environments and may promote maladaptive habit formation among poor decision-makers. These data strengthen our previous work identifying biomarkers of vulnerability to develop psychiatric disorders and demonstrate the relevance of inter-individual differences to model maladaptive behaviors.

A systematic survey of the integration of animal behavior into conservation

USGS Publications Warehouse

Berger-Tal, Oded; Blumstein, Daniel T.; Carroll, Scott; Fisher, Robert N.; Mesnick, Sarah L.; Owen, Megan A.; Saltz, David; St. Claire, Colleen Cassady; Swaisgood, Ronald R.

2016-01-01

The role of behavioral ecology in improving wildlife conservation and management has been the subject of much recent debate. We aim to answer two foundational questions about the current use of behavioral knowledge in conservation: 1. To what extent is behavioral knowledge used in wildlife conservation and management? 2. How does the use of behavior differ among conservation fields in both frequency and types of use? To answer these questions, we searched the literature for intersections between key fields of animal behavior and conservation biology and created a systematic ‘heat’ map to visualize relative efforts. Our analysis challenges previous suggestions that there is little association between the fields of behavioral ecology and conservation and reveals tremendous variation in the use of different behaviors in conservation. For instance, some behaviors, such as foraging and dispersal, are commonly considered, but other behaviors such as learning, social or anti-predatory behaviors are hardly considered. Our analysis suggests that in many cases awareness of the importance of behavior does not translate into applicable management tools. We recommend that researchers should focus on developing research in underutilized intersections of behavior and conservation themes for which preliminary work show a potential for improving conservation and management, on translating behavioral theory into applicable and testable predictions, and on creating systematic reviews to summarize the behavioral evidence within the behavior-conservation intersections for which many studies exist.

Health-related lifestyle behaviors among male and female rural-to-urban migrant workers in Shanghai, China.

PubMed

Yang, Hua; He, Fang; Wang, Tianhao; Liu, Yao; Shen, Yao; Gong, Jian; Dai, Wei; Zhou, Jing; Gu, Jie; Tu, Yimin; Wang, Tianying; Shen, Lei; Wu, Yumiao; Xia, Xiuping; Xu, Donghao; Pan, Zhigang; Zhu, Shanzhu

2015-01-01

Lifestyle behaviors significantly impact health, yet remain poorly defined in Chinese rural-to-urban migrants. In a cross-sectional study of health-related behaviors of 5484 rural-to-urban migrants who had worked in Shanghai for at least six months, we assessed the contribution of demographics and physical and mental health to lifestyle behaviors in male and female participants by multiple stepwise cumulative odds logistic regression. Respondents were 51.3% male. 9.9% exhibited abnormal blood pressure; 27.0% were overweight or obese; 11.2% reported abnormal mental health; 36.9% reported healthy lifestyle. Multiple stepwise cumulative odds logistic regression indicated that men working in manufacturing reported less unhealthy lifestyle than those in hospitality (cumulative odds ratio (COR) = 1.806, 95%CI 1.275-2.559) or recreation/leisure (COR = 3.248, 95%CI 2.379-4.435); and women working in manufacturing and construction reported less unhealthy lifestyle than those in all other sectors. Unhealthy lifestyle was associated with small workplaces for men (COR = 1.422, 95%CI 1.154-1.752), working more than 8 or 11 hours per day for women and men, respectively, and earning over 3500 RMB in women (COR = 1.618, 95%CI 1.137-2.303). Single women and women who had previously resided in three or more cities were more likely to report unhealthy lifestyle (COR = 2.023, 95%CI 1.664-2.461, and COR = 1.311, 95%CI 1.072-1.602, respectively). Abnormal mental status was also correlated with unhealthy lifestyle in men (COR = 3.105, 95%CI 2.454-3.930) and women (COR = 2.566, 95%CI 2.024-3.252). There were different risk factors of unhealthy lifestyle score in male and female rural-to-urban migrants, especially in number of cities experienced, salary, marital status, work place scale. Several demographic groups: employment sectors (e.g. hospitality and recreation/leisure), working conditions (e.g. long hours) and abnormal mental status were associated with unhealthy lifestyle behaviors in Chinese rural-to-urban migrants, and health interventions should be targeted to these groups.

Health-Related Lifestyle Behaviors among Male and Female Rural-to-Urban Migrant Workers in Shanghai, China

PubMed Central

Yang, Hua; He, Fang; Wang, Tianhao; Liu, Yao; Shen, Yao; Gong, Jian; Dai, Wei; Zhou, Jing; Gu, Jie; Tu, Yimin; Wang, Tianying; Shen, Lei; Wu, Yumiao; Xia, Xiuping; Xu, Donghao; Pan, Zhigang; Zhu, Shanzhu

2015-01-01

Background Lifestyle behaviors significantly impact health, yet remain poorly defined in Chinese rural-to-urban migrants. Methods In a cross-sectional study of health-related behaviors of 5484 rural-to-urban migrants who had worked in Shanghai for at least six months, we assessed the contribution of demographics and physical and mental health to lifestyle behaviors in male and female participants by multiple stepwise cumulative odds logistic regression. Results Respondents were 51.3% male. 9.9% exhibited abnormal blood pressure; 27.0% were overweight or obese; 11.2% reported abnormal mental health; 36.9% reported healthy lifestyle. Multiple stepwise cumulative odds logistic regression indicated that men working in manufacturing reported less unhealthy lifestyle than those in hospitality (cumulative odds ratio (COR) = 1.806, 95%CI 1.275–2.559) or recreation/leisure (COR = 3.248, 95%CI 2.379–4.435); and women working in manufacturing and construction reported less unhealthy lifestyle than those in all other sectors. Unhealthy lifestyle was associated with small workplaces for men (COR = 1.422, 95%CI 1.154–1.752), working more than 8 or 11 hours per day for women and men, respectively, and earning over 3500 RMB in women (COR = 1.618, 95%CI 1.137–2.303). Single women and women who had previously resided in three or more cities were more likely to report unhealthy lifestyle (COR = 2.023, 95%CI 1.664–2.461, and COR = 1.311, 95%CI 1.072–1.602, respectively). Abnormal mental status was also correlated with unhealthy lifestyle in men (COR = 3.105, 95%CI 2.454–3.930) and women (COR = 2.566, 95%CI 2.024–3.252). Conclusions There were different risk factors of unhealthy lifestyle score in male and female rural-to-urban migrants, especially in number of cities experienced, salary, marital status, work place scale. Several demographic groups: employment sectors (e.g. hospitality and recreation/leisure), working conditions (e.g. long hours) and abnormal mental status were associated with unhealthy lifestyle behaviors in Chinese rural-to-urban migrants, and health interventions should be targeted to these groups. PMID:25710464

Aggression from Patients or Next of Kin and Exposure to Bullying Behaviors: A Conglomerate Experience?

PubMed Central

Notelaers, Guy; Bjorvatn, Bjørn; Moen, Bente Elisabeth; Einarsen, Ståle

2017-01-01

Although workplace violence and aggression have been identified as important stressors in the nursing profession, studies simultaneously comparing patient-initiated aggression and exposure to bullying behaviors at work are rather scarce. The aim of this study was to compare aggression from patients or next of kin and exposure to bullying behaviors in terms of prevalence, health-related quality of life outcomes, and potential overlap in those targeted. In the period of 2008-2009, data were collected among 2059 members of the Norwegian Nurses Organization. Latent class (LC) analysis and a multivariate analysis of variance (MANOVA) were used to investigate the proposed relationships. The results showed that aggression from patients or next of kin and exposure to bullying behaviors were perceived as separate and independent stressors. Although aggression from patients or next of kin was more frequent than workplace bullying, the latter was the only significant stressor related to health-related quality of life in terms of reduced mental health functioning. Although being a rather infrequent experience, exposure to bullying behaviors seems to have more severe health-related outcomes for nurses than aggression from patients or next of kin. Hence, the results of the study strengthen previous findings and suggest that managers must aim to maintain a positive psychosocial work environment with zero-tolerance for bullying. PMID:28270936

Utility of eButton images for identifying food preparation behaviors and meal-related tasks in adolescents.

PubMed

Raber, Margaret; Patterson, Monika; Jia, Wenyan; Sun, Mingui; Baranowski, Tom

2018-02-24

Food preparation skills may encourage healthy eating. Traditional assessment of child food preparation employs self- or parent proxy-reporting methods, which are prone to error. The eButton is a wearable all-day camera that has promise as an objective, passive method for measuring child food preparation practices. This paper explores the feasibility of the eButton to reliably capture home food preparation behaviors and practices in a sample of pre- and early adolescents (ages 9 to 13). This is a secondary analysis of two eButton pilot projects evaluating the dietary intake of pre- and early adolescents in or around Houston, Texas. Food preparation behaviors were coded into seven major categories including: browsing, altering food/adding seasoning, food media, meal related tasks, prep work, cooking and observing. Inter-coder reliability was measured using Cohen's kappa and percent agreement. Analysis was completed on data for 31 participants. The most common activity was browsing in the pantry or fridge. Few participants demonstrated any food preparation work beyond unwrapping of food packages and combining two or more ingredients; actual cutting or measuring of foods were rare. Although previous research suggests children who "help" prepare meals may obtain some dietary benefit, accurate assessment tools of food preparation behavior are lacking. The eButton offers a feasible approach to food preparation behavior measurement among pre- and early adolescents. Follow up research exploring the validity of this method in a larger sample, and comparisons between cooking behavior and dietary intake are needed.

Meditation awareness training for the treatment of workaholism: A controlled trial.

PubMed

Van Gordon, William; Shonin, Edo; Dunn, Thomas J; Garcia-Campayo, Javier; Demarzo, Marcelo M P; Griffiths, Mark D

2017-06-01

Background and aims Workaholism is a form of behavioral addiction that can lead to reduced life and job satisfaction, anxiety, depression, burnout, work-family conflict, and impaired productivity. Given the number of people affected, there is a need for more targeted workaholism treatments. Findings from previous case studies successfully utilizing second-generation mindfulness-based interventions (SG-MBIs) for treating behavioral addiction suggest that SG-MBIs may be suitable for treating workaholism. This study conducted a controlled trial to investigate the effects of an SG-MBI known as meditation awareness training (MAT) on workaholism. Methods Male and female adults suffering from workaholism (n = 73) were allocated to MAT or a waiting-list control group. Assessments were performed at pre-, post-, and 3-month follow-up phases. Results MAT participants demonstrated significant and sustained improvements over control-group participants in workaholism symptomatology, job satisfaction, work engagement, work duration, and psychological distress. Furthermore, compared to the control group, MAT participants demonstrated a significant reduction in hours spent working but without a decline in job performance. Discussion and conclusions MAT may be a suitable intervention for treating workaholism. Further controlled intervention studies investigating the effects of SG-MBIs on workaholism are warranted.

Postural Hand Synergies during Environmental Constraint Exploitation

PubMed Central

Della Santina, Cosimo; Bianchi, Matteo; Averta, Giuseppe; Ciotti, Simone; Arapi, Visar; Fani, Simone; Battaglia, Edoardo; Catalano, Manuel Giuseppe; Santello, Marco; Bicchi, Antonio

2017-01-01

Humans are able to intuitively exploit the shape of an object and environmental constraints to achieve stable grasps and perform dexterous manipulations. In doing that, a vast range of kinematic strategies can be observed. However, in this work we formulate the hypothesis that such ability can be described in terms of a synergistic behavior in the generation of hand postures, i.e., using a reduced set of commonly used kinematic patterns. This is in analogy with previous studies showing the presence of such behavior in different tasks, such as grasping. We investigated this hypothesis in experiments performed by six subjects, who were asked to grasp objects from a flat surface. We quantitatively characterized hand posture behavior from a kinematic perspective, i.e., the hand joint angles, in both pre-shaping and during the interaction with the environment. To determine the role of tactile feedback, we repeated the same experiments but with subjects wearing a rigid shell on the fingertips to reduce cutaneous afferent inputs. Results show the persistence of at least two postural synergies in all the considered experimental conditions and phases. Tactile impairment does not alter significantly the first two synergies, and contact with the environment generates a change only for higher order Principal Components. A good match also arises between the first synergy found in our analysis and the first synergy of grasping as quantified by previous work. The present study is motivated by the interest of learning from the human example, extracting lessons that can be applied in robot design and control. Thus, we conclude with a discussion on implications for robotics of our findings. PMID:28900393

The interaction between monoamine oxidase A and punitive discipline in the development of antisocial behavior: Mediation by maladaptive social information processing.

PubMed

Galán, Chardée A; Choe, Daniel Ewon; Forbes, Erika E; Shaw, Daniel S

2017-10-01

Previous studies demonstrate that boys' monoamine oxidase A (MAOA) genotype interacts with adverse rearing environments in early childhood, including punitive discipline, to predict later antisocial behavior. Yet the mechanisms by which MAOA and punitive parenting interact during childhood to amplify risk for antisocial behavior are not well understood. In the present study, hostile attributional bias and aggressive response generation during middle childhood, salient aspects of maladaptive social information processing, were tested as possible mediators of this relation in a sample of 187 low-income men followed prospectively from infancy into early adulthood. Given racial-ethnic variation in MAOA allele frequencies, analyses were conducted separately by race. In both African American and Caucasian men, those with the low-activity MAOA allele who experienced more punitive discipline at age 1.5 generated more aggressive responses to perceived threat at age 10 relative to men with the high-activity variant. In the African American subsample only, formal mediation analyses indicated a marginally significant indirect effect of maternal punitiveness on adult arrest records via aggressive response generation in middle childhood. The findings suggest that maladaptive social information processing may be an important mechanism underlying the association between MAOA × Parenting interactions and antisocial behavior in early adulthood. The present study extends previous work in the field by demonstrating that MAOA and harsh parenting assessed in early childhood interact to not only predict antisocial behavior in early adulthood, but also predict social information processing, a well-established social-cognitive correlate of antisocial behavior.

Fragile X mental retardation protein knockdown in the developing Xenopus tadpole optic tectum results in enhanced feedforward inhibition and behavioral deficits.

PubMed

Truszkowski, Torrey L S; James, Eric J; Hasan, Mashfiq; Wishard, Tyler J; Liu, Zhenyu; Pratt, Kara G; Cline, Hollis T; Aizenman, Carlos D

2016-08-08

Fragile X Syndrome is the leading monogenetic cause of autism and most common form of intellectual disability. Previous studies have implicated changes in dendritic spine architecture as the primary result of loss of Fragile X Mental Retardation Protein (FMRP), but recent work has shown that neural proliferation is decreased and cell death is increased with either loss of FMRP or overexpression of FMRP. The purpose of this study was to investigate the effects of loss of FMRP on behavior and cellular activity. We knocked down FMRP expression using morpholino oligos in the optic tectum of Xenopus laevis tadpoles and performed a series of behavioral and electrophysiological assays. We investigated visually guided collision avoidance, schooling, and seizure propensity. Using single cell electrophysiology, we assessed intrinsic excitability and synaptic connectivity of tectal neurons. We found that FMRP knockdown results in decreased swimming speed, reduced schooling behavior and decreased seizure severity. In single cells, we found increased inhibition relative to excitation in response to sensory input. Our results indicate that the electrophysiological development of single cells in the absence of FMRP is largely unaffected despite the large neural proliferation defect. The changes in behavior are consistent with an increase in inhibition, which could be due to either changes in cell number or altered inhibitory drive, and indicate that FMRP can play a significant role in neural development much earlier than previously thought.

Structure-property relations and modeling of small crack fatigue behavior of various magnesium alloys

NASA Astrophysics Data System (ADS)

Bernard, Jairus Daniel

Lightweight structural components are important to the automotive and aerospace industries so that better fuel economy can be realized. Magnesium alloys in particular are being examined to fulfill this need due to their attractive stiffness- and strength-to-weight ratios when compared to other materials. However, when introducing a material into new roles, one needs to properly characterize its mechanical properties. Fatigue behavior is especially important considering aerospace and automotive component applications. Therefore, quantifying the structure-property relationships and accurately predicting the fatigue behavior for these materials are vital. This study has two purposes. The first is to quantify the structure-property relationships for the fatigue behavior in an AM30 magnesium alloy. The second is to use the microstructural-based MultiStage Fatigue (MSF) model in order to accurately predict the fatigue behavior of three magnesium alloys: AM30, Elektron 21, and AZ61. While some studies have previously quantified the MSF material constants for several magnesium alloys, detailed research into the fatigue regimes, notably the microstructurally small crack (MSC) region, is lacking. Hence, the contribution of this work is the first of its kind to experimentally quantify the fatigue crack incubation and MSC regimes that are used for the MultiStage Fatigue model. Using a multi-faceted experimental approach, these regimes were explored with a replica method that used a dual-stage silicone based compound along with previously published in situ fatigue tests. These observations were used in calibrating the MultiStage Fatigue model.

Sex, gender roles and sexual attitudes in university students.

PubMed

García-Vega, Elena; Rico, Rosana; Fernández, Paula

2017-05-01

Previous studies usually refer to a greater repertoire of sexual behav-iors and a higher level of erotophilia in men than in women. The main goal of this work is to relate sex, gender roles and sexual attitudes to sexual behavior. 411 un-dergraduate students (218 women and 193 men) at theof University of Oviedo (Spain) completed the following instruments: the Bem Sex Roles Inventory to operationalize the variable gender, the Sexual Inventory which reflects sexual behaviors, and the Sexual Opinion Survey about sexual attitudes. 27% of the sample was typified as an-drogynous. There are were no differences in attitudes, either by sex (p= .50) or by gen-der (p= .77). Sexual behaviors depended on the degree of erotophilia (p= .000). the results suggest that, although regarding sex, the fact that women’s erotophilic attitudes have increased their erotophilic attitudes, although they refer to more conventional sexual behaviors than mens’s attitudes. With regard to gender, a tendency towards androgyny is observed, androgynous women and men report positive attitudes towards sexuality. Gender could act as a mediator of sexual behavior through the attitudinal component.

Eating your feelings? Testing a model of employees' work-related stressors, sleep quality, and unhealthy eating.

PubMed

Liu, Yihao; Song, Yifan; Koopmann, Jaclyn; Wang, Mo; Chang, Chu-Hsiang Daisy; Shi, Junqi

2017-08-01

Although organizational research on health-related behaviors has become increasingly popular, little attention has been paid to unhealthy eating. Drawing on the self-regulation perspective, we conducted 2 daily diary studies to examine the relationships between work-related stressors, sleep quality, negative mood, and eating behaviors. Study 1 sampled 125 participants from 5 Chinese information technology companies and showed that when participants experienced higher levels of job demands in the morning, they consumed more types of unhealthy food and fewer types of healthy food in the evening. In addition, sleep quality from the previous night buffered the effect of morning job demands on evening unhealthy food consumption. Study 2 used data from 110 customer service employees from a Chinese telecommunications company and further demonstrated a positive association between morning customer mistreatment and evening overeating behaviors, as well as the buffering effect of sleep quality. Results from Study 2 also supported afternoon negative mood as a mediator linking morning customer mistreatment to evening overeating behaviors. Finally, our findings revealed that the buffering effect of sleep quality was channeled through employees' vigor in the morning, which subsequently weakened the effect of customer mistreatment on negative mood. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A Time Series Analysis of Cancer-Related Information Seeking: Hints From the Health Information National Trends Survey (HINTS) 2003-2014.

PubMed

Huerta, Timothy R; Walker, Daniel M; Johnson, Tyler; Ford, Eric W

2016-09-01

Recent technological changes, such as the growth of the Internet, have made cancer information widely available. However, it remains unknown whether changes in access have resulted in concomitant changes in information seeking behavior. Previous work explored the cancer information seeking behaviors of the general population using the 2003 Health Information National Trends Survey (HINTS). This article aims to reproduce, replicate, and extend that existing analysis using the original dataset and five additional iterations of HINTS (2007, 2011, 2012, 2013, 2014). This approach builds on the earlier work by quantifying the magnitude of change in information seeking behaviors. Bivariate comparison of the 2003 and 2014 data revealed very similar results; however, the multivariate model including all years of data indicated differences between the original and extended models: individuals age 65 and older were no longer less likely to seek cancer information than the 18-35 reference population, and Hispanics were also no longer less likely to be cancer information seekers. The results of our analysis indicate an overall shift in cancer information seeking behaviors and also illuminate the impact of increased Internet usage over the past decade, suggesting specific demographic groups that may benefit from cancer information seeking encouragement.

Reproducing the nonlinear dynamic behavior of a structured beam with a generalized continuum model

NASA Astrophysics Data System (ADS)

Vila, J.; Fernández-Sáez, J.; Zaera, R.

2018-04-01

In this paper we study the coupled axial-transverse nonlinear vibrations of a kind of one dimensional structured solids by application of the so called Inertia Gradient Nonlinear continuum model. To show the accuracy of this axiomatic model, previously proposed by the authors, its predictions are compared with numeric results from a previously defined finite discrete chain of lumped masses and springs, for several number of particles. A continualization of the discrete model equations based on Taylor series allowed us to set equivalent values of the mechanical properties in both discrete and axiomatic continuum models. Contrary to the classical continuum model, the inertia gradient nonlinear continuum model used herein is able to capture scale effects, which arise for modes in which the wavelength is comparable to the characteristic distance of the structured solid. The main conclusion of the work is that the proposed generalized continuum model captures the scale effects in both linear and nonlinear regimes, reproducing the behavior of the 1D nonlinear discrete model adequately.

Organizational identification and commitment: correlates of sense of belonging and affective commitment.

PubMed

Dávila, Ma Celeste; Jiménez García, Gemma

2012-03-01

The general purpose of this work is to analyze the overlap between organizational identification and commitment. Specifically, our study focuses on the analysis of the differences and similarities between sense of belonging (a dimension of organizational identification) and affective commitment (a dimension of organizational commitment). In order to do this, we analyzed their discriminant validity and raised their relationship with variables that previous research had showed like precedent and subsequent variables of them: value congruence, perceived support, organizational citizenship behavior, and intention to continue in the organization. A total of 292 people at one organization completed surveys measuring the variables previously described. The results showed that sense of belonging and affective commitment are different concepts and they have different relationships with relation to precedent and subsequent variables. Affective commitment seems to be more useful than sense of belonging to predict organizational citizenship behavior aimed at the organization and intention to continue. Some practical implications are described.

Chronic Stress Impairs Prefrontal Cortex-Dependent Response Inhibition and Spatial Working Memory

PubMed Central

Mika, Agnieszka; Mazur, Gabriel J.; Hoffman, Ann N.; Talboom, Joshua S.; Bimonte-Nelson, Heather A.; Sanabria, Federico; Conrad, Cheryl D.

2012-01-01

Chronic stress leads to neurochemical and structural alterations in the prefrontal cortex (PFC) that correspond to deficits in PFC-mediated behaviors. The present study examined the effects of chronic restraint stress on response inhibition (using a response-withholding task, fixed-minimum interval schedule of reinforcement, or FMI), and working memory (using a radial arm water maze, RAWM). Adult male Sprague Dawley rats were first trained on the RAWM and subsequently trained on FMI. Following acquisition of FMI, rats were assigned to a restraint stress (6h/d/28d in wire mesh restrainers) or control condition. Immediately after chronic stress, rats were tested on FMI and subsequently on RAWM. FMI results suggest that chronic stress reduces response inhibition capacity and motivation to initiate the task on selective conditions when food reward was not obtained on the preceding trial. RAWM results suggest that chronic stress produces transient deficits in working memory without altering previously consolidated reference memory. Behavioral measures from FMI failed to correlate with metrics from RAWM except for one in which changes in FMI timing precision negatively correlated with changes in RAWM working memory errors for the controls, a finding that was not observed following chronic stress. Fisher’s r to z transformation revealed no significant differences between control and stress with correlation coefficients. These findings are the first to show that chronic stress impairs both response inhibition and working memory, two behaviors that have never been direct compared within the same animals following chronic stress, using FMI, an appetitive task, and RAWM, a non-appetitive task. PMID:22905921

Cognitive Training Sustainably Improves Executive Functioning in Middle-Aged Industry Workers Assessed by Task Switching: A Randomized Controlled ERP Study

PubMed Central

Gajewski, Patrick D.; Freude, Gabriele; Falkenstein, Michael

2017-01-01

Recently, we reported results of a cross-sectional study investigating executive functions in dependence of aging and type of work. That study showed deficits in performance and electrophysiological activity in middle-aged workers with long-term repetitive and unchallenging work. Based on these findings, we conducted a longitudinal study that aimed at ameliorating these cognitive deficits by means of a trainer-guided cognitive training (CT) in 57 further middle-aged workers with repetitive type of work from the same factory. This study was designed as a randomized controlled trail with pre- (t1), post- (t2), and a 3-month follow-up (t3) measure. The waiting control group was trained between t2 and t3. The training lasted 3 months (20 sessions) and was evaluated with the same task switching paradigm used in the previous cross-sectional study. The CT improved performance in accuracy at the behavioral level and affected the electrophysiological correlates of retrieval of stimulus-response sets (P2), response selection (N2), and error detection (Ne), thus unveiling the neuronal background of the behavioral effects. The same training effects were observed in the waiting control group after CT at t3. Moreover, at t3, most of the behavioral and electrophysiological training-induced changes were found stable. Hence, CT appears to be an important intervention for compensating cognitive deficits in executive functions in middle-aged employees with cognitively unchallenging work. PMID:28275347

Personality and prosocial behavior: linking basic traits and social value orientations.

PubMed

Hilbig, Benjamin E; Glöckner, Andreas; Zettler, Ingo

2014-09-01

Concerning the dispositional determinants of prosocial behavior and cooperation, work based on the classic 5 personality factors, and especially Agreeableness, has turned out somewhat inconsistent. A clearer picture has emerged from consideration of the HEXACO model of personality--though supported entirely by hypothetical behavior as criterion, so far. Thus, in 2 studies and a reanalysis, we investigated "actual behavior" in the form of individually and socially consequential distribution decisions. As expected, HEXACO Honesty-Humility consistently predicted prosocial behavior, including a theory-consistent pattern on the facet level. Importantly, this pattern might explain why five-factor Agreeableness has only sometimes been found to account for prosocial behavior. Indeed, further results indicate that five-factor Agreeableness comprises some aspects that are predictive of prosocial behavior--aspects well covered by HEXACO Honesty-Humility--but also others that play no role for this criterion. As such, the links between five-factor Agreeableness and prosocial behavior are well-covered by HEXACO Honesty-Humility, but not vice versa. Taken together, these findings hint that especially HEXACO Honesty-Humility (and certain aspects of five-factor Agreeableness) account for prosocial behavior--thus explaining previous inconsistencies and providing a more nuanced understanding of the links between basic personality and prosocial or cooperative behavior. 2014 APA, all rights reserved

Technology Transition Pull: A Case Study of Rate Monotonic Analysis (Part 2).

DTIC Science & Technology

1995-04-01

met in software-intensive real - time systems . RMA allows engineers to under- stand and predict the timing behavior of real-time software to a degree...not previously possible. The Rate Monotonic Analysis for Real - Time Systems (RMARTS) Project at the SEI has dem- onstrated how to design, implement...troubleshoot, and maintain real - time systems using RMA. From 1987-1992, the project worked to develop the technology and encourage its widespread

Maternal-Newborn and Surgical Nurses’ Perceptions of Professional Autonomy During the Development of Shared Governance

DTIC Science & Technology

1993-01-01

women in general (Schutzenhofer, 1988b). Pinch (1981) and Gilligan (1979) noted that most developmental theorists have studied male development and...previous developmental stages . Men find identity through their work, while a woman’s identity is defined by relationships (Gilligan, 1977), since, until...was only .54, while the realistic behavior subscale produced an alpha of .70. Nunnally (1978) recommends that tools in early stages of development

Linear study of the nonmodal growth of drift waves in dusty plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manz, P.; Greiner, F.

2010-06-15

The main effect of dust on drift wave turbulence is the enhancement of the nonadiabaticity. Previous work found that nonmodal behavior is important in the nonadiabatic regime of the drift wave system. Here, the modal and nonmodal properties of the linear Hasegawa-Wakatani system of dusty plasmas are investigated. The non-normality of the linear evolution operator can lead to enhanced transient growth rates compared to the modal growth rates.

Behavioral health care for adolescents with poorly controlled diabetes via Skype: does working alliance remain intact?

PubMed

Freeman, Kurt A; Duke, Danny C; Harris, Michael A

2013-05-01

Increasingly various technologies are being tested to deliver behavioral health care. Delivering services via videoconferencing shows promise. Given that the patient-provider relationship is a strong predictor of patient adherence to medical regimens, addressing relationship quality when services are not delivered face-to-face is critical. To that end, we compared the therapeutic alliance when behavioral health care was delivered to youth with poorly controlled type 1 diabetes mellitus (T1DM) and their caregivers in-clinic with the same services delivered via Internet-based videoconferencing (i.e., Skype™). Seventy-one adolescents with poorly controlled T1DM (hemoglobin A1c ≥9%) and one of their caregivers received up to 10 sessions of a family-based behavioral health intervention previously shown to improve adherence to diabetes regimens and family functioning; 32 were randomized to the Skype condition. Youth and caregivers completed the working alliance inventory (WAI), a 36-item measure of therapeutic alliance, at the end of treatment. Additionally, the number of behavioral health sessions completed was tracked. No significant differences in WAI scores were found for those receiving behavioral health care via Skype versus in-clinic. Youth WAI goal and total scores were significantly associated with the number of sessions completed for those in the clinic group. Behavioral health can be delivered to youth with T1DM via Internet-based videoconferencing without significantly impacting the therapeutic relationship. Thus, for those adolescents with T1DM who require specialized behavioral health care that targets T1DM management, Internet-based teleconferencing represents a viable alternative to clinic-based care. © 2013 Diabetes Technology Society.

Behaving safely under pressure: The effects of job demands, resources, and safety climate on employee physical and psychosocial safety behavior.

PubMed

Bronkhorst, Babette

2015-12-01

Previous research has shown that employees who experience high job demands are more inclined to show unsafe behaviors in the workplace. In this paper, we examine why some employees behave safely when faced with these demands while others do not. We add to the literature by incorporating both physical and psychosocial safety climate in the job demands and resources (JD-R) model and extending it to include physical and psychosocial variants of safety behavior. Using a sample of 6230 health care employees nested within 52 organizations, we examined the relationship between job demands and (a) resources, (b) safety climate, and (c) safety behavior. We conducted multilevel analyses to test our hypotheses. Job demands (i.e., work pressure), job resources (i.e., job autonomy, supervisor support, and co-worker support) and safety climate (both physical and psychosocial safety climate) are directly associated with, respectively, lower and higher physical and psychosocial safety behavior. We also found some evidence that safety climate buffers the negative impact of job demands (i.e., work-family conflict and job insecurity) on safety behavior and strengthens the positive impact of job resources (i.e., co-worker support) on safety behavior. Regardless of whether the focus is physical or psychological safety, our results show that strengthening the safety climate within an organization can increase employees' safety behavior. Practical implication: An organization's safety climate is an optimal target of intervention to prevent and ameliorate negative physical and psychological health and safety outcomes, especially in times of uncertainty and change. Copyright © 2015 Elsevier Ltd and National Safety Council. All rights reserved.

Behavioral Health Care for Adolescents with Poorly Controlled Diabetes via Skype: Does Working Alliance Remain Intact?

PubMed Central

Freeman, Kurt A.; Duke, Danny C.; Harris, Michael A.

2013-01-01

Background: Increasingly various technologies are being tested to deliver behavioral health care. Delivering services via videoconferencing shows promise. Given that the patient–provider relationship is a strong predictor of patient adherence to medical regimens, addressing relationship quality when services are not delivered face-to-face is critical. To that end, we compared the therapeutic alliance when behavioral health care was delivered to youth with poorly controlled type 1 diabetes mellitus (T1DM) and their caregivers in-clinic with the same services delivered via Internet-based videoconferencing (i.e., Skype™). Methods: Seventy-one adolescents with poorly controlled T1DM (hemoglobin A1c ≥9%) and one of their caregivers received up to 10 sessions of a family-based behavioral health intervention previously shown to improve adherence to diabetes regimens and family functioning; 32 were randomized to the Skype condition. Youth and caregivers completed the working alliance inventory (WAI), a 36-item measure of therapeutic alliance, at the end of treatment. Additionally, the number of behavioral health sessions completed was tracked. Results: No significant differences in WAI scores were found for those receiving behavioral health care via Skype versus in-clinic. Youth WAI goal and total scores were significantly associated with the number of sessions completed for those in the clinic group. Conclusion: Behavioral health can be delivered to youth with T1DM via Internet-based videoconferencing without significantly impacting the therapeutic relationship. Thus, for those adolescents with T1DM who require specialized behavioral health care that targets T1DM management, Internet-based teleconferencing represents a viable alternative to clinic-based care. PMID:23759406

Attention Alters Neural Responses to Evocative Faces in Behaviorally Inhibited Adolescents

PubMed Central

Pérez-Edgar, Koraly; Roberson-Nay, Roxann; Hardin, Michael G.; Poeth, Kaitlin; Guyer, Amanda E.; Nelson, Eric E.; McClure, Erin B.; Henderson, Heather A.; Fox, Nathan A.; Pine, Daniel S.; Ernst, Monique

2007-01-01

Behavioral inhibition (BI) is a risk factor for anxiety disorders. While the two constructs bear behavioral similarities, previous work has not extended these parallels to the neural level. This study examined amygdala reactivity during a task previously used with clinically anxious adolescents. Adolescents were selected for enduring patterns of BI or non-inhibition (BN). We examined amygdala response to evocative emotion faces in BI (N=10, mean 12.8 years) and BN (N=17, mean 12.5 years) adolescents while systematically manipulating attention. Analyses focused on amygdala response during subjective ratings of internal fear (constrained attention) and passive viewing (unconstrained attention) during the presentation of emotion faces (Happy, Angry, Fearful, and Neutral). BI adolescents, relative to BN adolescents, showed exaggerated amygdala response during subjective fear ratings and deactivation during passive viewing, across all emotion faces. In addition, the BI group showed an abnormally high amygdala response to a task condition marked by novelty and uncertainty (i.e., rating fear state to a Happy face). Perturbations in amygdala function are evident in adolescents temperamentally at risk for anxiety. Attention state alters the underlying pattern of neural processing, potentially mediating the observed behavioral patterns across development. BI adolescents also show a heightened sensitivity to novelty and uncertainty, which has been linked to anxiety. These patterns of reactivity may help sustain early temperamental biases over time and contribute to the observed relation between BI and anxiety. PMID:17376704

Effect of Thermal Cycling on the Tensile Behavior of Polymer Composites Reinforced by Basalt and Carbon Fibers

NASA Astrophysics Data System (ADS)

Khalili, S. Mohammad Reza; Najafi, Moslem; Eslami-Farsani, Reza

2017-01-01

The aim of the present work was to investigate the effect of thermal cycling on the tensile behavior of three types of polymer-matrix composites — a phenolic resin reinforced with woven basalt fibers, woven carbon fibers, and hybrid basalt and carbon fibers — in an ambient environment. For this purpose, tensile tests were performed on specimens previously subjected to a certain number of thermal cycles. The ultimate tensile strength of the specimen reinforced with woven basalt fibers had by 5% after thermal cycling, but the strength of the specimen with woven carbon fibers had reduced to a value by 11% higher than that before thermal cycling.

Protonation-dependent base flipping in the catalytic triad of a small RNA

NASA Astrophysics Data System (ADS)

Sun, Zhaoxi; Wang, Xiaohui; Zhang, John Z. H.

2017-09-01

Protonation dependent base flipping in RNA has never been studied theoretically. In this work we studied protonation-dependent behavior of the base flipping in the catalytic triad of a single-stranded RNA which was previously characterized by NMR experiment. Molecular dynamics simulation reveals that the GA mismatch in this region accounts for this behavior. Free energy profiles show that the stable point for flipping dihedral shifts about 35° and the free energy barrier along the flipping pathway is elevated upon protonation. The orientation of Guanine from syn to anti conformation is coupled with protonation-dependent base flipping and G-HA+ base pair is formed under acidic condition.

Ferromagnetic resonance study of the non-stoichiometric double perovskite Sr2Fe1+xMo1-xO6

NASA Astrophysics Data System (ADS)

Medina, J. De La Torre; Piraux, L.; Soto, T. E.; Morales, R.; Navarro, O.

2018-02-01

In this work we report a ferromagnetic resonance study on the magnetic properties of double perovskite compounds fab-ricated by solid state reaction. Based on a mean field approach, along with morphological considerations, we accurately determined the saturation magnetization of the non-stoichiometric double perovskite Sr2Fe1+xMo1-xO6. Our approach has revealed a direct in-fluence of composition on the overall magnetic behavior of these materials, providing complementary experimental evidence that corroborates previous theoretical findings. The understanding of the influence of composition is of paramount importance for the design of ferromagnetic oxides with tunable magnetic and magneto-transport behavior.

SECULAR BEHAVIOR OF EXOPLANETS: SELF-CONSISTENCY AND COMPARISONS WITH THE PLANET-PLANET SCATTERING HYPOTHESIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Timpe, Miles; Barnes, Rory; Kopparapu, Ravikumar

2013-09-15

If mutual gravitational scattering among exoplanets occurs, then it may produce unique orbital properties. For example, two-planet systems that lie near the boundary between circulation and libration of their periapses could result if planet-planet scattering ejected a former third planet quickly, leaving one planet on an eccentric orbit and the other on a circular orbit. We first improve upon previous work that examined the apsidal behavior of known multiplanet systems by doubling the sample size and including observational uncertainties. This analysis recovers previous results that demonstrated that many systems lay on the apsidal boundary between libration and circulation. We thenmore » performed over 12,000 three-dimensional N-body simulations of hypothetical three-body systems that are unstable, but stabilize to two-body systems after an ejection. Using these synthetic two-planet systems, we test the planet-planet scattering hypothesis by comparing their apsidal behavior, over a range of viewing angles, to that of the observed systems and find that they are statistically consistent regardless of the multiplicity of the observed systems. Finally, we combine our results with previous studies to show that, from the sampled cases, the most likely planetary mass function prior to planet-planet scattering follows a power law with index -1.1. We find that this pre-scattering mass function predicts a mutual inclination frequency distribution that follows an exponential function with an index between -0.06 and -0.1.« less

Selective updating of working memory content modulates meso-cortico-striatal activity.

PubMed

Murty, Vishnu P; Sambataro, Fabio; Radulescu, Eugenia; Altamura, Mario; Iudicello, Jennifer; Zoltick, Bradley; Weinberger, Daniel R; Goldberg, Terry E; Mattay, Venkata S

2011-08-01

Accumulating evidence from non-human primates and computational modeling suggests that dopaminergic signals arising from the midbrain (substantia nigra/ventral tegmental area) mediate striatal gating of the prefrontal cortex during the selective updating of working memory. Using event-related functional magnetic resonance imaging, we explored the neural mechanisms underlying the selective updating of information stored in working memory. Participants were scanned during a novel working memory task that parses the neurophysiology underlying working memory maintenance, overwriting, and selective updating. Analyses revealed a functionally coupled network consisting of a midbrain region encompassing the substantia nigra/ventral tegmental area, caudate, and dorsolateral prefrontal cortex that was selectively engaged during working memory updating compared to the overwriting and maintenance of working memory content. Further analysis revealed differential midbrain-dorsolateral prefrontal interactions during selective updating between low-performing and high-performing individuals. These findings highlight the role of this meso-cortico-striatal circuitry during the selective updating of working memory in humans, which complements previous research in behavioral neuroscience and computational modeling. Published by Elsevier Inc.

Workplace social capital, mental health and health behaviors among Brazilian female workers.

PubMed

Pattussi, Marcos Pascoal; Olinto, Maria Teresa Anselmo; Canuto, Raquel; da Silva Garcez, Anderson; Paniz, Vera Maria Vieira; Kawachi, Ichiro

2016-09-01

Previous studies have investigated the relationship between workplace social capital and mental health, yet few have sought to examine the mediating mechanisms. We sought to explore the role of workplace social capital on health related behaviors and on mental health among female employees in Brazil. A cross-sectional study was undertaken with 553 women aged 28-50 years working in the production line of a poultry processing plant. We assessed workplace social capital, common mental disorders, stress (Perceived Stress Scale) and health related behaviors (physical activity, healthy eating habits and co-occurrence of risk behaviors). We used structural equation modeling to clarify relationships between exposures, outcomes, and mediating variables. Our model demonstrated a direct effect of social capital on the outcomes studied. Higher workplace social capital was associated with lower stress and common mental disorders as well as more favorable health-related behaviors. Our model also showed an indirect effect of social capital on mental health and on behaviors that was mediated by lower levels of perceived stress. Workplace social cohesion may play an important role in the promotion of mental health and healthy behaviors among women employees.

Examining relationships between multiple health risk behaviors, well-being, and productivity.

PubMed

Evers, Kerry E; Castle, Patricia H; Prochaska, James O; Prochaska, Janice M

2014-06-01

Traditionally, the concept of health promotion has emphasized the reduction of health risk behaviors to reduce disease and impairment. Well-being research expands this focus to include positive constructs such as thriving, productivity, life-evaluation, and emotional and physical health. The objective of the present study was to examine the relationships between health risk behaviors and specific measures of individual well-being. Participants (N = 790) from 49 states completed a one-time online assessment that included the Life-Evaluation Index, Emotional and Physical Health Ladders, the Health Risk Intervention Assessment, and the Work Productivity and Activity Improvement Questionnaire for General Health. Life Evaluation and physical and emotional health were all inversely related to the number of health risk behaviors, with higher well-being scores associated with lower number of risk behaviors. Across the three Life Evaluation categories (Suffering, Struggling, and Thriving) the number of health risk behaviors decreased, productivity loss decreased, and emotional and physical health increased. The results add to previous research on how reducing multiple health risk behaviors can be combined with well-being, i.e., an emphasis on increasing life-evaluation, emotional and physical health, better functioning, and productivity.

Characterization of the mechanical properties of resected porcine organ tissue using optical fiber photoelastic polarimetry.

PubMed

Hudnut, Alexa W; Babaei, Behzad; Liu, Sonya; Larson, Brent K; Mumenthaler, Shannon M; Armani, Andrea M

2017-10-01

Characterizing the mechanical behavior of living tissue presents an interesting challenge because the elasticity varies by eight orders of magnitude, from 50Pa to 5GPa. In the present work, a non-destructive optical fiber photoelastic polarimetry system is used to analyze the mechanical properties of resected samples from porcine liver, kidney, and pancreas. Using a quasi-linear viscoelastic fit, the elastic modulus values of the different organ systems are determined. They are in agreement with previous work. In addition, a histological assessment of compressed and uncompressed tissues confirms that the tissue is not damaged during testing.

Secondary scattering on the intensity dependence of the capture velocity in a magneto-optical trap

NASA Astrophysics Data System (ADS)

Loos, M. R.; Massardo, S. B.; de S. Zanon, R. A.; de Oliveira, A. L.

2005-08-01

In this work, we consider a three-dimensional model to simulate the capture velocity behavior in a sample of cold-trapped sodium atoms as a function of the trapping laser intensity. We expand on previous work [V. S. Bagnato, L. G. Marcassa, S. G. Miranda, S. R. Muniz, and A. L. de Oliveira, Phys. Rev. A 62, 013404 (2000)] by calculating the capture velocity over a broad range of light intensities considering the secondary scattering in a magneto-optical trap. Our calculations are in a good agreement with recent measured values [S. R. Muniz , Phys. Rev. A 65, 015402 (2001)].

Recent Progress on Modeling Slip Deformation in Shape Memory Alloys

NASA Astrophysics Data System (ADS)

Sehitoglu, H.; Alkan, S.

2018-03-01

This paper presents an overview of slip deformation in shape memory alloys. The performance of shape memory alloys depends on their slip resistance often quantified through the Critical Resolved Shear Stress (CRSS) or the flow stress. We highlight previous studies that identify the active slip systems and then proceed to show how non- Schmid effects can be dominant in shape memory slip behavior. The work is mostly derived from our recent studies while we highlight key earlier works on slip deformation. We finally discuss the implications of understanding the role of slip on curtailing the transformation strains and also the temperature range over which superelasticity prevails.

Work and Non-Work Physical Activity Predict Real-Time Smoking Level and Urges in Young Adults.

PubMed

Nadell, Melanie J; Mermelstein, Robin J; Hedeker, Donald; Marquez, David X

2015-07-01

Physical activity (PA) and smoking are inversely related. However, evidence suggests that some types of PA, namely work-related PA, may show an opposite effect. Despite growing knowledge, there remains a paucity of studies examining the context of these behaviors in naturalistic settings or in young adults, a high-risk group for escalation. Participants were 188 young adults (mean age = 21.32; 53.2% female; 91% current smokers) who participated in an electronic diary week to assess daily smoking and urges and a PA recall to examine daily PA. PA was coded into non-work-related and work-related activity to examine differential effects. We considered both participants' weekly average PA and their daily deviations from their average. Mixed-effects regression models revealed that higher weekly average non-work PA was associated with lower smoking level and urges. Daily deviations in non-work PA did not predict urges; however, increased daily non-work PA relative to participants' weekly average was associated with lower smoking for females but higher levels for males. Regarding work PA, only higher weekly average work PA was associated with higher smoking level for both genders; work PA did not predict urges. Results extend previous literature by documenting differential associations between non-work and work PA and young adult smoking and suggest that young adults engaged in work PA should be considered a high-risk group for escalation. Findings provide theoretical and clinical implications for the use of PA in intervention and highlight the necessity of considering PA as a multidimensional construct when examining its links to health behavior. © The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A continuous time-resolved measure decoded from EEG oscillatory activity predicts working memory task performance.

PubMed

Astrand, Elaine

2018-06-01

Working memory (WM), crucial for successful behavioral performance in most of our everyday activities, holds a central role in goal-directed behavior. As task demands increase, inducing higher WM load, maintaining successful behavioral performance requires the brain to work at the higher end of its capacity. Because it is depending on both external and internal factors, individual WM load likely varies in a continuous fashion. The feasibility to extract such a continuous measure in time that correlates to behavioral performance during a working memory task remains unsolved. Multivariate pattern decoding was used to test whether a decoder constructed from two discrete levels of WM load can generalize to produce a continuous measure that predicts task performance. Specifically, a linear regression with L2-regularization was chosen with input features from EEG oscillatory activity recorded from healthy participants while performing the n-back task, [Formula: see text]. The feasibility to extract a continuous time-resolved measure that correlates positively to trial-by-trial working memory task performance is demonstrated (r  =  0.47, p  <  0.05). It is furthermore shown that this measure allows to predict task performance before action (r  =  0.49, p  <  0.05). We show that the extracted continuous measure enables to study the temporal dynamics of the complex activation pattern of WM encoding during the n-back task. Specifically, temporally precise contributions of different spectral features are observed which extends previous findings of traditional univariate approaches. These results constitute an important contribution towards a wide range of applications in the field of cognitive brain-machine interfaces. Monitoring mental processes related to attention and WM load to reduce the risk of committing errors in high-risk environments could potentially prevent many devastating consequences or using the continuous measure as neurofeedback opens up new possibilities to develop novel rehabilitation techniques for individuals with degraded WM capacity.

A continuous time-resolved measure decoded from EEG oscillatory activity predicts working memory task performance

NASA Astrophysics Data System (ADS)

Astrand, Elaine

2018-06-01

Objective. Working memory (WM), crucial for successful behavioral performance in most of our everyday activities, holds a central role in goal-directed behavior. As task demands increase, inducing higher WM load, maintaining successful behavioral performance requires the brain to work at the higher end of its capacity. Because it is depending on both external and internal factors, individual WM load likely varies in a continuous fashion. The feasibility to extract such a continuous measure in time that correlates to behavioral performance during a working memory task remains unsolved. Approach. Multivariate pattern decoding was used to test whether a decoder constructed from two discrete levels of WM load can generalize to produce a continuous measure that predicts task performance. Specifically, a linear regression with L2-regularization was chosen with input features from EEG oscillatory activity recorded from healthy participants while performing the n-back task, n\\in [1,2] . Main results. The feasibility to extract a continuous time-resolved measure that correlates positively to trial-by-trial working memory task performance is demonstrated (r  =  0.47, p  <  0.05). It is furthermore shown that this measure allows to predict task performance before action (r  =  0.49, p  <  0.05). We show that the extracted continuous measure enables to study the temporal dynamics of the complex activation pattern of WM encoding during the n-back task. Specifically, temporally precise contributions of different spectral features are observed which extends previous findings of traditional univariate approaches. Significance. These results constitute an important contribution towards a wide range of applications in the field of cognitive brain–machine interfaces. Monitoring mental processes related to attention and WM load to reduce the risk of committing errors in high-risk environments could potentially prevent many devastating consequences or using the continuous measure as neurofeedback opens up new possibilities to develop novel rehabilitation techniques for individuals with degraded WM capacity.

Directed Forgetting and Directed Remembering in Visual Working Memory

PubMed Central

Williams, Melonie; Woodman, Geoffrey F.

2013-01-01

A defining characteristic of visual working memory is its limited capacity. This means that it is crucial to maintain only the most relevant information in visual working memory. However, empirical research is mixed as to whether it is possible to selectively maintain a subset of the information previously encoded into visual working memory. Here we examined the ability of subjects to use cues to either forget or remember a subset of the information already stored in visual working memory. In Experiment 1, participants were cued to either forget or remember one of two groups of colored squares during a change-detection task. We found that both types of cues aided performance in the visual working memory task, but that observers benefited more from a cue to remember than a cue to forget a subset of the objects. In Experiment 2, we show that the previous findings, which indicated that directed-forgetting cues are ineffective, were likely due to the presence of invalid cues that appear to cause observers to disregard such cues as unreliable. In Experiment 3, we recorded event-related potentials (ERPs) and show that an electrophysiological index of focused maintenance is elicited by cues that indicate which subset of information in visual working memory needs to be remembered, ruling out alternative explanations of the behavioral effects of retention-interval cues. The present findings demonstrate that observers can focus maintenance mechanisms on specific objects in visual working memory based on cues indicating future task relevance. PMID:22409182

Maximum Likelihood Time-of-Arrival Estimation of Optical Pulses via Photon-Counting Photodetectors

NASA Technical Reports Server (NTRS)

Erkmen, Baris I.; Moision, Bruce E.

2010-01-01

Many optical imaging, ranging, and communications systems rely on the estimation of the arrival time of an optical pulse. Recently, such systems have been increasingly employing photon-counting photodetector technology, which changes the statistics of the observed photocurrent. This requires time-of-arrival estimators to be developed and their performances characterized. The statistics of the output of an ideal photodetector, which are well modeled as a Poisson point process, were considered. An analytical model was developed for the mean-square error of the maximum likelihood (ML) estimator, demonstrating two phenomena that cause deviations from the minimum achievable error at low signal power. An approximation was derived to the threshold at which the ML estimator essentially fails to provide better than a random guess of the pulse arrival time. Comparing the analytic model performance predictions to those obtained via simulations, it was verified that the model accurately predicts the ML performance over all regimes considered. There is little prior art that attempts to understand the fundamental limitations to time-of-arrival estimation from Poisson statistics. This work establishes both a simple mathematical description of the error behavior, and the associated physical processes that yield this behavior. Previous work on mean-square error characterization for ML estimators has predominantly focused on additive Gaussian noise. This work demonstrates that the discrete nature of the Poisson noise process leads to a distinctly different error behavior.

Viscoelastic behavior of discrete human collagen fibrils.

PubMed

Svensson, René B; Hassenkam, Tue; Hansen, Philip; Peter Magnusson, S

2010-01-01

Whole tendon and fibril bundles display viscoelastic behavior, but to the best of our knowledge this property has not been directly measured in single human tendon fibrils. In the present work an atomic force microscopy (AFM) approach was used for tensile testing of two human patellar tendon fibrils. Fibrils were obtained from intact human fascicles, without any pre-treatment besides frozen storage. In the dry state a single isolated fibril was anchored to a substrate using epoxy glue, and the end of the fibril was glued on to an AFM cantilever for tensile testing. In phosphate buffered saline, cyclic testing was performed in the pre-yield region at different strain rates, and the elastic response was determined by a stepwise stress relaxation test. The elastic stress-strain response corresponded to a second-order polynomial fit, while the viscous response showed a linear dependence on the strain. The slope of the viscous response showed a strain rate dependence corresponding to a power function of powers 0.242 and 0.168 for the two patellar tendon fibrils, respectively. In conclusion, the present work provides direct evidence of viscoelastic behavior at the single fibril level, which has not been previously measured.

Scaling analysis of the non-Abelian quasiparticle tunneling in Z}}_k FQH states

NASA Astrophysics Data System (ADS)

Li, Qi; Jiang, Na; Wan, Xin; Hu, Zi-Xiang

2018-06-01

Quasiparticle tunneling between two counter propagating edges through point contacts could provide information on its statistics. Previous study of the short distance tunneling displays a scaling behavior, especially in the conformal limit with zero tunneling distance. The scaling exponents for the non-Abelian quasiparticle tunneling exhibit some non-trivial behaviors. In this work, we revisit the quasiparticle tunneling amplitudes and their scaling behavior in a full range of the tunneling distance by putting the electrons on the surface of a cylinder. The edge–edge distance can be smoothly tuned by varying the aspect ratio for a finite size cylinder. We analyze the scaling behavior of the quasiparticles for the Read–Rezayi states for and 4 both in the short and long tunneling distance region. The finite size scaling analysis automatically gives us a critical length scale where the anomalous correction appears. We demonstrate this length scale is related to the size of the quasiparticle at which the backscattering between two counter propagating edges starts to be significant.

Strategies for the Integration of Cough and Swallow to Maintain Airway Protection in Humans.

PubMed

Huff, Alyssa; Reed, Mitchell D; Smith, Barbara K; Brown, Edward H; Ovechkin, Alexander V; Pitts, Teresa

2018-06-20

Airway protective behaviors, like cough and swallow, deteriorate in many populations suffering from neurologic disorders. While coordination of these behaviors has been investigated in an animal model, it has not been tested in humans. We used a novel protocol, adapted from previous work in the cat, to assess cough and swallow independently and their coordination strategies in seven healthy males (26 ± 6 years). Surface electromyograms of the submental complex and external oblique complex, spirometry, and thoracic and abdominal wall kinematics, were used to evaluate the timing of swallow, cough, and breathing as well as lung volume (LV) during these behaviors. Unlike the cat, there was significant variability in the cough-swallow phase preference; however, there was a targeted LV range in which swallow occurred. These results give insight into the differences between the cat and human models in airway protective strategies related to the coordination of cough and swallow behaviors, allowing for better understanding of dystussia and dysphagia.

A Framework to Describe, Analyze and Generate Interactive Motor Behaviors

PubMed Central

Jarrassé, Nathanaël; Charalambous, Themistoklis; Burdet, Etienne

2012-01-01

While motor interaction between a robot and a human, or between humans, has important implications for society as well as promising applications, little research has been devoted to its investigation. In particular, it is important to understand the different ways two agents can interact and generate suitable interactive behaviors. Towards this end, this paper introduces a framework for the description and implementation of interactive behaviors of two agents performing a joint motor task. A taxonomy of interactive behaviors is introduced, which can classify tasks and cost functions that represent the way each agent interacts. The role of an agent interacting during a motor task can be directly explained from the cost function this agent is minimizing and the task constraints. The novel framework is used to interpret and classify previous works on human-robot motor interaction. Its implementation power is demonstrated by simulating representative interactions of two humans. It also enables us to interpret and explain the role distribution and switching between roles when performing joint motor tasks. PMID:23226231

Behavior and structure of metal vapor arc plasma between molten electrodes

NASA Astrophysics Data System (ADS)

Zanner, F. J.; Williamson, R. L.; Hareland, W. A.; Bertram, L. A.

A metal vapor arc is utilized in the industrially important vacuum arc remelting (VAR) process to produce materials by melting and resolidification which have improved structure and chemical homogeneity. Homogeneity is dependent on achieving quasi-steady conditions in the plasma because of its thermal and MHD coupling with the molten pool atop the ingot. Optimal operating conditions of low pressure (approx. = 0.01 torr) and short electrode gap (less than 15 mm) produce a diffuse arc and cathode spot behavior similar to that observed for the vacuum breaker arc. Under these conditions the arc provides a quasi-steady heat source that is considered to be the bench mark arc of the VAR process. Previous work has shown that deviation from the bench mark arc behavior can occur under production conditions, and is caused by electrode irregularities and liberation of gases such as CO from the molten pool. This study is an effort to characterize these behavioral deviations and discover operational conditions which stabilize the bench mark arc.

Noradrenaline and dopamine neurons in the reward/effort trade-off: a direct electrophysiological comparison in behaving monkeys.

PubMed

Varazzani, Chiara; San-Galli, Aurore; Gilardeau, Sophie; Bouret, Sebastien

2015-05-20

Motivation determines multiple aspects of behavior, including action selection and energization of behavior. Several components of the underlying neural systems have been examined closely, but the specific role of the different neuromodulatory systems in motivation remains unclear. Here, we compare directly the activity of dopaminergic neurons from the substantia nigra pars compacta and noradrenergic neurons from the locus coeruleus in monkeys performing a task manipulating the reward/effort trade-off. Consistent with previous reports, dopaminergic neurons encoded the expected reward, but we found that they also anticipated the upcoming effort cost in connection with its negative influence on action selection. Conversely, the firing of noradrenergic neurons increased with both pupil dilation and effort production in relation to the energization of behavior. Therefore, this work underlines the contribution of dopamine to effort-based decision making and uncovers a specific role of noradrenaline in energizing behavior to face challenges. Copyright © 2015 the authors 0270-6474/15/357866-12$15.00/0.

A framework to describe, analyze and generate interactive motor behaviors.

PubMed

Jarrassé, Nathanaël; Charalambous, Themistoklis; Burdet, Etienne

2012-01-01

While motor interaction between a robot and a human, or between humans, has important implications for society as well as promising applications, little research has been devoted to its investigation. In particular, it is important to understand the different ways two agents can interact and generate suitable interactive behaviors. Towards this end, this paper introduces a framework for the description and implementation of interactive behaviors of two agents performing a joint motor task. A taxonomy of interactive behaviors is introduced, which can classify tasks and cost functions that represent the way each agent interacts. The role of an agent interacting during a motor task can be directly explained from the cost function this agent is minimizing and the task constraints. The novel framework is used to interpret and classify previous works on human-robot motor interaction. Its implementation power is demonstrated by simulating representative interactions of two humans. It also enables us to interpret and explain the role distribution and switching between roles when performing joint motor tasks.

Trait liabilities and specific promotive processes in psychopathology: The example of suicidal behavior.

PubMed

Buchman-Schmitt, Jennifer M; Brislin, Sarah J; Venables, Noah C; Joiner, Thomas E; Patrick, Christopher J

2017-07-01

The RDoC matrix framework calls for investigation of mental health problems through analysis of core biobehavioral processes quantified and studied across multiple domains of measurement. Critics have raised concerns about RDoC, including overemphasis on biological concepts/measures and disregard for the principle of multifinality, which holds that identical biological predispositions can give rise to differing behavioral outcomes. The current work illustrates an ontogenetic process approach to addressing these concerns, focusing on biobehavioral traits corresponding to RDoC constructs as predictors, and suicidal behavior as the outcome variable. Data were collected from a young adult sample (N=105), preselected to enhance rates of suicidality. Participants completed self-report measures of traits (threat sensitivity, response inhibition) and suicide-specific processes. We show that previously reported associations for traits of threat sensitivity and weak inhibitory control with suicidal behavior are mediated by more specific suicide-promoting processes-namely, thwarted belongingness, perceived burdensomeness, and capability for suicide. The sample was relatively small and the data were cross-sectional, limiting conclusions that can be drawn from the mediation analyses. Given prior research documenting neurophysiological as well as psychological bases to these trait dispositions, the current work sets the stage for an intensive RDoC-oriented investigation of suicidal tendencies in which both traits and suicide-promoting processes are quantified using indicators from different domains of measurement. More broadly, this work illustrates how an RDoC research approach can contribute to a nuanced understanding of specific clinical problems, through consideration of how general biobehavioral liabilities interface with distinct problem-promoting processes. Copyright © 2016 Elsevier B.V. All rights reserved.

Autistic-spectrum disorders in Down syndrome: further delineation and distinction from other behavioral abnormalities.

PubMed

Carter, John C; Capone, George T; Gray, Robert M; Cox, Christiane S; Kaufmann, Walter E

2007-01-05

The present study extends our previous work characterizing the behavioral features of autistic-spectrum disorder (ASD) in Down syndrome (DS) using the Aberrant Behavior Checklist (ABC) and Autism Behavior Checklist (AutBehav). We examined which specific behaviors distinguished the behavioral phenotype of DS + ASD from other aberrant behavior disorders in DS, by determining the relative contribution of ABC and AutBehav subscales and items to the diagnosis of ASD. A total of 127 subjects (aged 2-24 years; mean age: 8.4 years; approximately 70% male), comprising: a cohort of 64 children and adolescents with DS and co-morbid ASD (DS + ASD), 19 with DS and stereotypic movement disorder (DS + SMD), 18 with DS and disruptive behaviors (DS + DB), and 26 with DS and no co-morbid behavior disorders (DS + none) were examined using the aforementioned measures of aberrant behavior. We found that subjects with DS + ASD showed the most severe aberrant behavior, especially stereotypy compared to DS + none and lethargy/social withdrawal and relating problems compared to DS + SMD. Specifically, relatively simple stereotypic behavior differentiated DS + ASD from DS + DB, whereas odd/bizarre stereotypic and anxious behavior characterized DS + ASD relative to DS + SMD and DS + none. Additionally, in a subset of subjects with DS + ASD and anxiety, social withdrawal was particularly pronounced. Overall, our findings indicate that a diagnosis of DS + ASD represents a distinctive set of aberrant behaviors marked by characteristic odd/bizarre stereotypic behavior, anxiety, and social withdrawal.

Sensitivity analysis as an aid in modelling and control of (poorly-defined) ecological systems. [closed ecological systems

NASA Technical Reports Server (NTRS)

Hornberger, G. M.; Rastetter, E. B.

1982-01-01

A literature review of the use of sensitivity analyses in modelling nonlinear, ill-defined systems, such as ecological interactions is presented. Discussions of previous work, and a proposed scheme for generalized sensitivity analysis applicable to ill-defined systems are included. This scheme considers classes of mathematical models, problem-defining behavior, analysis procedures (especially the use of Monte-Carlo methods), sensitivity ranking of parameters, and extension to control system design.

The influence of previous low back trouble, general health, and working conditions on future sick-listing because of low back trouble. A 15-year follow-up study of risk indicators for self-reported sick-listing caused by low back trouble.

PubMed

Müller, C F; Monrad, T; Biering-Sørensen, F; Darre, E; Deis, A; Kryger, P

1999-08-01

A 15-year follow-up study. To find risk indicators for self-reported sick-listing because of low back trouble and to evaluate which variables were the most important indicators of work incapacity resulting from low back trouble during the follow-up period of 15 years. The initial data were obtained from a health survey conducted in a general population from the Municipality of Glostrup, Denmark. The follow-up data included information from the Central Person Register, the Early Retirement Pension Register, and a postal questionnaire regarding self-reported sick-listing because of low back trouble. An epidemiologic study, in which logistic regression analyses were used for evaluation of the data. The model used consisted of the variable in question, age, gender, and previous experience of low back trouble, along with interactions. It was found that 22 of 37 variables were risk indicators for later self-reported sick-listing because of low back trouble during the preceding year or the 7 years before the date of follow-up evaluation. In analyzing the most significant variables simultaneously, it was found that information from the initial investigation about sick-listing in general during the previous 10 years, sciatic pain, use of analgesics for low back trouble, previous sick-listing because of low back trouble, and occupation were the most important risk indicators for self-reported work incapacity resulting from low back trouble during the follow-up period of 15 years. Findings showed that the strongest prognostic indicators of later sick-listing because of low back trouble involve information from the person about previous sick-listing behavior in general and previous experience of low back trouble episodes, especially if these had been accompanied by sciatic pain, use of analgesics, or previous low back trouble sick-listing.

Minimizing Restraint and Seclusion in Schools: A Response to Beaudoin and Moore.

PubMed

Walker, Virginia L; Pinkelman, Sarah E

2018-06-01

Increasing efforts have been made in the field of special education to identify positive, evidence-based practices (EBPs) to meet the needs of students who engage in problem behavior, with a major goal being to eliminate or limit the use of reactive measures such as restraint and seclusion ( Snell & Walker, 2014 ). Various stakeholders, including families and self-advocates, have voiced concerns about the dangers of restraint and seclusion and the lack of protection afforded to students who engage in severe problem behavior. In the previous article in this issue of Intellectual and Developmental Disabilities, Beaudoin and Moore (2018) echo these concerns in their account of a family's experience with restraint as told from the perspective of a father whose son was subjected to restraint, resulting in a number of adverse short- and long-term consequences that affected the entire family. In response to Beaudoin and Moore, we provide readers with a brief review of the current status of restraint and seclusion in school settings and evidence-based strategies that can be used to address severe problem behavior and reduce the need for restraint and seclusion. For readers interested in exploring restraint and seclusion in greater depth, we suggest recent work by Trader and colleagues (2017) . We also have outlined guidelines for behavior support planning that should be considered by various stakeholders as educators work toward establishing safe and supportive school environments that address a wide range of student behavioral needs.

The Pizzagame: A virtual public goods game to assess cooperative behavior in children and adolescents.

PubMed

Keil, Jan; Michel, Andrea; Sticca, Fabio; Leipold, Kristina; Klein, Annette M; Sierau, Susan; von Klitzing, Kai; White, Lars O

2017-08-01

Social dilemmas are characterized by conflicts between immediate self-interest and long-term collective goals. Although such conflicts lie at the heart of various challenging social interactions, we know little about how cooperation in these situations develops. To extend work on social dilemmas to child and adolescent samples, we developed an age-appropriate computer task (the Pizzagame) with the structural features of a public goods game (PGG). We administered the Pizzagame to a sample of 191 children 9 to 16 years of age. Subjects were led to believe they were playing the game over the Internet with three sets of two same-aged, same-sex co-players. In fact, the co-players were computer-generated and programmed to expose children to three consecutive conditions: (1) a cooperative strategy, (2) a selfish strategy, and (3) divergent cooperative-selfish strategies. Supporting the validity of the Pizzagame, our results revealed that children and adolescents displayed conditional cooperation, such that their contributions rose with the increasing cooperativeness of their co-players. Age and gender did not influence children and adolescents' cooperative behavior within each condition. However, older children adapted their behavior more flexibly between conditions to parallel the strategies of their co-players. These results support the utility of the Pizzagame as a feasible, reliable, and valid instrument for assessing and quantifying child and adolescent cooperative behavior. Moreover, these findings extend previous work showing that age influences cooperative behavior in the PGG.

Internal migration to Nairobi's slums: linking migrant streams to sexual risk behavior.

PubMed

Greif, Meredith J; Nii-Amoo Dodoo, F

2011-01-01

Despite what is currently the most rapid urbanization on the globe, an alarming growth of impoverished urban slum settlements in Africa, and the highest rates of HIV in the world - with greater prevalence in urban than rural areas - insufficient attention has been paid to the relationship between urban poverty and risky sexual behavior. Although emerging research has focused on how slum residence is linked to risky behavior, there is a paucity of work on how migration to slums is related to risky sex. Using a sample of sexually active women from the 2000 Nairobi Cross-Sectional Slum Survey (NCSS), this paper demonstrates that the relationship between slum residence and risky behavior is a multifaceted one. Beyond the effect of current residence in slums migratory factors, specifically previous place of residence and length of time since arrival, prove to be significant cofactors, with the effect of the former conditioned by the latter. Perhaps more importantly, where migrants moved from appears to influence risky behavior in a non-uniform manner. Copyright © 2010 Elsevier Ltd. All rights reserved.

Impulsive Choice in Mice Lacking Paternal Expression of Grb10 Suggests Intragenomic Conflict in Behavior.

PubMed

Dent, Claire L; Humby, Trevor; Lewis, Katie; Ward, Andrew; Fischer-Colbrie, Reiner; Wilkinson, Lawrence S; Wilkins, Jon F; Isles, Anthony R

2018-05-01

Imprinted genes are expressed from one parental allele only as a consequence of epigenetic events that take place in the mammalian germ line and are thought to have evolved through intragenomic conflict between parental alleles. We demonstrate, for the first time, oppositional effects of imprinted genes on brain and behavior. Specifically, we show that mice lacking paternal Grb10 make fewer impulsive choices, with no dissociable effects on a separate measure of impulsive action. Taken together with previous work showing that mice lacking maternal Nesp55 make more impulsive choices, this suggests that impulsive choice behavior is a substrate for the action of genomic imprinting. Moreover, the contrasting effect of these two genes suggests that impulsive choices are subject to intragenomic conflict and that maternal and paternal interests pull this behavior in opposite directions. Finally, these data may also indicate that an imbalance in expression of imprinted genes contributes to pathological conditions such as gambling and drug addiction, where impulsive behavior becomes maladaptive. Copyright © 2018 Dent et al.

Spontaneous revisitation during visual exploration as a link among strategic behavior, learning, and the hippocampus.

PubMed

Voss, Joel L; Warren, David E; Gonsalves, Brian D; Federmeier, Kara D; Tranel, Dan; Cohen, Neal J

2011-08-02

Effective exploratory behaviors involve continuous updating of sensory sampling to optimize the efficacy of information gathering. Despite some work on this issue in animals, little information exists regarding the cognitive or neural mechanisms for this sort of behavioral optimization in humans. Here we examined a visual exploration phenomenon that occurred when human subjects studying an array of objects spontaneously looked "backward" in their scanning paths to view recently seen objects again. This "spontaneous revisitation" of recently viewed objects was associated with enhanced hippocampal activity and superior subsequent memory performance in healthy participants, but occurred only rarely in amnesic patients with severe damage to the hippocampus. These findings demonstrate the necessity of the hippocampus not just in the aspects of long-term memory with which it has been associated previously, but also in the short-term adaptive control of behavior. Functional neuroimaging showed hippocampal engagement occurring in conjunction with frontocerebellar circuits, thereby revealing some of the larger brain circuitry essential for the strategic deployment of information-seeking behaviors that optimize learning.

Innovativeness and the effects of urbanization on risk-taking behaviors in wild Barbados birds.

PubMed

Ducatez, Simon; Audet, Jean-Nicolas; Rodriguez, Jordi Ros; Kayello, Lima; Lefebvre, Louis

2017-01-01

The effects of urbanization on avian cognition remain poorly understood. Risk-taking behaviors like boldness, neophobia and flight distance are thought to affect opportunism and innovativeness, and should also vary with urbanization. Here, we investigate variation in risk-taking behaviors in the field in an avian assemblage of nine species that forage together in Barbados and for which innovation rate is known from previous work. We predicted that birds from highly urbanized areas would show more risk-taking behavior than conspecifics from less urbanized parts of the island and that the differences would be strongest in the most innovative of the species. Overall, we found that urban birds are bolder, less neophobic and have shorter flight distances than their less urbanized conspecifics. Additionally, we detected between-species differences in the effect of urbanization on flight distance, more innovative species showing smaller differences in flight distance between areas. Our results suggest that, within successful urban colonizers, species differences in innovativeness may affect the way species change their risk-taking behaviors in response to the urban environment.

Use of photostress and strain gages to analyze behavior of weldments and use of photostress and strain gages to analyze behavior of an aft skirt test specimen

NASA Technical Reports Server (NTRS)

Gambrell, S. C.; Karr, Gerald R.

1993-01-01

Previous work using Photostress on TIG welded, heat treated specimens of 2219-T87 parent material and 2319 weld material indicated that behavior of the joint can be highly irregular and non-uniform. Welded joints 1.40 inches thick exhibited a totally non-uniform behavior through the weld thickness with the 'wide' side of the weld being much more ductile than the 'narrow' side. It is believed that this difference in behavior through the weld is, in part, caused by procedures used when laying the weld bead. Joints similar to weldments in references 1 and 2 are an integral part of the aft skirt of the SRB of the shuttle. Since the ultimate safety factor for the lower portion of the weld is below the minimum required safety factor, a photostress analysis of this lower portion will be conducted in the vicinity of the weld. A test program using photostress will be conducted in accordance with the project planning document entitled 'Photostress Evaluation Requirements for AFT Skirt Test Article No. 4'.

Learning and exploration in action-perception loops.

PubMed

Little, Daniel Y; Sommer, Friedrich T

2013-01-01

Discovering the structure underlying observed data is a recurring problem in machine learning with important applications in neuroscience. It is also a primary function of the brain. When data can be actively collected in the context of a closed action-perception loop, behavior becomes a critical determinant of learning efficiency. Psychologists studying exploration and curiosity in humans and animals have long argued that learning itself is a primary motivator of behavior. However, the theoretical basis of learning-driven behavior is not well understood. Previous computational studies of behavior have largely focused on the control problem of maximizing acquisition of rewards and have treated learning the structure of data as a secondary objective. Here, we study exploration in the absence of external reward feedback. Instead, we take the quality of an agent's learned internal model to be the primary objective. In a simple probabilistic framework, we derive a Bayesian estimate for the amount of information about the environment an agent can expect to receive by taking an action, a measure we term the predicted information gain (PIG). We develop exploration strategies that approximately maximize PIG. One strategy based on value-iteration consistently learns faster than previously developed reward-free exploration strategies across a diverse range of environments. Psychologists believe the evolutionary advantage of learning-driven exploration lies in the generalized utility of an accurate internal model. Consistent with this hypothesis, we demonstrate that agents which learn more efficiently during exploration are later better able to accomplish a range of goal-directed tasks. We will conclude by discussing how our work elucidates the explorative behaviors of animals and humans, its relationship to other computational models of behavior, and its potential application to experimental design, such as in closed-loop neurophysiology studies.

Long-term effects of a single exposure to stress in adult rats on behavior and hypothalamic-pituitary-adrenal responsiveness: comparison of two outbred rat strains.

PubMed

Belda, Xavier; Márquez, Cristina; Armario, Antonio

2004-10-05

We have previously observed that a single exposure to immobilization (IMO), a severe stressor, caused long-term (days to weeks) desensitization of the response of the hypothalamic-pituitary-adrenal (HPA) axis to the homotypic stressor, with no changes in behavioral reactivity to novel environments. In contrast, other laboratories have reported that a single exposure to footshock induced a long-term sensitization of both HPA and behavioral responses to novel environments. To test whether these apparent discrepancies can be explained by the use of different stressors or different strains of rats, we studied in the present work the long-term effects of a single exposure to two different stressors (footshock or IMO) in two different strains of rats (Sprague-Dawley from Iffa-Credo and Wistar rats from Harlan). We found that both strains showed desensitization of the HPA response to the same (homotypic) stressor after a previous exposure to either shock or IMO. The long-term effects were higher after IMO than shock. No major changes in behavior in two novel environments (circular corridor, CC and elevated plus-maze, EPM) were observed after a single exposure to shock or IMO in neither strain, despite the fact that shocked rats showed a conditioned freezing response to the shock boxes. The present results demonstrate that long-term stress-induced desensitization of the HPA axis is a reliable phenomenon that can be observed with different stressors and strains. However, only behavioral changes related to shock-induced conditioned fear were found, which suggests that so far poorly characterized factors are determining the long-term behavioral consequences of a single exposure to stress.

Do work relationships matter? Characteristics of workplace interactions that enhance or detract from employee perceptions of well-being and health behaviors.

PubMed

Mastroianni, Karen; Storberg-Walker, Julia

2014-01-01

This qualitative case study adopted the position that health and health behaviors are complex social constructs influenced by multiple factors. Framed by the social ecological model, the study explored how work interactions enhanced or detracted from the perceptions of well-being and health behaviors. Despite the fact that previous studies indicated that the social workplace environment contributed to employee health, there was little information regarding the characteristics. Specifically, little was known about how employees perceived the connections between workplace interactions and health, or how social interactions enhanced or detracted from well-being and health behaviors. The participants included 19 volunteers recruited from four companies, who shared their experiences of workplace interactions through interviews and journaling assignments. The findings indicated that feelings of well-being were enhanced by work interactions, which were trusting, collaborative, and positive, as well as when participants felt valued and respected. The study also found that interactions detracted from well-being and health behaviors when interactions lacked the aforementioned characteristics, and also included lack of justice and empathy. The enhancing and detracting relationships generated physical symptoms, and influenced sleeping and eating patterns, socializing, exercise, personal relations, careers, and energy. Surprisingly, the study found that regardless of how broadly participants defined health, when they were asked to rate their health, participants uniformly rated theirs on physical attributes alone. The exclusive consideration of physical attributes suggests that participants may have unconsciously adopted the typical western medical view of health - an individually determined and physiologic characteristic. Despite research suggesting health is more than biology, and despite defining health broadly, participants uniformly adopted this traditional view. The study also offers human resource development professionals with evidence supporting interventions aimed at minimizing workplace incivility. Interventions designed to improve employee engagement could minimize financial and human costs of negative interactions. The bottom line is that workplaces should be physically, emotionally, and psychologically safe for well-being and healthy behaviors to flourish.

Do work relationships matter? Characteristics of workplace interactions that enhance or detract from employee perceptions of well-being and health behaviors

PubMed Central

Mastroianni, Karen; Storberg-Walker, Julia

2014-01-01

This qualitative case study adopted the position that health and health behaviors are complex social constructs influenced by multiple factors. Framed by the social ecological model, the study explored how work interactions enhanced or detracted from the perceptions of well-being and health behaviors. Despite the fact that previous studies indicated that the social workplace environment contributed to employee health, there was little information regarding the characteristics. Specifically, little was known about how employees perceived the connections between workplace interactions and health, or how social interactions enhanced or detracted from well-being and health behaviors. The participants included 19 volunteers recruited from four companies, who shared their experiences of workplace interactions through interviews and journaling assignments. The findings indicated that feelings of well-being were enhanced by work interactions, which were trusting, collaborative, and positive, as well as when participants felt valued and respected. The study also found that interactions detracted from well-being and health behaviors when interactions lacked the aforementioned characteristics, and also included lack of justice and empathy. The enhancing and detracting relationships generated physical symptoms, and influenced sleeping and eating patterns, socializing, exercise, personal relations, careers, and energy. Surprisingly, the study found that regardless of how broadly participants defined health, when they were asked to rate their health, participants uniformly rated theirs on physical attributes alone. The exclusive consideration of physical attributes suggests that participants may have unconsciously adopted the typical western medical view of health – an individually determined and physiologic characteristic. Despite research suggesting health is more than biology, and despite defining health broadly, participants uniformly adopted this traditional view. The study also offers human resource development professionals with evidence supporting interventions aimed at minimizing workplace incivility. Interventions designed to improve employee engagement could minimize financial and human costs of negative interactions. The bottom line is that workplaces should be physically, emotionally, and psychologically safe for well-being and healthy behaviors to flourish. PMID:25750820

Docosahexaenoic acid for reading, cognition and behavior in children aged 7-9 years: a randomized, controlled trial (the DOLAB Study).

PubMed

Richardson, Alexandra J; Burton, Jennifer R; Sewell, Richard P; Spreckelsen, Thees F; Montgomery, Paul

2012-01-01

Omega-3 fatty acids are dietary essentials, and the current low intakes in most modern developed countries are believed to contribute to a wide variety of physical and mental health problems. Evidence from clinical trials indicates that dietary supplementation with long-chain omega-3 may improve child behavior and learning, although most previous trials have involved children with neurodevelopmental disorders such as attention-deficit/hyperactivity disorder (ADHD) or developmental coordination disorder (DCD). Here we investigated whether such benefits might extend to the general child population. To determine the effects of dietary supplementation with the long-chain omega-3 docosahexaenoic acid (DHA) on the reading, working memory, and behavior of healthy schoolchildren. Parallel group, fixed-dose, randomized, double-blind, placebo-controlled trial (RCT). Mainstream primary schools in Oxfordshire, UK (n = 74). Healthy children aged 7-9 years initially underperforming in reading (≤ 33(rd) centile). 1376 invited, 362 met study criteria. 600 mg/day DHA (from algal oil), or taste/color matched corn/soybean oil placebo. Age-standardized measures of reading, working memory, and parent- and teacher-rated behavior. ITT analyses showed no effect of DHA on reading in the full sample, but significant effects in the pre-planned subgroup of 224 children whose initial reading performance was ≤ 20(th) centile (the target population in our original study design). Parent-rated behavior problems (ADHD-type symptoms) were significantly reduced by active treatment, but little or no effects were seen for either teacher-rated behaviour or working memory. DHA supplementation appears to offer a safe and effective way to improve reading and behavior in healthy but underperforming children from mainstream schools. Replication studies are clearly warranted, as such children are known to be at risk of low educational and occupational outcomes in later life. ClinicalTrials.gov NCT01066182 and Controlled-Trials.com ISRCTN99771026.

Acculturative Stress and Risky Sexual Behavior: The Roles of Sexual Compulsivity and Negative Affect.

PubMed

Jardin, Charles; Garey, Lorra; Sharp, Carla; Zvolensky, Michael J

2016-01-01

Recent syndemic models of sexual health disparities affecting racial/ethnic minorities have highlighted the role of discrimination. Yet no previous work has examined how acculturative stress (distress at the transition from one's original culture toward a new culture) associates with sexual HIV-risk behavior (SHRB). Work among other minority populations suggests sexual compulsivity (SC) may contribute to syndemic sexual health disparities as a means of coping with distress. With this in mind, the present study examined whether SC explained the relation between acculturative stress and SHRB. Separate analyses were conducted for males and females within a sample of 758 sexually initiated racial/ethnic minority college students. Among males and females, acculturative stress had an indirect effect on SHRB via SC. As the first study to examine SHRB in relation to acculturative stress, findings provide preliminary evidence that targeting SC among racial/ethnic minorities may help reduce sexual health disparities. © The Author(s) 2015.

Syndemic theory and HIV-related risk among young transgender women: the role of multiple, co-occurring health problems and social marginalization.

PubMed

Brennan, Julia; Kuhns, Lisa M; Johnson, Amy K; Belzer, Marvin; Wilson, Erin C; Garofalo, Robert

2012-09-01

We assessed whether multiple psychosocial factors are additive in their relationship to sexual risk behavior and self-reported HIV status (i.e., can be characterized as a syndemic) among young transgender women and the relationship of indicators of social marginalization to psychosocial factors. Participants (n = 151) were aged 15 to 24 years and lived in Chicago or Los Angeles. We collected data on psychosocial factors (low self-esteem, polysubstance use, victimization related to transgender identity, and intimate partner violence) and social marginalization indicators (history of commercial sex work, homelessness, and incarceration) through an interviewer-administered survey. Syndemic factors were positively and additively related to sexual risk behavior and self-reported HIV infection. In addition, our syndemic index was significantly related to 2 indicators of social marginalization: a history of sex work and previous incarceration. These findings provide evidence for a syndemic of co-occurring psychosocial and health problems in young transgender women, taking place in a context of social marginalization.

Possible selves in patients with right- versus left-onset Parkinson's disease.

PubMed

Harris, Erica; McNamara, Patrick; Durso, Raymon

2017-03-01

Possible selves can be used to self-regulate and guide behavior towards what is desired to be achieved or avoided in life. Previous work suggests laterality effects exist within the brain regarding approach and avoidance systems to achieve self-regulation. A modified version of the possible selves task was administered to 45 patients with PD (22 right-onset and 23 left-onset) and 25 community dwelling control subjects (CS). Only 11.1% of patients exhibited balance among their hoped-for and feared possible selves versus 28% of CS. More right-onset patients used a promotion strategy whereas more left-onset patients used a prevention strategy. Patients with left-onset PD thought more about their feared selves, exhibiting reduced goal-directed behavior. Findings among the left-onset group indicate relative dependence of self-regulation on right-sided avoidance brain systems. This may point to an inability to move away from negative outcomes and to work towards rewarding outcomes, which could affect psychological health.

Light-Stimulated Synaptic Devices Utilizing Interfacial Effect of Organic Field-Effect Transistors.

PubMed

Dai, Shilei; Wu, Xiaohan; Liu, Dapeng; Chu, Yingli; Wang, Kai; Yang, Ben; Huang, Jia

2018-06-14

Synaptic transistors stimulated by light waves or photons may offer advantages to the devices, such as wide bandwidth, ultrafast signal transmission, and robustness. However, previously reported light-stimulated synaptic devices generally require special photoelectric properties from the semiconductors and sophisticated device's architectures. In this work, a simple and effective strategy for fabricating light-stimulated synaptic transistors is provided by utilizing interface charge trapping effect of organic field-effect transistors (OFETs). Significantly, our devices exhibited highly synapselike behaviors, such as excitatory postsynaptic current (EPSC) and pair-pulse facilitation (PPF), and presented memory and learning ability. The EPSC decay, PPF curves, and forgetting behavior can be well expressed by mathematical equations for synaptic devices, indicating that interfacial charge trapping effect of OFETs can be utilized as a reliable strategy to realize organic light-stimulated synapses. Therefore, this work provides a simple and effective strategy for fabricating light-stimulated synaptic transistors with both memory and learning ability, which enlightens a new direction for developing neuromorphic devices.

Associations between state minimum wage policy and health care access: a multi-level analysis of the 2004 Behavioral Risk Factor survey.

PubMed

McCarrier, Kelly P; Martin, Diane P; Ralston, James D; Zimmerman, Frederick J

2010-05-01

Minimum wage policies have been advanced as mechanisms to improve the economic conditions of the working poor. Both positive and negative effects of such policies on health care access have been hypothesized, but associations have yet to be thoroughly tested. To examine whether the presence of minimum wage policies in excess of the federal standard of $5.15 per hour was associated with health care access indicators among low-skilled adults of working age, a cross-sectional analysis of 2004 Behavioral Risk Factor Surveillance System data was conducted. Self-reported health insurance status and experience with cost-related barriers to needed medical care were adjusted in multi-level logistic regression models to control for potential confounding at the state, county, and individual levels. State-level wage policy was not found to be associated with insurance status or unmet medical need in the models, providing early evidence that increased minimum wage rates may neither strengthen nor weaken access to care as previously predicted.

Genetic differences in NMDA and D1 receptor levels, and operant responding for food and morphine in Lewis and Fischer 344 rats.

PubMed

Martín, Sonsoles; Lyupina, Yulia; Crespo, José Antonio; González, Begoña; García-Lecumberri, Carmen; Ambrosio, Emilio

2003-05-30

Previously, we have shown that Lewis (LEW) rats acquire faster than Fischer 344 (F344) rats operant food- and morphine-reinforced tasks under fixed-ratio schedules of reinforcement. The first purpose of the present work has been to study if differences in operant responding behavior may participate in the reported differences in morphine self-administration behavior between both inbred rat strains. To this end, we have analyzed the microstructure of responding obtained under a variable-interval (VI) of food reinforcement by calculating the inter-response time (IRT) for each rat strain. LEW rats exhibited shorter IRTs than F344 rats, suggesting that LEW rats may have an inherent high or compulsive operant responding activity. When subjects of both inbred rat strains were submitted to a schedule of morphine reinforcement of high responding requirements such as progressive ratio schedules, LEW rats also reached significantly higher breaking points and final response ratio than F344 rats for i.v. morphine self-administration. Given that there are neurochemical differences between both rat strains and that glutamatergic N-methyl-D-aspartate (NMDA) and dopaminergic D(1) receptors have been involved in operant responding behavior, a second purpose of this work has been to measure basal NMDA and D(1) receptor levels in these rat strains by quantitative receptor autoradiography. Compared to F344 rats, LEW rats showed higher basal NMDA receptor levels in frontal and cingulate cortex, caudate putamen, central amygdaloid nuclei, and intermediate white layer of superior colliculus, and higher basal D(1) receptor levels in several areas of hippocampus and thalamus, and substantia nigra pars reticulata. Taken together, these results suggest that an inherent high operant responding activity of LEW rats may have a role in the previous reported faster acquisition of opiate-reinforced behavior in operant self-administration paradigms under fixed-ratio schedules of reinforcement. In addition, a basal higher NMDA and D(1) receptor levels of LEW rats compared to F344 rats may participate in the neurochemical background that mediates the behavioral differences between both inbred rat strains.

Methodology Developed for Modeling the Fatigue Crack Growth Behavior of Single-Crystal, Nickel-Base Superalloys

NASA Technical Reports Server (NTRS)

1996-01-01

Because of their superior high-temperature properties, gas generator turbine airfoils made of single-crystal, nickel-base superalloys are fast becoming the standard equipment on today's advanced, high-performance aerospace engines. The increased temperature capabilities of these airfoils has allowed for a significant increase in the operating temperatures in turbine sections, resulting in superior propulsion performance and greater efficiencies. However, the previously developed methodologies for life-prediction models are based on experience with polycrystalline alloys and may not be applicable to single-crystal alloys under certain operating conditions. One of the main areas where behavior differences between single-crystal and polycrystalline alloys are readily apparent is subcritical fatigue crack growth (FCG). The NASA Lewis Research Center's work in this area enables accurate prediction of the subcritical fatigue crack growth behavior in single-crystal, nickel-based superalloys at elevated temperatures.

Identification and Emotions Experienced after a Celebrity Cancer Death Shape Information Sharing and Prosocial Behavior.

PubMed

Myrick, Jessica Gall

2017-06-01

Based on the previous work investigating public reactions to celebrity cancer deaths as well as on the appraisal theory of emotions, an online survey (N = 641) was conducted after the cancer death of popular sportscaster Stuart Scott. The aim was to better understand how the public shared news and reactions with others and if this social sharing impacted prosocial cancer-related behaviors (e.g., donating, volunteering, talking to others about cancer research). Two hierarchical logistic regression models were run. In the first, identification with Scott and emotional reactions to hearing about his death were significant predictors of sharing, even after controlling for demographics. In the second, feeling hopeful and having shared information with others predicted prosocial cancer-related behaviors. These results suggest promising strategies for designing more effective cancer awareness messages and fundraising campaigns after celebrity cancer announcements.

Comparison of precursor infiltration into polymer thin films via atomic layer deposition and sequential vapor infiltration using in-situ quartz crystal microgravimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Padbury, Richard P.; Jur, Jesse S., E-mail: jsjur@ncsu.edu

Previous research exploring inorganic materials nucleation behavior on polymers via atomic layer deposition indicates the formation of hybrid organic–inorganic materials that form within the subsurface of the polymer. This has inspired adaptations to the process, such as sequential vapor infiltration, which enhances the diffusion of organometallic precursors into the subsurface of the polymer to promote the formation of a hybrid organic–inorganic coating. This work highlights the fundamental difference in mass uptake behavior between atomic layer deposition and sequential vapor infiltration using in-situ methods. In particular, in-situ quartz crystal microgravimetry is used to compare the mass uptake behavior of trimethyl aluminummore » in poly(butylene terephthalate) and polyamide-6 polymer thin films. The importance of trimethyl aluminum diffusion into the polymer subsurface and the subsequent chemical reactions with polymer functional groups are discussed.« less

Preliminary evidence that testosterone's association with aggression depends on self-construal.

PubMed

Welker, Keith M; Norman, Rachel E; Goetz, Stefan; Moreau, Benjamin J P; Kitayama, Shinobu; Carré, Justin M

2017-06-01

A contribution to a special issue on Hormones and Human Competition. Previous research and theory suggest testosterone is an important hormone for modulating aggression and self-regulation. We propose that self-construal, a culturally-relevant difference in how individuals define the self in relation to others, may be an important moderator of the relationship between testosterone and behaviors linked to aggression. Within two studies (Study 1 N=80; Study 2 N=237) and an integrated data analysis, we find evidence suggesting that acute testosterone changes in men are positively associated with aggressive behavior for those with more independent self-construals, whereas basal testosterone is negatively associated with aggression when individuals have more interdependent self-construals. Although preliminary, these findings suggest that self-construal moderates the association between testosterone and aggression, thereby paving the way toward future work examining the potential cultural moderation of the behavioral effects of testosterone. Copyright © 2016 Elsevier Inc. All rights reserved.

Diet and Exercise in Parenthood: A Social Control Perspective

PubMed Central

Reczek, Corinne; Beth Thomeer, Mieke; Lodge, Amy C.; Umberson, Debra; Underhill, Megan

2014-01-01

Previous work on social control—the direct and indirect regulation of an individual’s health behaviors by others—suggests that parent–child relationships promote healthy diet and exercise. Yet parenthood is associated with less healthy diet and exercise patterns. The authors investigated this paradox by examining social control processes in 40 in-depth interviews with mothers and fathers. They found that parenthood involves social control processes that both promote and compromise healthy behavior, contributing to contradictory perceived effects of parenthood on health behavior. Moreover, the dynamics of social control appear to unfold in different ways for mothers and fathers and depend on the child’s gender and life stage, suggesting that gender and age dyads are central to understanding the seemingly contradictory consequences of parenthood at the population level. These articulations of gendered social control processes provide new insight into the consequences of the gendered organization of parenthood for diet and exercise. PMID:25328244

Stepping Up the Pressure: Arousal Can Be Associated with a Reduction in Male Aggression

PubMed Central

Ward, Andrew; Mann, Traci; Westling, Erika H.; Creswell, J. David; Ebert, Jeffrey P.; Wallaert, Matthew

2009-01-01

The attentional myopia model of behavioral control (Mann & Ward, 2007) was tested in an experiment investigating the relationship between physiological arousal and aggression. Drawing on previous work linking arousal and narrowed attentional focus, the model predicts that arousal will lead to behavior that is relatively disinhibited in situations in which promoting pressures to aggress are highly salient. In situations in which inhibitory pressures are more salient, the model predicts behavior that is relatively restrained. In the experiment, 81 male undergraduates delivered noise-blasts against a provoking confederate while experiencing either high or low levels of physiological arousal and, at the same time, being exposed to cues that served either to promote or inhibit aggression. In addition to supporting the predictions of the model, this experiment provided some of the first evidence for enhanced control of aggression under conditions of heightened physiological arousal. Implications for interventions designed to reduce aggression are discussed. PMID:18561301

An Experimental Test of the Roles of Audience Involvement and Message Frame in Shaping Public Reactions to Celebrity Illness Disclosures.

PubMed

Myrick, Jessica Gall

2018-04-13

Much research has investigated what happens when celebrities disclose an illness (via media) to the public. While audience involvement (i.e., identification and parasocial relationships) is often the proposed mechanism linking illness disclosures with audience behavior change, survey designs have prevented researchers from understanding if audience involvement prior to the illness disclosure actually predicts post-disclosure emotions, cognitions, and behaviors. Rooted in previous work on audience involvement as well as the Extended Parallel Process Model, the present study uses a national online experiment (N = 1,068) to test how pre-disclosure audience involvement may initiate post-disclosure effects for the message context of skin cancer. The data demonstrate that pre-disclosure audience involvement as well as the celebrity's framing of the disclosure can shape emotional responses (i.e., fear and hope), and that cognitive perceptions of the illness itself also influence behavioral intentions.

Chronic stress impairs prefrontal cortex-dependent response inhibition and spatial working memory.

PubMed

Mika, Agnieszka; Mazur, Gabriel J; Hoffman, Ann N; Talboom, Joshua S; Bimonte-Nelson, Heather A; Sanabria, Federico; Conrad, Cheryl D

2012-10-01

Chronic stress leads to neurochemical and structural alterations in the prefrontal cortex (PFC) that correspond to deficits in PFC-mediated behaviors. The present study examined the effects of chronic restraint stress on response inhibition (using a response-withholding task, the fixed-minimum interval schedule of reinforcement, or FMI), and working memory (using a radial arm water maze, RAWM). Adult male Sprague-Dawley rats were first trained on the RAWM and subsequently trained on FMI. After acquisition of FMI, rats were assigned to a restraint stress (6h/d/28d in wire mesh restrainers) or control condition. Immediately after chronic stress, rats were tested on FMI and subsequently on RAWM. FMI results suggest that chronic stress reduces response inhibition capacity and motivation to initiate the task on selective conditions when sucrose reward was not obtained on the preceding trial. RAWM results suggest that chronic stress produces transient deficits in working memory without altering previously consolidated reference memory. Behavioral measures from FMI failed to correlate with metrics from RAWM except for one in which changes in FMI timing imprecision negatively correlated with changes in RAWM working memory errors for the controls, a finding that was not observed following chronic stress. Fisher's r-to-z transformation revealed no significant differences between control and stress groups with correlation coefficients. These findings are the first to show that chronic stress impairs both response inhibition and working memory, two behaviors that have never been directly compared within the same animals after chronic stress, using FMI, an appetitive task, and RAWM, a nonappetitive task. PsycINFO Database Record (c) 2012 APA, all rights reserved.

Maternal distress explains the relationship of young African American mothers' violence exposure with their preschoolers' behavior.

PubMed

Mitchell, Stephanie J; Lewin, Amy; Rasmussen, Andrew; Horn, Ivor B; Joseph, Jill G

2011-02-01

Adolescent mothers and their children are particularly susceptible to witnessing or directly experiencing violence. Such violence exposure predicts maternal distress, parenting, and child behavior problems. The current study examined how mothers' depressive symptoms, aggression, harsh disciplinary practices, and home environment independently explain the association between mothers' violence exposure and children's externalizing and internalizing behavior, controlling for their children's violence exposure. Data were collected from 230 African American mothers living in Washington, DC who gave birth as adolescents and whose children were 3 to 5 years old. Path analysis revealed that the effect of mothers' experienced violence on children's externalizing and internalizing behavior was mediated by mothers' depressive symptoms and aggression. However, neither harsh discipline nor stimulation in the home environment acted as significant mediators, and there were no direct or indirect effects of mothers' witnessed violence on child behavior. This study builds on previous work by identifying an association between maternal violence exposure and children's behavior, independent of children's own violence exposure that is explained by mothers' increased distress but not their parenting. These findings suggest that a potential means of preventing behavior problems in minority children born to adolescent mothers is to identify mothers who have been directly exposed to violence and treat their depressive symptoms and aggressive behaviors.

Thinking about dying and trying and intending to die: results on suicidal behavior from a large Web-based sample.

PubMed

de Araújo, Rafael M F; Mazzochi, Leonardo; Lara, Diogo R; Ottoni, Gustavo L

2015-03-01

Suicide is an important worldwide public health problem. The aim of this study was to characterize risk factors of suicidal behavior using a large Web-based sample. The data were collected by the Brazilian Internet Study on Temperament and Psychopathology (BRAINSTEP) from November 2010 to July 2011. Suicidal behavior was assessed by an instrument based on the Suicidal Behaviors Questionnaire. The final sample consisted of 48,569 volunteers (25.9% men) with a mean ± SD age of 30.7 ± 10.1 years. More than 60% of the sample reported having had at least a passing thought of killing themselves, and 6.8% of subjects had previously attempted suicide (64% unplanned). The demographic features with the highest risk of attempting suicide were female gender (OR = 1.82, 95% CI = 1.65 to 2.00); elementary school as highest education level completed (OR = 2.84, 95% CI = 2.48 to 3.25); being unable to work (OR = 5.32, 95% CI = 4.15 to 6.81); having no religion (OR = 2.08, 95% CI = 1.90 to 2.29); and, only for female participants, being married (OR = 1.19, 95% CI = 1.08 to 1.32) or divorced (OR = 1.66, 95% CI = 1.41 to 1.96). A family history of a suicide attempt and of a completed suicide showed the same increment in the risk of suicidal behavior. The higher the number of suicide attempts, the higher was the real intention to die (P < .05). Those who really wanted to die reported more emptiness/loneliness (OR = 1.58, 95% CI = 1.35 to 1.85), disconnection (OR = 1.54, 95% CI = 1.30 to 1.81), and hopelessness (OR = 1.74, 95% CI = 1.49 to 2.03), but their methods were not different from the methods of those who did not mean to die. This large Web survey confirmed results from previous studies on suicidal behavior and pointed out the relevance of the number of previous suicide attempts and of a positive family history, even for a noncompleted suicide, as important risk factors. © Copyright 2015 Physicians Postgraduate Press, Inc.

Memristive behavior in BaTiO 3 thin films integrated with semiconductors

NASA Astrophysics Data System (ADS)

Singamaneni, Srinivasa Rao; Prater, John; Narayan, Jay

BaTiO3 has been studied for emerging non-volatile memory applications. However, most of the previous work has focused on this material when it was deposited on insulting oxide substrates such as SrTiO3. Unfortunately, this substrate is not suitable for CMOS-based microelectronics applications. This motivated us to carry out the present work. We have studied the resistive switching behavior in BaTiO3/La0.7Sr0.3MnO3 (BTO/LSMO) heterostructures integrated with Si (100) using pulsed laser deposition1,2. I-V measurements were conducted on BTO (500nm)/LSMO (25nm) devices at 200K, with the compliance current of 10mA. Here, Pt was used as a top electrode and LSMO served as bottom electrode. A few important observations are noted: (a) broad hysteresis in forward and reverse voltage sweeps -ideal for memory applications, (b) the ratio of high resistance to low resistance state is ~600 -important for switching devices, (c) the device is stable at least up to 50 cycles. However, we found that hysteretic behavior was collapsed after 36 cycles upon oxygen annealing of the device at 1 atmospheric pressure, 200o C for 1 hour, inferring the important role of oxygen vacancies in the resistive switching behavior of BTO/LSMO device. The comprehensive experimental data will be presented and discussed.1,2.

Short term total sleep deprivation in the rat increases antioxidant responses in multiple brain regions without impairing spontaneous alternation behavior

PubMed Central

Ramanathan, Lalini; Hu, Shuxin; Frautschy, Sally A.; Siegel, Jerome M.

2009-01-01

Total sleep deprivation (TSD) induces a broad spectrum of cognitive, behavioral and cellular changes. We previously reported that long term (5–11 days) TSD in the rat, by the disk-over-water method, decreases the activity of the antioxidant enzyme superoxide dismutase (SOD) in the brainstem and hippocampus. To gain insight into the mechanisms causing cognitive impairment, here we explore the early associations between metabolic activity, antioxidant responses and working memory (one form of cognitive impairment). Specifically we investigated the impact of short term (6 h) TSD, by gentle handling, on the levels of the endogenous antioxidant, total glutathione (GSHt), and the activities of the antioxidative enzymes, SOD and glutathione peroxidase (GPx). Short term TSD had no significant impact on SOD activity, but increased GSHt levels in the rat cortex, brainstem and basal forebrain, and GPx activity in the rat hippocampus and cerebellum. We also observed increased activity of hexokinase, (HK), the rate limiting enzyme of glucose metabolism, in the rat cortex and hypothalamus. We further showed that 6h of TSD leads to increased exploratory behavior to a new environment, without impairing spontaneous alternation behavior (SAB) in the Y maze. We conclude that acute (6h) sleep loss may trigger compensatory mechanisms (like increased antioxidant responses) that prevent initial deterioration in working memory. PMID:19850085

The Relationship between Emotion Comprehension and Internalizing and Externalizing Behavior in 7- to 10-Year-Old Children

PubMed Central

Göbel, Ariane; Henning, Anne; Möller, Corina; Aschersleben, Gisa

2016-01-01

The influence of internalizing and externalizing problems on children’s understanding of others’ emotions has mainly been investigated on basic levels of emotion comprehension. So far, studies assessing more sophisticated levels of emotion comprehension reported deficits in the ability to understand others’ emotions in children with severe internalizing or externalizing symptoms. The aim of this study was to investigate the relation between emotion comprehension and interindividual differences, with a focus on internalizing and externalizing behavior in children aged 7–10 years from the general population. A sample of 135 children was tested for emotion understanding using the Test of Emotion Comprehension. Information on internalizing and externalizing behavior was assessed with the Child Behavior Checklist 4/18. Age, bilingual upbringing, and amount of paternal working hours were significant control variables for emotion comprehension. In contrast to prior research, overall level of emotion understanding was not related to externalizing symptoms and correlated positively with elevated levels of somatic complaints and anxious/depressed symptoms. In addition, and in line with previous work, higher levels of social withdrawal were associated with worse performance in understanding emotions elicited by reminders. The present results implicate not only an altered understanding of emotions among more specific internalizing symptoms, but also that these alterations occur already on a low symptom level in a community based sample. PMID:28018262

Implications of behavioral architecture for the evolution of self-organized division of labor.

PubMed

Duarte, A; Scholtens, E; Weissing, F J

2012-01-01

Division of labor has been studied separately from a proximate self-organization and an ultimate evolutionary perspective. We aim to bring together these two perspectives. So far this has been done by choosing a behavioral mechanism a priori and considering the evolution of the properties of this mechanism. Here we use artificial neural networks to allow for a more open architecture. We study whether emergent division of labor can evolve in two different network architectures; a simple feedforward network, and a more complex network that includes the possibility of self-feedback from previous experiences. We focus on two aspects of division of labor; worker specialization and the ratio of work performed for each task. Colony fitness is maximized by both reducing idleness and achieving a predefined optimal work ratio. Our results indicate that architectural constraints play an important role for the outcome of evolution. With the simplest network, only genetically determined specialization is possible. This imposes several limitations on worker specialization. Moreover, in order to minimize idleness, networks evolve a biased work ratio, even when an unbiased work ratio would be optimal. By adding self-feedback to the network we increase the network's flexibility and worker specialization evolves under a wider parameter range. Optimal work ratios are more easily achieved with the self-feedback network, but still provide a challenge when combined with worker specialization.

Implications of Behavioral Architecture for the Evolution of Self-Organized Division of Labor

PubMed Central

Duarte, A.; Scholtens, E.; Weissing, F. J.

2012-01-01

Division of labor has been studied separately from a proximate self-organization and an ultimate evolutionary perspective. We aim to bring together these two perspectives. So far this has been done by choosing a behavioral mechanism a priori and considering the evolution of the properties of this mechanism. Here we use artificial neural networks to allow for a more open architecture. We study whether emergent division of labor can evolve in two different network architectures; a simple feedforward network, and a more complex network that includes the possibility of self-feedback from previous experiences. We focus on two aspects of division of labor; worker specialization and the ratio of work performed for each task. Colony fitness is maximized by both reducing idleness and achieving a predefined optimal work ratio. Our results indicate that architectural constraints play an important role for the outcome of evolution. With the simplest network, only genetically determined specialization is possible. This imposes several limitations on worker specialization. Moreover, in order to minimize idleness, networks evolve a biased work ratio, even when an unbiased work ratio would be optimal. By adding self-feedback to the network we increase the network's flexibility and worker specialization evolves under a wider parameter range. Optimal work ratios are more easily achieved with the self-feedback network, but still provide a challenge when combined with worker specialization. PMID:22457609

Examining the concurrent and longitudinal relationship between diurnal cortisol rhythms and conduct problems during childhood.

PubMed

Salis, Katie Lee; Bernard, Kristin; Black, Sarah R; Dougherty, Lea R; Klein, Daniel

2016-09-01

Previous literature indicates that both hypoactivity and hyperactivity of the HPA axis may be related to conduct disorder and externalizing behaviors in young children. Using a longitudinal sample of 283 typically-developing children, the current study examined both the concurrent and the longitudinal association between HPA functioning and externalizing behavior problems, such as conduct problems. Diurnal cortisol rhythms and externalizing problems were assessed at ages 6 and 9. Results suggest that concurrent HPA functioning is not significantly related to externalizing behavior at ages 6 or 9. However, more blunted cortisol rhythms at age 6 (less change across the day from morning to evening) predicted a greater increase in externalizing behavior between age 6 and age 9 than did steeper cortisol rhythms. Further analyses revealed that this association was driven by conduct problems and aggressive behavior, rather than attention problems. The relationship between HPA functioning and subsequent externalizing behavior in children adds to the limited longitudinal work on this topic, suggesting that the association changes over time. These results may serve to clarify the inconsistencies in the cross-sectional literature, particularly with respect to young school-age children. Copyright © 2016 Elsevier Ltd. All rights reserved.

Examining the Concurrent and Longitudinal Relationship between Diurnal Cortisol Rhythms and Conduct Problems during Childhood

PubMed Central

Salis, Katie Lee; Bernard, Kristin; Black, Sarah R.; Dougherty, Lea R.; Klein, Daniel

2017-01-01

Previous literature indicates that both hypoactivity and hyperactivity of the HPA axis may be related to conduct disorder and externalizing behaviors in young children. Using a longitudinal sample of 283 typically-developing children, the current study examined both the concurrent and the longitudinal association between HPA functioning and externalizing behavior problems, such as conduct problems. Diurnal cortisol rhythms and externalizing problems were assessed at ages 6 and 9. Results suggest that concurrent HPA functioning is not significantly related to externalizing behavior at ages 6 or 9. However, more blunted cortisol rhythms at age 6 (less change across the day from morning to evening) predicted a greater increase in externalizing behavior between age 6 and age 9 than did steeper cortisol rhythms. Further analyses revealed that this association was driven by conduct problems and aggressive behavior, rather than attention problems. The relationship between HPA functioning and subsequent externalizing behavior in children adds to the limited longitudinal work on this topic, suggesting that the association changes over time. These results may serve to clarify the inconsistencies in the cross-sectional literature, particularly with respect to young school-age children. PMID:27266968

Variations in condom use by locale: a comparison of mobile Chinese female sex workers in Hong Kong and mainland China.

PubMed

Lau, Joseph T F; Tsui, H Y; Ho, Shara P Y

2007-12-01

The present study investigated the prevalence of HIV and HIV-related behaviors and perceptions among 336 female sex workers (FSW) traveling from mainland China to work in Hong Kong. None of the participants tested HIV positive. Of the participants, 13.2% and 26.8%, respectively, would have unprotected sex with a client in Hong Kong or in mainland China if they liked the client; 16.7% and 21.7%, respectively, would have unprotected sex with a client in Hong Kong and in mainland China if he paid more. Of the participants, 98.5% used condoms in the last episode of sex work in Hong Kong and 78.1% were consistent condom users in Hong Kong in the last month. Yet, among those who previously worked as FSW in mainland China (n = 141), only 28.6% used condoms consistently in mainland China in the last year; 60% of those who used condoms inconsistently while in mainland China became consistent condom users in Hong Kong. Among those who did not use condoms in mainland China, willingness to have unprotected sex with a client who was liked by the FSW was a strong predictor for consistent condom use in Hong Kong (OR = 18.67, p < .001). Among those who were consistent condom users in Hong Kong, the same variable predicted inconsistent condom use while in mainland China (OR = 14.02, p < .05). Condom use behaviors change when FSW are working in different social contexts and behavioral changes are possible. Education programs should take socio-contextual factors into account.

Impact of compressibility and a guide field on Fermi acceleration during magnetic island coalescence

NASA Astrophysics Data System (ADS)

Montag, Peter; Egedal, Jan; Lichko, Emily; Wetherton, Blake

2017-10-01

Previous work has shown that Fermi acceleration can be an effective heating mechanism during magnetic island coalescence, where electrons may undergo repeated reflections as the magnetic field lines contract. This energization has the potential to account for the power-law distributions of particle energy inferred from observations of solar flares. Here, we develop a generalized framework for the analysis of Fermi acceleration that can incorporate the effects of compressibility and non-uniformity along field lines, which have commonly been neglected in previous treatments of the problem. Applying this framework to the simplified case of the uniform flux tube allows us to find both the power-law scaling of the distribution function and the rate at which the power-law behavior develops. We find that a guide magnetic field of order unity effectively suppresses the development of power-law distributions. The work was supported by NASA Grant No. NNX14AC68G, NSF GEM Grant No. 1405166, NSF Award 1404166, and NASA Award NNX15AJ73G.

Scaling of chaos in strongly nonlinear lattices.

PubMed

Mulansky, Mario

2014-06-01

Although it is now understood that chaos in complex classical systems is the foundation of thermodynamic behavior, the detailed relations between the microscopic properties of the chaotic dynamics and the macroscopic thermodynamic observations still remain mostly in the dark. In this work, we numerically analyze the probability of chaos in strongly nonlinear Hamiltonian systems and find different scaling properties depending on the nonlinear structure of the model. We argue that these different scaling laws of chaos have definite consequences for the macroscopic diffusive behavior, as chaos is the microscopic mechanism of diffusion. This is compared with previous results on chaotic diffusion [M. Mulansky and A. Pikovsky, New J. Phys. 15, 053015 (2013)], and a relation between microscopic chaos and macroscopic diffusion is established.

Corvid caching: Insights from a cognitive model.

PubMed

van der Vaart, Elske; Verbrugge, Rineke; Hemelrijk, Charlotte K

2011-07-01

Caching and recovery of food by corvids is well-studied, but some ambiguous results remain. To help clarify these, we built a computational cognitive model. It is inspired by similar models built for humans, and it assumes that memory strength depends on frequency and recency of use. We compared our model's behavior to that of real birds in previously published experiments. Our model successfully replicated the outcomes of two experiments on recovery behavior and two experiments on cache site choice. Our "virtual birds" reproduced declines in recovery accuracy across sessions, revisits to previously emptied cache sites, a lack of correlation between caching and recovery order, and a preference for caching in safe locations. The model also produced two new explanations. First, that Clark's nutcrackers may become less accurate as recovery progresses not because of differential memory for different cache sites, as was once assumed, but because of chance effects. And second, that Western scrub jays may choose their cache sites not on the basis of negative recovery experiences only, as was previously thought, but on the basis of positive recovery experiences instead. Alternatively, both "punishment" and "reward" may be playing a role. We conclude with a set of new insights, a testable prediction, and directions for future work. PsycINFO Database Record (c) 2011 APA, all rights reserved

Employee problems and their consequences in the technology industry: evidence from surveys and counseling records.

PubMed

Wang, Ching-Wen; Lin, Po-Chang; Sha, Chyuan

2014-06-01

To support employees' work and health, organizations should help employees cope with common problems. Previous studies have focused primarily on work-related problems across multiple industries rather than on evaluating industry-specific issues. Here, two approaches identified common work and non-work employee problems in the technology industry with the strongest correlations with psychosomatic health and life satisfaction. Study 1 used questionnaires to identify the problems that were perceived as the most frequent by lower-level employees (N = 355) working in the technology industry. Study 2 evaluated employees' coping behaviors by analyzing (with permission) counseling records collected from an employee assistance service company (N = 276). Employees reported a variety of problems; work problems were the only problems (of the top 5 problems) reported in both studies. Several problems emerged in the counseling records (e.g., legal issues, career development, family and marriage problems, and emotional problems) but not in the surveys. Future research should apply these observations to develop scales for measuring employee stressors.

An Attitude Strength and Self-Perception Framework Regarding the Bi-directional Relationship of Job Satisfaction with Extra-Role and In-Role Behavior: The Doubly Moderating Role of Work Centrality

PubMed Central

Ziegler, Rene; Schlett, Christian

2016-01-01

Studies have identified variables either moderating the extent to which job satisfaction predicts work behavior or moderating the reverse impact of work behavior on job satisfaction. Based on an attitude strength and self-perception framework, we argue that certain variables may moderate both the predictive utility of job satisfaction for work behavior and the impact of work behavior on job satisfaction. Specifically focusing on work centrality, we hold that high work centrality renders job satisfaction a strong job attitude, whereas low work centrality renders job satisfaction a weak job attitude. Hence, the predictive utility of job satisfaction for both extra-role behavior and in-role behavior should be higher the more work is central to employees. In contrast, the influence of extra-role behavior, but not of in-role behavior, on job satisfaction should be higher the less work is central to employees. Results of a two-wave study (N = 176) were in line with these predictions. We discuss further variables that may play a similar role for the bi-directional relationship between job satisfaction and work behavior. PMID:26973556

An Attitude Strength and Self-Perception Framework Regarding the Bi-directional Relationship of Job Satisfaction with Extra-Role and In-Role Behavior: The Doubly Moderating Role of Work Centrality.

PubMed

Ziegler, Rene; Schlett, Christian

2016-01-01

Studies have identified variables either moderating the extent to which job satisfaction predicts work behavior or moderating the reverse impact of work behavior on job satisfaction. Based on an attitude strength and self-perception framework, we argue that certain variables may moderate both the predictive utility of job satisfaction for work behavior and the impact of work behavior on job satisfaction. Specifically focusing on work centrality, we hold that high work centrality renders job satisfaction a strong job attitude, whereas low work centrality renders job satisfaction a weak job attitude. Hence, the predictive utility of job satisfaction for both extra-role behavior and in-role behavior should be higher the more work is central to employees. In contrast, the influence of extra-role behavior, but not of in-role behavior, on job satisfaction should be higher the less work is central to employees. Results of a two-wave study (N = 176) were in line with these predictions. We discuss further variables that may play a similar role for the bi-directional relationship between job satisfaction and work behavior.

Meditation awareness training for the treatment of workaholism: A controlled trial

PubMed Central

Van Gordon, William; Shonin, Edo; Dunn, Thomas J.; Garcia-Campayo, Javier; Demarzo, Marcelo M. P.; Griffiths, Mark D.

2017-01-01

Background and aims Workaholism is a form of behavioral addiction that can lead to reduced life and job satisfaction, anxiety, depression, burnout, work–family conflict, and impaired productivity. Given the number of people affected, there is a need for more targeted workaholism treatments. Findings from previous case studies successfully utilizing second-generation mindfulness-based interventions (SG-MBIs) for treating behavioral addiction suggest that SG-MBIs may be suitable for treating workaholism. This study conducted a controlled trial to investigate the effects of an SG-MBI known as meditation awareness training (MAT) on workaholism. Methods Male and female adults suffering from workaholism (n = 73) were allocated to MAT or a waiting-list control group. Assessments were performed at pre-, post-, and 3-month follow-up phases. Results MAT participants demonstrated significant and sustained improvements over control-group participants in workaholism symptomatology, job satisfaction, work engagement, work duration, and psychological distress. Furthermore, compared to the control group, MAT participants demonstrated a significant reduction in hours spent working but without a decline in job performance. Discussion and conclusions MAT may be a suitable intervention for treating workaholism. Further controlled intervention studies investigating the effects of SG-MBIs on workaholism are warranted. PMID:28425778

Children’s Emotional and Behavioral Problems and Their Mothers’ Labor Supply

PubMed Central

Gaskin, Darrell J.; Alexandre, Pierre K.; Burke, Laura S.; Younis, Mustafa

2014-01-01

It has been documented that about 20% of children and adolescents suffer from a diagnosable mental or addictive disorder in the United States. The high prevalence of children’s emotional and behavioral problems (EBP) might have a negative effect on their mothers’ labor market outcomes because children with EBP require additional time for treatment. However, these children may require additional financial resources, which might promote mothers’ labor supply. Previous studies have only considered chronic conditions in analyzing the impact of children’s health on parental work activities. Moreover, most of these studies have not accounted for endogeneity in children’s health. This article estimates the effects of children’s EBP on their mothers’ labor supply by family structure while accounting for endogeneity in children’s health. We used the 1997 and 2002 Child Development Supplements (CDS) to the Panel Study of Income Dynamics (PSID). We used probit and bivariate probit models to estimate mothers’ probability of employment, and tobit and instrumental variable tobit models to estimate the effects of children’s EBP on their mothers’ work hours. Findings show negative effects of children’s EBP on their married mothers’ employment and on their single mothers’ work hours. PMID:25466413

Children's emotional and behavioral problems and their mothers' labor supply.

PubMed

Richard, Patrick; Gaskin, Darrell J; Alexandre, Pierre K; Burke, Laura S; Younis, Mustafa

2014-01-01

It has been documented that about 20% of children and adolescents suffer from a diagnosable mental or addictive disorder in the United States. The high prevalence of children's emotional and behavioral problems (EBP) might have a negative effect on their mothers' labor market outcomes because children with EBP require additional time for treatment. However, these children may require additional financial resources, which might promote mothers' labor supply. Previous studies have only considered chronic conditions in analyzing the impact of children's health on parental work activities. Moreover, most of these studies have not accounted for endogeneity in children's health. This article estimates the effects of children's EBP on their mothers' labor supply by family structure while accounting for endogeneity in children's health. We used the 1997 and 2002 Child Development Supplements (CDS) to the Panel Study of Income Dynamics (PSID). We used probit and bivariate probit models to estimate mothers' probability of employment, and tobit and instrumental variable tobit models to estimate the effects of children's EBP on their mothers' work hours. Findings show negative effects of children's EBP on their married mothers' employment and on their single mothers' work hours. © The Author(s) 2014.

Voluntary inhibition of pain avoidance behavior: an fMRI study.

PubMed

Lynn, Margaret T; Demanet, Jelle; Krebs, Ruth M; Van Dessel, Pieter; Brass, Marcel

2016-04-01

Behavioral inhibition has classically been considered to rely upon a neural network centered at the right inferior frontal cortex [rIFC; Aron et al. (8:170-177, 2004; 18:177-185, 2014)]. However, the vast majority of inhibition studies have entailed exogenous stop signals instructing participants to withhold responding. More recent work has begun to examine the neural underpinnings of endogenous inhibition, revealing a distinct cortical basis in the dorsal fronto-median cortex [dFMC; Brass and Haggard (27:9141-9145, 2007); Kühn et al. (30:2834-3843, 2009)]. Yet, contrary to everyday experiences of voluntary behavioral suppression, the paradigms employed to investigate action inhibition have thus far been somewhat artificial, and involve little persuasive motivation to act. Accordingly, the present fMRI study seeks to compare and contrast intentional with instructed inhibition in a novel pain paradigm that recruits 'hot' incentive response systems. Participants received increasing thermal stimulation to their inner wrists, and were required to occasionally withhold their natural impulse to withdraw from the compelling pain sensation at peak temperature, in both instructed and free-choice conditions. Consistent with previous research, we observed inhibition-related activity in the dFMC and the rIFC. However, these regions displayed equivalent activation levels for both inhibition types. These data extend previous research by demonstrating that under ecologically valid conditions with a strong motivation to act, both stopping networks operate in concert to enable suppression of unwanted behavior.

Drug-seeking behavior in an invertebrate system: evidence of morphine-induced reward, extinction and reinstatement in crayfish

PubMed Central

Nathaniel, Thomas I.; Panksepp, Jules; Huber, Robert

2009-01-01

Several lines of evidence suggest that exploring the neurochemical basis of reward in invertebrate species may provide clues for the fundamental behavioral and neurobiology underpinnings of drug addiction. How the presence of drug-sensitive reward relates to a decrease in drug-seeking behavior and reinstatement of drug seeking behavior in invertebrate systems is not known. The present study of a conditioned place preference (CPP) paradigm in crayfish (Orconectes rusticus) explores morphine-induced reward, extinction and reinstatement. Repeated intra-circulatory infusions of 2.5μg/g, 5.0μg/g and 10.0μg/g doses of morphine over 5 days serve as a reward when paired with a distinct visual or tactile environment. Morphine-induced CPP was extinguished after repeated saline injections for 5 days in the previously morphine-paired compartment. After the previously established CPP had been eliminated during the extinction phase, morphine-experienced crayfish were challenged with 2.5 μg/g, 5.0 μg/g and 10.0 μg/g respectively. The priming injections of morphine reinstated CPP in all training doses, suggesting that morphine-induced CPP is unrelenting, and that with time, it can be reinstated by morphine following extinction in an invertebrate model just like in mammals. Together with other recent studies, this work demonstrates the advantage of using crayfish as an invertebrate animal model to investigate the basic biological processes that underline exposure to mammalian drugs of abuse. PMID:18822319

Ductile Fracture Behaviour of Hot Isostatically Pressed Inconel 690 Superalloy

NASA Astrophysics Data System (ADS)

Cooper, A. J.; Brayshaw, W. J.; Sherry, A. H.

2018-04-01

Herein we assess the differences in Charpy impact behavior between Hot Isostatically Pressed and forged Inconel 690 alloy over the temperature range of 300 °C to - 196 °C. The impact toughness of forged 690 exhibited a relatively small temperature dependence, with a maximum difference of ca. 40 J measured between 300 °C and - 196 °C, whereas the HIP'd alloy exhibited a difference of approximately double that of the forged alloy over the same temperature range. We have conducted Charpy impact testing, tensile testing, and metallographic analyses on the as-received materials as well as fractography of the failed Charpy specimens in order to understand the mechanisms that cause the observed differences in material fracture properties. The work supports a recent series of studies which assess differences in fundamental fracture behavior between Hot Isostatically Pressed and forged austenitic stainless steel materials of equivalent grades, and the results obtained in this study are compared to those of the previous stainless steel investigations to paint a more general picture of the comparisons between HIP vs forged material fracture behavior. Inconel 690 was selected in this study since previous studies were unable to completely omit the effects of strain-induced martensitic transformation at the tip of the Chary V-notch from the fracture mechanism; Inconel 690 is unable to undergo strain-induced martensitic transformation due to the alloy's high nickel content, thereby providing a sister study with the omission of any martensitic transformation effects on ductile fracture behavior.

Usability Flaws in Medication Alerting Systems: Impact on Usage and Work System.

PubMed

Marcilly, R; Ammenwerth, E; Roehrer, E; Pelayo, S; Vasseur, F; Beuscart-Zéphir, M-C

2015-08-13

Previous research has shown that medication alerting systems face usability issues. There has been no previous attempt to systematically explore the consequences of usability flaws in such systems on users (i.e. usage problems) and work systems (i.e. negative outcomes). This paper aims at exploring and synthesizing the consequences of usability flaws in terms of usage problems and negative outcomes on the work system. A secondary analysis of 26 papers included in a prior systematic review of the usability flaws in medication alerting was performed. Usage problems and negative outcomes were extracted and sorted. Links between usability flaws, usage problems, and negative outcomes were also analyzed. Poor usability generates a large variety of consequences. It impacts the user from a cognitive, behavioral, emotional, and attitudinal perspective. Ultimately, usability flaws have negative consequences on the workflow, the effectiveness of the technology, the medication management process, and, more importantly, patient safety. Only few complete pathways leading from usability flaws to negative outcomes were identified. Usability flaws in medication alerting systems impede users, and ultimately their work system, and negatively impact patient safety. Therefore, the usability dimension may act as a hidden explanatory variable that could explain, at least partly, the (absence of) intended outcomes of new technology.

Usability Flaws in Medication Alerting Systems: Impact on Usage and Work System

PubMed Central

Ammenwerth, E.; Roehrer, E.; Pelayo, S.; Vasseur, F.; Beuscart-Zéphir, M.-C.

2015-01-01

Summary Objectives Previous research has shown that medication alerting systems face usability issues. There has been no previous attempt to systematically explore the consequences of usability flaws in such systems on users (i.e. usage problems) and work systems (i.e. negative outcomes). This paper aims at exploring and synthesizing the consequences of usability flaws in terms of usage problems and negative outcomes on the work system. Methods A secondary analysis of 26 papers included in a prior systematic review of the usability flaws in medication alerting was performed. Usage problems and negative outcomes were extracted and sorted. Links between usability flaws, usage problems, and negative outcomes were also analyzed. Results Poor usability generates a large variety of consequences. It impacts the user from a cognitive, behavioral, emotional, and attitudinal perspective. Ultimately, usability flaws have negative consequences on the workflow, the effectiveness of the technology, the medication management process, and, more importantly, patient safety. Only few complete pathways leading from usability flaws to negative outcomes were identified. Conclusion Usability flaws in medication alerting systems impede users, and ultimately their work system, and negatively impact patient safety. Therefore, the usability dimension may act as a hidden explanatory variable that could explain, at least partly, the (absence of) intended outcomes of new technology. PMID:26123906

Stability characteristics of a single-phase free convection loop

NASA Technical Reports Server (NTRS)

Creveling, H. F.; De Paz, J. F.; Baladi, J. Y.; Schoenhals, R. J.

1975-01-01

Experiments investigating the stability characteristics of a single-phase free convection loop are reported. Results of the study confirm the contention made by previous workers that instabilities near the thermodynamic critical point can occur for ordinary fluids as well as those with unusual behavior in the near-critical region. Such a claim runs counter to traditional beliefs, but it is supported by the observation of such instabilities for water at atmospheric pressure and moderate temperatures in the present work.

On the relevance of Gibson's affordance concept for geographical information science (GISc).

PubMed

Jonietz, David; Timpf, Sabine

2015-09-01

J. J. Gibson's concept of affordances has provided a theoretical basis for various studies in geographical information science (GISc). This paper sets out to explain its popularity from a GISc perspective. Based on a short review of previous work, it will be argued that its main contributions to GISc are twofold, including an action-centered view of spatial entities and the notion of agent-environment mutuality. Using the practical example of pedestrian behavior simulation, new potentials for using and extending affordances are discussed.

Effects of Four Task Stressors on Blood Pressure Responses in Persons Differing in Type A Coronary Prone Behavior and Cognitive Complexity.

DTIC Science & Technology

1983-03-01

requirements are available. Video game task: a non-social, task-oriented setting in which the person works alone against different levels of experimentally...instructed to watch a video I screen. After the experimenter left the room, videotaped instructions for a video game (similar to Pac Man) were presented on...the screen. Instructions were detailed enough to allow all subjects, including those who had no previous experience with video games , to understand

Using chaotic artificial neural networks to model memory in the brain

NASA Astrophysics Data System (ADS)

Aram, Zainab; Jafari, Sajad; Ma, Jun; Sprott, Julien C.; Zendehrouh, Sareh; Pham, Viet-Thanh

2017-03-01

In the current study, a novel model for human memory is proposed based on the chaotic dynamics of artificial neural networks. This new model explains a biological fact about memory which is not yet explained by any other model: There are theories that the brain normally works in a chaotic mode, while during attention it shows ordered behavior. This model uses the periodic windows observed in a previously proposed model for the brain to store and then recollect the information.

Men’s Facial Width-to-Height Ratio Predicts Aggression: A Meta-Analysis

PubMed Central

Haselhuhn, Michael P.; Ormiston, Margaret E.; Wong, Elaine M.

2015-01-01

Recent research has identified men’s facial width-to-height ratio (fWHR) as a reliable predictor of aggressive tendencies and behavior. Other research, however, has failed to replicate the fWHR-aggression relationship and has questioned whether previous findings are robust. In the current paper, we synthesize existing work by conducting a meta-analysis to estimate whether and how fWHR predicts aggression. Our results indicate a small, but significant, positive relationship between men’s fWHR and aggression. PMID:25849992

Cognitive Modeling for Agent-Based Simulation of Child Maltreatment

NASA Astrophysics Data System (ADS)

Hu, Xiaolin; Puddy, Richard

This paper extends previous work to develop cognitive modeling for agent-based simulation of child maltreatment (CM). The developed model is inspired from parental efficacy, parenting stress, and the theory of planned behavior. It provides an explanatory, process-oriented model of CM and incorporates causality relationship and feedback loops from different factors in the social ecology in order for simulating the dynamics of CM. We describe the model and present simulation results to demonstrate the features of this model.

Easily constructed spectroelectrochemical cell for batch and flow injection analyses.

PubMed

Flowers, Paul A; Maynor, Margaret A; Owens, Donald E

2002-02-01

The design and performance of an easily constructed spectroelectrochemical cell suitable for batch and flow injection measurements are described. The cell is fabricated from a commercially available 5-mm quartz cuvette and employs 60 ppi reticulated vitreous carbon as the working electrode, resulting in a reasonable compromise between optical sensitivity and thin-layer electrochemical behavior. The spectroelectrochemical traits of the cell in both batch and flow modes were evaluated using aqueous ferricyanide and compare favorably to those reported previously for similar cells.

Work and retirement among a cohort of older men in the United States, 1966-1983.

PubMed

Hayward, M D; Grady, W R

1990-08-01

Multivariate increment-decrement working life tables are estimated for a cohort of older men in the United States for the period 1966-1983. The approach taken allows multiple processes to be simultaneously incorporated into a single model, resulting in a more realistic portrayal of a cohort's late-life labor force behavior. In addition, because the life table model is developed from multivariate hazard equations, we identify the effects of sociodemographic characteristics on the potentially complex process by which the labor force career is ended. In contrast to the assumed homogeneity of previous working life table analyses, the present study shows marked differences in labor force mobility and working and nonworking life expectancy according to occupation, class of worker, education, race, and marital status. We briefly discuss the implications of these findings for inequities of access to retirement, private and public pension consumption, and future changes in the retirement process.

Evaluation of impairment of the upper extremity.

PubMed

Blair, S J; McCormick, E; Bear-Lehman, J; Fess, E E; Rader, E

1987-08-01

Evaluation of impairment of the upper extremity is the product of a team effort by the physician, occupational therapist, physical therapist, and rehabilitation counselor. A careful recording of the anatomic impairment should be made because this is critical in determining the subsequent functional activities of the extremity. The measurement criteria for clinical and functional evaluation includes condition assessment instruments. Some assess the neurovascular system, others assess movements including the monitoring of articular motion and musculotendinous function. Sensibility assessment instruments measure sympathetic response and detect single joint stimulus, discrimination, quantification, and recognition abilities. A detailed description of each assessment is recorded and physical capacity evaluation is only one component of the entire vocational evaluation. This evaluation answers questions regarding the injured worker's ability to return to his previous job. The work simulator is a useful instrument that allows rehabilitation and testing of the injured upper extremity. Job site evaluation includes assessment criteria for work performance, work behavior, and work environment.

The cost of misremembering: Inferring the loss function in visual working memory.

PubMed

Sims, Chris R

2015-03-04

Visual working memory (VWM) is a highly limited storage system. A basic consequence of this fact is that visual memories cannot perfectly encode or represent the veridical structure of the world. However, in natural tasks, some memory errors might be more costly than others. This raises the intriguing possibility that the nature of memory error reflects the costs of committing different kinds of errors. Many existing theories assume that visual memories are noise-corrupted versions of afferent perceptual signals. However, this additive noise assumption oversimplifies the problem. Implicit in the behavioral phenomena of visual working memory is the concept of a loss function: a mathematical entity that describes the relative cost to the organism of making different types of memory errors. An optimally efficient memory system is one that minimizes the expected loss according to a particular loss function, while subject to a constraint on memory capacity. This paper describes a novel theoretical framework for characterizing visual working memory in terms of its implicit loss function. Using inverse decision theory, the empirical loss function is estimated from the results of a standard delayed recall visual memory experiment. These results are compared to the predicted behavior of a visual working memory system that is optimally efficient for a previously identified natural task, gaze correction following saccadic error. Finally, the approach is compared to alternative models of visual working memory, and shown to offer a superior account of the empirical data across a range of experimental datasets. © 2015 ARVO.

A systematic survey of the integration of animal behavior into conservation.

PubMed

Berger-Tal, Oded; Blumstein, Daniel T; Carroll, Scott; Fisher, Robert N; Mesnick, Sarah L; Owen, Megan A; Saltz, David; St Claire, Colleen Cassady; Swaisgood, Ronald R

2016-08-01

The role of behavioral ecology in improving wildlife conservation and management has been the subject of much recent debate. We sought to answer 2 foundational questions about the current use of behavioral knowledge in conservation: To what extent is behavioral knowledge used in wildlife conservation and management, and how does the use of animal behavior differ among conservation fields in both frequency and types of use? We searched the literature for intersections between key fields of animal behavior and conservation and created a systematic heat map (i.e., graphical representation of data where values are represented as colors) to visualize relative efforts. Some behaviors, such as dispersal and foraging, were commonly considered (mean [SE] of 1147.38 [353.11] and 439.44 [108.85] papers per cell, respectively). In contrast, other behaviors, such as learning, social, and antipredatory behaviors were rarely considered (mean [SE] of 33.88 [7.62], 44.81 [10.65], and 22.69 [6.37] papers per cell, respectively). In many cases, awareness of the importance of behavior did not translate into applicable management tools. Our results challenge previous suggestions that there is little association between the fields of behavioral ecology and conservation and reveals tremendous variation in the use of different behaviors in conservation. We recommend that researchers focus on examining underutilized intersections of behavior and conservation themes for which preliminary work shows a potential for improving conservation and management, translating behavioral theory into applicable and testable predictions, and creating systematic reviews to summarize the behavioral evidence within the behavior-conservation intersections for which many studies exist. © 2015 Society for Conservation Biology.

Equilibrium Conformations of Concentric-tube Continuum Robots

PubMed Central

Rucker, D. Caleb; Webster, Robert J.; Chirikjian, Gregory S.; Cowan, Noah J.

2013-01-01

Robots consisting of several concentric, preshaped, elastic tubes can work dexterously in narrow, constrained, and/or winding spaces, as are commonly found in minimally invasive surgery. Previous models of these “active cannulas” assume piecewise constant precurvature of component tubes and neglect torsion in curved sections of the device. In this paper we develop a new coordinate-free energy formulation that accounts for general preshaping of an arbitrary number of component tubes, and which explicitly includes both bending and torsion throughout the device. We show that previously reported models are special cases of our formulation, and then explore in detail the implications of torsional flexibility for the special case of two tubes. Experiments demonstrate that this framework is more descriptive of physical prototype behavior than previous models; it reduces model prediction error by 82% over the calibrated bending-only model, and 17% over the calibrated transmissional torsion model in a set of experiments. PMID:25125773

Language Networks Associated with Computerized Semantic Indices

PubMed Central

Pakhomov, Serguei V. S.; Jones, David T.; Knopman, David S.

2014-01-01

Tests of generative semantic verbal fluency are widely used to study organization and representation of concepts in the human brain. Previous studies demonstrated that clustering and switching behavior during verbal fluency tasks is supported by multiple brain mechanisms associated with semantic memory and executive control. Previous work relied on manual assessments of semantic relatedness between words and grouping of words into semantic clusters. We investigated a computational linguistic approach to measuring the strength of semantic relatedness between words based on latent semantic analysis of word co-occurrences in a subset of a large online encyclopedia. We computed semantic clustering indices and compared them to brain network connectivity measures obtained with task-free fMRI in a sample consisting of healthy participants and those differentially affected by cognitive impairment. We found that semantic clustering indices were associated with brain network connectivity in distinct areas including fronto-temporal, fronto-parietal and fusiform gyrus regions. This study shows that computerized semantic indices complement traditional assessments of verbal fluency to provide a more complete account of the relationship between brain and verbal behavior involved organization and retrieval of lexical information from memory. PMID:25315785

Supportive intervention using a mobile phone in behavior modification.

PubMed

Hareva, David H; Okada, Hiroki; Kitawaki, Tomoki; Oka, Hisao

2009-04-01

The authors previously developed a mobile ecological momentary assessment (EMA) system as a real-time data collection device using a mobile phone. In this study, a real-time advice function and real-time reporting function were added to the previous system as a supportive intervention. The improved system was found to work effectively and was applied to several clinical cases, including patients with depressive disorder, dizziness, smoking habit, and bronchial asthma. The average patient compliance rate was high (89%) without the real-time advice and higher (93%) with the advice. The trends in clinical data for patients using a mobile EMA with/without the new function were analyzed for up to several months. In the case of dizziness, an improving trend in its clinical data was observed after applying the real-time advice, and in the case of depressive disorder, a stabilizing trend was observed. The mobile EMA system with the real-time advice function could be useful as a supportive intervention in behavior modification and for motivating patients in self-management of their disease.

Egoistic, altruistic, and biospheric environmental concerns: a path analytic investigation of their determinants.

PubMed

Swami, Viren; Chamorro-Premuzic, Tomas; Snelgar, Rosemary; Furnham, Adrian

2010-04-01

Previous studies have shown that environmental concerns (ECs) can be reduced to a three-factor model - comprising altruistic, biospheric, and egoistic concerns - but there have been few studies examining individual difference predictors of ECs. In this study with 203 individuals from a British community sample, we show that biospheric concern was significantly associated with participants' age, political orientation, Machiavellianism, and the Big Five personality traits of Agreeableness, Emotional Stability, and Conscientiousness. Altruistic concern was significantly associated with sex, age, political orientation, and Machiavellianism, but not the Big Five traits, whereas egoistic concern was not significantly associated with any of these predictors except sex. These results are discussed in relation to previous work on ECs and pro-environmental behavior.

Cytoplasmic DNA synthesis in Amoeba proteus. II. On the behavior and possible nature of the DNA-containing elements.

PubMed

RABINOVITCH, M; PLAUT, W

1962-12-01

Nucleic acid-containing particles in the cytoplasm of Amoeba proteus (cf. reference 1) were counted after acridine orange staining. The number of particles per ameba was found to be correlated with cell age and size. Fresh daughters had a mean particle number of 5400, whereas predivision amebae contained around 11,000 particles. Amebae from two other strains contained similar particles. The particles were found to be clustered in fasted cells and redispersed after feeding. A marked increase in the particle population was noted in anucleate fragments. These results, together with those previously presented, suggest that the particles multiply intracellularly. Their nature and their relationship to previous work on nucleic acid labeling in Amoeba are discussed.

Moderating effects of nurses' organizational justice between organizational support and organizational citizenship behaviors for evidence-based practice.

PubMed

Chang, Ching-Sheng

2014-10-01

Lack of existing literature on the correlation among organizational justice, organizational support, and organizational citizenship behaviors has created a research gap in previous evidence-based practice (EBP) studies on nursing personnel. To investigate whether organizational justice among nurses has a moderating effect between their organizational support and organizational citizenship behaviors in order to bridge such a gap of existing literature with the EBP study on nursing personnel. Nursing staff of one large and influential hospital in Taiwan was surveyed. Four hundred questionnaires were distributed, and 386 were collected with a valid response rate of 96.50%. SPSS 17.0 and Amos 17.0 statistical software packages were used for data analysis. Nurses' organizational support positively influences their organizational citizenship behaviors, and their organizational justice perception has a positive moderating effect between organizational support and organizational citizenship behaviors. Results call hospitals' attention to the type of individual behaviors that may improve organizational performance. When nursing staff perceive fair and impartial treatment by the organization and supportive emotional attachment, behaviors beneficial for the organization are expressed in return. Subjective perceptions of nursing staff play an important role in organizational exchange relationship; the higher the degree of nursing staff's perceived organizational justice, the higher the degree of their organizational support, perception, and exhibition of organizational citizenship behaviors such as altruistic behavior and dedication to the work. © 2014 Sigma Theta Tau International.

Long-term Behavioral Consequences of Brief, Repeated Neonatal Isolation

PubMed Central

Knuth, Emily D.; Etgen, Anne M.

2007-01-01

Rats subjected to stressful stimuli during the stress hyporesponsive period exhibit varied neuroendocrine and behavioral changes as neonates, adolescents and adults. The current work examined the effects of neonatal isolation stress, using a within-litter design, on adult anxiety-related behavior and endocrine stress reactivity. Neonatal rats were isolated daily for 1 hr from postnatal day (P) 4-9, a manipulation previously shown to induce hypothalamic-pituitary-adrenal (HPA) responses on P9 (Knuth and Etgen, 2005). Control animals were either handled briefly or left undisturbed (with-dam). Adult rats were tested for anxiety-related behavior using the elevated plus maze and open field, and for endocrine responses following restraint stress. Neonatal isolation decreased center exploration of the open field following 1 hr restraint, including decreased time in the center compared to with-dam or handled controls, and decreased center entries and distance traveled in the center compared to with-dam controls. It also decreased time in and entries into the open arms of the elevated plus maze compared to handled controls, suggesting enhanced anxiety-related behavior. Neonatal isolation had no effect on basal or restraint-induced levels of ACTH or corticosterone. These findings indicate that neonatal isolation may enhance anxiety-related behaviors, especially in response to stress, without altering HPA function. Section: Cognitive and Behavioral Neuroscience PMID:17125746

Modulated cortical control of individual fingers in experienced musicians: an EEG study. Electroencephalographic study.

PubMed

Slobounov, S; Chiang, H; Johnston, J; Ray, W

2002-12-01

The present research was designed to address the nature of interdependency between fingers during force production tasks in subjects with varying experience in performing independent finger manipulation. Specifically, behavioral and electroencephalographic (EEG) measures associated with controllability of the most enslaved (ring) and the least enslaved (index) fingers was examined in musicians and non-musicians. Six piano players and 6 age-matched control subjects performed a series of isometric force production tasks with the index and ring fingers. Subjects produced 3 different force levels with either their index or ring fingers. We measured the isometric force output produced by all 4 fingers (index, ring, middle and little), including both ramp and static phases of force production. We applied time-domain averaging of EEG single trials in order to extract 4 components of the movement-related cortical potentials (MRCP) preceding and accompanying force responses. Three behavioral findings were observed. First, musicians were more accurate than non-musicians at reaching the desired force level. Second, musicians showed less enslaving as compared to non-musicians. And third, the amount of enslaving increased with the increment of nominal force levels regardless of whether the index or ring finger was used as the master finger. In terms of EEG measures, we found differences between tasks performed with the index and ring fingers in non-musicians. For musicians, we found larger MRCP amplitudes at most electrode sites for the ring finger. Our data extends previous enslaving research and suggest an important role for previous experience in terms of the independent use of the fingers. Given that a variety of previous work has shown finger independence to be reflected in cortical representation in the brain and our findings of MRCP amplitude associated with greater independence of fingers in musicians, this suggests that what has been considered to be stable constraints in terms of finger movements can be modulated by experience. This work supports the idea that experience is associated with changes in behavioral and EEG correlates of task performance and may have clinical implications in disorders such as stroke or focal hand dystonia. Practice-related procedures offer useful approaches to rehabilitation strategies.

A Modification and Analysis of Lagrangian Trajectory Modeling and Granular Dynamics of Lunar Dust Particles

NASA Technical Reports Server (NTRS)

Long, Jason M.; Lane, John E.; Metzger, Philip T.

2008-01-01

A previously developed mathematical model is amended to more accurately incorporate the effects of lift and drag on single dust particles in order to predict their behavior in the wake of high velocity gas flow. The model utilizes output from a CFD or DSMC simulation of exhaust from a rocket nozzle hot gas jet. An extension of the Saffman equation for lift based on the research of McLaughlin (1991) and Mei (1992) is used, while an equation for the Magnus force modeled after the work of Oesterle (1994) and Tsuji et al (1985) is applied. A relationship for drag utilizing a particle shape factor (phi = 0.8) is taken from the work of Haider and Levenspiel (1989) for application to non-spherical particle dynamics. The drag equation is further adjusted to account for rarefaction and compressibility effects in rarefied and high Mach number flows according to the work of Davies (1945) and Loth (2007) respectively. Simulations using a more accurate model with the correction factor (Epsilon = 0.8 in a 20% particle concentration gas flow) given by Richardson and Zaki (1954) and Rowe (1961) show that particles have lower ejection angles than those that were previously calculated. This is more prevalent in smaller particles, which are shown through velocity and trajectory comparison to be more influenced by the flow of the surrounding gas. It is shown that particles are more affected by minor changes to drag forces than larger adjustments to lift forces, demanding a closer analysis of the shape and behavior of lunar dust particles and the composition of the surrounding gas flow.

Predictors of sun protection in northern Australian men with a history of nonmelanoma skin cancer.

PubMed

Woolley, Torres; Buettner, Petra G; Lowe, John

2004-08-01

It is important to understand what predicts regular use of sun protection in men susceptible to skin cancer. A questionnaire survey of men with previous nonmelanoma skin cancer (n = 300) was conducted. Participants who typically used sunscreen tended to be younger, have fewer excised skin lesions, work indoors, and have spent most of their life in the tropics. Predictors of wearing a long-sleeved shirt with a wide-brimmed hat were not enjoying sun exposure, not having barriers to using sun protection, having more skin lesions previously excised, working for a company with a mandatory policy of sun protection, attitudes that the benefits of a suntan do not outweigh the risks and that skin cancers cannot be easily treated, and age over 50. Men who adequately protect themselves from the sun and who have better attitudes to sun exposure were more often those with a high level of negative experience with skin cancer. Therefore, the sun protection attitudes and behaviors of some men may only improve after significant sun damage. This study recommends that the use of appropriate sun protective clothing should be made mandatory for all who work outdoors in high-sun-exposure occupations.

Lattice Boltzmann method simulations of Stokes number effects on particle motion in a channel flow

NASA Astrophysics Data System (ADS)

Zhang, Lenan; Jebakumar, Anand Samuel; Abraham, John

2016-06-01

In a recent experimental study by Lau and Nathan ["Influence of Stokes number on the velocity and concentration distributions in particle-laden jets," J. Fluid Mech. 757, 432 (2014)], it was found that particles in a turbulent pipe flow tend to migrate preferentially toward the wall or the axis depending on their Stokes number (St). Particles with a higher St (>10) are concentrated near the axis while those with lower St (<1) move toward the walls. Jebakumar et al. ["Lattice Boltzmann method simulations of Stokes number effects on particle trajectories in a wall-bounded flow," Comput. Fluids 124, 208 (2016)] have carried out simulations of a particle in a laminar channel flow to investigate this behavior. In their work, they report a similar behavior where particles with low St migrate toward the wall and oscillate about a mean position near the wall while those with high St oscillate about the channel center plane. They have explained this behavior in terms of the Saffman lift, Magnus lift, and wall repulsion forces acting on the particle. The present work extends the previous work done by Jebakumar et al. and aims to study the behavior of particles at intermediate St ranging from 10 to 20. It is in this range where the equilibrium position of the particle changes from near the wall to the axis and the particle starts oscillating about the axis. The Lattice Boltzmann method is employed to carry out this study. It is shown that the change in mean equilibrium position is related to increasing oscillations of the particle with mean position near the wall which results in the particle moving past the center plane to the opposite side. The responsible mechanisms are explained in detail.

Moral license in video games: when being right can mean doing wrong.

PubMed

Ellithorpe, Morgan E; Cruz, Carlos; Velez, John A; Ewoldsen, David R; Bogert, Adam K

2015-04-01

Research on video game violence has found largely consistent evidence that violence in video games tends to be associated with an increase in antisocial behavior. However, this body of work has mostly ignored one prominent feature of many violent games: moral decision making. It is possible that the influence of video game violence could change when moral decisions are brought into the context. One way video games change behavior is through changes in players' self-perceptions, a process called identity simulation. In addition, a perspective called moral license predicts that these effects should not necessarily be consistent across behaviors, in that people should try to balance selfishness with keeping the moral high ground across many behaviors. Therefore, moral choices (or immoral choices) in a video game may predict less moral (or more moral) behaviors right after the game. However, later behavior may revert yet again, creating a cycle of pro- and antisocial behaviors. The present experiment asks participants to make moral choices in a video game, and then measures their behavior on two subsequent tasks. Results indicate that taking what participants perceive to be the more moral mind-set in the video game predicts more antisocial behavior on the first task, but more pro-social behavior on the next task. These results support identity simulation and moral license processes in a video game and moral behavior context, and indicate that there may be greater complexity in video game violence effects than previously understood.

Conservation in Mammals of Genes Associated with Aggression-Related Behavioral Phenotypes in Honey Bees

PubMed Central

Robinson, Gene E.; Jakobsson, Eric

2016-01-01

The emerging field of sociogenomics explores the relations between social behavior and genome structure and function. An important question is the extent to which associations between social behavior and gene expression are conserved among the Metazoa. Prior experimental work in an invertebrate model of social behavior, the honey bee, revealed distinct brain gene expression patterns in African and European honey bees, and within European honey bees with different behavioral phenotypes. The present work is a computational study of these previous findings in which we analyze, by orthology determination, the extent to which genes that are socially regulated in honey bees are conserved across the Metazoa. We found that the differentially expressed gene sets associated with alarm pheromone response, the difference between old and young bees, and the colony influence on soldier bees, are enriched in widely conserved genes, indicating that these differences have genomic bases shared with many other metazoans. By contrast, the sets of differentially expressed genes associated with the differences between African and European forager and guard bees are depleted in widely conserved genes, indicating that the genomic basis for this social behavior is relatively specific to honey bees. For the alarm pheromone response gene set, we found a particularly high degree of conservation with mammals, even though the alarm pheromone itself is bee-specific. Gene Ontology identification of human orthologs to the strongly conserved honey bee genes associated with the alarm pheromone response shows overrepresentation of protein metabolism, regulation of protein complex formation, and protein folding, perhaps associated with remodeling of critical neural circuits in response to alarm pheromone. We hypothesize that such remodeling may be an adaptation of social animals to process and respond appropriately to the complex patterns of conspecific communication essential for social organization. PMID:27359102

Conservation in Mammals of Genes Associated with Aggression-Related Behavioral Phenotypes in Honey Bees.

PubMed

Liu, Hui; Robinson, Gene E; Jakobsson, Eric

2016-06-01

The emerging field of sociogenomics explores the relations between social behavior and genome structure and function. An important question is the extent to which associations between social behavior and gene expression are conserved among the Metazoa. Prior experimental work in an invertebrate model of social behavior, the honey bee, revealed distinct brain gene expression patterns in African and European honey bees, and within European honey bees with different behavioral phenotypes. The present work is a computational study of these previous findings in which we analyze, by orthology determination, the extent to which genes that are socially regulated in honey bees are conserved across the Metazoa. We found that the differentially expressed gene sets associated with alarm pheromone response, the difference between old and young bees, and the colony influence on soldier bees, are enriched in widely conserved genes, indicating that these differences have genomic bases shared with many other metazoans. By contrast, the sets of differentially expressed genes associated with the differences between African and European forager and guard bees are depleted in widely conserved genes, indicating that the genomic basis for this social behavior is relatively specific to honey bees. For the alarm pheromone response gene set, we found a particularly high degree of conservation with mammals, even though the alarm pheromone itself is bee-specific. Gene Ontology identification of human orthologs to the strongly conserved honey bee genes associated with the alarm pheromone response shows overrepresentation of protein metabolism, regulation of protein complex formation, and protein folding, perhaps associated with remodeling of critical neural circuits in response to alarm pheromone. We hypothesize that such remodeling may be an adaptation of social animals to process and respond appropriately to the complex patterns of conspecific communication essential for social organization.

Impulsive aggression, delay discounting, and adolescent suicide attempts: effects of current psychotropic medication use and family history of suicidal behavior.

PubMed

Bridge, Jeffrey A; Reynolds, Brady; McBee-Strayer, Sandra M; Sheftall, Arielle H; Ackerman, John; Stevens, Jack; Mendoza, Kristen; Campo, John V; Brent, David A

2015-03-01

Impulsive-aggressive behaviors have been consistently implicated in the phenomenology, neurobiology, and familial aggregation of suicidal behavior. The purpose of this study was to extend previous work by examining laboratory behavioral measures of delayed reward impulsivity and impulsive aggression in adolescent suicide attempters and never-suicidal comparison subjects. Using the Point Subtraction Aggression Paradigm (PSAP) and the Delay Discounting Task (DDQ), the authors examined delay discounting and impulsive aggression in 40 adolescent suicide attempters, ages 13-18, and 40 never-suicidal, demographically matched psychiatric comparison subjects. Overall, suicide attempters and comparison subjects performed similarly on the PSAP and DDQ. There was a significant group by current psychotropic medication use interaction (p=0.013) for mean aggressive responses on the PSAP. Group comparisons revealed that attempters emitted more aggressive responses per provocation than comparison subjects, only in those not on psychotropic medication (p=0.049), whereas for those currently treated with psychotropic medication, there were no group differences (p>0.05). This interaction effect was specific to current antidepressant use. Among all subjects, family history of suicidal behavior (suicide or suicide attempt) in first degree relatives was significantly correlated with both delay discounting (r=-0.22, p=0.049), and aggressive responding (r=0.27, p=0.015). Family history of suicidal behavior was associated with delay discounting, but not with aggressive responding on the PSAP, after controlling for relevant covariates. In this study, impulsive-aggressive responding was associated with suicide attempt only in those not being treated with antidepressants. Future work to replicate and extend these findings could have important therapeutic implications for the treatment of depressed suicide attempters, many of whom are affected by impulsive aggression.

Impulsive Aggression, Delay Discounting, and Adolescent Suicide Attempts: Effects of Current Psychotropic Medication Use and Family History of Suicidal Behavior

PubMed Central

Reynolds, Brady; McBee-Strayer, Sandra M.; Sheftall, Arielle H.; Ackerman, John; Stevens, Jack; Mendoza, Kristen; Campo, John V.; Brent, David A.

2015-01-01

Abstract Objective: Impulsive-aggressive behaviors have been consistently implicated in the phenomenology, neurobiology, and familial aggregation of suicidal behavior. The purpose of this study was to extend previous work by examining laboratory behavioral measures of delayed reward impulsivity and impulsive aggression in adolescent suicide attempters and never-suicidal comparison subjects. Methods: Using the Point Subtraction Aggression Paradigm (PSAP) and the Delay Discounting Task (DDQ), the authors examined delay discounting and impulsive aggression in 40 adolescent suicide attempters, ages 13–18, and 40 never-suicidal, demographically matched psychiatric comparison subjects. Results: Overall, suicide attempters and comparison subjects performed similarly on the PSAP and DDQ. There was a significant group by current psychotropic medication use interaction (p=0.013) for mean aggressive responses on the PSAP. Group comparisons revealed that attempters emitted more aggressive responses per provocation than comparison subjects, only in those not on psychotropic medication (p=0.049), whereas for those currently treated with psychotropic medication, there were no group differences (p>0.05). This interaction effect was specific to current antidepressant use. Among all subjects, family history of suicidal behavior (suicide or suicide attempt) in first degree relatives was significantly correlated with both delay discounting (r=−0.22, p=0.049), and aggressive responding (r=0.27, p=0.015). Family history of suicidal behavior was associated with delay discounting, but not with aggressive responding on the PSAP, after controlling for relevant covariates. Conclusions: In this study, impulsive-aggressive responding was associated with suicide attempt only in those not being treated with antidepressants. Future work to replicate and extend these findings could have important therapeutic implications for the treatment of depressed suicide attempters, many of whom are affected by impulsive aggression. PMID:25745870

Sexual behavior at work: Fun or folly?

PubMed

Berdahl, Jennifer L; Aquino, Karl

2009-01-01

Sexual behavior at work (e.g., sexual jokes and propositions) has been largely portrayed as offensive and harmful. The current research represents the first studies to test whether this is typically the case. Study 1 surveyed manufacturing and social service workers (N = 238) about their psychological well-being, work withdrawal, and exposure to sexual behavior at work. Respondents indicated how often they were exposed to different sexual behaviors and how much they enjoyed or were bothered by them. Study 2 surveyed university staff (N = 1,004) about their psychological well-being, drug use, feelings of being valued at work, and exposure to sexual behavior at work. Fifty-eight percent of employees in Study 1 were exposed to sexual behavior in the past 2 years; 40% of employees in Study 2 were exposed to sexual behavior in the past year. Some women and many men reported enjoying sexual behavior at work. Despite this, exposure to sexual behavior at work predicted negative employee work and psychological well-being, even for employees who said they enjoyed the experience. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

Common mental disorders and subsequent work disability: a population-based Health 2000 Study.

PubMed

Ahola, Kirsi; Virtanen, Marianna; Honkonen, Teija; Isometsä, Erkki; Aromaa, Arpo; Lönnqvist, Jouko

2011-11-01

Work disability due to common mental disorders has increased in Western countries during the past decade. The contribution of depressive, anxiety, and alcohol use disorders to all disability pensions at the population level is not known. Epidemiological health data from the Finnish Health 2000 Study, gathered in 2000-2001, was linked to the national register on disability pensions granted due to the ICD-10 diagnoses up to December 2007. Mental health at baseline was assessed using the Composite International Diagnostic Interview (CIDI). Sociodemographic, clinical, and work-related factors, health behaviors, and treatment setting were used as covariates in the logistic regression analyses among the 3164 participants aged 30-58 years. Anxiety, depressive, and comorbid common mental disorders predicted disability pension when adjusted for sex and age. In the fully adjusted multivariate model, comorbid common mental disorders, as well as physical illnesses, age over 45 years, short education, high job strain, and previous long-term sickness absence predicted disability pension. The study population included persons aged 30 or over. Sub groups according to mental disorders were quite small which may have diminished statistical power in some sub groups. Baseline predictors were measured only once and the length of exposure could not be determined. The systems regarding financial compensation to employees differ between countries. Comorbid mental disorders pose a high risk for disability pension. Other independent predictors of work disability include socio-demographic, clinical, work-related, and treatment factors, but not health behavior. More attention should be paid to work-related factors in order to prevent chronic work disability. Copyright © 2011 Elsevier B.V. All rights reserved.

The Importance of Pro-Environmental Behavior in Adolescent

NASA Astrophysics Data System (ADS)

Palupi, Tyas; Sawitri, Dian R.

2018-02-01

Studies regarding pro-environmental behavior in adolescents are lacking. This study aimed to examine the importance of pro-environmental behavior in adolescents (high school and university students) by conducting literature review from previous studies on pro environmental behavior. Pro-environmental behavior is the behavior of individuals that contributes towards environmental preservation. Based on previous studies, measurement of pro-environmental behavior were investigated on several theories, namely theory of planned behavior (TPB) and value, belief, norms (VBN) by using aspects of pro environmental behavior. Young people with critical thinking, and good environmental education, are expected to behave more environmentally friendly for creating a sustainable future.

Sleep-Dependent Consolidation of Rewarded Behavior Is Diminished in Children with Attention Deficit Hyperactivity Disorder and a Comorbid Disorder of Social Behavior

PubMed Central

Wiesner, Christian D.; Molzow, Ina; Prehn-Kristensen, Alexander; Baving, Lioba

2017-01-01

Children suffering from attention-deficit hyperactivity disorder (ADHD) often also display impaired learning and memory. Previous research has documented aberrant reward processing in ADHD as well as impaired sleep-dependent consolidation of declarative memory. We investigated whether sleep also fosters the consolidation of behavior learned by probabilistic reward and whether ADHD patients with a comorbid disorder of social behavior show deficits in this memory domain, too. A group of 17 ADHD patients with comorbid disorders of social behavior aged 8–12 years and healthy controls matched for age, IQ, and handedness took part in the experiment. During the encoding task, children worked on a probabilistic learning task acquiring behavioral preferences for stimuli rewarded most often. After a 12-hr retention interval of either sleep at night or wakefulness during the day, a reversal task was presented where the contingencies were reversed. Consolidation of rewarded behavior is indicated by greater resistance to reversal learning. We found that healthy children consolidate rewarded behavior better during a night of sleep than during a day awake and that the sleep-dependent consolidation of rewarded behavior by trend correlates with non-REM sleep but not with REM sleep. In contrast, children with ADHD and comorbid disorders of social behavior do not show sleep-dependent consolidation of rewarded behavior. Moreover, their consolidation of rewarded behavior does not correlate with sleep. The results indicate that dysfunctional sleep in children suffering from ADHD and disorders of social behavior might be a crucial factor in the consolidation of behavior learned by reward. PMID:28228742

Sexual behavior of migrant workers in Shanghai, China.

PubMed

Dai, Wei; Gao, Jian; Gong, Jian; Xia, Xiuping; Yang, Hua; Shen, Yao; Gu, Jie; Wang, Tianhao; Liu, Yao; Zhou, Jing; Shen, Zhiping; Zhu, Shanzhu; Pan, Zhigang

2015-10-17

Rapid urbanization of China has resulted in significant domestic migration. The purpose of the present study was to survey the sexual behavior of migrant workers in Shanghai and determine the risk factors for unprotected sex. A cross-sectional study of the sexual behavior of 5996 migrant workers was conducted in 7 administrative regions of Shanghai in 2012 from August to October. A self-administered questionnaire was used to collect data. Five thousand seven hundred seventy two out of the 5996 migrants enrolled into the present study were primarily young adults aged 34.3 ± 10.6 years. Of them, 73.5 % were married, 51.1 % graduated from junior high school, 46.0 % earned 1500-2500 yuan (RMB) monthly. The majority (82.3 %) of the migrants engaged in sexual behavior, and 58.0 % did not use condoms in sexual intercourse. Some of the participants (15.2 %) had casual extramarital partners within the previous 12 months; among them, 76.2 % never or only occasionally used condoms. The results of the multivariate logistic regression analysis suggested that condom use was associated with age, occupation, monthly income, education, and housing conditions. Having temporary sexual partners was significantly associated with several factors such as unmarried (OR: 0.47, 95 % CI: 0.38-0.57), working at domestic (OR: 1.65,95 % CI: 1.17-2.34), working at wholesale/retail(OR: 1.65, 95 % CI: 1.13-2.13), and male migrants (OR: 2.37, 95 % CI: 1.96-2.85), but not with other factors such as age, monthly income, or education. Having casual extramarital partners was significantly associated with female migrants working at domestic (OR: 1.89, 95 % CI: 1.09-3.28), unmarried male migrants (OR: 0.51, 95 % CI: 0.36-0.74). Closer attention should be paid to sexual health education among migrant workers, especially women and those working in domestic and wholesale/retail occupations. The use of condoms should be promoted for older (>35 y), low-income, and less-educated individuals.

ENU-mutagenesis mice with a non-synonymous mutation in Grin1 exhibit abnormal anxiety-like behaviors, impaired fear memory, and decreased acoustic startle response

PubMed Central

2013-01-01

Background The Grin1 (glutamate receptor, ionotropic, NMDA1) gene expresses a subunit of N-methyl-D-aspartate (NMDA) receptors that is considered to play an important role in excitatory neurotransmission, synaptic plasticity, and brain development. Grin1 is a candidate susceptibility gene for neuropsychiatric disorders, including schizophrenia, bipolar disorder, and attention deficit/hyperactivity disorder (ADHD). In our previous study, we examined an N-ethyl-N-nitrosourea (ENU)-generated mutant mouse strain (Grin1Rgsc174/Grin1+) that has a non-synonymous mutation in Grin1. These mutant mice showed hyperactivity, increased novelty-seeking to objects, and abnormal social interactions. Therefore, Grin1Rgsc174/Grin1+ mice may serve as a potential animal model of neuropsychiatric disorders. However, other behavioral characteristics related to these disorders, such as working memory function and sensorimotor gating, have not been fully explored in these mutant mice. In this study, to further investigate the behavioral phenotypes of Grin1Rgsc174/Grin1+ mice, we subjected them to a comprehensive battery of behavioral tests. Results There was no significant difference in nociception between Grin1Rgsc174/Grin1+ and wild-type mice. The mutants did not display any abnormalities in the Porsolt forced swim and tail suspension tests. We confirmed the previous observations that the locomotor activity of these mutant mice increased in the open field and home cage activity tests. They displayed abnormal anxiety-like behaviors in the light/dark transition and the elevated plus maze tests. Both contextual and cued fear memory were severely deficient in the fear conditioning test. The mutant mice exhibited slightly impaired working memory in the eight-arm radial maze test. The startle amplitude was markedly decreased in Grin1Rgsc174/Grin1+ mice, whereas no significant differences between genotypes were detected in the prepulse inhibition (PPI) test. The mutant mice showed no obvious deficits in social behaviors in three different social interaction tests. Conclusions This study demonstrated that the Grin1Rgsc174/Grin1+ mutation causes abnormal anxiety-like behaviors, a deficiency in fear memory, and a decreased startle amplitude in mice. Although Grin1Rgsc174/Grin1+ mice only partially recapitulate symptoms of patients with ADHD, schizophrenia, and bipolar disorder, they may serve as a unique animal model of a certain subpopulation of patients with these disorders. PMID:23688147

Gender, Health Behavior, and Intimate Relationships: Lesbian, Gay, and Straight Contexts

PubMed Central

Reczek, Corinne; Umberson, Debra

2012-01-01

Many studies focus on health behavior within the context of intimate ties. However, this literature is limited by reliance on gender socialization theory and a focus on straight (i.e., heterosexual) marriage. We extend this work with an analysis of relationship dynamics around health behavior in 20 long-term straight marriages as well as 15 gay and 15 lesbian long-term cohabiting partnerships in the United States (N=100 individual in-depth interviews). We develop the concept of “health behavior work” to align activities done to promote health behavior with theories on unpaid work in the home. Respondents in all couple types describe specialized health behavior work, wherein one partner works to shape the other partner’s health behavior. In straight couples, women perform the bulk of specialized health behavior work. Most gay and lesbian respondents—but few straight respondents—also describe cooperative health behavior work, wherein partners mutually influence one another’s health behaviors. Findings suggest that the gendered relational context of an intimate partnership shapes the dynamics of and explanations for health behavior work. PMID:22227238

Further examination of factors that influence preference for positive versus negative reinforcement.

PubMed

Kodak, Tiffany; Lerman, Dorothea C; Volkert, Valerie M; Trosclair, Nicole

2007-01-01

Factors that influence choice between qualitatively different reinforcers (e.g., a food item or a break from work) are important to consider when arranging treatments for problem behavior. Previous findings indicate that children who engage in problem behavior maintained by escape from demands may choose a food item over the functional reinforcer during treatment (DeLeon, Neidert, Anders, & Rodriguez-Catter, 2001; Lalli et al., 1999). However, a number of variables may influence choice between concurrently available forms of reinforcement. An analogue for treatment situations in which positive reinforcement for compliance is in direct competition with negative reinforcement for problem behavior was used in the current study to evaluate several variables that may influence choice. Participants were 5 children who had been diagnosed with developmental disabilities and who engaged in problem behavior maintained by escape from demands. In the first phase, the effects of task preference and schedule of reinforcement on choice between a 30-s break and a high-preference food item were evaluated. The food item was preferred over the break, regardless of the preference level of the task or the reinforcement schedule, for all but 1 participant. In the second phase, the quality of the break was manipulated by combining escape with toys, attention, or both. Only 1 participant showed preference for the enriched break. In the third phase, choice of a medium- or low-preference food item versus the enriched break was evaluated. Three of 4 participants showed preference for the break over the less preferred food item. Results extend previous research by identifying some of the conditions under which individuals who engage in escape-maintained behavior will prefer a food reinforcer over the functional one.

Further Examination of Factors that Influence Preference for Positive Versus Negative Reinforcement

PubMed Central

Kodak, Tiffany; Lerman, Dorothea C; Volkert, Valerie M; Trosclair, Nicole

2007-01-01

Factors that influence choice between qualitatively different reinforcers (e.g., a food item or a break from work) are important to consider when arranging treatments for problem behavior. Previous findings indicate that children who engage in problem behavior maintained by escape from demands may choose a food item over the functional reinforcer during treatment (DeLeon, Neidert, Anders, & Rodriguez-Catter, 2001; Lalli et al., 1999). However, a number of variables may influence choice between concurrently available forms of reinforcement. An analogue for treatment situations in which positive reinforcement for compliance is in direct competition with negative reinforcement for problem behavior was used in the current study to evaluate several variables that may influence choice. Participants were 5 children who had been diagnosed with developmental disabilities and who engaged in problem behavior maintained by escape from demands. In the first phase, the effects of task preference and schedule of reinforcement on choice between a 30-s break and a high-preference food item were evaluated. The food item was preferred over the break, regardless of the preference level of the task or the reinforcement schedule, for all but 1 participant. In the second phase, the quality of the break was manipulated by combining escape with toys, attention, or both. Only 1 participant showed preference for the enriched break. In the third phase, choice of a medium- or low-preference food item versus the enriched break was evaluated. Three of 4 participants showed preference for the break over the less preferred food item. Results extend previous research by identifying some of the conditions under which individuals who engage in escape-maintained behavior will prefer a food reinforcer over the functional one. PMID:17471792

The Effect of Pitching Phase on the Vortex Circulation for a Flapping Wing During Stroke Reversal

NASA Astrophysics Data System (ADS)

Burge, Matthew; Ringuette, Matthew

2017-11-01

We study the effect of pitching-phase on the circulation behavior for the 3D flow structures produced during stroke reversal for a 2-degree-of-freedom flapping wing executing hovering kinematics. Previous research has related the choice in pitching-phase with respect to the wing rotation during stroke reversal (advanced vs. symmetric pitch-timing) to a lift peak preceding stroke reversal. However, results from experiments on the time-varying circulation contributions from the 3D vortex structures across the span produced by both rotation and pitching are lacking. The objective of this research is to quantitatively examine how the spanwise circulation of these structures is affected by the pitching-phase for several reduced pitching frequencies. We employ a scaled wing model in a glycerin-water mixture and measure the time-varying velocity using multiple planes of stereo digital particle image velocimetry. Data-plane positions along the wing span are informed by the unsteady behavior of the 3D vortex structures found in our prior flow visualization movies. Individual vortices are identified to calculate their circulation. This work is aimed at understanding how the behavior of the vortex structures created during stroke reversal vary with key motion parameters. This work is supported by the National Science Foundation, Award Number 1336548, supervised by Dr. Ronald Joslin.

Time-varying mixed logit model for vehicle merging behavior in work zone merging areas.

PubMed

Weng, Jinxian; Du, Gang; Li, Dan; Yu, Yao

2018-08-01

This study aims to develop a time-varying mixed logit model for the vehicle merging behavior in work zone merging areas during the merging implementation period from the time of starting a merging maneuver to that of completing the maneuver. From the safety perspective, vehicle crash probability and severity between the merging vehicle and its surrounding vehicles are regarded as major factors influencing vehicle merging decisions. Model results show that the model with the use of vehicle crash risk probability and severity could provide higher prediction accuracy than previous models with the use of vehicle speeds and gap sizes. It is found that lead vehicle type, through lead vehicle type, through lag vehicle type, crash probability of the merging vehicle with respect to the through lag vehicle, crash severities of the merging vehicle with respect to the through lead and lag vehicles could exhibit time-varying effects on the merging behavior. One important finding is that the merging vehicle could become more and more aggressive in order to complete the merging maneuver as quickly as possible over the elapsed time, even if it has high vehicle crash risk with respect to the through lead and lag vehicles. Copyright © 2018 Elsevier Ltd. All rights reserved.

An improved k-epsilon model for near wall turbulence

NASA Technical Reports Server (NTRS)

Shih, T. H.; Hsu, Andrew T.

1991-01-01

An improved k-epsilon model for low Reynolds number turbulence near a wall is presented. In the first part of this work, the near-wall asymptotic behavior of the eddy viscosity and the pressure transport term in the turbulent kinetic energy equation are analyzed. Based on these analyses, a modified eddy viscosity model with the correct near-wall behavior is suggested, and a model for the pressure transport term in the k-equation is proposed. In addition, a modeled dissipation rate equation is reformulated, and a boundary condition for the dissipation rate is suggested. In the second part of the work, one of the deficiencies of the existing k-epsilon models, namely, the wall distance dependency of the equations and the damping functions, is examined. An improved model that does not depend on any wall distance is introduced. Fully developed turbulent channel flows and turbulent boundary layers over a flat plate are studied as validations for the proposed new models. Numerical results obtained from the present and other previous k-epsilon models are compared with data from direct numerical simulation. The results show that the present k-epsilon model, with added robustness, performs as well as or better than other existing models in predicting the behavior of near-wall turbulence.

History of concussion impacts electrophysiological correlates of working memory.

PubMed

Hudac, Caitlin M; Cortesa, Cathryn S; Ledwidge, Patrick S; Molfese, Dennis L

2017-10-10

Sports-related concussions occur in approximately 21% of college athletes with implications for long-term cognitive impairments in working memory. Working memory involves the capacity to maintain short-term information and integrate with higher-order cognitive processing for planning and behavior execution, critical skills for optimal cognitive and athletic performance. This study quantified working memory impairments in 36 American football college athletes (18-23years old) using event-related potentials (ERPs). Despite performing similarly in a standard 2-back working memory task, athletes with history of concussion exhibited larger P1 and P3 amplitudes compared to Controls. Concussion History group latencies were slower for the P1 and faster for the N2. Source estimation analyses indicated that previously concussed athletes engaged different brain regions compared to athletes with no concussion history. These findings suggest that ERPs may be a sensitive and objective measure to detect long-term cognitive consequences of concussion. Copyright © 2017 Elsevier B.V. All rights reserved.

Prevalence and Co-Occurrence of Addictive Behaviors Among Russian and Spanish Youth.

PubMed

Tsai, Jennifer; Huh, Jimi; Idrisov, Bulat; Galimov, Artur; Espada, Jose P; Gonzálvez, María T; Sussman, Steve

2017-01-01

Recently, an addiction matrix measure was assessed among U.S. former alternative high school youth. This presentation seeks to examine the generalizability of findings using this measure among Russian and Spanish high school adolescents. Latent class analysis was used to explore addiction subgroups among adolescents in Russia (average age = 16.27; n = 715) and Spain (average age = 14.9; n = 811). Last 30-day prevalence of one or more of 11 addictions reviewed in the previous work was the primary focus (i.e., cigarettes, alcohol, hard drugs, eating, gambling, Internet, love, sex, exercise, work, and shopping) among Russian youth, and last-30 prevalence of one or more of 8 addictions among Spanish youth (the three drug use items had not been included in the questionnaire for these youths). Results confirmed a two-class model (addicted class and non-addicted class) among both Russian and Spanish adolescents. The mean number of addictions reported was 1.39 ( SD = 1.78) addictions among Russian youth and 1.56 ( SD = 1.68) addictions among Spanish youth. The prevalence of the sample that constituted the "addicted group" in Russia and Spain was 32.2% and 28.6%, respectively. The most prevalent addictions (i.e., love, Internet, exercise) were similar. These results are similar to the findings previously reported for U.S. Latent class structures for addictive behaviors are similar across international adolescent populations. Our results highlight the need to address multiple addictions in health education programming.

Episodic memories predict adaptive value-based decision-making

PubMed Central

Murty, Vishnu; FeldmanHall, Oriel; Hunter, Lindsay E.; Phelps, Elizabeth A; Davachi, Lila

2016-01-01

Prior research illustrates that memory can guide value-based decision-making. For example, previous work has implicated both working memory and procedural memory (i.e., reinforcement learning) in guiding choice. However, other types of memories, such as episodic memory, may also influence decision-making. Here we test the role for episodic memory—specifically item versus associative memory—in supporting value-based choice. Participants completed a task where they first learned the value associated with trial unique lotteries. After a short delay, they completed a decision-making task where they could choose to re-engage with previously encountered lotteries, or new never before seen lotteries. Finally, participants completed a surprise memory test for the lotteries and their associated values. Results indicate that participants chose to re-engage more often with lotteries that resulted in high versus low rewards. Critically, participants not only formed detailed, associative memories for the reward values coupled with individual lotteries, but also exhibited adaptive decision-making only when they had intact associative memory. We further found that the relationship between adaptive choice and associative memory generalized to more complex, ecologically valid choice behavior, such as social decision-making. However, individuals more strongly encode experiences of social violations—such as being treated unfairly, suggesting a bias for how individuals form associative memories within social contexts. Together, these findings provide an important integration of episodic memory and decision-making literatures to better understand key mechanisms supporting adaptive behavior. PMID:26999046

Functional MRI of Handwriting Tasks: A Study of Healthy Young Adults Interacting with a Novel Touch-Sensitive Tablet

PubMed Central

Karimpoor, Mahta; Churchill, Nathan W.; Tam, Fred; Fischer, Corinne E.; Schweizer, Tom A.; Graham, Simon J.

2018-01-01

Handwriting is a complex human activity that engages a blend of cognitive and visual motor skills. Current understanding of the neural correlates of handwriting has largely come from lesion studies of patients with impaired handwriting. Task-based fMRI studies would be useful to supplement this work. To address concerns over ecological validity, previously we developed a fMRI-compatible, computerized tablet system for writing and drawing including visual feedback of hand position and an augmented reality display. The purpose of the present work is to use the tablet system in proof-of-concept to characterize brain activity associated with clinically relevant handwriting tasks, originally developed to characterize handwriting impairments in Alzheimer’s disease patients. As a prelude to undertaking fMRI studies of patients, imaging was performed of twelve young healthy subjects who copied sentences, phone numbers, and grocery lists using the fMRI-compatible tablet. Activation maps for all handwriting tasks consisted of a distributed network of regions in reasonable agreement with previous studies of handwriting performance. In addition, differences in brain activity were observed between the test subcomponents consistent with different demands of neural processing for successful task performance, as identified by investigating three quantitative behavioral metrics (writing speed, stylus contact force and stylus in air time). This study provides baseline behavioral and brain activity results for fMRI studies that adopt this handwriting test to characterize patients with brain impairments. PMID:29487511

Functional MRI of Handwriting Tasks: A Study of Healthy Young Adults Interacting with a Novel Touch-Sensitive Tablet.

PubMed

Karimpoor, Mahta; Churchill, Nathan W; Tam, Fred; Fischer, Corinne E; Schweizer, Tom A; Graham, Simon J

2018-01-01

Handwriting is a complex human activity that engages a blend of cognitive and visual motor skills. Current understanding of the neural correlates of handwriting has largely come from lesion studies of patients with impaired handwriting. Task-based fMRI studies would be useful to supplement this work. To address concerns over ecological validity, previously we developed a fMRI-compatible, computerized tablet system for writing and drawing including visual feedback of hand position and an augmented reality display. The purpose of the present work is to use the tablet system in proof-of-concept to characterize brain activity associated with clinically relevant handwriting tasks, originally developed to characterize handwriting impairments in Alzheimer's disease patients. As a prelude to undertaking fMRI studies of patients, imaging was performed of twelve young healthy subjects who copied sentences, phone numbers, and grocery lists using the fMRI-compatible tablet. Activation maps for all handwriting tasks consisted of a distributed network of regions in reasonable agreement with previous studies of handwriting performance. In addition, differences in brain activity were observed between the test subcomponents consistent with different demands of neural processing for successful task performance, as identified by investigating three quantitative behavioral metrics (writing speed, stylus contact force and stylus in air time). This study provides baseline behavioral and brain activity results for fMRI studies that adopt this handwriting test to characterize patients with brain impairments.

Understanding less than nothing: children's neural response to negative numbers shifts across age and accuracy.

PubMed

Gullick, Margaret M; Wolford, George

2013-01-01

We examined the brain activity underlying the development of our understanding of negative numbers, which are amounts lacking direct physical counterparts. Children performed a paired comparison task with positive and negative numbers during an fMRI session. As previously shown in adults, both pre-instruction fifth-graders and post-instruction seventh-graders demonstrated typical behavioral and neural distance effects to negative numbers, where response times and parietal and frontal activity increased as comparison distance decreased. We then determined the factors impacting the distance effect in each age group. Behaviorally, the fifth-grader distance effect for negatives was significantly predicted only by positive comparison accuracy, indicating that children who were generally better at working with numbers were better at comparing negatives. In seventh-graders, negative number comparison accuracy significantly predicted their negative number distance effect, indicating that children who were better at working with negative numbers demonstrated a more typical distance effect. Across children, as age increased, the negative number distance effect increased in the bilateral IPS and decreased frontally, indicating a frontoparietal shift consistent with previous numerical development literature. In contrast, as negative comparison task accuracy increased, the parietal distance effect increased in the left IPS and decreased in the right, possibly indicating a change from an approximate understanding of negatives' values to a more exact, precise representation (particularly supported by the left IPS) with increasing expertise. These shifts separately indicate the effects of increasing maturity generally in numeric processing and specifically in negative number understanding.

[Exposure to aggressive patient behaviour and its' association with the nurses' "work ability" in Germany].

PubMed

Galatsch, Michael; Iskenius, Mario; Schlarmann, Jörg Grosse; Schmidt, Sascha G; Müller, Bernd Hans; Hasselhorn, Hans Martin

2013-11-01

Aggressive behavior and violence in patients, residents or clients are growing challenges in nursing. Aggressive behavior can have both, physical and psychological consequences for nurses and can lead to a reduced performance at work, demotivation, sickness absence and the premature exit from the nursing profession. To develop purposive strategies and to deal with aggressive behavior and health promotion programs, it is crucial to know more about the prevalence of aggressive behavior from patients and the effect on the work ability of nurses in different types of institutions. Data of 1735 German nurses was derived from the European NEXT-Study. Description and analysis of variance for each working area (hospital ward, Intensive Care Unit, psychiatric ward, nursing home and home care) were conducted. The work ability was measured with the Work Ability Index (WAI). The aggressive behavior was measured by one item developed by the NEXT Study Group. Linear regression models were applied to analyze the effect of aggressive behavior on the work ability of nurses in a comparison of the five different working areas. A total of 84.9 percent of the nurses were "sometimes" or "often/always" confronted with aggressive behavior from patients. In the comparison of the five working areas, nurses were exposed to different levels of aggressive behavior, while differences in the work ability of nurses were also observed. It was found that aggressive behavior from patients was associated with reduced work ability in nurses working in hospital wards, nursing homes and home care, but not nurses working in ICUs and psychiatric wards. The findings indicate that many nurses in Germany are exposed to aggressive behavior from patients, which has negative effect on the nurses' work ability. However, it is assumed that strategies to deal with aggressive behavior could play a buffer role between aggressive behavior and work ability of nurses, highlighting one possibility of intervention in future.

Fostering change in back pain beliefs and behaviors: when public education is not enough.

PubMed

Gross, Douglas P; Deshpande, Sameer; Werner, Erik L; Reneman, Michiel F; Miciak, Maxi A; Buchbinder, Rachelle

2012-11-01

Mass media campaigns designed to alter societal views and individual behaviors about back pain have been undertaken and evaluated in multiple countries. In contrast to the original Australian campaign, subsequent campaigns have been less successful, with improvements observed in beliefs without the corresponding changes in related behaviors. This article summarizes the results of a literature review, expert panel, and workshop held at the Melbourne International Forum XI: Primary Care Research on Low Back Pain in March 2011 on the role and interplay of various social behavior change strategies, including public education, law and legislation, healthy public policy, and social marketing in achieving a sustained reduction in the societal burden of back pain. Given the complexities inherent to health-related behaviors change, the Rothschild framework is applied in which behavior change strategies are viewed on a continuum from public education at one end through law and health policy at the other. Educational endeavors should likely be augmented with social marketing endeavors and supportive laws and health policy to foster sustained change in outcomes such as work disability and health utilization. Practical suggestions are provided for future interventions aimed at changing back pain-related behaviors. Evaluation of previous back pain mass media campaigns reveals that education alone is unlikely to foster positive and persisting behavioral change without concomitant strategies. Copyright © 2012 Elsevier Inc. All rights reserved.

Scaling analysis of the non-Abelian quasiparticle tunneling in [Formula: see text] FQH states.

PubMed

Li, Qi; Jiang, Na; Wan, Xin; Hu, Zi-Xiang

2018-06-27

Quasiparticle tunneling between two counter propagating edges through point contacts could provide information on its statistics. Previous study of the short distance tunneling displays a scaling behavior, especially in the conformal limit with zero tunneling distance. The scaling exponents for the non-Abelian quasiparticle tunneling exhibit some non-trivial behaviors. In this work, we revisit the quasiparticle tunneling amplitudes and their scaling behavior in a full range of the tunneling distance by putting the electrons on the surface of a cylinder. The edge-edge distance can be smoothly tuned by varying the aspect ratio for a finite size cylinder. We analyze the scaling behavior of the quasiparticles for the Read-Rezayi [Formula: see text] states for [Formula: see text] and 4 both in the short and long tunneling distance region. The finite size scaling analysis automatically gives us a critical length scale where the anomalous correction appears. We demonstrate this length scale is related to the size of the quasiparticle at which the backscattering between two counter propagating edges starts to be significant.

Predicting mixture phase equilibria and critical behavior using the SAFT-VRX approach.

PubMed

Sun, Lixin; Zhao, Honggang; Kiselev, Sergei B; McCabe, Clare

2005-05-12

The SAFT-VRX equation of state combines the SAFT-VR equation with a crossover function that smoothly transforms the classical equation into a nonanalytical form close to the critical point. By a combinination of the accuracy of the SAFT-VR approach away from the critical region with the asymptotic scaling behavior seen at the critical point of real fluids, the SAFT-VRX equation can accurately describe the global fluid phase diagram. In previous work, we demonstrated that the SAFT-VRX equation very accurately describes the pvT and phase behavior of both nonassociating and associating pure fluids, with a minimum of fitting to experimental data. Here, we present a generalized SAFT-VRX equation of state for binary mixtures that is found to accurately predict the vapor-liquid equilibrium and pvT behavior of the systems studied. In particular, we examine binary mixtures of n-alkanes and carbon dioxide + n-alkanes. The SAFT-VRX equation accurately describes not only the gas-liquid critical locus for these systems but also the vapor-liquid equilibrium phase diagrams and thermal properties in single-phase regions.

Novel polypropylene/inorganic fullerene-like WS2 nanocomposites containing a β-nucleating agent: isothermal crystallization and melting behavior.

PubMed

Naffakh, Mohammed; Marco, Carlos; Ellis, Gary

2012-02-16

The isothermal crystallization and subsequent melting behavior of isotactic polypropylene (iPP) nucleated with different nucleating agents (NAs) are investigated. Tungsten disulfide (IF-WS(2)) and N,N'-dicyclohexyl-2,6-naphthalene (NJ) and dual-additive mixtures are introduced into an iPP matrix to generate new materials that exhibit variable α- and β-polymorphism. As shown in previous work, small amounts of IF-WS(2) or NJ have a nucleating effect during the crystallization of iPP. However, the isothermal crystallization and melting behavior of iPP nucleated by dual α(IF-WS(2))/β(NJ) additive systems are dependent on both the NA composition balance and the crystallization temperature. In particular, our results demonstrate that it is possible to obtain any α-phase to β-phase content ratio by controlling the composition of NAs under appropriate isothermal crystallization conditions. The nucleating behavior of the additives can be illustrated by competitive nucleation, and the correlation between crystallization and melting temperatures and relative α- and β-crystals content in iPP in the nanocomposites is discussed.

Do Different Mental Models Influence Cybersecurity Behavior? Evaluations via Statistical Reasoning Performance.

PubMed

Brase, Gary L; Vasserman, Eugene Y; Hsu, William

2017-01-01

Cybersecurity research often describes people as understanding internet security in terms of metaphorical mental models (e.g., disease risk, physical security risk, or criminal behavior risk). However, little research has directly evaluated if this is an accurate or productive framework. To assess this question, two experiments asked participants to respond to a statistical reasoning task framed in one of four different contexts (cybersecurity, plus the above alternative models). Each context was also presented using either percentages or natural frequencies, and these tasks were followed by a behavioral likelihood rating. As in previous research, consistent use of natural frequencies promoted correct Bayesian reasoning. There was little indication, however, that any of the alternative mental models generated consistently better understanding or reasoning over the actual cybersecurity context. There was some evidence that different models had some effects on patterns of responses, including the behavioral likelihood ratings, but these effects were small, as compared to the effect of the numerical format manipulation. This points to a need to improve the content of actual internet security warnings, rather than working to change the models users have of warnings.

Do Different Mental Models Influence Cybersecurity Behavior? Evaluations via Statistical Reasoning Performance

PubMed Central

Brase, Gary L.; Vasserman, Eugene Y.; Hsu, William

2017-01-01

Cybersecurity research often describes people as understanding internet security in terms of metaphorical mental models (e.g., disease risk, physical security risk, or criminal behavior risk). However, little research has directly evaluated if this is an accurate or productive framework. To assess this question, two experiments asked participants to respond to a statistical reasoning task framed in one of four different contexts (cybersecurity, plus the above alternative models). Each context was also presented using either percentages or natural frequencies, and these tasks were followed by a behavioral likelihood rating. As in previous research, consistent use of natural frequencies promoted correct Bayesian reasoning. There was little indication, however, that any of the alternative mental models generated consistently better understanding or reasoning over the actual cybersecurity context. There was some evidence that different models had some effects on patterns of responses, including the behavioral likelihood ratings, but these effects were small, as compared to the effect of the numerical format manipulation. This points to a need to improve the content of actual internet security warnings, rather than working to change the models users have of warnings. PMID:29163304

Effect of Charge Patterning on the Phase Behavior of Polymer Coacervates for Charge Driven Self Assembly

NASA Astrophysics Data System (ADS)

Radhakrishna, Mithun; Sing, Charles E.

Oppositely charged polymers can undergo associative liquid-liquid phase separation when mixed under suitable conditions of ionic strength, temperature and pH to form what are known as `polymeric complex coacervates'. Polymer coacervates find use in diverse array of applications like microencapsulation, drug delivery, membrane filtration and underwater adhesives. The similarity between complex coacervate environments and those in biological systems has also found relevance in areas of bio-mimicry. Our previous works have demonstrated how local charge correlations and molecular connectivity can drastically affect the phase behavior of coacervates. The precise location of charges along the chain therefore dramatically influences the local charge correlations, which consequently influences the phase behavior of coacervates. We investigate the effect of charge patterning along the polymer chain on the phase behavior of coacervates in the framework of the Restricted Primitive Model using Gibbs Ensemble Monte Carlo simulations. Our results show that charge patterning dramatically changes the phase behavior of polymer coacervates, which contrasts with the predictions of the classical Voorn-Overbeek theory. This provides the basis for designing new materials through charge driven self assembly by controlling the positioning of the charged monomers along the chain.

An Evaluation of Imitation Recognition Abilities in Typically Developing Children and Young Children with Autism Spectrum Disorder.

PubMed

Berger, Natalie I; Ingersoll, Brooke

2015-08-01

Previous work has indicated that both typically developing children and children with Autism Spectrum Disorder (ASD) display a range of imitation recognition behaviors in response to a contingent adult imitator. However, it is unknown how the two groups perform comparatively on this construct. In this study, imitation recognition behaviors for children with ASD and typically developing children were observed during periods of contingent imitation imbedded in a naturalistic imitation task. Results from this study indicate that children with ASD are impaired in their ability to recognize being imitated relative to typically developing peers as demonstrated both by behaviors representing basic social attention and more mature imitation recognition. Display of imitation recognition behaviors was independent of length of contingent imitation period in typically developing children, but rate of engagement in imitation recognition behaviors was positively correlated with length of contingent imitation period in children with ASD. Exploratory findings also suggest a link between the ability to demonstrate recognition of being imitated and ASD symptom severity, language, and object imitation for young children with ASD. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

Sci-Fin: Visual Mining Spatial and Temporal Behavior Features from Social Media

PubMed Central

Pu, Jiansu; Teng, Zhiyao; Gong, Rui; Wen, Changjiang; Xu, Yang

2016-01-01

Check-in records are usually available in social services, which offer us the opportunity to capture and analyze users’ spatial and temporal behaviors. Mining such behavior features is essential to social analysis and business intelligence. However, the complexity and incompleteness of check-in records bring challenges to achieve such a task. Different from the previous work on social behavior analysis, in this paper, we present a visual analytics system, Social Check-in Fingerprinting (Sci-Fin), to facilitate the analysis and visualization of social check-in data. We focus on three major components of user check-in data: location, activity, and profile. Visual fingerprints for location, activity, and profile are designed to intuitively represent the high-dimensional attributes. To visually mine and demonstrate the behavior features, we integrate WorldMapper and Voronoi Treemap into our glyph-like designs. Such visual fingerprint designs offer us the opportunity to summarize the interesting features and patterns from different check-in locations, activities and users (groups). We demonstrate the effectiveness and usability of our system by conducting extensive case studies on real check-in data collected from a popular microblogging service. Interesting findings are reported and discussed at last. PMID:27999398

Sci-Fin: Visual Mining Spatial and Temporal Behavior Features from Social Media.

PubMed

Pu, Jiansu; Teng, Zhiyao; Gong, Rui; Wen, Changjiang; Xu, Yang

2016-12-20

Check-in records are usually available in social services, which offer us the opportunity to capture and analyze users' spatial and temporal behaviors. Mining such behavior features is essential to social analysis and business intelligence. However, the complexity and incompleteness of check-in records bring challenges to achieve such a task. Different from the previous work on social behavior analysis, in this paper, we present a visual analytics system, Social Check-in Fingerprinting (Sci-Fin), to facilitate the analysis and visualization of social check-in data. We focus on three major components of user check-in data: location, activity, and profile. Visual fingerprints for location, activity, and profile are designed to intuitively represent the high-dimensional attributes. To visually mine and demonstrate the behavior features, we integrate WorldMapper and Voronoi Treemap into our glyph-like designs. Such visual fingerprint designs offer us the opportunity to summarize the interesting features and patterns from different check-in locations, activities and users (groups). We demonstrate the effectiveness and usability of our system by conducting extensive case studies on real check-in data collected from a popular microblogging service. Interesting findings are reported and discussed at last.

The effects of central pro-and anti-inflammatory immune challenges on depressive-like behavior induced by chronic forced swim stress in rats.

PubMed

Pan, Yuqin; Lin, Wenjuan; Wang, Weiwen; Qi, Xiaoli; Wang, Donglin; Tang, Mingming

2013-06-15

Although increasing evidence demonstrates that both chronic stressors and inflammatory immune activation contribute to pathophysiology and behavioral alterations associated with major depression, little is known about the interaction effect of central inflammatory immune activation and stress on depressive-like behavior. Our previous work has shown that 14-day chronic forced swim stress induces significant depressive-like behavior. The present investigation assessed whether pro-inflammatory cytokine and anti-inflammatory cytokine challenges have differential interaction effect on depressive-like behavior induced by chronic forced swim stress in rats. The pro-inflammatory and anti-inflammatory immune challenges were achieved respectively by central administration of lipopolysaccharide (LPS), a pro-inflammatory cytokine inducer, and interleukin-10 (IL-10), an anti-inflammatory cytokine. It was found that either central LPS treatment alone or chronic forced swim stress alone significantly induced depressive-like behavior, including reduced body weight gain, reduced saccharin preference and reduced locomotor activity. However, there was no significant synergistic or additive effect of central LPS treatment and stress on depressive-like behavior. LPS treatment did not exacerbate the depressive-like behavior induced by forced swim stress. Nevertheless, IL-10 reversed depressive-like behavior induced by forced swim stress, a finding indicating that IL-10 has antidepressant effect on behavioral depression induced by stress. The present findings provide new insight into the complexity of the immunity-inflammation hypothesis of depression. Copyright © 2013 Elsevier B.V. All rights reserved.

Coarse-grained theory of a realistic tetrahedral liquid model

NASA Astrophysics Data System (ADS)

Procaccia, I.; Regev, I.

2012-02-01

Tetrahedral liquids such as water and silica-melt show unusual thermodynamic behavior such as a density maximum and an increase in specific heat when cooled to low temperatures. Previous work had shown that Monte Carlo and mean-field solutions of a lattice model can exhibit these anomalous properties with or without a phase transition, depending on the values of the different terms in the Hamiltonian. Here we use a somewhat different approach, where we start from a very popular empirical model of tetrahedral liquids —the Stillinger-Weber model— and construct a coarse-grained theory which directly quantifies the local structure of the liquid as a function of volume and temperature. We compare the theory to molecular-dynamics simulations and show that the theory can rationalize the simulation results and the anomalous behavior.

[Low Fidelity Simulation of a Zero-Y Robot

NASA Technical Reports Server (NTRS)

Sweet, Adam

2001-01-01

The item to be cleared is a low-fidelity software simulation model of a hypothetical freeflying robot designed for use in zero gravity environments. This simulation model works with the HCC simulation system that was developed by Xerox PARC and NASA Ames Research Center. HCC has been previously cleared for distribution. When used with the HCC software, the model computes the location and orientation of the simulated robot over time. Failures (such as a broken motor) can be injected into the simulation to produce simulated behavior corresponding to the failure. Release of this simulation will allow researchers to test their software diagnosis systems by attempting to diagnose the simulated failure from the simulated behavior. This model does not contain any encryption software nor can it perform any control tasks that might be export controlled.

Being in a "Green" Building Elicits "Greener" Recycling, but Not Necessarily "Better" Recycling.

PubMed

Wu, David W-L; DiGiacomo, Alessandra; Lenkic, Peter J; Wong, Vanessa K; Kingstone, Alan

2016-01-01

Previous observational work revealed that transient populations in a sustainable building disposed of waste more accurately when compared to patrons in a non-sustainable building. The current study uses an experimental design to replicate this observed effect and to investigate whether or not the built environment influences motivational factors to impact behavior. We find support that a building designed and built to communicate an atmosphere of sustainability can influence waste disposal behavior. Participants in the sustainable building used the garbage receptacle significantly less and compensated by tending to select the containers and organics receptacle more, which actually resulted in more errors overall. Our findings suggest that building atmospherics can motivate people to recycle more. However, atmospherics alone do not appear to be sufficient to elicit the desired performance outcome.

Melting behavior of nanometer sized gold isomers

NASA Astrophysics Data System (ADS)

Liu, H. B.; Ascencio, J. A.; Perez-Alvarez, M.; Yacaman, M. J.

2001-09-01

In the present work, the melting behavior of nanometer sized gold isomers was studied using a tight-binding potential with a second momentum approximation. The cases of cuboctahedra, icosahedra, Bagley decahedra, Marks decahedra and star-like decahedra were considered. We calculated the temperature dependence of the total energy and volume during melting and the melting point for different types and sizes of clusters. In addition, the structural evolutions of the nanosized clusters during the melting transition were monitored and revealed. It is found that the melting process has three characteristic time periods for the intermediate nanosized clusters. The whole process includes surface disordering and reordering, followed by surface melting and a final rapid overall melting. This is a new observation, which it is in contrast with previous reports where surface melting is the dominant step.

Controlling Surface Chemistry to Deconvolute Corrosion Benefits Derived from SMAT Processing

NASA Astrophysics Data System (ADS)

Murdoch, Heather A.; Labukas, Joseph P.; Roberts, Anthony J.; Darling, Kristopher A.

2017-07-01

Grain refinement through surface plastic deformation processes such as surface mechanical attrition treatment has shown measureable benefits for mechanical properties, but the impact on corrosion behavior has been inconsistent. Many factors obfuscate the particular corrosion mechanisms at work, including grain size, but also texture, processing contamination, and surface roughness. Many studies attempting to link corrosion and grain size have not been able to decouple these effects. Here we introduce a preprocessing step to mitigate the surface contamination effects that have been a concern in previous corrosion studies on plastically deformed surfaces; this allows comparison of corrosion behavior across grain sizes while controlling for texture and surface roughness. Potentiodynamic polarization in aqueous NaCl solution suggests that different corrosion mechanisms are responsible for samples prepared with the preprocessing step.

Causation, constitution and context. Comment on "Seeing mental states: An experimental strategy for measuring the observability of other minds" by Cristina Becchio et al.

NASA Astrophysics Data System (ADS)

Zahavi, Dan

2018-03-01

In their new article [1], Becchio and her colleagues argue that recent claims concerning the possibility of directly perceiving other people's mental states will remain speculative as long as one has failed to demonstrate the availability of mentalistic information in observable behavior [p. 4]. The ambitious goal of the authors is then to outline an experimental setup that will permit one to determine whether and to what extent a mental state is observable. Drawing on Becchio's previous work on how regularities in the kinematic patterns specify the mental states of the agent, the authors suggest that a similar approach can be adopted to probe the observability of any mental state instantiated in behavioral patterns [p. 19].

A defect density-based constitutive crystal plasticity framework for modeling the plastic deformation of Fe-Cr-Al cladding alloys subsequent to irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patra, Anirban; Wen, Wei; Martinez Saez, Enrique

2016-02-05

It is essential to understand the deformation behavior of these Fe-Cr-Al alloys, in order to be able to develop models for predicting their mechanical response under varied loading conditions. Interaction of dislocations with the radiation-induced defects governs the crystallographic deformation mechanisms. A crystal plasticity framework is employed to model these mechanisms in Fe-Cr-Al alloys. This work builds on a previously developed defect density-based crystal plasticity model for bcc metals and alloys, with necessary modifications made to account for the defect substructure observed in Fe-Cr-Al alloys. The model is implemented in a Visco-Plastic Self Consistent (VPSC) framework, to predict the mechanicalmore » behavior under quasi-static loading.« less

Boredom at work: proximal and distal consequences of affective work-related boredom.

PubMed

van Hooff, Madelon L M; van Hooft, Edwin A J

2014-07-01

Boredom is an emotion that occurs regularly at the workplace, with negative consequences for the employee and the organization. It is therefore important to understand why work-related boredom leads to such adverse consequences and what can be done to mitigate its occurrence and its negative consequences. In the present study we proposed a model suggesting that feelings of boredom at work induce immediate affect-based bored behaviors, and that such bored behavior leads to depressive complaints, distress, and counterproductive work behavior. We further posed that job crafting can mitigate work-related boredom and its negative outcomes. Results of a survey study among 189 employees showed that work-related boredom and bored behavior are empirically distinct, though related, constructs. Work-related boredom was positively related to depressive complaints, distress, and counterproductive work behavior, and these associations were fully mediated by bored behavior. Job crafting related negatively to work-related boredom, and attenuated the relationship of work-related boredom with bored behavior. Moreover, the indirect effects of work-related boredom through bored behavior on its outcomes were smaller the more employees engaged in job crafting. This research enhances insight into work-related boredom by showing that boredom as an affective state can be distinguished from its proximal behavioral consequences, and by providing a first onset to obtain insight in moderating and mediating mechanisms that may explain work-related boredom's consequences. It highlights the importance of employees' opportunities to work in jobs that do not cause work-related boredom to develop, and the role of job crafting as a potential intervention tool.

Type A behavior pattern, accident optimism and fatalism: an investigation into non-compliance with safety work behaviors among hospital nurses.

PubMed

Ugwu, Fabian O; Onyishi, Ike E; Ugwu, Chidi; Onyishi, Charity N

2015-01-01

Safety work behavior has continued to attract the interest of organizational researchers and practitioners especially in the health sector. The goal of the study was to investigate whether personality type A, accident optimism and fatalism could predict non-compliance with safety work behaviors among hospital nurses. One hundred and fifty-nine nursing staff sampled from three government-owned hospitals in a state in southeast Nigeria, participated in the study. Data were collected through Type A Behavior Scale (TABS), Accident Optimism, Fatalism and Compliance with Safety Behavior (CSB) Scales. Our results showed that personality type A, accident optimism and fatalism were all related to non-compliance with safety work behaviors. Personality type A individuals tend to comply less with safety work behaviors than personality type B individuals. In addition, optimistic and fatalistic views about accidents and existing safety rules also have implications for compliance with safety work behaviors.

Selective transfer of visual working memory training on Chinese character learning.

PubMed

Opitz, Bertram; Schneiders, Julia A; Krick, Christoph M; Mecklinger, Axel

2014-01-01

Previous research has shown a systematic relationship between phonological working memory capacity and second language proficiency for alphabetic languages. However, little is known about the impact of working memory processes on second language learning in a non-alphabetic language such as Mandarin Chinese. Due to the greater complexity of the Chinese writing system we expect that visual working memory rather than phonological working memory exerts a unique influence on learning Chinese characters. This issue was explored in the present experiment by comparing visual working memory training with an active (auditory working memory training) control condition and a passive, no training control condition. Training induced modulations in language-related brain networks were additionally examined using functional magnetic resonance imaging in a pretest-training-posttest design. As revealed by pre- to posttest comparisons and analyses of individual differences in working memory training gains, visual working memory training led to positive transfer effects on visual Chinese vocabulary learning compared to both control conditions. In addition, we found sustained activation after visual working memory training in the (predominantly visual) left infero-temporal cortex that was associated with behavioral transfer. In the control conditions, activation either increased (active control condition) or decreased (passive control condition) without reliable behavioral transfer effects. This suggests that visual working memory training leads to more efficient processing and more refined responses in brain regions involved in visual processing. Furthermore, visual working memory training boosted additional activation in the precuneus, presumably reflecting mental image generation of the learned characters. We, therefore, suggest that the conjoint activity of the mid-fusiform gyrus and the precuneus after visual working memory training reflects an interaction of working memory and imagery processes with complex visual stimuli that fosters the coherent synthesis of a percept from a complex visual input in service of enhanced Chinese character learning. © 2013 Published by Elsevier Ltd.

Cognitive processes involved in smooth pursuit eye movements: behavioral evidence, neural substrate and clinical correlation

PubMed Central

Fukushima, Kikuro; Fukushima, Junko; Warabi, Tateo; Barnes, Graham R.

2013-01-01

Smooth-pursuit eye movements allow primates to track moving objects. Efficient pursuit requires appropriate target selection and predictive compensation for inherent processing delays. Prediction depends on expectation of future object motion, storage of motion information and use of extra-retinal mechanisms in addition to visual feedback. We present behavioral evidence of how cognitive processes are involved in predictive pursuit in normal humans and then describe neuronal responses in monkeys and behavioral responses in patients using a new technique to test these cognitive controls. The new technique examines the neural substrate of working memory and movement preparation for predictive pursuit by using a memory-based task in macaque monkeys trained to pursue (go) or not pursue (no-go) according to a go/no-go cue, in a direction based on memory of a previously presented visual motion display. Single-unit task-related neuronal activity was examined in medial superior temporal cortex (MST), supplementary eye fields (SEF), caudal frontal eye fields (FEF), cerebellar dorsal vermis lobules VI–VII, caudal fastigial nuclei (cFN), and floccular region. Neuronal activity reflecting working memory of visual motion direction and go/no-go selection was found predominantly in SEF, cerebellar dorsal vermis and cFN, whereas movement preparation related signals were found predominantly in caudal FEF and the same cerebellar areas. Chemical inactivation produced effects consistent with differences in signals represented in each area. When applied to patients with Parkinson's disease (PD), the task revealed deficits in movement preparation but not working memory. In contrast, patients with frontal cortical or cerebellar dysfunction had high error rates, suggesting impaired working memory. We show how neuronal activity may be explained by models of retinal and extra-retinal interaction in target selection and predictive control and thus aid understanding of underlying pathophysiology. PMID:23515488

The Role of Occupational Status in the Association between Job Strain and Ambulatory Blood Pressure during Working and Nonworking Days

PubMed Central

Joseph, Nataria T.; Muldoon, Matthew F.; Manuck, Stephen B.; Matthews, Karen A.; MacDonald, Leslie A.; Grosch, James; Kamarck, Thomas W.

2016-01-01

Objective The objectives of this study were to determine whether job strain is more strongly associated with higher ambulatory blood pressure (ABP) among blue-collar workers compared to white-collar workers; to examine whether this pattern generalizes across working and nonworking days and across sex; and to examine whether this pattern is accounted for by psychosocial factors or health behaviors during daily life. Methods 480 healthy workers (mean age = 43; 53% female)in the Adult Health and Behavior Project – Phase 2 (AHAB-II)completed ABP monitoring during 3 working days and 1 nonworking day. Job strain was operationalized as high psychological demand (> sample median) combined with low decision latitude (< sample median) (Karasek model; Job Content Questionnaire). Results Covariate-adjusted multilevel random coefficients regressions demonstrated that associations between job strain and systolic and diastolic ABP were stronger among blue-collar workers compared to white-collar workers (b = 6.53, F(1, 464)= 3.89, p = .049 and b = 5.25, F(1, 464)= 6.09, p = .014, respectively). This pattern did not vary by sex but diastolic ABP findings were stronger when participants were at work. The stronger association between job strain and ABP among blue-collar workers was not accounted for by education, momentary physical activity or substance use, but was partially accounted for by covariation between higher hostility and blue-collar status. Conclusions Job strain is associated with ABP among blue-collar workers. These results extend previous findings to a mixed-sex sample and nonworking days and provide, for the first time, comprehensive exploration of several behavioral and psychosocial explanations for this finding. PMID:27359177

Structure and validity of sluggish cognitive tempo using an expanded item pool in children with attention-deficit/hyperactivity disorder.

PubMed

McBurnett, Keith; Villodas, Miguel; Burns, G Leonard; Hinshaw, Stephen P; Beaulieu, Allyson; Pfiffner, Linda J

2014-01-01

We evaluated the latent structure and validity of an expanded pool of Sluggish Cognitive Tempo (SCT) items. An experimental rating scale with 44 candidate SCT items was administered to parents and teachers of 165 children in grades 2-5 (ages 7-11) recruited for a randomized clinical trial of a psychosocial intervention for Attention-Deficit/Hyperactivity Disorder, Predominantly Inattentive Type. Exploratory factor analyses (EFA) were used to extract items with high loadings (>0.59) on primary factors of SCT and low cross-loadings (0.30 or lower) on other SCT factors and on the Inattention factor of ADHD. Items were required to meet these criteria for both informants. This procedure reduced the pool to 15 items. Generally, items representing slowness and low initiative failed these criteria. SCT factors (termed Daydreaming, Working Memory Problems, and Sleepy/Tired) showed good convergent and discriminant validity in EFA and in a confirmatory model with ADHD factors. Simultaneous regressions of impairment and comorbidity on SCT and ADHD factors found that Daydreams was associated with global impairment, and Sleepy/Tired was associated with organizational problems and depression ratings, across both informants. For teachers, Daydreams also predicted ODD (inversely); Sleepy/Tired also predicted poor academic behavior, low social skills, and problem social behavior; and Working Memory Problems predicted organizational problems and anxiety. When depression, rather than ADHD, was included among the predictors, the only SCT-related associations rendered insignificant were the teacher-reported associations of Daydreams with ODD; Working Memory Problems with anxiety, and Sleepy/Tired with poor social skills. SCT appears to be meaningfully associated with impairment, even when controlling for depression. Common behaviors resembling Working Memory problems may represent a previously undescribed factor of SCT.

Variability in Dopamine Genes Dissociates Model-Based and Model-Free Reinforcement Learning

PubMed Central

Bath, Kevin G.; Daw, Nathaniel D.; Frank, Michael J.

2016-01-01

Considerable evidence suggests that multiple learning systems can drive behavior. Choice can proceed reflexively from previous actions and their associated outcomes, as captured by “model-free” learning algorithms, or flexibly from prospective consideration of outcomes that might occur, as captured by “model-based” learning algorithms. However, differential contributions of dopamine to these systems are poorly understood. Dopamine is widely thought to support model-free learning by modulating plasticity in striatum. Model-based learning may also be affected by these striatal effects, or by other dopaminergic effects elsewhere, notably on prefrontal working memory function. Indeed, prominent demonstrations linking striatal dopamine to putatively model-free learning did not rule out model-based effects, whereas other studies have reported dopaminergic modulation of verifiably model-based learning, but without distinguishing a prefrontal versus striatal locus. To clarify the relationships between dopamine, neural systems, and learning strategies, we combine a genetic association approach in humans with two well-studied reinforcement learning tasks: one isolating model-based from model-free behavior and the other sensitive to key aspects of striatal plasticity. Prefrontal function was indexed by a polymorphism in the COMT gene, differences of which reflect dopamine levels in the prefrontal cortex. This polymorphism has been associated with differences in prefrontal activity and working memory. Striatal function was indexed by a gene coding for DARPP-32, which is densely expressed in the striatum where it is necessary for synaptic plasticity. We found evidence for our hypothesis that variations in prefrontal dopamine relate to model-based learning, whereas variations in striatal dopamine function relate to model-free learning. SIGNIFICANCE STATEMENT Decisions can stem reflexively from their previously associated outcomes or flexibly from deliberative consideration of potential choice outcomes. Research implicates a dopamine-dependent striatal learning mechanism in the former type of choice. Although recent work has indicated that dopamine is also involved in flexible, goal-directed decision-making, it remains unclear whether it also contributes via striatum or via the dopamine-dependent working memory function of prefrontal cortex. We examined genetic indices of dopamine function in these regions and their relation to the two choice strategies. We found that striatal dopamine function related most clearly to the reflexive strategy, as previously shown, and that prefrontal dopamine related most clearly to the flexible strategy. These findings suggest that dissociable brain regions support dissociable choice strategies. PMID:26818509

Return to work after work-related stress: a randomized controlled trial of a work-focused cognitive behavioral intervention.

PubMed

Dalgaard, Vita Ligaya; Aschbacher, Kirstin; Andersen, Johan Hviid; Glasscock, David John; Willert, Morten Vejs; Carstensen, Ole; Biering, Karin

2017-09-01

Objectives This study aimed to evaluate the effect of a stress management intervention (SMI) on lasting return to work (RTW) among patients with work-related stress complaints. Methods Sickness benefit departments from three local municipalities referred patients on sick leave with work-related adjustment disorders or mild depression to the Department of Occupational Medicine, Regional Hospital West Jutland. A 2× randomization procedure allocated patients into one of three groups: intervention (N=58), control A (which received a clinical assessment; N=56), or control B (no assessment; N=49). Treatment comprised individual work-focused cognitive behavioral therapy (CBT) with an optional workplace intervention. The outcome was time until lasting RTW (16 and 44 weeks follow-up) using register data. Results Median number of weeks until lasting RTW was 15, 19, and 32 for the intervention group, control A, and control B respectively. However, for group B, clinical assessment was not part of the inclusion process, which may have introduced selection bias. In the fully-adjusted Cox regression model, the intervention group exhibited significantly faster lasting RTW at 44 weeks; hazard ratio (HR) 1.57 [95% confidence interval (95% CI) 1.01-2.44] relative to control group A, with a non-significant trend evident at 16 weeks; HR 1.70 (95% CI 0.94-3.10), when controlling for age, gender, occupation, sick leave during previous year, full or partial sick leave, and diagnosis. Unadjusted analyses remained directionally consistent but were reduced to marginal significance. Conclusions There was a tendency towards faster lasting RTW in the intervention group compared to control A, which received clinical assessment, in all analyses. The intervention group returned to work about 4 weeks earlier than control A, which could translate into substantial financial gains.

Working Memory Contributions to Reinforcement Learning Impairments in Schizophrenia

PubMed Central

Brown, Jaime K.; Gold, James M.; Waltz, James A.; Frank, Michael J.

2014-01-01

Previous research has shown that patients with schizophrenia are impaired in reinforcement learning tasks. However, behavioral learning curves in such tasks originate from the interaction of multiple neural processes, including the basal ganglia- and dopamine-dependent reinforcement learning (RL) system, but also prefrontal cortex-dependent cognitive strategies involving working memory (WM). Thus, it is unclear which specific system induces impairments in schizophrenia. We recently developed a task and computational model allowing us to separately assess the roles of RL (slow, cumulative learning) mechanisms versus WM (fast but capacity-limited) mechanisms in healthy adult human subjects. Here, we used this task to assess patients' specific sources of impairments in learning. In 15 separate blocks, subjects learned to pick one of three actions for stimuli. The number of stimuli to learn in each block varied from two to six, allowing us to separate influences of capacity-limited WM from the incremental RL system. As expected, both patients (n = 49) and healthy controls (n = 36) showed effects of set size and delay between stimulus repetitions, confirming the presence of working memory effects. Patients performed significantly worse than controls overall, but computational model fits and behavioral analyses indicate that these deficits could be entirely accounted for by changes in WM parameters (capacity and reliability), whereas RL processes were spared. These results suggest that the working memory system contributes strongly to learning impairments in schizophrenia. PMID:25297101

Exploring universal patterns in human home-work commuting from mobile phone data.

PubMed

Kung, Kevin S; Greco, Kael; Sobolevsky, Stanislav; Ratti, Carlo

2014-01-01

Home-work commuting has always attracted significant research attention because of its impact on human mobility. One of the key assumptions in this domain of study is the universal uniformity of commute times. However, a true comparison of commute patterns has often been hindered by the intrinsic differences in data collection methods, which make observation from different countries potentially biased and unreliable. In the present work, we approach this problem through the use of mobile phone call detail records (CDRs), which offers a consistent method for investigating mobility patterns in wholly different parts of the world. We apply our analysis to a broad range of datasets, at both the country (Portugal, Ivory Coast, and Saudi Arabia), and city (Boston) scale. Additionally, we compare these results with those obtained from vehicle GPS traces in Milan. While different regions have some unique commute time characteristics, we show that the home-work time distributions and average values within a single region are indeed largely independent of commute distance or country (Portugal, Ivory Coast, and Boston)-despite substantial spatial and infrastructural differences. Furthermore, our comparative analysis demonstrates that such distance-independence holds true only if we consider multimodal commute behaviors-as consistent with previous studies. In car-only (Milan GPS traces) and car-heavy (Saudi Arabia) commute datasets, we see that commute time is indeed influenced by commute distance. Finally, we put forth a testable hypothesis and suggest ways for future work to make more accurate and generalizable statements about human commute behaviors.

Muscle-tendon mechanics explain unexpected effects of exoskeleton assistance on metabolic rate during walking.

PubMed

Jackson, Rachel W; Dembia, Christopher L; Delp, Scott L; Collins, Steven H

2017-06-01

The goal of this study was to gain insight into how ankle exoskeletons affect the behavior of the plantarflexor muscles during walking. Using data from previous experiments, we performed electromyography-driven simulations of musculoskeletal dynamics to explore how changes in exoskeleton assistance affected plantarflexor muscle-tendon mechanics, particularly for the soleus. We used a model of muscle energy consumption to estimate individual muscle metabolic rate. As average exoskeleton torque was increased, while no net exoskeleton work was provided, a reduction in tendon recoil led to an increase in positive mechanical work performed by the soleus muscle fibers. As net exoskeleton work was increased, both soleus muscle fiber force and positive mechanical work decreased. Trends in the sum of the metabolic rates of the simulated muscles correlated well with trends in experimentally observed whole-body metabolic rate ( R 2 =0.9), providing confidence in our model estimates. Our simulation results suggest that different exoskeleton behaviors can alter the functioning of the muscles and tendons acting at the assisted joint. Furthermore, our results support the idea that the series tendon helps reduce positive work done by the muscle fibers by storing and returning energy elastically. We expect the results from this study to promote the use of electromyography-driven simulations to gain insight into the operation of muscle-tendon units and to guide the design and control of assistive devices. © 2017. Published by The Company of Biologists Ltd.

Physical Activity, Mind Wandering, Affect, and Sleep: An Ecological Momentary Assessment.

PubMed

Fanning, Jason; Mackenzie, Michael; Roberts, Sarah; Crato, Ines; Ehlers, Diane; McAuley, Edward

2016-08-31

A considerable portion of daily thought is spent in mind wandering. This behavior has been related to positive (eg, future planning, problem solving) and negative (eg, unhappiness, impaired cognitive performance) outcomes. Based on previous research suggesting future-oriented (ie, prospective) mind wandering may support autobiographical planning and self-regulation, this study examined associations between hourly mind wandering and moderate-to-vigorous physical activity (MVPA), and the impact of affect and daily sleep on these relations. College-aged adults (N=33) participated in a mobile phone-delivered ecological momentary assessment study for 1 week. Sixteen hourly prompts assessing mind wandering and affect were delivered daily via participants' mobile phones. Perceived sleep quality and duration was assessed during the first prompt each day, and participants wore an ActiGraph accelerometer during waking hours throughout the study week. Study findings suggest present-moment mind wandering was positively associated with future MVPA (P=.03), and this relationship was moderated by affective state (P=.04). Moreover, excessive sleep the previous evening was related to less MVPA across the following day (P=.007). Further, mind wandering was positively related to activity only among those who did not oversleep (P=.007). Together, these results have implications for multiple health behavior interventions targeting physical activity, affect, and sleep. Researchers may also build on this work by studying these relationships in the context of other important behaviors and psychosocial factors (eg, tobacco use, depression, loneliness).

Optothermal transport behavior in whispering gallery mode optical cavities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soltani, Soheil; Armani, Andrea M., E-mail: armani@usc.edu; Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089

Over the past century, whispering gallery mode optical cavities have enabled numerous advances in science and engineering, such as discoveries in quantum mechanics and non-linear optics, as well as the development of optical gyroscopes and add drop filters. One reason for their widespread appeal is their ability to confine light for long periods of time, resulting in high circulating intensities. However, when sufficiently large amounts of optical power are coupled into these cavities, they begin to experience optothermal or photothermal behavior, in which the optical energy is converted into heat. Above the optothermal threshold, the resonance behavior is no longermore » solely defined by electromagnetics. Previous work has primarily focused on the role of the optothermal coefficient of the material in this instability. However, the physics of this optothermal behavior is significantly more complex. In the present work, we develop a predictive theory based on a generalizable analytical expression in combination with a geometry-specific COMSOL Multiphysics finite element method model. The simulation couples the optical and thermal physics components, accounting for geometry variations as well as the temporal and spatial profile of the optical field. To experimentally verify our theoretical model, the optothermal thresholds of a series of silica toroidal resonant cavities are characterized at different wavelengths (visible through near-infrared) and using different device geometries. The silica toroid offers a particularly rigorous case study for the developed optothermal model because of its complex geometrical structure which provides multiple thermal transport paths.« less

Laban movement analysis to classify emotions from motion

NASA Astrophysics Data System (ADS)

Dewan, Swati; Agarwal, Shubham; Singh, Navjyoti

2018-04-01

In this paper, we present the study of Laban Movement Analysis (LMA) to understand basic human emotions from nonverbal human behaviors. While there are a lot of studies on understanding behavioral patterns based on natural language processing and speech processing applications, understanding emotions or behavior from non-verbal human motion is still a very challenging and unexplored field. LMA provides a rich overview of the scope of movement possibilities. These basic elements can be used for generating movement or for describing movement. They provide an inroad to understanding movement and for developing movement efficiency and expressiveness. Each human being combines these movement factors in his/her own unique way and organizes them to create phrases and relationships which reveal personal, artistic, or cultural style. In this work, we build a motion descriptor based on a deep understanding of Laban theory. The proposed descriptor builds up on previous works and encodes experiential features by using temporal windows. We present a more conceptually elaborate formulation of Laban theory and test it in a relatively new domain of behavioral research with applications in human-machine interaction. The recognition of affective human communication may be used to provide developers with a rich source of information for creating systems that are capable of interacting well with humans. We test our algorithm on UCLIC dataset which consists of body motions of 13 non-professional actors portraying angry, fear, happy and sad emotions. We achieve an accuracy of 87.30% on this dataset.

Extinction of an instrumental response: a cognitive behavioral assay in Fmr1 knockout mice.

PubMed

Sidorov, M S; Krueger, D D; Taylor, M; Gisin, E; Osterweil, E K; Bear, M F

2014-06-01

Fragile X (FX) is the most common genetic cause of intellectual disability and autism. Previous studies have shown that partial inhibition of metabotropic glutamate receptor signaling is sufficient to correct behavioral phenotypes in a mouse model of FX, including audiogenic seizures, open-field hyperactivity and social behavior. These phenotypes model well the epilepsy (15%), hyperactivity (20%) and autism (30%) that are comorbid with FX in human patients. Identifying reliable and robust mouse phenotypes to model cognitive impairments is critical considering the 90% comorbidity of FX and intellectual disability. Recent work characterized a five-choice visuospatial discrimination assay testing cognitive flexibility, in which FX model mice show impairments associated with decreases in synaptic proteins in prefrontal cortex (PFC). In this study, we sought to determine whether instrumental extinction, another process requiring PFC, is altered in FX model mice, and whether downregulation of metabotropic glutamate receptor signaling pathways is sufficient to correct both visuospatial discrimination and extinction phenotypes. We report that instrumental extinction is consistently exaggerated in FX model mice. However, neither the extinction phenotype nor the visuospatial discrimination phenotype is corrected by approaches targeting metabotropic glutamate receptor signaling. This work describes a novel behavioral extinction assay to model impaired cognition in mouse models of neurodevelopmental disorders, provides evidence that extinction is exaggerated in the FX mouse model and suggests possible limitations of metabotropic glutamate receptor-based pharmacotherapy. © 2014 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Problematic sexual behavior in young adults: Associations across clinical, behavioral, and neurocognitive variables.

PubMed

Leppink, Eric W; Chamberlain, Samuel R; Redden, Sarah A; Grant, Jon E

2016-12-30

A notable number of young adults struggle to control impulsive behavior, resulting in impairment and distress. Assessments of problematic sexual behavior (PSB) have noted clinical differences relative to other populations, but neurocognitive findings have varied. This analysis assesses the clinical presentation and neurocognitive profile of patients with PSB relative to participants without PSB symptoms. A total of 492 participants (18-29) were recruited for a study on impulsivity in young adults. Participants completed diagnostic, self-report, and neurocognitive measures which assessed several cognitive domains. PSB was defined as endorsing fantasies, urges, or sexual behavior that felt out of control or was causing distress. In the sample, 54 (11%) participants reported current PSB. This group was older, reported earlier sexual experiences and alcohol use, and lower quality of life and self-esteem. Comorbidity was greater in the PSB group, particularly for depression and alcohol dependence. The PSB group also showed differences in impulsivity, decision making, spatial working memory, problem solving, and emotional dysregulation. Results suggest associations between PSB psychosocial dysfunction, greater comorbidity, and neurocognitive differences. These associations suggest a more salient impact than typical sexual behavior. Furthermore, this study demonstrated several neurocognitive deficits in the PSB group which have found more mixed support previously. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

"Economic man" in cross-cultural perspective: behavioral experiments in 15 small-scale societies.

PubMed

Henrich, Joseph; Boyd, Robert; Bowles, Samuel; Camerer, Colin; Fehr, Ernst; Gintis, Herbert; McElreath, Richard; Alvard, Michael; Barr, Abigail; Ensminger, Jean; Henrich, Natalie Smith; Hill, Kim; Gil-White, Francisco; Gurven, Michael; Marlowe, Frank W; Patton, John Q; Tracer, David

2005-12-01

Researchers from across the social sciences have found consistent deviations from the predictions of the canonical model of self-interest in hundreds of experiments from around the world. This research, however, cannot determine whether the uniformity results from universal patterns of human behavior or from the limited cultural variation available among the university students used in virtually all prior experimental work. To address this, we undertook a cross-cultural study of behavior in ultimatum, public goods, and dictator games in a range of small-scale societies exhibiting a wide variety of economic and cultural conditions. We found, first, that the canonical model - based on self-interest - fails in all of the societies studied. Second, our data reveal substantially more behavioral variability across social groups than has been found in previous research. Third, group-level differences in economic organization and the structure of social interactions explain a substantial portion of the behavioral variation across societies: the higher the degree of market integration and the higher the payoffs to cooperation in everyday life, the greater the level of prosociality expressed in experimental games. Fourth, the available individual-level economic and demographic variables do not consistently explain game behavior, either within or across groups. Fifth, in many cases experimental play appears to reflect the common interactional patterns of everyday life.

LINEBACKER: LINE-speed Bio-inspired Analysis and Characterization for Event Recognition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oehmen, Christopher S.; Bruillard, Paul J.; Matzke, Brett D.

2016-08-04

The cyber world is a complex domain, with digital systems mediating a wide spectrum of human and machine behaviors. While this is enabling a revolution in the way humans interact with each other and data, it also is exposing previously unreachable infrastructure to a worldwide set of actors. Existing solutions for intrusion detection and prevention that are signature-focused typically seek to detect anomalous and/or malicious activity for the sake of preventing or mitigating negative impacts. But a growing interest in behavior-based detection is driving new forms of analysis that move the emphasis from static indicators (e.g. rule-based alarms or tripwires)more » to behavioral indicators that accommodate a wider contextual perspective. Similar to cyber systems, biosystems have always existed in resource-constrained hostile environments where behaviors are tuned by context. So we look to biosystems as an inspiration for addressing behavior-based cyber challenges. In this paper, we introduce LINEBACKER, a behavior-model based approach to recognizing anomalous events in network traffic and present the design of this approach of bio-inspired and statistical models working in tandem to produce individualized alerting for a collection of systems. Preliminary results of these models operating on historic data are presented along with a plugin to support real-world cyber operations.« less

Inferring the Limit Behavior of Some Elementary Cellular Automata

NASA Astrophysics Data System (ADS)

Ruivo, Eurico L. P.; de Oliveira, Pedro P. B.

Cellular automata locally define dynamical systems, discrete in space, time and in the state variables, capable of displaying arbitrarily complex global emergent behavior. One core question in the study of cellular automata refers to their limit behavior, that is, to the global dynamical features in an infinite time evolution. Previous works have shown that for finite time evolutions, the dynamics of one-dimensional cellular automata can be described by regular languages and, therefore, by finite automata. Such studies have shown the existence of growth patterns in the evolution of such finite automata for some elementary cellular automata rules and also inferred the limit behavior of such rules based upon the growth patterns; however, the results on the limit behavior were obtained manually, by direct inspection of the structures that arise during the time evolution. Here we present the formalization of an automatic method to compute such structures. Based on this, the rules of the elementary cellular automata space were classified according to the existence of a growth pattern in their finite automata. Also, we present a method to infer the limit graph of some elementary cellular automata rules, derived from the analysis of the regular expressions that describe their behavior in finite time. Finally, we analyze some attractors of two rules for which we could not compute the whole limit set.

Improving Hall Thruster Plume Simulation through Refined Characterization of Near-field Plasma Properties

NASA Astrophysics Data System (ADS)

Huismann, Tyler D.

Due to the rapidly expanding role of electric propulsion (EP) devices, it is important to evaluate their integration with other spacecraft systems. Specifically, EP device plumes can play a major role in spacecraft integration, and as such, accurate characterization of plume structure bears on mission success. This dissertation addresses issues related to accurate prediction of plume structure in a particular type of EP device, a Hall thruster. This is done in two ways: first, by coupling current plume simulation models with current models that simulate a Hall thruster's internal plasma behavior; second, by improving plume simulation models and thereby increasing physical fidelity. These methods are assessed by comparing simulated results to experimental measurements. Assessment indicates the two methods improve plume modeling capabilities significantly: using far-field ion current density as a metric, these approaches used in conjunction improve agreement with measurements by a factor of 2.5, as compared to previous methods. Based on comparison to experimental measurements, recent computational work on discharge chamber modeling has been largely successful in predicting properties of internal thruster plasmas. This model can provide detailed information on plasma properties at a variety of locations. Frequently, experimental data is not available at many locations that are of interest regarding computational models. Excepting the presence of experimental data, there are limited alternatives for scientifically determining plasma properties that are necessary as inputs into plume simulations. Therefore, this dissertation focuses on coupling current models that simulate internal thruster plasma behavior with plume simulation models. Further, recent experimental work on atom-ion interactions has provided a better understanding of particle collisions within plasmas. This experimental work is used to update collision models in a current plume simulation code. Previous versions of the code assume an unknown dependence between particles' pre-collision velocities and post-collision scattering angles. This dissertation focuses on updating several of these types of collisions by assuming a curve fit based on the measurements of atom-ion interactions, such that previously unknown angular dependences are well-characterized.

Limit cycles and conformal invariance

NASA Astrophysics Data System (ADS)

Fortin, Jean-François; Grinstein, Benjamín; Stergiou, Andreas

2013-01-01

There is a widely held belief that conformal field theories (CFTs) require zero beta functions. Nevertheless, the work of Jack and Osborn implies that the beta functions are not actually the quantites that decide conformality, but until recently no such behavior had been exhibited. Our recent work has led to the discovery of CFTs with nonzero beta functions, more precisely CFTs that live on recurrent trajectories, e.g., limit cycles, of the beta-function vector field. To demonstrate this we study the S function of Jack and Osborn. We use Weyl consistency conditions to show that it vanishes at fixed points and agrees with the generator Q of limit cycles on them. Moreover, we compute S to third order in perturbation theory, and explicitly verify that it agrees with our previous determinations of Q. A byproduct of our analysis is that, in perturbation theory, unitarity and scale invariance imply conformal invariance in four-dimensional quantum field theories. Finally, we study some properties of these new, "cyclic" CFTs, and point out that the a-theorem still governs the asymptotic behavior of renormalization-group flows.

Visual Search Elicits the Electrophysiological Marker of Visual Working Memory

PubMed Central

Emrich, Stephen M.; Al-Aidroos, Naseem; Pratt, Jay; Ferber, Susanne

2009-01-01

Background Although limited in capacity, visual working memory (VWM) plays an important role in many aspects of visually-guided behavior. Recent experiments have demonstrated an electrophysiological marker of VWM encoding and maintenance, the contralateral delay activity (CDA), which has been shown in multiple tasks that have both explicit and implicit memory demands. Here, we investigate whether the CDA is evident during visual search, a thoroughly-researched task that is a hallmark of visual attention but has no explicit memory requirements. Methodology/Principal Findings The results demonstrate that the CDA is present during a lateralized search task, and that it is similar in amplitude to the CDA observed in a change-detection task, but peaks slightly later. The changes in CDA amplitude during search were strongly correlated with VWM capacity, as well as with search efficiency. These results were paralleled by behavioral findings showing a strong correlation between VWM capacity and search efficiency. Conclusions/Significance We conclude that the activity observed during visual search was generated by the same neural resources that subserve VWM, and that this activity reflects the maintenance of previously searched distractors. PMID:19956663

Syndemic Theory and HIV-Related Risk Among Young Transgender Women: The Role of Multiple, Co-Occurring Health Problems and Social Marginalization

PubMed Central

Brennan, Julia; Kuhns, Lisa M.; Johnson, Amy K.; Belzer, Marvin; Wilson, Erin C.

2012-01-01

Objectives. We assessed whether multiple psychosocial factors are additive in their relationship to sexual risk behavior and self-reported HIV status (i.e., can be characterized as a syndemic) among young transgender women and the relationship of indicators of social marginalization to psychosocial factors. Methods. Participants (n = 151) were aged 15 to 24 years and lived in Chicago or Los Angeles. We collected data on psychosocial factors (low self-esteem, polysubstance use, victimization related to transgender identity, and intimate partner violence) and social marginalization indicators (history of commercial sex work, homelessness, and incarceration) through an interviewer-administered survey. Results. Syndemic factors were positively and additively related to sexual risk behavior and self-reported HIV infection. In addition, our syndemic index was significantly related to 2 indicators of social marginalization: a history of sex work and previous incarceration. Conclusions. These findings provide evidence for a syndemic of co-occurring psychosocial and health problems in young transgender women, taking place in a context of social marginalization. PMID:22873480

A Good Beginning

NASA Astrophysics Data System (ADS)

Sayre, W. G.; Sayre, Nancy E.

1999-05-01

The first-period activity in the classroom is critical for success in the general chemistry course. Past first-day activities at Slippery Rock University have included administering the Toledo test or an in-house mathematics readiness test to help the students understand their degree of readiness for the course. In the past students with poor preparation were shunted into a prep chem course. If no tests were administered then the students received the "this is a university-level course-you must work hard, etc." lecture. This fall the first-period activity was shifted from the intellectual readiness or hard work focus to a behavioral/attitude activity. This resulted in the best performance on the first hour exam in ten years, 2.1 times better than the previous best performance.

Fuel thermal conductivity (FTHCON). Status report. [PWR; BWR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hagrman, D. L.

1979-02-01

An improvement of the fuel thermal conductivity subcode is described which is part of the fuel rod behavior modeling task performed at EG and G Idaho, Inc. The original version was published in the Materials Properties (MATPRO) Handbook, Section A-2 (Fuel Thermal Conductivity). The improved version incorporates data which were not included in the previous work and omits some previously used data which are believed to come from cracked specimens. The models for the effect of porosity on thermal conductivity and for the electronic contribution to thermal coductivity have been completely revised in order to place these models on amore » more mechanistic basis. As a result of modeling improvements the standard error of the model with respect to its data base has been significantly reduced.« less

Working memory effects of gap-predictions in normal adults: an event-related potentials study.

PubMed

Hestvik, Arild; Bradley, Evan; Bradley, Catherine

2012-12-01

The current study examined the relationship between verbal memory span and the latency with which a filler-gap dependency is constructed. A previous behavioral study found that low span listeners did not exhibit antecedent reactivation at gap sites in relative clauses, in comparison to high verbal memory span subjects (Roberts et al. in J Psycholinguist Res 36(2):175-188, 2007), which suggests that low span subjects are delayed at gap filling. This possibility was examined in the current study. Using an event-related potentials paradigm, it was found that low span subjects have an onset latency delay of about 200 ms in brain responses to violations of syntactic expectancies after the gap site, thus providing a time course measure of the delay hypothesized by previous literature.

Reinforcement Probability Modulates Temporal Memory Selection and Integration Processes

PubMed Central

Matell, Matthew S.; Kurti, Allison N.

2013-01-01

We have previously shown that rats trained in a mixed-interval peak procedure (tone = 4s, light = 12s) respond in a scalar manner at a time in between the trained peak times when presented with the stimulus compound (Swanton & Matell, 2011). In our previous work, the two component cues were reinforced with different probabilities (short = 20%, long = 80%) to equate response rates, and we found that the compound peak time was biased toward the cue with the higher reinforcement probability. Here, we examined the influence that different reinforcement probabilities have on the temporal location and shape of the compound response function. We found that the time of peak responding shifted as a function of the relative reinforcement probability of the component cues, becoming earlier as the relative likelihood of reinforcement associated with the short cue increased. However, as the relative probabilities of the component cues grew dissimilar, the compound peak became non-scalar, suggesting that the temporal control of behavior shifted from a process of integration to one of selection. As our previous work has utilized durations and reinforcement probabilities more discrepant than those used here, these data suggest that the processes underlying the integration/selection decision for time are based on cue value. PMID:23896560

Correlated Time-Variation of Asphalt Rheology and Bulk Microstructure

NASA Astrophysics Data System (ADS)

Ramm, Adam; Nazmus, Sakib; Bhasin, Amit; Downer, Michael

We use noncontact optical microscopy and optical scattering in the visible and near-infrared spectrum on Performance Grade (PG) asphalt binder to confirm the existence of microstructures in the bulk. The number of visible microstructures increases linearly as penetration depth of the incident radiation increases, which verifies a uniform volume distribution of microstructures. We use dark field optical scatter in the near-infrared to measure the temperature dependent behavior of the bulk microstructures and compare this behavior with Dynamic Shear Rheometer (DSR) measurements of the bulk complex shear modulus | G* (T) | . The main findings are: (1) After reaching thermal equilibrium, both temperature dependent optical scatter intensity (I (T)) and bulk shear modulus (| G* (T) |) continue to change appreciably for times much greater than thermal equilibration times. (2) The hysteresis behavior during a complete temperature cycle seen in previous work derives from a larger time dependence in the cooling step compared with the heating step. (3) Different binder aging conditions show different thermal time-variations for both I (T) and | G* (T) | .

Improving dynamic performances of PWM-driven servo-pneumatic systems via a novel pneumatic circuit.

PubMed

Taghizadeh, Mostafa; Ghaffari, Ali; Najafi, Farid

2009-10-01

In this paper, the effect of pneumatic circuit design on the input-output behavior of PWM-driven servo-pneumatic systems is investigated and their control performances are improved using linear controllers instead of complex and costly nonlinear ones. Generally, servo-pneumatic systems are well known for their nonlinear behavior. However, PWM-driven servo-pneumatic systems have the advantage of flexibility in the design of pneumatic circuits which affects the input-output linearity of the whole system. A simple pneumatic circuit with only one fast switching valve is designed which leads to a quasi-linear input-output relation. The quasi-linear behavior of the proposed circuit is verified both experimentally and by simulations. Closed loop position control experiments are then carried out using linear P- and PD-controllers. Since the output position is noisy and cannot be directly differentiated, a Kalman filter is designed to estimate the velocity of the cylinder. Highly improved tracking performances are obtained using these linear controllers, compared to previous works with nonlinear controllers.

Behavioral evidence for left-hemisphere specialization of motor planning

PubMed Central

Meulenbroek, Ruud G. J.; Steenbergen, Bert

2010-01-01

Recent studies suggest that the left hemisphere is dominant for the planning of motor actions. This left-hemisphere specialization hypothesis was proposed in various lines of research, including patient studies, motor imagery studies, and studies involving neurophysiological techniques. However, most of these studies are primarily based on experiments involving right-hand-dominant participants. Here, we present the results of a behavioral study with left-hand-dominant participants, which follows up previous work in right-hand-dominant participants. In our experiment, participants grasped CD casings and replaced them in a different, pre-cued orientation. Task performance was measured by the end-state comfort effect, i.e., the anticipated degree of physical comfort associated with the posture that is planned to be adopted at movement completion. Both left- and right-handed participants showed stronger end-state comfort effects for their right hand compared to their left hand. These results lend behavioral support to the left-hemisphere-dominance motion-planning hypothesis. PMID:21184219

Attitudes and self-reported behavior of patients, doctors, and pharmacists in New Zealand and Belgium toward direct-to-consumer advertising of medication.

PubMed

Dens, Nathalie; Eagle, Lynne C; De Pelsmacker, Patrick

2008-01-01

Patients', doctors', and pharmacists' attitudes toward direct-to-consumer advertising (DTCA) for medication and their perceptions of its impact on patient self-reported behavior in terms of request for, and consumption of, advertised medication were investigated. Data were obtained in New Zealand, 1 of only 2 countries that allow mass-media DTCA for prescription medication, and in Belgium, which does not. Attitudes were relatively negative in both countries, but significantly more positive in New Zealand than in Belgium. The impact of DTCA (both in a positive and a negative sense) on self-reported patient behavior and patient interaction with doctors and pharmacists was limited in both countries. Although -- as already established in previous work -- the informativeness and reliability of DTCA can be much improved, and the attitude of medical professionals toward DTCA is negative in both countries, from the point of view of medical professionals and patients, DTCA does not harm the self-reported relationship between doctors, pharmacists, and patients.

Observations of Turbulence in a Kelvin-Helmholtz Event on 8 September 2015 by the Magnetospheric Multiscale Mission

NASA Technical Reports Server (NTRS)

Stawarz, J. E.; Eriksson, S.; Wilder, F. D.; Ergun, R. E.; Schwartz, S. J.; Pouquet, A.; Burch, J. L.; Giles, B. L.; Khotyaintsev, Y.; Le Contel, O.;

The impact of fatigue on latent print examinations as revealed by behavioral and eye gaze testing.

PubMed

Busey, Thomas; Swofford, Henry J; Vanderkolk, John; Emerick, Brandi

2015-06-01

Eye tracking and behavioral methods were used to assess the effects of fatigue on performance in latent print examiners. Eye gaze was measured both before and after a fatiguing exercise involving fine-grained examination decisions. The eye tracking tasks used similar images, often laterally reversed versions of previously viewed prints, which holds image detail constant while minimizing prior recognition. These methods, as well as a within-subject design with fine grained analyses of the eye gaze data, allow fairly strong conclusions despite a relatively small subject population. Consistent with the effects of fatigue on practitioners in other fields such as radiology, behavioral performance declined with fatigue, and the eye gaze statistics suggested a smaller working memory capacity. Participants also terminated the search/examination process sooner when fatigued. However, fatigue did not produce changes in inter-examiner consistency as measured by the Earth Mover Metric. Implications for practice are discussed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Interplay between Marital Attributions and Conflict Behavior in Predicting Depressive Symptoms

PubMed Central

Ellison, Jenna K.; Kouros, Chrystyna D.; Papp, Lauren M.; Cummings, E. Mark

2015-01-01

Marital attributions--i.e., causal inferences and explanations spouses make about their partners’ behavior--have been implicated as predictors of relationship functioning. Extending previous work, we examined marital attributions as a moderator of the link between marital conflict and depressive symptoms one year later. Participants were 284 couples who reported on marital attributions and depressive symptoms. Couples also engaged in a videotaped marital conflict interaction, which was later coded for specific conflict behaviors. The results showed that husbands’ and wives’ marital attributions about their partner moderated relations between marital conflict behavior and later depressive symptoms, controlling for global marital sentiments. For husbands, positive behavior and affect during marital conflict predicted a decrease in depressive symptoms, but only for husbands’ who made low levels of responsibility and causal attributions about their wives. Wives’ causal attributions about their partner also moderated relations between positive behavior and affect during marital conflict and husbands’ later depressive symptoms. Reflecting an unexpected finding, negative behavior and affect during marital conflict predicted increases in wives’ depressive symptoms, but only for wives who made low levels of responsibility attributions about their partner. The findings suggest that, for husbands, low levels of negative marital attributions for spouses may be protective, strengthening the positive effect of constructive conflict behaviors for their mental health, whereas for wives low levels of responsibility attributions about their spouse may be a risk factor, exacerbating the negative effect of negative marital conflict behaviors on their later depressive symptoms. PMID:26751758

Interplay between marital attributions and conflict behavior in predicting depressive symptoms.

PubMed

Ellison, Jenna K; Kouros, Chrystyna D; Papp, Lauren M; Cummings, E Mark

2016-03-01

Marital attributions-that is, causal inferences and explanations spouses make about their partners' behavior-have been implicated as predictors of relationship functioning. Extending previous work, we examined marital attributions as a moderator of the link between marital conflict and depressive symptoms 1 year later. Participants were 284 couples who reported on marital attributions and depressive symptoms. Couples also engaged in a videotaped marital conflict interaction, which was later coded for specific conflict behaviors. The results showed that husbands' and wives' marital attributions about their partner moderated relations between marital conflict behavior and later depressive symptoms, controlling for global marital sentiments. For husbands, positive behavior and affect during marital conflict predicted a decrease in depressive symptoms, but only for husbands' who made low levels of responsibility and causal attributions about their wives. Wives' causal attributions about their partner also moderated relations between positive behavior and affect during marital conflict and husbands' later depressive symptoms. Reflecting an unexpected finding, negative behavior and affect during marital conflict predicted increases in wives' depressive symptoms, but only for wives who made low levels of responsibility attributions about their partner. The findings suggest that, for husbands, low levels of negative marital attributions for spouses may be protective, strengthening the positive effect of constructive conflict behaviors for their mental health, whereas for wives low levels of responsibility attributions about their spouse may be a risk factor, exacerbating the negative effect of negative marital conflict behaviors on their later depressive symptoms. (c) 2016 APA, all rights reserved).

Perceptions of Unprofessional Attitudes and Behaviors: Implications for Faculty Role Modeling and Teaching Professionalism During Pathology Residency.

PubMed

Brissette, Mark D; Johnson, Kristen A; Raciti, Patricia M; McCloskey, Cindy B; Gratzinger, Dita A; Conran, Richard Michael; Domen, Ronald E; Hoffman, Robert D; Post, Miriam D; Roberts, Cory Anthony; Rojiani, Amyn M; Powell, Suzanne Zein-Eldin

2017-10-01

- Changes occurring in medicine have raised issues about medical professionalism. Professionalism is included in the Core Competencies and Milestones for all pathology residents. Previous studies have looked at resident professionalism attitudes and behaviors in primary care but none have looked specifically at pathology. - To examine behavior and attitudes toward professionalism within pathology and to determine how professionalism is taught in residency programs. - Surveys were sent to all College of American Pathologists junior members and all pathology residency program directors, and responses were compared. - Although no single behavior received the same professionalism rating among residents and program directors, both groups identified the same behaviors as being the most unprofessional: posting identifiable patient information or case images to social media, making a disparaging comment about a physician colleague or member of the support staff on social media or in a public hospital space, and missing work without reporting the time off. Faculty were observed displaying most of these behaviors as often or more often than residents by both groups. The most common means to teach professionalism in pathology residencies is providing feedback as situations arise and teaching by example. Age differences were found within each group and between groups for observed behaviors and attitudes. - As teaching by example was identified as a common educational method, faculty must be aware of the role their behavior and attitudes have in shaping resident behavior and attitudes. These results suggest a need for additional resources to teach professionalism during pathology residency.

A path analysis model for explaining unsafe behavior in workplaces: the effect of perceived work pressure.

PubMed

Ghasemi, Fakhradin; Kalatpour, Omid; Moghimbeigi, Abbas; Mohhamadfam, Iraj

2018-06-01

Unsafe behavior is closely related to occupational accidents. Work pressure is one the main factors affecting employees' behavior. The aim of the present study was to provide a path analysis model for explaining how work pressure affects safety behavior. Using a self-administered questionnaire, six variables supposed to affect safety employees' behavior were measured. The path analysis model was constructed based on several hypotheses. The goodness of fit of the model was assessed using both absolute and comparative fit indices. Work pressure was determined not to influence safety behavior directly. However, it negatively influenced other variables. Group attitude and personal attitude toward safety were the main factors mediating the effect of work pressure on safety behavior. Among the variables investigated in the present study, group attitude, personal attitude and work pressure had the strongest effects on safety behavior. Managers should consider that in order to improve employees' safety behavior, work pressure should be reduced to a reasonable level, and concurrently a supportive environment, which ensures a positive group attitude toward safety, should be provided. Replication of the study is recommended.

The mediating effects of self-leadership on perceived entrepreneurial orientation and innovative work behavior in the banking sector.

PubMed

Kör, Burcu

2016-01-01

Innovative work behavior has been one of the essential attribute of high performing firms, and the roles of entrepreneurial orientation and self-leadership have been important for promoting innovative work behavior. This study advances research on innovative work behavior by examining the mediating role of self-leadership in the relationship between perceived entrepreneurial orientation and innovative work behavior. Structural equation modelling is employed to analyze data from a survey of 404 employees in banking sector. The results of reliability measures and confirmatory factor analysis strongly support the scale of the study. The results from an empirical survey study in the deposit banks reveal that participants' perceptions about high levels of entrepreneurial orientation have a positive impact on innovative work behavior. The results also provide support for the full mediating role of self-leadership in the relationship between participants' perceptions of entrepreneurial orientation and innovative work behavior. Additionally, this study provides some implications for practitioners in the banking sector to facilitate innovative work behavior through entrepreneurial orientation and self- leadership.

Disruptions of working memory and inhibition mediate the association between exposure to institutionalization and symptoms of attention deficit hyperactivity disorder.

PubMed

Tibu, F; Sheridan, M A; McLaughlin, K A; Nelson, C A; Fox, N A; Zeanah, C H

2016-02-01

Young children raised in institutions are exposed to extreme psychosocial deprivation that is associated with elevated risk for psychopathology and other adverse developmental outcomes. The prevalence of attention deficit hyperactivity disorder (ADHD) is particularly high in previously institutionalized children, yet the mechanisms underlying this association are poorly understood. We investigated whether deficits in executive functioning (EF) explain the link between institutionalization and ADHD. A sample of 136 children (aged 6-30 months) was recruited from institutions in Bucharest, Romania, and 72 never institutionalized community children matched for age and gender were recruited through general practitioners' offices. At 8 years of age, children's performance on a number of EF components (working memory, response inhibition and planning) was evaluated. Teachers completed the Health and Behavior Questionnaire, which assesses two core features of ADHD, inattention and impulsivity. Children with history of institutionalization had higher inattention and impulsivity than community controls, and exhibited worse performance on working memory, response inhibition and planning tasks. Lower performances on working memory and response inhibition, but not planning, partially mediated the association between early institutionalization and inattention and impulsivity symptom scales at age 8 years. Institutionalization was associated with decreased EF performance and increased ADHD symptoms. Deficits in working memory and response inhibition were specific mechanisms leading to ADHD in previously institutionalized children. These findings suggest that interventions that foster the development of EF might reduce risk for psychiatric problems in children exposed to early deprivation.

Research on the equivalent circuit model of a circular flexural-vibration-research on the equivalent circuit model of a circular flexural-vibration-mode piezoelectric transformer with moderate thickness.

PubMed

Huang, Yihua; Huang, Wenjin; Wang, Qinglei; Su, Xujian

2013-07-01

The equivalent circuit model of a piezoelectric transformer is useful in designing and optimizing the related driving circuits. Based on previous work, an equivalent circuit model for a circular flexural-vibration-mode piezoelectric transformer with moderate thickness is proposed and validated by finite element analysis. The input impedance, voltage gain, and efficiency of the transformer are determined through computation. The basic behaviors of the transformer are shown by numerical results.

Complexity reduction of rate-equations models for two-choice decision-making.

PubMed

Carrillo, José Antonio; Cordier, Stéphane; Deco, Gustavo; Mancini, Simona

2013-01-01

We are concerned with the complexity reduction of a stochastic system of differential equations governing the dynamics of a neuronal circuit describing a decision-making task. This reduction is based on the slow-fast behavior of the problem and holds on the whole phase space and not only locally around the spontaneous state. Macroscopic quantities, such as performance and reaction times, computed applying this reduction are in agreement with previous works in which the complexity reduction is locally performed at the spontaneous point by means of a Taylor expansion.

Radiating gravitational collapse with shearing motion and bulk viscosity

NASA Astrophysics Data System (ADS)

Chan, R.

2001-03-01

A model is proposed of a collapsing radiating star consisting of a shearing fluid with bulk viscosity undergoing radial heat flow with outgoing radiation. The pressure of the star, at the beginning of the collapse, is isotropic but due to the presence of the bulk viscosity the pressure becomes more and more anisotropic. The behavior of the density, pressure, mass, luminosity, the effective adiabatic index and the Kretschmann scalar is analyzed. Our work is compared to the case of a collapsing shearing fluid of a previous model, for a star with 6 Msun.

Geant4 simulation of ion chambers response to 60Co spectrum of LNMRI/IRD Shepherd 81-14D Radiator

NASA Astrophysics Data System (ADS)

Queiroz Filho, P. P.; Da Silva, C. N. M.

2018-03-01

The National Ionizing Radiation Metrology Laboratory of the Radioprotection and Dosimetry Institute (LNMRI / IRD) has recently acquired a Shepherd 81-14D Radiator. In this work we simulate, using Geant4, the behavior with the inverse square law radiation for 3 models of PTW spherical chambers used in radioprotection, a relevant information to planning the measurements. We did the corrections for the attenuation and scattering in the air for each distance, where we used the 60Co spectrum simulated previously.

Reliable High Performance Peta- and Exa-Scale Computing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bronevetsky, G

2012-04-02

As supercomputers become larger and more powerful, they are growing increasingly complex. This is reflected both in the exponentially increasing numbers of components in HPC systems (LLNL is currently installing the 1.6 million core Sequoia system) as well as the wide variety of software and hardware components that a typical system includes. At this scale it becomes infeasible to make each component sufficiently reliable to prevent regular faults somewhere in the system or to account for all possible cross-component interactions. The resulting faults and instability cause HPC applications to crash, perform sub-optimally or even produce erroneous results. As supercomputers continuemore » to approach Exascale performance and full system reliability becomes prohibitively expensive, we will require novel techniques to bridge the gap between the lower reliability provided by hardware systems and users unchanging need for consistent performance and reliable results. Previous research on HPC system reliability has developed various techniques for tolerating and detecting various types of faults. However, these techniques have seen very limited real applicability because of our poor understanding of how real systems are affected by complex faults such as soft fault-induced bit flips or performance degradations. Prior work on such techniques has had very limited practical utility because it has generally focused on analyzing the behavior of entire software/hardware systems both during normal operation and in the face of faults. Because such behaviors are extremely complex, such studies have only produced coarse behavioral models of limited sets of software/hardware system stacks. Since this provides little insight into the many different system stacks and applications used in practice, this work has had little real-world impact. My project addresses this problem by developing a modular methodology to analyze the behavior of applications and systems during both normal and faulty operation. By synthesizing models of individual components into a whole-system behavior models my work is making it possible to automatically understand the behavior of arbitrary real-world systems to enable them to tolerate a wide range of system faults. My project is following a multi-pronged research strategy. Section II discusses my work on modeling the behavior of existing applications and systems. Section II.A discusses resilience in the face of soft faults and Section II.B looks at techniques to tolerate performance faults. Finally Section III presents an alternative approach that studies how a system should be designed from the ground up to make resilience natural and easy.« less

AIDS-related health behavior: coping, protection motivation, and previous behavior.

PubMed

Van der Velde, F W; Van der Pligt, J

1991-10-01

The purpose of this study was to examine Rogers' protection motivation theory and aspects of Janis and Mann's conflict theory in the context of AIDS-related health behavior. Subjects were 84 heterosexual men and women and 147 homosexual men with multiple sexual partners; LISREL's path-analysis techniques were used to evaluate the goodness of fit of the structural equation models. Protection motivation theory did fit the data but had considerably more explanatory power for heterosexual than for homosexual subjects (49 vs. 22%, respectively). When coping styles were added, different patterns of findings were found among both groups. Adding variables such as social norms and previous behavior increased the explained variance to 73% for heterosexual subjects and to 44% for homosexual subjects. It was concluded that although protection motivation theory did fit the data fairly adequately, expanding the theory with other variables--especially those related to previous behavior--could improve our understanding of AIDS-related health behavior.

Perceived Work Ability in the Light of Long-Term and Stress-Related Unhealthy Behaviors-a Prospective Cohort Study.

PubMed

Nevanperä, Nina; Seitsamo, Jorma; Ala-Mursula, Leena; Remes, Jouko; Hopsu, Leila; Auvinen, Juha; Tammelin, Tuija; Järvelin, Marjo-Riitta; Laitinen, Jaana

2016-04-01

Most of the few studies that exist on the longitudinal associations between health behaviors and work ability target to single health behaviors. To investigate how lifetime clusters of unhealthy behaviors associate with perceived work ability in early midlife. The study population consisted of 46-year-old men and women (n = 3107) born in Northern Finland in 1966. Their current perceived work ability compared to lifetime best, and their unhealthy behaviors (physical inactivity, smoking, and alcohol consumption) were assessed by questionnaires. We determined clusters of unhealthy behaviors at the ages of 14, 31, and 46 and created lifetime development trajectories of health behaviors. We also assessed stress-related eating and drinking at the ages of 31 and 46. Cross-tabulations and multivariate logistic regression models were used to investigate the associations between clusters of health behaviors, stress-related eating and drinking, and work ability at 46 years. The analyses were controlled for basic education and physical strenuousness of work, psychosocial job characteristics, perceived work ability, and BMI (kg/m(2)) at 31 years. Four health behavior trajectories emerged: always healthy, moderate (reference group), deteriorated. and always unhealthy. Among men, always unhealthy behaviors [OR (95 % confidence interval) 2.81 (1.35, 5.86)], and among women, deteriorated health behaviors [1.67 (1.07, 2.58)] associated with poor perceived work ability at 46 years. In addition, stress-related eating and drinking associated independently with poor perceived work ability at 46 years [men 2.58 (1.62, 4.12) and women 2.48 (1.70, 3.61)]. Long-lasting and stress-related unhealthy behaviors increase the risk of poor work ability in midlife.

The hydrodynamic and ultrasound-induced forces on microbubbles under high Reynolds number flow representative of the human systemic circulation

NASA Astrophysics Data System (ADS)

Clark, Alicia; Aliseda, Alberto

2016-11-01

Ultrasound contrast agents (UCAs) are micron-sized bubbles that are used in conjunction with ultrasound (US) in medical applications such as thrombolysis and targeted intravenous drug delivery. Previous work has shown that the Bjerknes force, due to the phase difference between the incoming US pressure wave and the bubble volume oscillations, can be used to manipulate the trajectories of microbubbles. Our work explores the behavior of microbubbles in medium sized blood vessels under both uniform and pulsatile flows at a range of physiologically relevant Reynolds and Womersley numbers. High speed images were taken of the microbubbles in an in-vitro flow loop that replicates physiological flow conditions. During the imaging, the microbubbles were insonified at different diagnostic ultrasound settings (varying center frequency, PRF, etc.). An in-house Lagrangian particle tracking code was then used to determine the trajectories of the microbubbles and, thus, a dynamic model for the microbubbles including the Bjerknes forces acting on them, as well as drag, lift, and added mass. Preliminary work has also explored the behavior of the microbubbles in a patient-specific model of a carotid artery bifurcation to demonstrate the feasibility of preferential steering of microbubbles towards the intracranial circulation with US.

Developmental and Adult GAP-43 Deficiency in Mice Dynamically Alters Hippocampal Neurogenesis and Mossy Fiber Volume

PubMed Central

Latchney, Sarah E.; Masiulis, Irene; Zaccaria, Kimberly J.; Lagace, Diane C.; Powell, Craig M.; McCasland, James S.; Eisch, Amelia J.

2014-01-01

Growth Associated Protein-43 (GAP-43) is a pre-synaptic protein that plays key roles in axonal growth and guidance and in modulating synapse formation. Previous work has demonstrated that mice lacking one allele of this gene [GAP-43(+/-) mice] exhibit hippocampal structural abnormalities and impaired spatial learning and stress-induced behavioral withdrawal and anxiety (Zaccaria et al., 2010), behaviors that are dependent on proper hippocampal circuitry and function. Given the correlation between hippocampal function, synaptic connectivity, and neurogenesis, we tested if behaviorally-naïve GAP-43(+/-) mice had alterations in either neurogenesis or synaptic connectivity in the hippocampus during early postnatal development and young adulthood, and following behavior testing in older adults. To test our hypothesis, we examined hippocampal cell proliferation (Ki67), number of immature neuroblasts (DCX), and mossy fiber volume (synaptoporin) in behaviorally-naïve postnatal (P) day 9 (P9), P26, and behaviorally-experienced 5-7 month old GAP-43(+/-) and (+/+) littermate mice. P9 GAP-43(+/-) mice had fewer Ki67+ and DCX+ cells compared to (+/+) mice, particularly in the posterior dentate gyrus, and smaller mossy fiber volume in the same region. In young adulthood, however, male GAP-43(+/-) mice had more Ki67+ and DCX+ cells and greater mossy fiber volume in the posterior dentate gyrus relative to male (+/+). These increases were not seen in females. In 5-7 month old GAP-43(+/-) mice whose behaviors were the focus of our prior publication (Zaccaria et al., 2010), there was no global change in number of proliferating or immature neurons relative to (+/+) mice. However, more detailed analysis revealed fewer proliferative DCX+ cells in the anterior dentate gyrus of male GAP-43(+/-) mice compared to male (+/+) mice. This reduction was not observed in females. These results suggest that young GAP-43(+/-) mice have decreased hippocampal neurogenesis and synaptic connectivity, but slightly older mice have greater hippocampal neurogenesis and synaptic connectivity. In conjunction with our previous study, these findings suggest GAP-43 is dynamically involved in early postnatal and adult hippocampal neurogenesis and synaptic connectivity, possibly contributing to the GAP-43(+/-) behavioral phenotype. PMID:24576816

Understanding multiple levels of norms about teen pregnancy and their relationships to teens' sexual behaviors.

PubMed

Mollborn, Stefanie; Domingue, Benjamin W; Boardman, Jason D

2014-06-01

Researchers seeking to understand teen sexual behaviors often turn to age norms, but they are difficult to measure quantitatively. Previous work has usually inferred norms from behavioral patterns or measured group-level norms at the individual level, ignoring multiple reference groups. Capitalizing on the multilevel design of the Add Health survey, we measure teen pregnancy norms perceived by teenagers, as well as average norms at the school and peer network levels. School norms predict boys' perceived norms, while peer network norms predict girls' perceived norms. Peer network and individually perceived norms against teen pregnancy independently and negatively predict teens' likelihood of sexual intercourse. Perceived norms against pregnancy predict increased likelihood of contraception among sexually experienced girls, but sexually experienced boys' contraceptive behavior is more complicated: When both the boy and his peers or school have stronger norms against teen pregnancy he is more likely to contracept, and in the absence of school or peer norms against pregnancy, boys who are embarrassed are less likely to contracept. We conclude that: (1) patterns of behavior cannot adequately operationalize teen pregnancy norms, (2) norms are not simply linked to behaviors through individual perceptions, and (3) norms at different levels can operate independently of each other, interactively, or in opposition. This evidence creates space for conceptualizations of agency, conflict, and change that can lead to progress in understanding age norms and sexual behaviors.

Bringing the patient back in: behavioral decision-making and choice in medical economics.

PubMed

Mendoza, Roger Lee

2018-04-01

We explore the behavioral methodology and "revolution" in economics through the lens of medical economics. We address two questions: (1) Are mainstream economic assumptions of utility-maximization realistic approximations of people's actual behavior? (2) Do people maximize subjective expected utility, particularly in choosing from among the available options? In doing so, we illustrate-in terms of a hypothetical experimental sample of patients with dry eye diagnosis-why and how utility in pharmacoeconomic assessments might be valued differently by patients when subjective psychological, social, cognitive, and emotional factors are considered. While experimentally-observed or surveyed behavior yields stated (rather than revealed) preferences, behaviorism offers a robust toolset in understanding drug, medical device, and treatment-related decisions compared to the optimizing calculus assumed by mainstream economists. It might also do so more perilously than economists have previously understood, in light of the intractable uncertainties, information asymmetries, insulated third-party agents, entry barriers, and externalities that characterize healthcare. Behavioral work has been carried out in many sub-fields of economics. Only recently has it been extended to healthcare. This offers medical economists both the challenge and opportunity of balancing efficiency presumptions with relatively autonomous patient choices, notwithstanding their predictable, yet seemingly consistent, irrationality. Despite its comparative youth and limitations, the scientific contributions of behaviorism are secure and its future in medical economics appears to be promising.

Understanding multiple levels of norms about teen pregnancy and their relationships to teens’ sexual behaviors

PubMed Central

Mollborn, Stefanie; Domingue, Benjamin W.; Boardman, Jason D.

2014-01-01

Researchers seeking to understand teen sexual behaviors often turn to age norms, but they are difficult to measure quantitatively. Previous work has usually inferred norms from behavioral patterns or measured group-level norms at the individual level, ignoring multiple reference groups. Capitalizing on the multilevel design of the Add Health survey, we measure teen pregnancy norms perceived by teenagers, as well as average norms at the school and peer network levels. School norms predict boys’ perceived norms, while peer network norms predict girls’ perceived norms. Peer network and individually perceived norms against teen pregnancy independently and negatively predict teens’ likelihood of sexual intercourse. Perceived norms against pregnancy predict increased likelihood of contraception among sexually experienced girls, but sexually experienced boys’ contraceptive behavior is more complicated: When both the boy and his peers or school have stronger norms against teen pregnancy he is more likely to contracept, and in the absence of school or peer norms against pregnancy, boys who are embarrassed are less likely to contracept. We conclude that: (1) patterns of behavior cannot adequately operationalize teen pregnancy norms, (2) norms are not simply linked to behaviors through individual perceptions, and (3) norms at different levels can operate independently of each other, interactively, or in opposition. This evidence creates space for conceptualizations of agency, conflict, and change that can lead to progress in understanding age norms and sexual behaviors. PMID:25104920

Intervention Effects on Safety Compliance and Citizenship Behaviors: Evidence from the Work, Family, and Health Study

PubMed Central

Hammer, Leslie B.; Johnson, Ryan C.; Crain, Tori L.; Bodner, Todd; Kossek, Ellen Ernst; Davis, Kelly; Kelly, Erin L.; Buxton, Orfeu M.; Karuntzos, Georgia; Chosewood, L. Casey; Berkman, Lisa

2015-01-01

We tested the effects of a work-family intervention on employee reports of safety compliance and organizational citizenship behaviors in 30 healthcare facilities using a group-randomized trial. Based on Conservation of Resources theory and the Work-Home Resources Model, we hypothesized that implementing a work-family intervention aimed at increasing contextual resources via supervisor support for work and family and employee control over work time would lead to improved personal resources and increased employee performance on the job in the form of self-reported safety compliance and organizational citizenship behaviors. Multilevel analyses used survey data from 1,524 employees at baseline, 6-month and 12-month post-intervention follow-ups. Significant intervention effects were observed for safety compliance at the 6-month and organizational citizenship behaviors at the 12-month follow-ups. More specifically, results demonstrate that the intervention protected against declines in employee self-reported safety compliance and organizational citizenship behaviors, compared to employees in the control facilities. The hypothesized mediators of perceptions of family supportive supervisor behaviors, control over work time, and work-family conflict (work-to-family conflict, family-to-work conflict) were not significantly improved by the intervention. However, baseline perceptions of family supportive supervisor behaviors, control over work time, and work-family climate were significant moderators of the intervention effect on the self-reported safety compliance and organizational citizenship behavior outcomes. PMID:26348479

The Ecology of Exercise: Mechanisms Underlying Individual Variation in Behavior, Activity, and Performance: An Introduction to Symposium.

PubMed

Killen, Shaun S; Calsbeek, Ryan; Williams, Tony D

2017-08-01

Wild animals often engage in intense physical activity while performing tasks vital for their survival and reproduction associated with foraging, avoiding predators, fighting, providing parental care, and migrating. In this theme issue we consider how viewing these tasks as "exercise"-analogous to that performed by human athletes-may help provide insight into the mechanisms underlying individual variation in these types of behaviors and the importance of physical activity in an ecological context. In this article and throughout this issue, we focus on four key questions relevant to the study of behavioral ecology that may be addressed by studying wild animal behavior from the perspective of exercise physiology: (1) How hard do individual animals work in response to ecological (or evolutionary) demands?; (2) Do lab-based studies of activity provide good models for understanding activity in free-living animals and individual variation in traits?; (3) Can animals work too hard during "routine" activities?; and (4) Can paradigms of "exercise" and "training" be applied to free-living animals? Attempts to address these issues are currently being facilitated by rapid technological developments associated with physiological measurements and the remote tracking of wild animals, to provide mechanistic insights into the behavior of free-ranging animals at spatial and temporal scales that were previously impossible. We further suggest that viewing the behaviors of non-human animals in terms of the physical exercise performed will allow us to fully take advantage of these technological advances, draw from knowledge and conceptual frameworks already in use by human exercise physiologists, and identify key traits that constrain performance and generate variation in performance among individuals. It is our hope that, by highlighting mechanisms of behavior and performance, the articles in this issue will spur on further synergies between physiologists and ecologists, to take advantage of emerging cross-disciplinary perspectives and technologies. © The Author 2017. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology.

Efficient reinforcement learning of a reservoir network model of parametric working memory achieved with a cluster population winner-take-all readout mechanism.

PubMed

Cheng, Zhenbo; Deng, Zhidong; Hu, Xiaolin; Zhang, Bo; Yang, Tianming

2015-12-01

The brain often has to make decisions based on information stored in working memory, but the neural circuitry underlying working memory is not fully understood. Many theoretical efforts have been focused on modeling the persistent delay period activity in the prefrontal areas that is believed to represent working memory. Recent experiments reveal that the delay period activity in the prefrontal cortex is neither static nor homogeneous as previously assumed. Models based on reservoir networks have been proposed to model such a dynamical activity pattern. The connections between neurons within a reservoir are random and do not require explicit tuning. Information storage does not depend on the stable states of the network. However, it is not clear how the encoded information can be retrieved for decision making with a biologically realistic algorithm. We therefore built a reservoir-based neural network to model the neuronal responses of the prefrontal cortex in a somatosensory delayed discrimination task. We first illustrate that the neurons in the reservoir exhibit a heterogeneous and dynamical delay period activity observed in previous experiments. Then we show that a cluster population circuit decodes the information from the reservoir with a winner-take-all mechanism and contributes to the decision making. Finally, we show that the model achieves a good performance rapidly by shaping only the readout with reinforcement learning. Our model reproduces important features of previous behavior and neurophysiology data. We illustrate for the first time how task-specific information stored in a reservoir network can be retrieved with a biologically plausible reinforcement learning training scheme. Copyright © 2015 the American Physiological Society.

The cortical basis of true memory and false memory for motion.

PubMed

Karanian, Jessica M; Slotnick, Scott D

2014-02-01

Behavioral evidence indicates that false memory, like true memory, can be rich in sensory detail. By contrast, there is fMRI evidence that true memory for visual information produces greater activity in earlier visual regions than false memory, which suggests true memory is associated with greater sensory detail. However, false memory in previous fMRI paradigms may have lacked sufficient sensory detail to recruit earlier visual processing regions. To investigate this possibility in the present fMRI study, we employed a paradigm that produced feature-specific false memory with a high degree of visual detail. During the encoding phase, moving or stationary abstract shapes were presented to the left or right of fixation. During the retrieval phase, shapes from encoding were presented at fixation and participants classified each item as previously "moving" or "stationary" within each visual field. Consistent with previous fMRI findings, true memory but not false memory for motion activated motion processing region MT+, while both true memory and false memory activated later cortical processing regions. In addition, false memory but not true memory for motion activated language processing regions. The present findings indicate that true memory activates earlier visual regions to a greater degree than false memory, even under conditions of detailed retrieval. Thus, the dissociation between previous behavioral findings and fMRI findings do not appear to be task dependent. Future work will be needed to assess whether the same pattern of true memory and false memory activity is observed for different sensory modalities. Copyright © 2013 Elsevier Ltd. All rights reserved.

Type A behavior and work situation: associations with burnout and work engagement.

PubMed

Hallberg, Ulrika E; Johansson, Gunn; Schaufeli, Wilmar B

2007-04-01

The aim of the present study was to investigate Type A behavior as well as perceived work situation, and associations with burnout and work engagement. The associations in focus were investigated through hierarchical regressions in a sample (N= 329) of Swedish Information Communication Technology consultants. The findings indicated that both work situation and Type A behavior was correlated with work engagement and burnout; however, no interactions between Type A behavior and work situation were elicited. The main conclusion was that the achievement striving aspect of Type A behavior appears as "non-toxic" and is related only to work engagement. However, the irritability/impatience aspect appears to be responsible for burnout complaints among Type A individuals, possibly through negative effects of the mood itself than through perceived stress at work.

Adolescents previously involved in Satanism experiencing mental health problems.

PubMed

Heathcote, H; Gmeiner, A; Poggenpoel, M

1999-06-01

No research has previously been done regarding the phenomenon of adolescents who have previously been involved in Satanism and who experience obstacles in their strive for mental health. Adolescents previously involved in Satanism present behavioral problems like aggressive outbursts, depression, "psychosis" or suicide attempts, that could lead to suicide. In the phenomenon-analysis semi-structured, phenomenological interviews were performed with the respondents and their parents. The respondents were requested to write a naïve sketch about their life. After completion of the data-control, guidelines for nursing staff were set. The guidelines are set for the management of adolescents who have previously been involved in Satanism and who experience obstacles in their strive for mental health. Interviews with experts in Satanism were conducted, literature in the form of books, magazines and newspaper-clippings were used to verify the research findings. The most important guidelines are that the caregivers have to be reborn Christians; they are not allowed to show any fear or sympathy; they must have sufficient knowledge about Satanism; the adolescents have to be unconditionally accepted; the caregivers have to work in a team and the adolescents have to be taught to deal with their emotions.

Listening to food workers: Factors that impact proper health and hygiene practice in food service.

PubMed

Clayton, Megan L; Clegg Smith, Katherine; Neff, Roni A; Pollack, Keshia M; Ensminger, Margaret

2015-01-01

Foodborne disease is a significant problem worldwide. Research exploring sources of outbreaks indicates a pronounced role for food workers' improper health and hygiene practice. To investigate food workers' perceptions of factors that impact proper food safety practice. Interviews with food service workers in Baltimore, MD, USA discussing food safety practices and factors that impact implementation in the workplace. A social ecological model organizes multiple levels of influence on health and hygiene behavior. Issues raised by interviewees include factors across the five levels of the social ecological model, and confirm findings from previous work. Interviews also reveal many factors not highlighted in prior work, including issues with food service policies and procedures, working conditions (e.g., pay and benefits), community resources, and state and federal policies. Food safety interventions should adopt an ecological orientation that accounts for factors at multiple levels, including workers' social and structural context, that impact food safety practice.

Spatial Working Memory Performance and fMRI Activation Interactions in Abstinent Adolescent Marijuana Users

PubMed Central

Padula, Claudia B.; Schweinsburg, Alecia D.; Tapert, Susan F.

2008-01-01

Previous studies have suggested neural disruption and reorganization in adult marijuana users. However, it remains unclear whether these effects persist in adolescents after 28 days of abstinence and, if they do, what Performance × Brain Response interactions occur. Adolescent marijuana users (n = 17) and controls (n = 17) aged 16–18 years were recruited from local schools. Functional magnetic resonance imaging data were collected after 28 days’ monitored abstinence as participants performed a spatial working memory task. Marijuana users show Performance × Brain Response interactions in the bilateral temporal lobes, left anterior cingulate, left parahippocampal gyrus, and right thalamus (clusters ≥ 1358 μl; p <.05), although groups do not differ on behavioral measures of task performance. Marijuana users show differences in brain response to a spatial working memory task despite adequate performance, suggesting a different approach to the task via altered neural pathways. PMID:18072830

I. WORKING MEMORY CAPACITY IN CONTEXT: MODELING DYNAMIC PROCESSES OF BEHAVIOR, MEMORY, AND DEVELOPMENT.

PubMed

Simmering, Vanessa R

2016-09-01

Working memory is a vital cognitive skill that underlies a broad range of behaviors. Higher cognitive functions are reliably predicted by working memory measures from two domains: children's performance on complex span tasks, and infants' performance in looking paradigms. Despite the similar predictive power across these research areas, theories of working memory development have not connected these different task types and developmental periods. The current project takes a first step toward bridging this gap by presenting a process-oriented theory, focusing on two tasks designed to assess visual working memory capacity in infants (the change-preference task) versus children and adults (the change detection task). Previous studies have shown inconsistent results, with capacity estimates increasing from one to four items during infancy, but only two to three items during early childhood. A probable source of this discrepancy is the different task structures used with each age group, but prior theories were not sufficiently specific to explain how performance relates across tasks. The current theory focuses on cognitive dynamics, that is, how memory representations are formed, maintained, and used within specific task contexts over development. This theory was formalized in a computational model to generate three predictions: 1) capacity estimates in the change-preference task should continue to increase beyond infancy; 2) capacity estimates should be higher in the change-preference versus change detection task when tested within individuals; and 3) performance should correlate across tasks because both rely on the same underlying memory system. I also tested a fourth prediction, that development across tasks could be explained through increasing real-time stability, realized computationally as strengthening connectivity within the model. Results confirmed these predictions, supporting the cognitive dynamics account of performance and developmental changes in real-time stability. The monograph concludes with implications for understanding memory, behavior, and development in a broader range of cognitive development. © 2016 The Society for Research in Child Development, Inc.

Ticketing aggressive cars and trucks (TACT): How does it work on city streets?

PubMed

Telford, Russell; Cook, Lawrence J; Olson, Lenora M

2018-02-17

The purpose of this study was to determine the feasibility of modifying the Ticking Aggressive Cars and Trucks (TACT) program, originally designed to work on state highways, within a metropolitan area to reduce unsafe interactions and their related crashes between drivers of large trucks and passenger vehicles. Using crash data, the driving behaviors most commonly associated with large truck and passenger vehicle crashes were identified. A public awareness campaign using media messaging and increased law enforcement was created targeting these associated behaviors. The frequency of these behaviors both before and after the public awareness campaign was determined through observation of traffic at 3 specific locations within the city. Each location had a sufficient volume of large truck and passenger traffic to observe frequent interactions. Pre- and postintervention data were compared using negative binomial regression with generalized estimating equations to evaluate whether the campaign was associated with a reduction in the identified driving behaviors. A comparison between crash data from before, during, and after the campaign and crashes during the same time periods in previous years did not show a significant difference (P =.081). The number of large trucks observed in traffic remained the same during pre- and postintervention periods (P =.625). The rates of negative interactions per 100 large trucks decreased for both large trucks and passenger vehicles after the intervention, with calculated rate ratios of 0.58 (95% confidence interval [CI], 0.48, 0.70) and 0.31 (95% CI, 0.20, 0.47). The greatest reduction was seen in passenger vehicles following too close, with a rate ratio of 0.21 (95% CI, 0.15, 0.30). Although designed for reducing crashes on highways, the TACT program can be an effective approach for improving driver behaviors on city streets.

A ‘frozen volume’ transition model and working mechanism for the shape memory effect in amorphous polymers

NASA Astrophysics Data System (ADS)

Lu, Haibao; Wang, Xiaodong; Yao, Yongtao; Qing Fu, Yong

2018-06-01

Phenomenological models based on frozen volume parameters could well predict shape recovery behavior of shape memory polymers (SMPs), but the physical meaning of using the frozen volume parameters to describe thermomechanical properties has not been well-established. In this study, the fundamental working mechanisms of the shape memory effect (SME) in amorphous SMPs, whose temperature-dependent viscoelastic behavior follows the Eyring equation, have been established with the considerations of both internal stress and its resulted frozen volume. The stress-strain constitutive relation was initially modeled to quantitatively describe effects of internal stresses at the macromolecular scale based on the transient network theory. A phenomenological ‘frozen volume’ model was then established to characterize the macromolecule structure and SME of amorphous SMPs based on a two-site stress-relaxation model. Effects of the internal stress, frozen volume and strain rate on shape memory behavior and thermomechanical properties of the SMP were investigated. Finally, the simulation results were compared with the experimental results reported in the literature, and good agreements between the theoretical and experimental results were achieved. The novelty and key differences of our newly proposed model with respect to the previous reports are (1). The ‘frozen volume’ in our study is caused by the internal stress and governed by the two-site model theory, thus has a good physical meaning. (2). The model can be applied to characterize and predict both the thermal and thermomechanical behaviors of SMPs based on the constitutive relationship with internal stress parameters. It is expected to provide a power tool to investigate the thermomechanical behavior of the SMPs, of which both the macromolecular structure characteristics and SME could be predicted using this ‘frozen volume’ model.

Development of a Theory-Based Intervention to Increase Clinical Measurement of Reactive Balance in Adults at Risk of Falls.

PubMed

Sibley, Kathryn M; Brooks, Dina; Gardner, Paula; Janaudis-Ferreira, Tania; McGlynn, Mandy; OʼHoski, Sachi; McEwen, Sara; Salbach, Nancy M; Shaffer, Jennifer; Shing, Paula; Straus, Sharon E; Jaglal, Susan B

2016-04-01

Effective balance reactions are essential for avoiding falls, but are not regularly measured by physical therapists. Physical therapists report wanting to improve reactive balance assessment, and theory-based approaches are recommended as the foundation for the development of interventions. This article describes how a behavior change theory for health care providers, the theoretical domains framework (TDF), was used to develop an intervention to increase reactive balance measurement among physical therapists who work in rehabilitation settings and treat adults who are at risk of falls. We employed published recommendations for using the TDF-guided intervention development. We identified what health care provider behavior is in need of change, relevant barriers and facilitators, strategies to address them, and how we would measure behavior change. In this case, identifying strategies required selecting both a reactive balance measure and behavior change techniques. Previous research had determined that physical therapists need to increase reactive balance measurement, and identified barriers and facilitators that corresponded to 8 TDF domains. A published review informed the selection of the Balance Evaluation Systems Test (Reactive Postural Responses Section) as addressing the barriers and facilitators, and existing research informed the selection of 9 established behavior change techniques corresponding to each identified TDF domain. The TDF framework were incorporated into a 12-month intervention with interactive group sessions, local champions, and health record modifications. Intervention effect can be evaluated using health record abstraction, questionnaires, and qualitative semistructured interviews. Although future research will evaluate the intervention in a controlled study, the process of theory-based intervention development can be applied to other rehabilitation research contexts, maximizing the impact of this work.Video Abstract is available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A123).

The impact of internet-based cognitive behavior therapy on work ability in patients with depression - a randomized controlled study.

PubMed

Hange, Dominique; Ariai, Nashmil; Kivi, Marie; Eriksson, Maria Cm; Nejati, Shabnam; Petersson, Eva-Lisa

2017-01-01

The aim of this randomized controlled trial (RCT) was to investigate the effects of internet-based cognitive behavior therapy (ICBT) treatment for depression compared to treatment-as-usual (TAU) on improving work ability and quality of life in patients with mild-to-moderate depression. We also examined whether patients treated with ICBT returned to work more rapidly, that is, had fewer days of sick leave, than patients treated with TAU. This study is based on material from the PRIM-NET RCT that took place between 2010 and 2013. Primary care centers in Region Vastra Gotaland, Sweden, population about 1.6 million. A total of 77 patients with depression randomized to either ICBT (46 patients) or TAU (31 patients). Mean age of participants was 35.8 years, and 67.5% were women. Work ability was measured with the Work Ability Index, depressive symptoms with Montgomery Asberg Depression Rating Scale - self-rating version (MADRS-S), quality of life with EuroQoL-5D (EQ-5D), and number of sick leave days. Both groups showed an association between improved work ability and reduction of depressive symptoms and between improved work ability and better quality of life. ICBT could not be shown to improve work ability more than TAU among patients with mild-to-moderate depression. There were no differences between the groups concerning number of patients with sick leave or number of sick leave days. Our study indicates that a high level of work ability has an association with high health-related quality of life in patients with mild-to-moderate depression, whether they are treated with ICBT or TAU. ICBT has previously been found to be cost-effective and can be seen as a good alternative to TAU. In addition to the ICBT, an intervention oriented toward the work place might improve work ability and reduce the number of sick leave days among patients with depression.

Why do people reject unintended inequity? Responders' rejection in a truncated ultimatum game.

PubMed

Ohmura, Yu; Yamagishi, Toshio

2005-04-01

Rejection of an inequitable and yet unintended outcome in a truncated ultimatum game was examined in an experiment with 46 undergraduate students (27 men and 19 women) from a large national university in Japan. In an ultimatum game, one of two players, the proposer, makes an offer to divide a fixed-sum of money. The other player, the responder, decides whether to accept or reject the offer. When the responder rejects the proposer's offer, neither of the two players receives a reward. Previous work examining the behavior of participants in the truncated ultimatum game employed strategy method in their experimental design. We examined whether these previous findings would be replicated in an experimental design that did not use the strategy method and instead used the standard one-shot game. Seven out of 46 responders given an inequitable offer rejected it, replicating prior results with the strategy method. We further found that subjects who rejected an offer that was involuntary and yet inequitable did not over-attribute intentions to the proposer's involuntary behavior more strongly than did acceptors. These findings strongly suggest that aversion to inequity is the explanation for the subjects' rejection of the inequitable offer.

Individual differences in the Behavioral Inhibition System are associated with orbitofrontal cortex and precuneus gray matter volume.

PubMed

Fuentes, Paola; Barrós-Loscertales, Alfonso; Bustamante, Juan Carlos; Rosell, Patricia; Costumero, Víctor; Ávila, César

2012-09-01

The Behavioral Inhibition System (BIS) is described in Gray's Reinforcement Sensitivity Theory as a hypothetical construct that mediates anxiety in animals and humans. The neuroanatomical correlates of this system are not fully clear, although they are known to involve the amygdala, the septohippocampal system, and the prefrontal cortex. Previous neuroimaging research has related individual differences in BIS with regional volume and functional variations in the prefrontal cortex, amygdala, and hippocampal formation. The aim of the present work was to study BIS-related individual differences and their relationship with brain regional volume. BIS sensitivity was assessed through the BIS/BAS questionnaire in a sample of male participants (N = 114), and the scores were correlated with brain regional volume in a voxel-based morphometry analysis. The results show a negative correlation between the BIS and the volume of the right and medial orbitofrontal cortices and the precuneus. Our results and previous findings suggest that individual differences in anxiety-related personality traits and their related psychopathology may be associated with reduced brain volume in certain structures relating to emotional control (i.e., the orbitofrontal cortex) and self-consciousness (i.e., the precuneus), as shown by our results.

Sex differences in neural efficiency: Are they due to the stereotype threat effect?☆

PubMed Central

Dunst, Beate; Benedek, Mathias; Bergner, Sabine; Athenstaedt, Ursula; Neubauer, Aljoscha C.

2013-01-01

The neural efficiency hypothesis postulates a more efficient use of brain resources in more intelligent people as compared to less intelligent ones. However, this relationship was found to be moderated by sex and task content. While the phenomenon of neural efficiency was previously supported for men when performing visuo-spatial tasks it occurred for women only when performing verbal tasks. One possible explanation for this finding could be provided by the well-studied phenomenon called stereotype threat. Stereotype threat arises when a negative stereotype of one’s own group is made salient and can result in behavior that confirms the stereotype. Overall, 32 boys and 31 girls of varying intellectual ability were tested with a mental rotation task, either under a stereotype exposure or a no-stereotype exposure condition while measuring their EEG. The behavioral results show that an activated negative stereotype not necessarily hampers the performance of girls. Physiologically, a confirmation of the neural efficiency phenomenon was only obtained for boys working under a no-stereotype exposure condition. This result pattern replicates previous findings without threat and thus suggests that sex differences in neural efficiency during visuo-spatial tasks may not be due to the stereotype threat effect. PMID:24092950

Unique heating curves generated by radiofrequency electric-field interactions with semi-aqueous solutions

NASA Astrophysics Data System (ADS)

Lara, Nadia C.; Haider, Asad A.; Wilson, Lon J.; Curley, Steven A.; Corr, Stuart J.

2017-01-01

Aqueous and nanoparticle-based solutions have been reported to heat when exposed to an alternating radiofrequency (RF) electric-field. Although the theoretical models have been developed to accurately model such a behavior given the solution composition as well as the geometrical constraints of the sample holder, these models have not been investigated across a wide-range of solutions where the dielectric properties differ, especially with regard to the real permittivity. In this work, we investigate the RF heating properties of non-aqueous solutions composed of ethanol, propylene glycol, and glycine betaine with and without varying amounts of NaCl and LiCl. This allowed us to modulate the real permittivity across the range 25-132, as well as the imaginary permittivity across the range 37-177. Our results are in excellent agreement with the previously developed theoretical models. We have shown that different materials generate unique RF heating curves that differ from the standard aqueous heating curves. The theoretical model previously described is robust and accounts for the RF heating behavior of materials with a variety of dielectric properties, which may provide applications in non-invasive RF cancer hyperthermia.

Injection efficiency of bound modes. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Egalon, Claudio Oliveira

1990-01-01

Previous work on efficiency of light injection into the core of a fiber from a thin film and a bulk distribution of sources in the cladding have used the fields of a weakly guiding fiber. This approximation simplifies the analysis of the power efficiency by introducing universal values for the eigenvalues of different fibers with the same V-number, but cannot predict accurately the behavior of the injected light into a fiber with arbitrary differences in indices of refraction. The exact field solution was used in the expressions of the power efficiency, p sub eff, and its behavior as a function of the fiber parameter was analyzed. Weakly guiding results obtained previously are confirmed. However, P sub eff does not always increase with the V-number but with the difference in the indices of refraction, eta sub core-eta sub clad. For the bulk distribution it was found that P sub eff increases with the wavelength, lambda, and decreases with the fiber core radius, a, i.e., it decreases with the V-number. However, for the thin film, the P sub eff remains almost constant with lambda and the fiber core radius.

Language networks associated with computerized semantic indices.

PubMed

Pakhomov, Serguei V S; Jones, David T; Knopman, David S

2015-01-01

Tests of generative semantic verbal fluency are widely used to study organization and representation of concepts in the human brain. Previous studies demonstrated that clustering and switching behavior during verbal fluency tasks is supported by multiple brain mechanisms associated with semantic memory and executive control. Previous work relied on manual assessments of semantic relatedness between words and grouping of words into semantic clusters. We investigated a computational linguistic approach to measuring the strength of semantic relatedness between words based on latent semantic analysis of word co-occurrences in a subset of a large online encyclopedia. We computed semantic clustering indices and compared them to brain network connectivity measures obtained with task-free fMRI in a sample consisting of healthy participants and those differentially affected by cognitive impairment. We found that semantic clustering indices were associated with brain network connectivity in distinct areas including fronto-temporal, fronto-parietal and fusiform gyrus regions. This study shows that computerized semantic indices complement traditional assessments of verbal fluency to provide a more complete account of the relationship between brain and verbal behavior involved organization and retrieval of lexical information from memory. Copyright © 2014 Elsevier Inc. All rights reserved.

Overcoming Barriers: Tailoring Climate Education for Latino and non-Latino Citizen to Impact Decision Making

NASA Astrophysics Data System (ADS)

Estrada, M.; Boudrias, M. A.; Silva-Send, N. J.; Gershunov, A.; Anders, S.

2013-12-01

Culture has been shown to be an important determinant of Latino/Hispanic American environmental attitudes (Schultz, Unipan, & Gamba, 2000), which might help to explain the underrepresentation of Latinos in the U.S. 'environmental' movement. With shifting U.S. demographics, however, there is increased urgency to understand how Latinos integrate into the community that is concerned and literate about climate change. As part of the Climate Education Partners (CEP) work in San Diego, we investigated how to address this ethnic group disparity. In this paper, we describe a study of how climate change science knowledge relates to Latino and Non-Latino citizen (a) engagement in conservation behaviors and (b) more informed decision-making. Drawing upon previous work on the Tripartite Integration Model of Social Influence (TIMSI) (Estrada et al., 2011), we hypothesized that climate change knowledge that promotes efficacy (i.e., a sense that one can do something) would relate to greater engagement in conservation behaviors and more informed decision-making (both common of community members concerned about climate change). To test this model, 1001 San Diego residence participated in a telephone survey in which the attitudes towards climate change were assessed using '6 Americas' segmentation (Leiserowitz et al., 2011), in addition to climate change science knowledge, efficacy, values, and engagement in weekly and yearly climate change friendly behaviors (e.g., conservation, transportation, community engagement behaviors). Results showed that there were significant differences in the 6 America segmentation distributions, knowledge, efficacy and behavioral engagement with Latinos significantly more concerned than Non-Latinos, and reporting greater knowledge, efficacy and engagement in behaviors. However, data from both groups showed support for the TIMSI theoretical framework, such that efficacy mediated the relationship between climate change knowledge and behavior. Thus, for both groups, climate change science knowledge was more likely to result in behavioral engagement when the science knowledge was accompanied with the belief that one has the ability to engage in behaviors that mitigate or adapt to climate change (i.e., efficacy). Implications for how to improve both Latino and Non-Latino climate change education that results in informed decision-making and greater integration into the community concerned about climate change will be discussed.

Emergent coordination underlying learning to reach to grasp with a brain-machine interface.

PubMed

Vaidya, Mukta; Balasubramanian, Karthikeyan; Southerland, Joshua; Badreldin, Islam; Eleryan, Ahmed; Shattuck, Kelsey; Gururangan, Suchin; Slutzky, Marc; Osborne, Leslie; Fagg, Andrew; Oweiss, Karim; Hatsopoulos, Nicholas G

2018-04-01

The development of coordinated reach-to-grasp movement has been well studied in infants and children. However, the role of motor cortex during this development is unclear because it is difficult to study in humans. We took the approach of using a brain-machine interface (BMI) paradigm in rhesus macaques with prior therapeutic amputations to examine the emergence of novel, coordinated reach to grasp. Previous research has shown that after amputation, the cortical area previously involved in the control of the lost limb undergoes reorganization, but prior BMI work has largely relied on finding neurons that already encode specific movement-related information. In this study, we taught macaques to cortically control a robotic arm and hand through operant conditioning, using neurons that were not explicitly reach or grasp related. Over the course of training, stereotypical patterns emerged and stabilized in the cross-covariance between the reaching and grasping velocity profiles, between pairs of neurons involved in controlling reach and grasp, and to a comparable, but lesser, extent between other stable neurons in the network. In fact, we found evidence of this structured coordination between pairs composed of all combinations of neurons decoding reach or grasp and other stable neurons in the network. The degree of and participation in coordination was highly correlated across all pair types. Our approach provides a unique model for studying the development of novel, coordinated reach-to-grasp movement at the behavioral and cortical levels. NEW & NOTEWORTHY Given that motor cortex undergoes reorganization after amputation, our work focuses on training nonhuman primates with chronic amputations to use neurons that are not reach or grasp related to control a robotic arm to reach to grasp through the use of operant conditioning, mimicking early development. We studied the development of a novel, coordinated behavior at the behavioral and cortical level, and the neural plasticity in M1 associated with learning to use a brain-machine interface.