Calculations of the minimal perimeter for N deformable cells of equal area confined in a circle

Candidates to the least perimeter partition of a disk into N?planar connected regions are calculated for N?≤?43. A Voronoi construction is used to randomly create the candidates and then the perimeter of each is found with the Surface Evolver. Formulae for the perimeter and number of peripheral regions are given, and the candidates classified according to their topology. The simulation technique also provides improved candidates to the unconstrained problem of finding the least perimeter arrangement of N planar regions.     

Effects of mental stressors on mitogen induced lymphocyte responses in the laboratory

Abstract

There is considerable evidence from naturalistic studies that psychosocial stressors affect human immune function. To achieve control over factors that could bias naturalistic studies, laboratory stressors developed by cardiovascular researchers were tested to determine if they affected immune function. Thirty volunteer students were exposed to 20 minutes of mental tasks. Psychophysiological indices (heart rate, blood pressure, skin conductance) and subjective responses were monitored prior to, during, and 1-hour after the tasks, blood, samples for immunological analyses were also drawn at these times. Thirteen subjects who were not exposed to the tasks served as controls. Subjects exposed to the tasks showed increased levels of subjective distress and increased psychophysiologic responses (except diastolic blood pressure) during the tasks. Relative to controls, stressed subjects had reduced lymphocyte proliferative responses to classic T cell mitogens both immediately after and 1-hour after the tasks were found in whole blood cultures, although responses of isolated lymphocytes were not significantly affected. There were only marginal differences in whole blood mitogen responses for stressed subjects with low versus high autonomic reactions to the stressor. These results support an emerging view that the immune system is sensitive to brief stressors and that laboratory models may be useful for exploring stress-induced changes in immune function.     

Attachment relationships and physical activity motivation of college students

This study was designed to assess the link of attachment relationships with physical activity motivation. Potential mediators of this link were examined in a cross-sectional study targeting college student physical activity motivation and behaviour. Participants completed self-reports of attachment relationships (with mother, father and best friend), self-determined motivation for physical activity, physical activity behaviour and the hypothesised mediator variables of perceived competence, autonomy and relatedness. The results provide support for the mediating role of these variables in the association of father attachment with self-determined motivation. Meaningful variance in self-determined motivation for physical activity and physical activity behaviour was explained. Overall, attachment relationships appear to be relevant, albeit modestly, to physical activity motivation of college students. The findings support continued efforts to integrate attachment and motivational perspectives in the study of college student health behaviour.     

The nature of caregiving in children of a parent with multiple sclerosis from multiple sources and the associations between caregiving activities and youth adjustment overtime

This study explored youth caregiving for a parent with multiple sclerosis (MS) from multiple perspectives, and examined associations between caregiving and child negative (behavioural emotional difficulties, somatisation) and positive (life satisfaction, positive affect, prosocial behaviour) adjustment outcomes overtime. A total of 88 families participated; 85 parents with MS, 55 partners and 130 children completed questionnaires at Time 1. Child caregiving was assessed by the Youth Activities of Caregiving Scale (YACS). Child and parent questionnaire data were collected at Time 1 and child data were collected 12 months later (Time 2). Factor analysis of the child and parent YACS data replicated the four factors (instrumental, social-emotional, personal-intimate, domestic-household care), all of which were psychometrically sound. The YACS factors were related to parental illness and caregiving context variables that reflected increased caregiving demands. The Time 1 instrumental and social-emotional care domains were associated with poorer Time 2 adjustment, whereas personal-intimate was related to better adjustment and domestic-household care was unrelated to adjustment. Children and their parents exhibited highest agreement on personal-intimate, instrumental and total caregiving, and least on domestic-household and social-emotional care. Findings delineate the key dimensions of young caregiving in MS and the differential links between caregiving activities and youth adjustment.     

Integrating interpersonal neurobiology with group psychotherapy

An understanding of the principles of neuroscience that illuminate how interpersonal relationships shape the brain, especially as articulated by interpersonal neurobiology (IPNB) (Siegel, 1999), may help group therapists 1) increase their holding capacity, 2) offer patients a framework that can decrease shame and increase regulation, and 3) identify methods of group interaction that can foster neuroplasticity, support neural integration, and lead to greater well-being and more fulfilling relationships. This paper introduces several aspects of neuroscience and discusses how therapist awareness and sharing of this knowledge with group participants at the right empathic moment can be both a psychoeducational support and a promoter of neural integration. While numerous neuroscience topics may be of help, here we will suggest three: early brain development, including the nature of implicit, explicit, and autobiographical memory; group as a source of regulation (with a brief mention of mirror neurons); and four domains of neural integration that are particularly useful in the setting of group therapy.     

Prompting safety belt use: comparative impact on the target behavior and relevant body language

ResearcherS used two behavioral prompts to compare increases in safety belt use: a Click It or Ticket prompt or a Flash-for-Life prompt. Participants were 1,822 unbuckled drivers exiting two student parking lots of a large university. Research assistants identified unbuckled drivers, flashed one of the two prompts, and recorded whether drivers buckled after the prompt and the drivers' facial expressions and hand gestures. Findings and implications are discussed.     

Minority-Specific Determinants of Mental Well-Being Among Lesbian, Gay, and Bisexual Youth

This study discusses the impact of stress specific to being lesbian, gay, or bisexual (LGB)—measured by means of the concepts of stigma consciousness and internalized homonegativity—on the mental well-being of LGB youth. Also, the effects of positive and negative social support were considered within the model. The sample consisted of 743 LGBs less than 26 years old who were recruited during the online ZZZIP survey in Flanders, Belgium. Hierarchical regression shows that LGB-specific unsupportive social interactions have the greatest direct effect on mental well-being of LGB youth, followed respectively by stigma consciousness, internalized homonegativity, and confidant support.     

Perfectionism: A contributor to social anxiety and its cognitive processes

The present study aimed to examine how perfectionism is contributing to social anxiety and its cognitive processes of post‐event rumination and self‐perception of performance following a speech task. Forty‐eight undergraduate students completed measures of perfectionism and trait social anxiety prior to performing a 3‐min impromptu speech task. Immediately following the speech task, participants rated their state anxiety and self‐perception of performance, and 24 hr later, their level of post‐event rumination was measured. Structural equation modelling revealed that perfectionism, in the form of socially prescribed perfectionism and doubts about actions, directly influences trait social anxiety, and indirectly influences post‐event rumination and self‐perception of performance through its relationship with trait social anxiety and state anxiety. This is the first study to investigate how perfectionism is contributing to social anxiety and its cognitive processes. The findings of this study provide evidence in support of the potential predictive role of perfectionism in social anxiety.