Prosocial and antisocial children's perceptions of peers' motives for prosocial behaviours

This study investigated whether peer-nominated prosocial and antisocial children have different perceptions of the motives underlying peers' prosocial actions. Eighty-seven children, aged 10-12 years old, completed peer-nomination measures of social behaviour. On the basis of numbers of social nominations received, a subsample of 51 children (32 who were peer-nominated as 'prosocial', and 18 who were peer-nominated as 'antisocial') then recorded their perceptions of peers' motives for prosocial behaviours. Expressed motives were categorized predominantly into three categories, coinciding with Turiel's (1978) 'moral', 'conventional', and 'personal domains'. Results indicate that children's social reputation is associated with the extent to which they perceive peers' prosocial motives as 'personal' or 'moral', with more prosocial children attributing moral motives, and more antisocial children attributing personal motives. Although traditionally Turiel's domain theory has been used to understand 'antisocial' children's behaviour, the current findings suggest that 'prosocial' children's behaviour may also be related to domains of judgment

Management of left-sided malignant colonic obstruction : an audit of a stent based protocol

Includes abstract.Includes bibliographical references.Colonic self-expanding metallic stents (SEMS) are proven to be safe and effective in the management of selected cases of malignant colonic obstruction. Since 2005, we have used endoscopic decompression with SEMS as the primary treatment of all patients with left-sided obstructing colorectal cancer, in the absence of perforation. The purpose of the study was to assess the safety and efficacy of this management protocol

Perceptions and correlates of peer-victimization and bullying

The experiences of peer-victimization and bullying are often treated empirically as though they are conceptually indistinct. Both involve repeated aggression,but definitions of bullying additionally emphasize the importance of aggressor intent and imbalance of power between the aggressor and the victim (Olweus, 1978; Whitney & Smith, 1993). The present study aimed to examine the extent to which peer-victimization and bullying are empirically similar. The sample comprised 1,429 pupils (50.2% male) aged between 8 and 13 years attending mainstream Scottish schools. Self-report questionnaire assessing peer-victimization and bullying, copingstrategy use (WCCL: Hunter, 2000), situational appraisal and depressive symptomatology (Birleson, 1981). Almost one-third (30.7%) of pupils reported experiencing peer-victimization, and of these 38.1% (11.7% of whole sample) were categorized as victims of bullying. Victims of bullying perceived higher levels of threat and lower levels of perceived control. They also reported using more Wishful Thinking and Social Support coping strategies, but did not differ on Problem Focused coping. Bullied pupils also reported higher levels of depressive symptomatology. Peer-victimization and bullying appear to be qualitatively different experiences for children and adolescents, with bullying being the more serious phenomenon

The fiscal residence of natural persons as it applies to South Africans working abroad: A study of South Africa, United States of America, United Kingdom and Australia and agreements for the avoidance of double taxation

For both natural and non-natural persons the basis of South African income tax changed for years of assessment commencing on or after 1 January 2001. Prior to 2001 South Africa's income tax regime was based on the source principle. Taking the cue from the Katz Commission Reports, Minister of Finance Trevor Manuel introduced the residence basis of taxation in his 2000 budget speech, thus ensuring that South African residents (as, defined in the Income Tax Act 58 of 1962 (as amended)(the 'Act')) became taxable on their worldwide income. This paper explores the South African ('SA') residence definition as well as those of the United States of America ('US'), United Kingdom ('UK') and Australia, taking cognisance of the effect of South African Agreements for the Avoidance of Double Taxation ('DTAs') with these countries (a summary table of the different treatments is presented in Appendix A). The scope of the paper has been limited to South African individuals only and specifically excludes non-natural persons and non-residents (for South African tax purposes). The choice of the countries selected was based largely on the (be it perceived or actual) popularity as destinations for South African short- and long-term contract (or other) workers. These countries are also major trading partners and have well developed economies and tax regimes, which provides for useful discussion. The scope of this paper has been limited to exclude a full discussion on the implications of capital gains tax. However, a short discussion on the change of a South African individual's residency status is pertinent to the paper and has been included at the end of the paper

Appraisal, emotion and coping in victims of peer-aggression and victimization

Presentation focusing on appraisal, emotion and coping in victims of peer-aggression and victimization

Hostile attributions bias and perceived self-efficacy of adolescent bullies, victims, bully-victims, and those uninvolved in bullying

Presentation focuses on hostile attributions bias and perceived self-efficacy of adolescent bullies, victims, bully-victims, and those uninvolved in bullying

A longitudinal investigation of threat as a mediator of the effect of peer-victimisation upon depressive symptoms

Models of stress and coping propose that cognitive appraisals can mediate the relationship between stressor and adjustment (Lazarus & Folkman, 1984). Threat is already known to be associated with levels of peer-victimisation (Hunter et al., 2007), and reflects interpretation of a situation as negative and potentially catastrophic. Such cognitions overlap with depressogenic attributional styles (Abramson et al., 1978), but are situation specific. Hence, we sought to evaluate whether the effects of changes in levels of peer-victimisation upon depressive symptomatology were mediated via changes in threat appraisal. Here, 349 pupils (47.9% male), aged eight to 10 years at Time 1, completed measures of peer-victimisation, threat appraisal, and depressive symptomatology on two occasions (18 months apart). Residual change scores were calculated for change in levels of victimisation and threat appraisal. Mediational analyses (controlling for gender, age, and depressive symptoms at T1) indicated that the effect of peer-victimisation on depressive symptomatology was partially mediated by change in threat appraisals. This represented a significant indirect path, with 43% of the effect of peer-victimisation upon depressive symptomatology mediated via threat appraisals. These results highlight the importance of tackling perceptions that children hold regarding their peer-victimisation and its potential social and psychological consequences for them

Perceived discrimination among ethnic minority young people : the role of psychological variables

Because of difficulties in objectively determining discrimination, attention has turned to individual differences in perceptions of discrimination. This study aimed to build on such work by investigating the role of psychological variables in predicting perceived discrimination (PD) in a UK sample of ethnic minority young people (n = 154). A series of multiple regression analyses yielded 3 pathways leading to PD. There was a direct effect of gender on PD. Depression and low self-esteem and need for approval predicted anxiety, which in turn was related to higher PD. Finally, private collective self-esteem correlated with public collective self-esteem, which in turn predicted lower PD. The results point to the importance of psychological variables, both personal and collective, in the perception of ethnic discrimination. Furthermore, the findings enhance our understanding of the complex associations between self-esteem, affect, and PD

A cellular automaton model of crystalline cellulose hydrolysis by cellulases

<p>Abstract</p> <p>Background</p> <p>Cellulose from plant biomass is an abundant, renewable material which could be a major feedstock for low emissions transport fuels such as cellulosic ethanol. Cellulase enzymes that break down cellulose into fermentable sugars are composed of different types - cellobiohydrolases I and II, endoglucanase and β-glucosidase - with separate functions. They form a complex interacting network between themselves, soluble hydrolysis product molecules, solution and solid phase substrates and inhibitors. There have been many models proposed for enzymatic saccharification however none have yet employed a cellular automaton approach, which allows important phenomena, such as enzyme crowding on the surface of solid substrates, denaturation and substrate inhibition, to be considered in the model.</p> <p>Results</p> <p>The Cellulase 4D model was developed <it>de novo </it>taking into account the size and composition of the substrate and surface-acting enzymes were ascribed behaviors based on their movements, catalytic activities and rates, affinity for, and potential for crowding of, the cellulose surface, substrates and inhibitors, and denaturation rates. A basic case modeled on literature-derived parameters obtained from <it>Trichoderma reesei </it>cellulases resulted in cellulose hydrolysis curves that closely matched curves obtained from published experimental data. Scenarios were tested in the model, which included variation of enzyme loadings, adsorption strengths of surface acting enzymes and reaction periods, and the effect on saccharide production over time was assessed. The model simulations indicated an optimal enzyme loading of between 0.5 and 2 of the base case concentrations where a balance was obtained between enzyme crowding on the cellulose crystal, and that the affinities of enzymes for the cellulose surface had a large effect on cellulose hydrolysis. In addition, improvements to the cellobiohydrolase I activity period substantially improved overall glucose production.</p> <p>Conclusions</p> <p>Cellulase 4D simulates the enzymatic hydrolysis of cellulose to glucose by surface and solution phase-acting enzymes and accounts for complex phenomena that have previously not been included in cellulose hydrolysis models. The model is intended as a tool for industry, researchers and educators alike to explore options for enzyme engineering and process development and to test hypotheses regarding cellulase mechanisms.</p