Radicals and Ideals of Affine Near-semirings over Brandt Semigroups

This work obtains all the right ideals, radicals, congruences and ideals of the affine near-semirings over Brandt semigroups.Comment: In Proceedings of the International Conference on Semigroups, Algebras and Operator Theory (ICSAOT-2014), Kochi, Indi

Hanging out with the right crowd : behavioral and neuroimaging studies of peer influence on decision-making in adolescence

Peer influence plays a crucial role in the rise of health-risk behaviors during adolescence. However, there is increasing evidence that peer influence can also lead to positive psychosocial outcomes, such as prosocial behavior. The main goal of this thesis was to investigate peer influence on risk-taking and prosocial behavior in adolescence and to unravel its underlying neural processes. Findings showed that effects of peers on risk-taking behavior are dependent on the context. Adolescents take into account both social norms from peer feedback and the uncertainty associated with outcomes in risky decisions. Moreover, peers can both increase and decrease prosocial behavior in typically developing (TD) adolescents and those with autism spectrum disorders (ASD), illustrating that peer influence can also lead to more adaptive outcomes. Finally, we studied the neural processes underlying prosocial peer feedback and results indicate that prosocial peer influence is underlined by the social brain network, regions involved in thinking about the self and others. Eventually, the results of this thesis can contribute to interventions aimed at decreasing risk-taking and promoting prosocial behavior in adolescence, with possibly long lasting effects into adulthood.NWO Research Talent Grant 406-11-019 awarded to Eveline Crone & Jorien van HoornPathways through Adolescenc

Turning a Blind Eye? Punishment of Friends and Unfamiliar Peers After Observed Exclusion in Adolescence

In order to decrease the occurrence of social exclusion in adolescence, we need to better understand how adolescents perceive and behave toward peers involved in exclusion. We examined the role of friendships in treatment of perpetrators and victims of social exclusion. Eighty‐nine participants (aged 9–16) observed exclusion of an unfamiliar peer (victim) by their best friend and another unfamiliar peer. Subsequently, participants could give up valuable coins to altruistically punish or help peers. Results showed that participants altruistically compensated victims and punished unfamiliar excluders, but refrained from punishing their friends. Our findings show that friendship with excluders modulates altruistic punishment of peers and provide mechanistic insight into how friendships may influence treatment of peers involved in social exclusion during adolescence.Pathways through Adolescenc

Ollivier-Ricci curvature convergence in random geometric graphs

Connections between continuous and discrete worlds tend to be elusive. One example is curvature. Even though there exist numerous nonequivalent definitions of graph curvature, none is rigorously known to converge in any limit to any traditional definition of curvature of a Riemannian manifold. Here we show that Ollivier curvature of random geometric graphs in any Riemannian manifold converges in the continuum limit to Ricci curvature of the underlying manifold. This result establishes the first rigorous link between a definition of curvature applicable to random graphs and a traditional definition of curvature of smooth space

Risks and rewards in adolescent decision-making.

Adolescent decision-making has been characterized as risky, and a heightened reward sensitivity may be one of the aspects contributing to riskier choice-behavior. Previous studies have targeted reward-sensitivity in adolescence and the neurobiological mechanisms of reward processing in the adolescent brain. In recent examples, researchers aim to disentangle the contributions of risk- and reward-sensitivity to adolescent risk-taking. Here, we discuss recent findings of adolescent's risk preferences and the associated neural mechanisms. We highlight potential frameworks that target individual differences in risk preferences in an effort to understand adolescent risk-taking, and with an ultimate goal of leveraging undesirable levels of risk taking.Pathways through Adolescenc

Hyponatraemia in imported malaria is common and associated with disease severity

<p>Abstract</p> <p>Background</p> <p>Hyponatraemia (serum sodium < 135 mmol/L) has long been recognized as a complication of malaria. However, few studies have been done in non-immune adult populations. It has not been investigated previously how hyponatraemia is distributed among the various <it>Plasmodium </it>species, and its association with malaria severity is unknown.</p> <p>The aim of this retrospective cohort study was to determine the prevalence of hyponatraemia and its association with malaria severity in a large cohort of patients with imported malaria caused by various <it>Plasmodium </it>species.</p> <p>Methods</p> <p>All patients that were diagnosed with malaria in the Harbour Hospital and Institute for Tropical Diseases in Rotterdam in the period 1999-2009 and who had available serum sodium on admission were included. Severe malaria was defined according to the modified WHO criteria. Prevalence of hyponatraemia and its association with malaria severity were investigated by univariate comparison, ROC analysis and multivariate logistic regression analysis.</p> <p>Results</p> <p>A total of 446 patients with malaria (severe falciparum malaria n = 35, non-severe falciparum malaria n = 280, non-falciparum malaria n = 131) was included. Hyponatraemia was present in 207 patients (46%). Prevalence and severity of hyponatraemia were greatest in severe falciparum malaria (77%, median serum sodium 129 mmol/L), followed by non-severe falciparum malaria (48%, median serum sodium 131 mmol/L), and non-falciparum malaria (34%, median serum sodium 132 mmol/L). Admission serum sodium < 133 mmol/L had a sensitivity of 0.69 and a specificity of 0.76 for predicting severe malaria. Multivariate logistic regression showed that serum sodium < 131 mmol/L was independently associated with severe falciparum malaria (odds ratio 10.4, 95% confidence interval 3.1-34.9). In patients with hyponatraemia, hypovolaemia did not appear to play a significant role in the development of hyponatraemia when prerenal azotaemia and haematocrit were considered as surrogate markers for hypovolaemia.</p> <p>Conclusions</p> <p>Hyponatraemia is common in imported malaria and is associated with severe falciparum malaria. From a clinical point of view, the predictive power of hyponatraemia for severe malaria is limited. The precise pathophysiological mechanisms of hyponatraemia in malaria require further study.</p

Hanging Out With the Right Crowd: Peer Influence on Risk‐Taking Behavior in Adolescence

Peer influence plays a key role in the increase of risk‐taking behavior during adolescence. However, its underlying processes are not fully understood. This study examined the effects of social norms, conveyed through peer advice, on risk‐taking behavior in 15‐ to 17‐year‐old adolescents (N = 76). Participants played a card‐guessing task alone and with online peer advice. Results showed that risk‐taking increased in the presence of peers. The results further showed that adolescents took into account the uncertainty associated with gambles, as well as the social norms conveyed by peers. Our findings suggest that peers are most influential in uncertain situations and demonstrate the value of a social norms approach in examining the processes underlying peer effects.Pathways through Adolescenc

The praxis of ‘alignment seeking’ in project work

Alignment seeking is the process of reaching agreement on what needs to be done and on the process that should be followed to complete the activity. This empirical study extends the scope of the current project-as-practice literature by providing descriptions of how project managers actually achieve alignment. Photographs taken by the research participants are used to trigger discussion in semi-structured interviews that explore the praxis of alignment seeking in project work. The practices found to enable alignment seeking include: creating a vision; storytelling; seeding ideas; identifying and using personal drivers, and appealing to stakeholders and team members' sense of a ‘higher good’. This paper highlights how alignment seeking can be achieved ‘in practice’ by project managers