http://repub.eur.nl/res/aut/14621/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/29637/ 2008-03-01T00:00:00Z Purpose: Combination chemotherapy regimens can improve survival in patients with advanced gastric and oesophageal adenocarcinoma. Docosahexaenoic acid (DHA)-paclitaxel is a novel conjugate formed by the covalent linkage of the fatty acid DHA to paclitaxel and may result in increased tumour exposure to paclitaxel without increased toxicity. Patients and methods: In this single arm, phase II study of DHA-paclitaxel, eligible patients with previously untreated, inoperable locally advanced or metastatic adenocarcinoma of the oesophagus, oesophago-gastric junction or stomach were treated with DHA-paclitaxel (1,100 mg/m2) administered by 2-h intravenous infusion every 21 days. Results: Fifty-four patients were recruited of whom 53 were evaluable for toxicity, and 48 for response. There were five confirmed partial responses (9.4%) by the RECIST criteria. The median duration of response was 87 days (range 49-97 days), the median time to progression was 84 days (95% CI 78-124 days), and median overall survival was 262 days (95% CI 205-357 days). Grade ≥3 neutropaenia occurred in 93% of patients, and febrile neutropaenia in 17% of patients. Conclusions: DHA-paclitaxel has modest activity in patients with oesophago-gastric cancer and with haematological toxicity that is comparable to paclitaxel and docetaxel. http://repub.eur.nl/res/pub/14573/ 2006-10-01T00:00:00Z Previous social dilemma research has shown that sanctioning defection may enhance cooperation. The authors argue that this finding may have resulted from restricting participants to two behaviors (cooperation and defection). In this article, the authors introduce the concept of a "social trilemma" (a social dilemma in which an alternative option to defect is present) and tested the effect of a sanction. The authors show that a sanction only increased cooperation and collective interests in the traditional social dilemma. In a social trilemma, the sanction failed because it caused some people to choose the alternative option to defect. Moreover, the results indicate that this was especially the case when people did not expect fellow group members to cooperate. In this case, the sanction even worked counterproductive because it decreased collective interests. It is concluded that allowing individuals to consider alternative options to defect can reveal the potential detrimental effects of sanctioning systems for the collective. http://repub.eur.nl/res/pub/14980/ 2006-03-01T00:00:00Z Sanctioning systems in social dilemmas are often meant to increase trust in others and to increase cooperation. We argue, however, that sanctioning systems may also give people the idea that others act in their own self-interest and undermine the belief that others are internally motivated to cooperate. We developed the “Removing The Sanction” paradigm and a new trust manipulation, and showed in three experiments that when there is a sanction on defection, trust in others being internally motivated to cooperate is undermined: Participants who had experienced the presence of a sanctioning system trusted fellow group members less than participants who had not. In a similar vein, the sanction undermined cooperation when trust was initially high. The implications of these paradoxical findings are discussed. http://repub.eur.nl/res/pub/14993/ 2005-06-01T00:00:00Z When do people support sanctioning systems in social dilemmas? Sanctions increase collective efficiency, but have the disadvantage of restricting people’s autonomy. This paper studies the effects of feedback about collective (in)efficiency and the influence of the presence or absence of a sanctioning system. The results show that, except after feedback about collective inefficiency, people were reluctant to support installation of a sanctioning system. When a sanctioning system was already present, however, sanction support was strong and not affected by feedback. Interestingly, the presence of a sanctioning system increased pessimism about attaining collective efficiency. This suggests that the mere presence of a sanctioning system creates the need to have that sanctioning system, and that installing one can have irreversible consequences. http://repub.eur.nl/res/pub/12199/ 2001-02-01T00:00:00Z In this study we argue that when powerholder and target operate in a cooperative context, the decision to use power is influenced by the motive to reach positive joint outcomes. When the context is competitive, the use of power is more dictated by the desire to gain positive outcomes at the expense of the target. Therefore, factors that are indicative of how to bring about positive outcomes for the target will only influence power use in a cooperative context. The results of an experimental study with a 2 (social context: cooperation vs. competition) x2 (relative competence: high vs. low) between-subjects design, with task components generating 2 levels of confidence as within-subjects variable, supported our line of reasoning. Competence of the powerholder as well as confidence as elicited by the task only affected power use in cooperation and not in competition. The results also indicated that the absolute level of power use in competition and cooperation did not differ. http://repub.eur.nl/res/pub/12255/ 1992-01-01T00:00:00Z Social categorization is claimed to elicit a tendency to conform to ingroup norms, which may result in attitude change after exposure to information on the opinions of other ingroup members. It was hypothesized that the degree to which arguments represented ingroup norms, i.e., were prototypical, would affect their potential influence on attitudes, such that prototypical arguments would be perceived as being of higher quality and would elicit more attitude change. Moreover, prototypical arguments were expected to elicit more argument elaboration. Two experiments were designed to test these predictions. In Experiment 1 subjects were exposed to both a set of pro and a set of contra arguments, while one of the sets was allegedly prototypical of ingroup attitudes. In Experiment 2 subjects were exposed to either prototypical or a-prototypical pro or contra arguments allegedly originating from in- or outgroup. In both studies conformity to ingroup norms was observed. In addition, prototypical ingroup arguments elicited higher quality ratings in the first study. Indications of higher elaboration of prototypical ingroup arguments were found.