3,296 research outputs found
Immune Regulation after Heart Transplantation: Dynamics of regulatory T cells in the transplanted heart and peripheral blood
Heart transplantation has become a rapidly evolving therapy for end-stage heart failure. To reduce the risk of rejection of the transplanted organ, patients are treated with immunosuppressive therapy. However, as immunosuppressive drugs carry severe side effects, true transplant tolerance (i.e., long-lasting nonreactivity of the immune system to donor antigens in the absence of immunosuppressive drugs) is a major goal in transplantation research. T-cell-mediated regulation of donor-reactive cells is one of the mechanisms that may be involved in the induction and maintenance of graft acceptance after organ transplantation. The identification and characterization of regulatory T cells that can control the anti-donor immune reactivity has therefore become the focus of many studies. Research in experimental transplant models has demonstrated that these regulators are important for the prevention of allograft rejection and the induction of transplant tolerance.1!
-4 Yet, it remains to be elucidated whether regulatory T cells control anti-donor immune reactivity in immunosuppressed organ transplant patients, thereby inducing and maintaining donor-specific nonresponsiveness. The central aim of this thesis was to investigate the role of regulatory T cells in the control of immune responses directed to the transplanted graft of heart transplant patients. We focused on two compartments where functional regulatory T cells may be present, i.e. the transplanted heart and the peripheral blood. Our studies demonstrated that various regulatory T-cell populations present in these compartments play a role in immunological processes, such as immunological quiescence and acute cellular rejection
Feel good, do-good!? On consistency and compensation in moral self-regulation
Studies in the behavioral ethics and moral psychology traditions have begun to reveal the important roles of self-related processes that underlie moral behavior. Unfortunately, this research has resulted in two distinct and opposing streams of findings that are usually referred to as moral consistency and moral compensation. Moral consistency research shows that a salient self-concept as a moral person promotes moral behavior. Conversely, moral compensation research reveals that a salient self-concept as an immoral person promotes moral behavior. The present studyâs aim was to integrate these two literatures. We argued that compensation forms a reactive, âdamage controlâ response in social situations, whereas consistency derives from a more proactive approach to reputation building and maintenance. Two experiments supported this prediction in showing that cognitive depletion (i.e., resulting in a reactive approach) results in moral compensation whereas consistency results when cognitive resources are available (i.e., resulting in a proactive approach). Experiment 2 revealed that these processes originate from reputational (rather than moral) considerations by showing that they emerge only under conditions of accountability. It can thus be concluded that reputational concerns are important for both moral compensation and moral consistency processes, and that which of these two prevails depends on the perspective that people take: a reactive or a proactive approach
Being âin Controlâ May Make You Lose Control: The Role of Self-Regulation in Unethical Leadership Behavior
In the present article, we argue that the constant pressure that leaders face may limit the willpower required to behave according to ethical norms and standards and may therefore lead to unethical behavior. Drawing upon the ego depletion and moral self-regulation literatures, we examined whether self-regulatory depletion that is contingent upon the moral identity of leaders may promote unethical leadership behavior. A laboratory experiment and a multisource field study revealed that regulatory resource depletion promotes unethical leader behaviors among leaders who are low in moral identity. No such effect was found among leaders with a high moral identity. This study extends our knowledge on why organizational leaders do not always conform to organizational goals. Specifically, we argue that the hectic and fragmented workdays of leaders may increase the likelihood that they violate ethical norms. This highlights the necessity to carefully schedule tasks that may have ethical implications. Similarly, organizations should be aware that overloading their managers with work may increase the likelihood of their leaders transgressing ethical norms
Out of Control!? How Loss of Self-Control Influences Prosocial Behavior: The Role of Power and Moral Values
Lack of self-control has been suggested to facilitate norm-transgressing behaviors because of the operation of automatic selfish impulses. Previous research, however, has shown that people having a high moral identity may not show such selfish impulses when their self-control resources are depleted. In the present research, we extended this effect to prosocial behavior. Moreover, we investigated the role of power in the interaction between moral identity and self-control depletion. More specifically, we expected that power facilitates the externalization of internal states, which implies that for people who feel powerful, rather than powerless, depletion decreases prosocial behavior especially for those low in moral identity. A laboratory experiment and a multisource field study supported our predictions. The present finding that the interaction between self-control depletion and moral identity is contingent upon peopleâs level of power suggests that power may enable people to refrain from helping behavior. Moreover, the findings suggest that if organizations want to improve prosocial behaviors, it may be effective to situationally induce moral values in their employees
Effect of viscosities of dispersed and continuous phases in microchannel oil-in-water emulsification
Although many aspects of microchannel emulsification have been covered in literature, one major uncharted area is the effect of viscosity of both phases on droplet size in the stable droplet generation regime. It is expected that for droplet formation to take place, the inflow of the continuous phase should be sufficiently fast compared to the outflow of the liquid that is forming the droplet. The ratio of the viscosities was therefore varied by using a range of continuous and dispersed phases, both experimentally and computationally. At high viscosity ratio (eta (d)/eta (c)), the droplet size is constant; the inflow of the continuous phase is fast compared to the outflow of the dispersed phase. At lower ratios, the droplet diameter increases, until a viscosity ratio is reached at which droplet formation is no longer possible (the minimal ratio). This was confirmed and elucidated through CFD simulations. The limiting value is shown to be a function of the microchannel design, and this should be adapted to the viscosity of the two fluids that need to be emulsified
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