Beyond the Bright Side: Dark Personality at Work

Despite the long history of the psychological study of dark personality characteristics and the recent surge of interest in the topic, much work remains to fully understand the breadth and depth of the impact of dark personality in the workplace. This commentary briefly covers the history of dark personality, discusses the place of this special issue within that history, and then proposes a number of avenues for future research in terms of defining, measuring, and providing a more comprehensive theoretical framework for the study of dark personality

Spectrosopic studies of jet-cooled NiAu and PtCu

Journal ArticleSpectroscopic investigations of NiAu and PtCu have revealed that both molecules possess 2?5/2 ground electronic states, and are in this respect analogous to the isovalent molecule NiCu. The ground-state bond lengths (r?) have been measured as 2.351?0.001 ? and 2.335?0.001 ? for NiAu and PtCu, respectively. Ionization potentials have been bracketed as well, giving IP (NiAu) = 8.33 ? 0.38 eV and IP( PtCu) = 8.26 ? 0.07 eV. A reanalysis of previous high-temperature Knudsen effusion mass spectrometric data provides Doo( NiAu) = 2.52 ? 0.17 eV. The implications of these results for the electronic structure and chemical bonding of NiAu and PtCu are discussed, and comparison is made to the other diatomic metals of the nickel and copper groups

Follower Perceptions Deserve a Closer Look

On the whole, we embrace the wisdom of Lord and Dinh’s suggestion that leadership researchers need to refocus our attention on the distinction between leadership perception and effectiveness. That said, we hope that the field can move one step further by recognizing the need to treat perceptual biases as more than systematic errors to be controlled for. As encoded in Lord and Dinh’s first two principles, followers are active participants in the construction of leadership phenomena, so the perceptual “baggage” that they bring into the leader–follower system is an important building block in that construction. We believe that by accounting for perceiver effects in leadership research we can not only help disentangle leadership perception from effectiveness but also open up new opportunities to explore how perceptions may drive effectiveness. In addition, we believe that a better understanding of follower perceptions can facilitate more effective management by allowing practicing managers to make sense of the idiosyncratic reactions followers may display in response to the decisions and behaviors of their leaders

Quantitative Analysis of the Efficiency of Clonal Deletion in the Thymus

One of the major mechanisms for establishing self-tolerance is the clonal deletion of self-reactive T cells during their development in the thymus. Using a TCR transgenic mouse model, we have established a quantitative ex vivo assay for examining the sensitivity and specificity of negative selection. Thymic organ cultures established from mice of varying MHC haplotypes were incubated with antigen, and the efficiency of clonal deletion assessed. We show here that clonal deletion of CD4+8+ thymocytes is sensitive to both the gene dosage and the allelic variation of MHC class II molecules expressed on thymic antigen-presenting cells. We also find that when epithelial cells in the thymic cortex are the only antigen-presenting cells expressing the appropriate MHC class II molecules, negative selection of CD4+8+ cells is as efficient as when antigen is presented on all thymic antigen-presenting cells. These studies demonstrate that the induction of self-tolerance via clonal deletion in the thymus is a function not only of antigen concentration, but also of MHC class II cell-surface density. In addition, together with the reports of others, these results confirm that cortical epithelial cells can mediate negative selection, and demonstrate that they do so in the intact thymic microenvironment