A Peptidoglycan Fragment Triggers β-lactam Resistance in Bacillus licheniformis

To resist to β-lactam antibiotics Eubacteria either constitutively synthesize a β-lactamase or a low affinity penicillin-binding protein target, or induce its synthesis in response to the presence of antibiotic outside the cell. In Bacillus licheniformis and Staphylococcus aureus, a membrane-bound penicillin receptor (BlaR/MecR) detects the presence of β-lactam and launches a cytoplasmic signal leading to the inactivation of BlaI/MecI repressor, and the synthesis of a β-lactamase or a low affinity target. We identified a dipeptide, resulting from the peptidoglycan turnover and present in bacterial cytoplasm, which is able to directly bind to the BlaI/MecI repressor and to destabilize the BlaI/MecI-DNA complex. We propose a general model, in which the acylation of BlaR/MecR receptor and the cellular stress induced by the antibiotic, are both necessary to generate a cell wall-derived coactivator responsible for the expression of an inducible β-lactam-resistance factor. The new model proposed confirms and emphasizes the role of peptidoglycan degradation fragments in bacterial cell regulation

Gender differences in dominance and affiliation during a demanding interaction

Evolution theory predicts that in social situations, men will show more behavioral dominance, whereas women will show more behavioral affiliation. To ensure maximum ecological validity, observation in a real-life situation that calls for uniform behavior is the strongest test. To reduce bias because of stereotyping within observers, the author used molecular behavioral observations, in which the verbal and nonverbal behavior of 10 men and 10 women was observed in an executive job selection assessment center where they were actual applicants. Men showed more dominance, especially head shaking, sitting in a closed posture, and using closed questions and directive remarks. Women showed more affiliation, especially in frequency of laughing, sitting in an open posture, and posing open questions

Facial attractiveness, sexual selection, and personnel selection:when evolved preferences matter

Using an evolutionary perspective, we looked at sex differences in the influence of facial attractiveness of applicants in hiring decisions, and determined whether expected contact intensity with applicants and experience in personnel selection moderated this influence. We found effects of evolved preferences regarding mate selection and intrasexual competition when the expected contact intensity was high. People showed a preference for attractive opposite-sex applicants (mate selection). Furthermore, women preferred female applicants with low attractiveness over female applicants with high attractiveness (intrasexual competition). We found no salient differences between HRM professionals and students. Copyright (c) 2006 John Wiley & Sons, Ltd

Eye color predicts disagreeableness in North Europeans: support in favor of Frost (2006)

The current study investigates whether eye color provides a marker of Agreeableness in North Europeans. Extrapolating from Frost’s (2006) research uncovering an unusually diverse range of hair and eye color in northern Europe, we tested the hypothesis that light eyed individuals of North European descent would be less agreeable (a personality marker for competitiveness) when compared to their dark eyed counterparts, whereas there would be no such effect for people of European descent in general. The hypothesis was tested in Australia to provide consistent environmental conditions for both groups of people. Results support the hypothesis. Implications and conclusions are discussed