Performance Benefits Of Reward Choice: A Procedural Justice Perspective

Reward choice – employees\u27 ability to exercise control over the formal rewards they receive from work – is an important part of many HRM strategies. Reward choice is expected to increase employee performance, but conflicting findings highlight the need to better understand how and when it will do so. Based on fairness heuristic theory, we predicted that procedural justice mediates reward choice\u27s influence on performance, and that choice attractiveness moderates that influence. A field study and an experiment both had similar results, supporting our predictions. Reward choice can increase performance by as much as 40 per cent, but only when the available choices are attractive to employees

Out of the Box? How Managing a subordinate\u27s Multiple Identities Affects the Quality of a Manager-Subordinate Relationship

Positive manager-subordinate relationships are invaluable to organizations because they enable positive employee attitudes, citizenship behaviors, task performance, and more effective organizations. Yet extant theory provides a limited perspective on the factors that create these types of relationships. We highlight the important role subordinates also play in affecting the resource pool and propose that a subordinate’s multiple identities can provide him or her with access to knowledge and social capital resources that can be utilized for work-based tasks and activities. A manager and a subordinate may prefer similar or different strategies for managing the subordinate’s multiple identities, however, which can affect resource utilization and the quality of the manager-subordinate relationship. Our variance model summarizes our predictions about the effect of managers’ and subordinates’ strategy choices on the quality of manager-subordinate relationships. In doing so we integrate three divergent relational theories (leader-member exchange theory, relational-cultural theory, and a positive organizational scholarship perspective on positive relationships at work) and offer new insights on the quality of manager-subordinate relationships

Making Sense of Whistle-Blowing's Antecedents: Learning from Research on Identity and Ethics Programs

Despite a significant increase in whistle-blowing practices in work organizations, we know little about what differentiates whistle-blowers from those who observe a wrongdoing but chose not to report it. In this review article, we first highlight the arenas in which research on whistle-blowing has produced inconsistent results and those in which the findings have been consistent. Second, we propose that the adoption of an identity approach will help clarify the inconsistent findings and extend prior work on individual-level motives behind whistle-blowing. Third, we argue that the integration of the whistle-blowing research with that on ethics programs will aid in systematically expanding our understanding of the situational antecedents of whistle-blowing. We conclude our review by discussing new theoretical and methodological arenas of research in the domain of whistle-blowing.No Full Tex

Making Sense of Whistle-Blowing's Antecedents: Learning from Research on Identity and Ethics Programs

Despite a significant increase in whistle-blowing practices in work organizations, we know little about what differentiates whistle-blowers from those who observe a wrongdoing but chose not to report it. In this review article, we first highlight the arenas in which research on whistle-blowing has produced inconsistent results and those in which the findings have been consistent. Second, we propose that the adoption of an identity approach will help clarify the inconsistent findings and extend prior work on individual-level motives behind whistle-blowing. Third, we argue that the integration of the whistle-blowing research with that on ethics programs will aid in systematically expanding our understanding of the situational antecedents of whistle-blowing. We conclude our review by discussing new theoretical and methodological arenas of research in the domain of whistle-blowing.No Full Tex

Mixing and matching siderophore clusters: structure and biosynthesis of serratiochelins from Serratia sp. v4

Studying the evolutionary history underlying the remarkable structures and biological activities of natural products has been complicated by not knowing the functions they have evolved to fulfill. Siderophores - soluble, low molecular weight compounds - have an easily understood and measured function: acquiring iron from the environment. Bacteria engage in a fierce competition for acquiring iron, which rewards the production of siderophores that bind iron tightly and cannot be used or pirated by competitors. The structures and biosyntheses of 'odd' siderophores can reveal the evolutionary strategy that led to their creation. Here, we here report a new Serratia strain that produces serratiochelin and an analog of serratiochelin. A genetic approach located the serratiochelin gene cluster, and targeted mutations in several genes implicated in serratiochelin biosynthesis were generated. Bioinformatic analyses and mutagenesis results demonstrate that genes from two well known siderophore clusters, the Escherichia coli enterobactin cluster and the Vibrio cholerae vibriobactin cluster, were shuffled to produce a new siderophore biosynthetic pathway. These results highlight how modular siderophore gene clusters can be mixed and matched during evolution to generate structural diversity in siderophores.This work was supported by the National Institutes of Health (Grants GM82137 to R.K., and AI057159 and GM086258 to J.C.). M.R.S. acknowledges support from the NIH Pathway to Independence Award (Grant 1K99 GM098299-01). S.C. and M.J.V. acknowledge support from the Portuguese Foundation for Science and Technology (PhD Grant SFRH/BD/38298/2007 to S.C.; Project PTDC/EBB-EBI/104263/2008 to M.J.V.)

Sequencing and functional annotation of avian pathogenic Escherichia coli serogroup O78 strains reveals the evolution of E. coli lineages pathogenic for poultry via distinct mechanisms

Avian pathogenic Escherichia coli (APEC) causes respiratory and systemic disease in poultry. Sequencing of a multilocus sequence type 95 (ST95) serogroup O1 strain previously indicated that APEC resembles E. coli causing extraintestinal human diseases. We sequenced the genomes of two strains of another dominant APEC lineage (ST23 serogroup O78 strains χ7122 and IMT2125) and compared them to each other and to the reannotated APEC O1 sequence. For comparison, we also sequenced a human enterotoxigenic E. coli (ETEC) strain of the same ST23 serogroup O78 lineage. Phylogenetic analysis indicated that the APEC O78 strains were more closely related to human ST23 ETEC than to APEC O1, indicating that separation of pathotypes on the basis of their extraintestinal or diarrheagenic nature is not supported by their phylogeny. The accessory genome of APEC ST23 strains exhibited limited conservation of APEC O1 genomic islands and a distinct repertoire of virulence-associated loci. In light of this diversity, we surveyed the phenotype of 2,185 signature-tagged transposon mutants of χ7122 following intra-air sac inoculation of turkeys. This procedure identified novel APEC ST23 genes that play strain- and tissue-specific roles during infection. For example, genes mediating group 4 capsule synthesis were required for the virulence of χ7122 and were conserved in IMT2125 but absent from APEC O1. Our data reveal the genetic diversity of E. coli strains adapted to cause the same avian disease and indicate that the core genome of the ST23 lineage serves as a chassis for the evolution of E. coli strains adapted to cause avian or human disease via acquisition of distinct virulence genes

Th17 Cytokines and the Gut Mucosal Barrier

Local immune responses serve to contain infections by pathogens to the gut while preventing pathogen dissemination to systemic sites. Several subsets of T cells in the gut (T-helper 17 cells, γδ T cells, natural killer (NK), and NK-T cells) contribute to the mucosal response to pathogens by secreting a subset of cytokines including interleukin (IL)-17A, IL-17F, IL-22, and IL-26. These cytokines induce the secretion of chemokines and antimicrobial proteins, thereby orchestrating the mucosal barrier against gastrointestinal pathogens. While the mucosal barrier prevents bacterial dissemination from the gut, it also promotes colonization by pathogens that are resistant to some of the inducible antimicrobial responses. In this review, we describe the contribution of Th17 cytokines to the gut mucosal barrier during bacterial infections

Enterobactin-Mediated Delivery of β-Lactam Antibiotics Enhances Antibacterial Activity against Pathogenic Escherichia coli

The design, synthesis, and characterization of enterobactin–antibiotic conjugates, hereafter Ent-Amp/Amx, where the β-lactam antibiotics ampicillin (Amp) and amoxicillin (Amx) are linked to a monofunctionalized enterobactin scaffold via a stable poly(ethylene glycol) linker are reported. Under conditions of iron limitation, these siderophore-modified antibiotics provide enhanced antibacterial activity against Escherichia coli strains, including uropathogenic E. coli CFT073 and UTI89, enterohemorrhagic E. coli O157:H7, and enterotoxigenic E. coli O78:H11, compared to the parent β-lactams. Studies with E. coli K-12 derivatives defective in ferric enterobactin transport reveal that the enhanced antibacterial activity observed for this strain requires the outer membrane ferric enterobactin transporter FepA. A remarkable 1000-fold decrease in minimum inhibitory concentration (MIC) value is observed for uropathogenic E. coli CFT073 relative to Amp/Amx, and time-kill kinetic studies demonstrate that Ent-Amp/Amx kill this strain more rapidly at 10-fold lower concentrations than the parent antibiotics. Moreover, Ent-Amp and Ent-Amx selectively kill E. coli CFT073 co-cultured with other bacterial species such as Staphylococcus aureus, and Ent-Amp exhibits low cytotoxicity against human T84 intestinal cells in both the apo and iron-bound forms. These studies demonstrate that the native enterobactin platform provides a means to effectively deliver antibacterial cargo across the outer membrane permeability barrier of Gram-negative pathogens utilizing enterobactin for iron acquisition.Pacific Southwest Regional Center of Excellence for Biodefense and Emerging Infectious DiseaseKinship Foundation. Searle Scholars ProgramMassachusetts Institute of Technology. Department of Chemistr