113 research outputs found
Transformational leadership and job performance: A social identity perspective
Drawing on social identity theory, this study provides a model explaining the underlying process through which transformational leadership influences creative behavior and organizational citizenship behaviors. Individual differentiation and group identification are proposed as social identity mechanisms reflecting the characteristics of personal and collective identity orientations that underpin the differential effects of transformational leadership behaviors on performance outcomes. The model is tested with data from a sample of 250 front-line employees and their immediate managers working in five banks in the People's Republic of China. Results of hierarchical linear modeling provide support for the model whereby group-focused and individual-focused transformational leadership behaviors exert differential impacts on individual differentiation and group identification. Furthermore, individual differentiation mediates the relationship between individual-focused transformational leadership and creative behavior, whereas group identification mediates the relationships between group-focused transformational leadership and OCBs toward individuals and groups. Implications for theory and practice are discussed and future research directions are outlined
A multilevel model of transformational leadership, affect, and creative process behavior in work teams
We develop a multilevel model to explain how affect and transformational leadership (TFL) influence team creative process behavior. We theorize, in particular, that a dual-level model of TFL, which incorporates both individual-focused TFL (addressing the individual differences of team members) and group-focused TFL (addressing the team as a whole) underlies affectβcreativity relationships. We argue moreover that these effects exist across three conceptual levels: (1) within-person, (2) interpersonal, and (3) group. We conclude with a discussion of the theoretical implications and limitations of our model and suggest potential avenues for future research
The effect of a brief mindfulness-based intervention on personal recovery in people with bipolar disorder: A randomized controlled trial (study protocol)
Background: With the advent of the recovery movement in mental health, a humanistic paradigm shift has occurred, placing the focus on personal recovery (i.e., hope, identity, and life meaning) instead of functional or clinical recovery only (i.e., symptom reduction or increases in physical function). Along the journey of recovery, people with bipolar disorder (BD) struggle to cope with recurring mood fluctuations between depression and mania. Mindfulness-based interventions (MBIs) have the potential to result in improvements in personal recovery outcomes. Thus, this protocol will evaluate the efficacy and mechanisms of a brief MBI for helping individuals with BD with their personal recovery. It is hypothesized that adults with BD randomly assigned to a brief MBI intervention will report greater improvements in personal recovery than those in a waiting list control condition. In addition, it is hypothesized that such benefits will be mediated by improvements in emotion awareness, emotion regulation, and illness acceptance. Moreover, the specific stage of BD is hypothesized to moderate the beneficial effects of the brief MBI, such that those in the early stage of BD will report more benefits regarding emotion awareness and emotion regulation, whereas those in the late stage of BD will report more advantages concerning illness acceptance. Method: One hundred and fifty-four adults with BD will be recruited from hospitals and community settings for this research project. This study will use a mixed methods design. A randomized-controlled trial will be conducted to compare a brief MBI (four sessions in total) group and a waiting list control group. Assessments will be made at baseline, after intervention, and at six-month follow-up. In addition, a qualitative and participatory research method called Photovoice will be employed to further understand the experiences of the participants who receive the brief MBI along their personal recovery journey. Discussion: If the study hypotheses are supported, the findings from this research project will provide empirical support for an alternative treatment. Moreover, by identifying the mechanisms of the beneficial effects of the brief MBI, the findings will highlight process variables that could be specifically targeted to make MBI treatment even more effective in this population. Trial registration: This study is registered with the Chinese Clinical Trial Registry (ChiCTR- 1900024658). Registered 20th July 2019
The electronic structure of amorphous silica: A numerical study
We present a computational study of the electronic properties of amorphous
SiO2. The ionic configurations used are the ones generated by an earlier
molecular dynamics simulations in which the system was cooled with different
cooling rates from the liquid state to a glass, thus giving access to
glass-like configurations with different degrees of disorder [Phys. Rev. B 54,
15808 (1996)]. The electronic structure is described by a tight-binding
Hamiltonian. We study the influence of the degree of disorder on the density of
states, the localization properties, the optical absorption, the nature of
defects within the mobility gap, and on the fluctuations of the Madelung
potential, where the disorder manifests itself most prominently. The
experimentally observed mismatch between a photoconductivity threshold of 9 eV
and the onset of the optical absorption around 7 eV is interpreted by the
picture of eigenstates localized by potential energy fluctuations in a mobility
gap of approximately 9 eV and a density of states that exhibits valence and
conduction band tails which are, even in the absence of defects, deeply located
within the former band gap.Comment: 21 pages of Latex, 5 eps figure
In Vivo Comparison of Two Human Norovirus Surrogates for Testing Ethanol-Based Handrubs: The Mouse Chasing the Cat!
Human noroviruses (HuNoV), a major cause of acute gastroenteritis worldwide, cannot be readily cultured in the lab. Therefore, a feline calicivirus (FCV) is often used as its surrogate to, among other things, test alcohol-based handrubs (ABHR). The more recent laboratory culture of a mouse norovirus (MNV) provides an alternative. While MNV is closer to HuNoV in several respects, to date, no comparative testing of FCV and MNV survival and inactivation on human hands has been performed. This study was designed to address the knowledge gap. The rates of loss in viability during drying on hands were β1.91 and β1.65% per minute for FCV and MNV, respectively. When the contaminated skin was exposed for 20 s to either a commercial ABHR with 62% (v/v) ethanol or to 75% (v/v) ethanol in water, FCV infectivity was reduced by <1 log10 while that of MNV by nearly 2.8 log10. Extending the contact time to 30 s reduced the FCV titer by almost 2 log10 by both test substances and that of MNV by >3.5 log10 by the commercial ABHR while 75% ethanol did not show any noticeable improvement in activity as compared to the 20 s contact. An 80% (v/v) aqueous solution of ethanol gave only a 1.75 log10 reduction in MNV activity after 20 s. The results show significant differences in the ethanol susceptibility of FCV and MNV in contact times relevant to field use of ABHR and also that 62% ethanol was a more effective virucide than either 75% or 80% ethanol. These findings indicate the need for a review of the continuing use of FCV as a surrogate for HuNoV
Occurrence of False Positive Results for the Detection of Carbapenemases in Carbapenemase-Negative Escherichia coli and Klebsiella pneumoniae Isolates
Adequate detection of the production of carbapenemase in Enterobacteriaceae isolates is crucial for infection control measures and the appropriate choice of antimicrobial therapy. In this study, we investigated the frequency of false positive results for the detection of carbapenemases in carbapenemase-negative Escherichia coli and Klebsiella pneumoniae clinical isolates by the modified Hodge test (MHT). Three hundred and one E. coli and K. pneumoniae clinical isolates were investigated. All produced extended spectrum Ξ²-lactamases (ESBLs) but were susceptible to carbapenems. Antimicrobial susceptibility testing was performed by the disk diffusion and agar dilution methods. The MHT was performed using the standard inoculum of test organisms recommended by the CLSI. Genes that encoded ESBLs and carbapenemases were identified by PCR and DNA sequencing. Among the 301 clinical isolates, none of the isolates conformed to the criteria for carbapenemase screening recommended by the CLSI. The susceptibility rates for imipenem, meropenem, and ertapenem all were 100.0%, 100.0%, and 100.0%, respectively. Of the 301 E. coli and K. pneumoniae isolates, none produced carbapenemase. The MHT gave a positive result for 3.3% (10/301) of the isolates. False positive results can occur when the MHT is used to detect carbapenemase in ESBL-producing isolates and clinical laboratories must be aware of this fact
Differences in genotype and virulence among four multidrug-resistant <i>Streptococcus pneumoniae</i> isolates belonging to the PMEN1 clone
We report on the comparative genomics and characterization of the virulence phenotypes of four <i>S. pneumoniae</i> strains that belong to the multidrug resistant clone PMEN1 (Spain<sup>23F</sup> ST81). Strains SV35-T23 and SV36-T3 were recovered in 1996 from the nasopharynx of patients at an AIDS hospice in New York. Strain SV36-T3 expressed capsule type 3 which is unusual for this clone and represents the product of an in vivo capsular switch event. A third PMEN1 isolate - PN4595-T23 - was recovered in 1996 from the nasopharynx of a child attending day care in Portugal, and a fourth strain - ATCC700669 - was originally isolated from a patient with pneumococcal disease in Spain in 1984. We compared the genomes among four PMEN1 strains and 47 previously sequenced pneumococcal isolates for gene possession differences and allelic variations within core genes. In contrast to the 47 strains - representing a variety of clonal types - the four PMEN1 strains grouped closely together, demonstrating high genomic conservation within this lineage relative to the rest of the species. In the four PMEN1 strains allelic and gene possession differences were clustered into 18 genomic regions including the capsule, the blp bacteriocins, erythromycin resistance, the MM1-2008 prophage and multiple cell wall anchored proteins. In spite of their genomic similarity, the high resolution chinchilla model was able to detect variations in virulence properties of the PMEN1 strains highlighting how small genic or allelic variation can lead to significant changes in pathogenicity and making this set of strains ideal for the identification of novel virulence determinant
Peptide Ligands for Pro-survival Protein Bfl-1 from Computationally Guided Library Screening
Pro-survival members of the Bcl-2 protein family inhibit cell death by binding short helical BH3 motifs in pro-apoptotic proteins. Mammalian pro-survival proteins Bcl-x[subscript L], Bcl-2, Bcl-w, Mcl-1, and Bfl-1 bind with varying affinities and specificities to native BH3 motifs, engineered peptides, and small molecules. Biophysical studies have determined interaction patterns for these proteins, particularly for the most-studied family members Bcl-x[subscript L] and Mcl-1. Bfl-1 is a pro-survival protein implicated in preventing apoptosis in leukemia, lymphoma, and melanoma. Although Bfl-1 is a promising therapeutic target, relatively little is known about its binding preferences. We explored the binding of Bfl-1 to BH3-like peptides by screening a peptide library that was designed to sample a high degree of relevant sequence diversity. Screening using yeast-surface display led to several novel high-affinity Bfl-1 binders and to thousands of putative binders identified through deep sequencing. Further screening for specificity led to identification of a peptide that bound to Bfl-1 with K[subscript d] < 1 nM and very slow dissociation from Bfl-1 compared to other pro-survival Bcl-2 family members. A point mutation in this sequence gave a peptide with ~50 nM affinity for Bfl-1 that was selective for Bfl-1 in equilibrium binding assays. Analysis of engineered Bfl-1 binders deepens our understanding of how the binding profiles of pro-survival proteins differ and may guide the development of targeted Bfl-1 inhibitors.National Institute of General Medical Sciences (U.S.) (Award GM084181)National Institute of General Medical Sciences (U.S.) (Award P50-GM68762
Guiding the Design of Synthetic DNA-Binding Molecules with Massively Parallel Sequencing
Genomic applications of DNA-binding molecules require an unbiased knowledge of their high affinity sites. We report the high-throughput analysis of pyrrole-imidazole polyamide DNA-binding specificity in a 10^(12)-member DNA sequence library using affinity purification coupled with massively parallel sequencing. We find that even within this broad context, the canonical pairing rules are remarkably predictive of polyamide DNA-binding specificity. However, this approach also allows identification of unanticipated high affinity DNA-binding sites in the reverse orientation for polyamides containing Ξ²/Im pairs. These insights allow the redesign of hairpin polyamides with different turn units capable of distinguishing 5β²-WCGCGW-3β² from 5β²-WGCGCW-3β². Overall, this study displays the power of high-throughput methods to aid the optimal targeting of sequence-specific minor groove binding molecules, an essential underpinning for biological and nanotechnological applications
The Complete Genome Sequence of Mycoplasma bovis Strain Hubei-1
Infection by Mycoplasma bovis (M. bovis) can induce diseases, such as pneumonia and otitis media in young calves and mastitis and arthritis in older animals. Here, we report the finished and annotated genome sequence of M. bovis strain Hubei-1, a strain isolated in 2008 that caused calf pneumonia on a Chinese farm. The genome of M. bovis strain Hubei-1 contains a single circular chromosome of 953,114 bp with a 29.37% GC content. We identified 803 open reading frames (ORFs) that occupy 89.5% of the genome. While 34 ORFs were Hubei-1 specific, 662 ORFs had orthologs in the M. bovis type strain PG45 genome. Genome analysis validated lateral gene transfer between M. bovis and the Mycoplasma mycoides subspecies mycoides, while phylogenetic analysis found that the closest M. bovis neighbor is Mycoplasma agalactiae. Glycerol may be the main carbon and energy source of M. bovis, and most of the biosynthesis pathways were incomplete. We report that 47 lipoproteins, 12 extracellular proteins and 18 transmembrane proteins are phase-variable and may help M. bovis escape the immune response. Besides lipoproteins and phase-variable proteins, genomic analysis found two possible pathogenicity islands, which consist of four genes and 11 genes each, and several other virulence factors including hemolysin, lipoate protein ligase, dihydrolipoamide dehydrogenase, extracellular cysteine protease and 5β²-nucleotidase
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