81 research outputs found

    Leadership as social identity management : introducing the Identity Leadership Inventory (ILI) to assess and validate a four-dimensional model

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    This work has been supported by a grant (FL110100199) from the Australian Research Council awarded to the second author, a grant from the Research Foundation Flanders awarded to the fifth author, and a grant from the National Natural Science Foundation of China (NSFC no. 70962001) awarded to the sixth author.Although nearly two decades of research have provided support for the social identity approach to leadership, most previous work has focused on leaders' identity prototypicality while neglecting the assessment of other equally important dimensions of social identity management. However, recent theoretical developments have argued that in order to mobilize and direct followers' energies, leaders need not only to ‘be one of us’ (identity prototypicality), but also to ‘do it for us’ (identity advancement), to ‘craft a sense of us’ (identity entrepreneurship), and to ‘embed a sense of us’ (identity impresarioship). In the present research we develop and validate an Identity Leadership Inventory (ILI) that assesses these dimensions in different contexts and with diverse samples from the US, China, and Belgium. Study 1 demonstrates that the scale has content validity such that the items meaningfully differentiate between the four dimensions. Studies 2, 3, and 4 provide evidence for the scale's construct validity (distinguishing between dimensions), discriminant validity (distinguishing identity leadership from authentic leadership, leaders' charisma, and perceived leader quality), and criterion validity (relating the ILI to key leadership outcomes). We conclude that by assessing multiple facets of leaders' social identity management the ILI has significant utility for both theory and practice.Publisher PDFPeer reviewe

    Design considerations and analysis planning of a phase 2a proof of concept study in rheumatoid arthritis in the presence of possible non-monotonicity

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    BACKGROUND: It is important to quantify the dose response for a drug in phase 2a clinical trials so the optimal doses can then be selected for subsequent late phase trials. In a phase 2a clinical trial of new lead drug being developed for the treatment of rheumatoid arthritis (RA), a U-shaped dose response curve was observed. In the light of this result further research was undertaken to design an efficient phase 2a proof of concept (PoC) trial for a follow-on compound using the lessons learnt from the lead compound. METHODS: The planned analysis for the Phase 2a trial for GSK123456 was a Bayesian Emax model which assumes the dose-response relationship follows a monotonic sigmoid "S" shaped curve. This model was found to be suboptimal to model the U-shaped dose response observed in the data from this trial and alternatives approaches were needed to be considered for the next compound for which a Normal dynamic linear model (NDLM) is proposed. This paper compares the statistical properties of the Bayesian Emax model and NDLM model and both models are evaluated using simulation in the context of adaptive Phase 2a PoC design under a variety of assumed dose response curves: linear, Emax model, U-shaped model, and flat response. RESULTS: It is shown that the NDLM method is flexible and can handle a wide variety of dose-responses, including monotonic and non-monotonic relationships. In comparison to the NDLM model the Emax model excelled with higher probability of selecting ED90 and smaller average sample size, when the true dose response followed Emax like curve. In addition, the type I error, probability of incorrectly concluding a drug may work when it does not, is inflated with the Bayesian NDLM model in all scenarios which would represent a development risk to pharmaceutical company. The bias, which is the difference between the estimated effect from the Emax and NDLM models and the simulated value, is comparable if the true dose response follows a placebo like curve, an Emax like curve, or log linear shape curve under fixed dose allocation, no adaptive allocation, half adaptive and adaptive scenarios. The bias though is significantly increased for the Emax model if the true dose response follows a U-shaped curve. CONCLUSIONS: In most cases the Bayesian Emax model works effectively and efficiently, with low bias and good probability of success in case of monotonic dose response. However, if there is a belief that the dose response could be non-monotonic then the NDLM is the superior model to assess the dose response

    Effectiveness of a new model of primary care management on knee pain and function in patients with knee osteoarthritis: Protocol for THE PARTNER STUDY

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    © 2018 The Author(s). Background: To increase the uptake of key clinical recommendations for non-surgical management of knee osteoarthritis (OA) and improve patient outcomes, we developed a new model of service delivery (PARTNER model) and an intervention to implement the model in the Australian primary care setting. We will evaluate the effectiveness and cost-effectiveness of this model compared to usual general practice care. Methods: We will conduct a mixed-methods study, including a two-arm, cluster randomised controlled trial, with quantitative, qualitative and economic evaluations. We will recruit 44 general practices and 572 patients with knee OA in urban and regional practices in Victoria and New South Wales. The interventions will target both general practitioners (GPs) and their patients at the practice level. Practices will be randomised at a 1:1 ratio. Patients will be recruited if they are aged =45 years and have experienced knee pain =4/10 on a numerical rating scale for more than three months. Outcomes are self-reported, patient-level validated measures with the primary outcomes being change in pain and function at 12 months. Secondary outcomes will be assessed at 6 and 12 months. The implementation intervention will support and provide education to intervention group GPs to deliver effective management for patients with knee OA using tailored online training and electronic medical record support. Participants with knee OA will have an initial GP visit to confirm their diagnosis and receive management according to GP intervention or control group allocation. As part of the intervention group GP management, participants with knee OA will be referred to a centralised multidisciplinary service: the PARTNER Care Support Team (CST). The CST will be trained in behaviour change support and evidence-based knee OA management. They will work with patients to develop a collaborative action plan focussed on key self-management behaviours, and communicate with the patients' GPs. Patients receiving care by intervention group GPs will receive tailored OA educational materials, a leg muscle strengthening program, and access to a weight-loss program as appropriate and agreed. GPs in the control group will receive no additional training and their patients will receive usual care. Discussion: This project aims to address a major evidence-to-practice gap in primary care management of OA by evaluating a new service delivery model implemented with an intervention targeting GP practice behaviours to improve the health of people with knee OA. Trial Registration: Australian New Zealand Clinical Trials Registry: ACTRN12617001595303, date of registration 1/12/2017

    Genetics of Sputum Gene Expression in Chronic Obstructive Pulmonary Disease

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    Previous expression quantitative trait loci (eQTL) studies have performed genetic association studies for gene expression, but most of these studies examined lymphoblastoid cell lines from non-diseased individuals. We examined the genetics of gene expression in a relevant disease tissue from chronic obstructive pulmonary disease (COPD) patients to identify functional effects of known susceptibility genes and to find novel disease genes. By combining gene expression profiling on induced sputum samples from 131 COPD cases from the ECLIPSE Study with genomewide single nucleotide polymorphism (SNP) data, we found 4315 significant cis-eQTL SNP-probe set associations (3309 unique SNPs). The 3309 SNPs were tested for association with COPD in a genomewide association study (GWAS) dataset, which included 2940 COPD cases and 1380 controls. Adjusting for 3309 tests (p<1.5e-5), the two SNPs which were significantly associated with COPD were located in two separate genes in a known COPD locus on chromosome 15: CHRNA5 and IREB2. Detailed analysis of chromosome 15 demonstrated additional eQTLs for IREB2 mapping to that gene. eQTL SNPs for CHRNA5 mapped to multiple linkage disequilibrium (LD) bins. The eQTLs for IREB2 and CHRNA5 were not in LD. Seventy-four additional eQTL SNPs were associated with COPD at p<0.01. These were genotyped in two COPD populations, finding replicated associations with a SNP in PSORS1C1, in the HLA-C region on chromosome 6. Integrative analysis of GWAS and gene expression data from relevant tissue from diseased subjects has located potential functional variants in two known COPD genes and has identified a novel COPD susceptibility locus

    The Magnitude of Global Marine Species Diversity

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    Background: The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered. Results: There are ∼226,000 eukaryotic marine species described. More species were described in the past decade (∼20,000) than in any previous one. The number of authors describing new species has been increasing at a faster rate than the number of new species described in the past six decades. We report that there are ∼170,000 synonyms, that 58,000–72,000 species are collected but not yet described, and that 482,000–741,000 more species have yet to be sampled. Molecular methods may add tens of thousands of cryptic species. Thus, there may be 0.7–1.0 million marine species. Past rates of description of new species indicate there may be 0.5 ± 0.2 million marine species. On average 37% (median 31%) of species in over 100 recent field studies around the world might be new to science. Conclusions: Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century

    Modelling implicit pre-cues and collision avoidance in a driving simulator: A pilot study

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    It is well-established that pre-cues, including those observed in an implicit manner, can affect motor skills and reaction times. However, little research currently exists on how pre-cues influence complex motor skills such as driving a car at high speed. This pilot study investigates the effect of implicit pre-cues on collision avoidance under a repeat trial experiment design using a car driving simulator. Seventeen par- ticipants (aged 23.8 ± 4.2 years) were included in this investigation, which consisted of four different one-kilometre driving scenarios. This investigation considers two of the four scenarios. Two scenarios had the stimulus of a child crossing the road, however only one of these scenarios had an implicit pre-cue appear before the stimulus. The remaining two scenarios had no stimulus or pre-cue and were included to reduce any learning effect by participants. The proportion of participants who had a collision differed significantly between scenarios with and without a pre-cue. The primary effect size of the pre-cue is modelled using a logis- tic regression and distributions for point estimators are obtained from bootstrapping results. A power analysis exploring different primary effect sizes is performed to inform sample size considerations for repeat studies. Implications for motor control, such as experiment design and statistical modelling methods, are discussed to inform future large scale trials. References J. A. Barela, A. A. Rocha, A. R. Novak, J. Fransen, and G. A. Figueiredo. Age differences in the use of implicit visual cues in a response time task. Braz. J. Motor Behav. 13.2 (2019), pp. 86–93. doi: 10.20338/bjmb.v13i2.139 J. Cohen. Statistical power analysis for the behavioral sciences. Routledge, 1988. doi: 10.4324/9780203771587 U. Eversheim and O. Bock. The role of precues in the preparation of motor responses in humans. J. Mot. Behav. 34.3 (2002), pp. 271–276. doi: 10.1080/00222890209601945 D. G. Jenkins and P. F. Quintana-Ascencio. A solution to minimum sample size for regressions. PLOS One 15.2 (2020), e0229345. doi: 10.1371/journal.pone.0229345 J. Jiang. Linear and generalized linear mixed models and their applications. Springer Series in Statistics. Springer, 2007. doi: 10.1007/978-0-387-47946-0 C. Kistin and M. Silverstein. Pilot studies: A critical but potentially misused component of interventional research. JAMA 314.15 (2015), pp. 1561–1562. doi: 10.1001/jama.2015.10962 H. C. Kraemer, J. Mintz, A. Noda, J. Tinklenberg, and J. A. Yesavage. Caution regarding the use of pilot studies to guide power calculations for study proposals. Arch. Gen. Psych. 63.5 (2006), pp. 484–489. doi: 10.1001/archpsyc.63.5.484 J. A. Nelder and R. W. M. Wedderburn. Generalized linear models. J. Roy. Stat. Soc. 135.3 (1972), pp. 370–384. doi: 10.2307/2344614 R. Stine. An introduction to bootstrap methods: Examples and ideas. Soc. Meth. Res. 18.2–3 (1989), pp. 243–291. doi: 10.1177/004912418901800200

    Happy but unhealthy: The relationship between social ties and health in an emerging network

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    Social connections are essential to health and wellbeing. However, when pursing social acceptance, people may sometimes engage in behavior that is detrimental to their health. Using a multi-time point design, we examined whether the structure of an emerging network of students in an academic summer school program correlated with their physical health and mental wellbeing. Participants who were more central in the network typically experienced greater symptoms of illness (e.g., cold/flu symptoms), engaged in riskier health behaviors (e.g., binge drinking), and had higher physiological reactivity to a stressor. At the same time, they were happier, felt more efficacious, and perceived less stress in response to a strenuous math task. These outcomes suggest that social ties in an emerging network are associated with better mental wellbeing but also with poorer physical health and health behaviors.status: publishe

    Separate Roles for Antigen Recognition and Lymph Node Inflammation in CD8 +

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    Priming of naive CD8(+) T cells by pathogens or vaccines generally involves their interaction with Ag-loaded dendritic cells (DCs) in the context of an inflamed lymph node. Lymph node activation fosters DC and T cell encounters and subsequently provides newly primed T cells with nurturing conditions. We dissected these two aspects by infusing in vitro primed CD8(+) T cells into naive recipient mice harboring a single activated lymph node and comparing the fate of these T cells with those infused into control recipients. Brief (20 h) in vitro priming empowered the T cells to expand in vivo without further Ag stimulation. This primary response was not affected by the presence or absence of a nonspecifically activated lymph node. In contrast, in vivo antigenic challenge after contraction of the primary response resulted in significantly stronger secondary T cell responses in mice harboring activated lymph nodes, demonstrating that the availability of an activated lymph node supported the generation of T cell memory in an Ag-unrelated manner. The presence of an activated lymph node during the expansion and contraction phase of the primary response did not endow T cells with an instructional program for increased survival or secondary expansion, but primarily served to conserve increased numbers of T cells
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