12,292 research outputs found
Nematic cells with defect-patterned alignment layers
Using Monte Carlo simulations of the Lebwohl--Lasher model we study the
director ordering in a nematic cell where the top and bottom surfaces are
patterned with a lattice of point topological defects of lattice
spacing . We find that the nematic order depends crucially on the ratio of
the height of the cell to . When the system is very
well--ordered and the frustration induced by the lattice of defects is relieved
by a network of half--integer defect lines which emerge from the point defects
and hug the top and bottom surfaces of the cell. When the
system is disordered and the half--integer defect lines thread through the cell
joining point defects on the top and bottom surfaces. We present a simple
physical argument in terms of the length of the defect lines to explain these
results. To facilitate eventual comparison with experimental systems we also
simulate optical textures and study the switching behavior in the presence of
an electric field
File audit to assess sustained fidelity to a recovery and wellbeing oriented mental health service model: An Australian case study
2019 The Author(s). Background: Over the past decade there has been increasing attention to implementing recovery-oriented approaches within mental health service practice and enhancing fidelity to such approaches. However, as is often the case with evidence-based practices, less attention has been paid to the sustainability of recovery-oriented approaches over time. This study sought to investigate whether fidelity to a recovery-oriented practice framework - the Collaborative Recovery Model could be sustained over time. Method: The study setting was an Australian community managed mental health organisation. A file audit of consumer support plans was undertaken using the Goal and Action Plan Instrument for Quality audit tool (GAP-IQ). The audit tool assessed 17 areas for quality. Consumers (n = 116) from a large community managed mental health organisation participated in the study. Sustained fidelity to the Collaborative Recovery Model (CRM) was determined by comparing results from the file audit to a similar audit conducted 3 years earlier. Results: The file audit revealed a significant increase in fidelity to CRM practices between 2011 and 2014. Fidelity to individual audit items that comprise the GAP-IQ was also found to significantly increase across 16 of the 17 GAP-IQ audit items, with the exception of the \u27Action Plan Review\u27 audit item. Conclusions: A comparison of file audit data across different time points within the same setting can provide useful feedback about whether or not a practice is being sustained over time. Although fidelity increased overtime the study design does not allow conclusions that training and coaching practices implemented by the organisation were responsible
Police Violence Against Black Protesters: A Public Health Issue
With the increased number of documented cases of violence perpetrated by police against protesters of the Black Lives Matter movement, public health officials are starting to list police violence as a health risk or a public health issue for black Americans. Using several timely theoretical explanations, we explore reasons why law enforcement officers routinely inflict violence against black protesters and avoid criminal stigma. Although police use of excessive force and untimely killings of blacks have always been criminal justice issues, the number of negative health consequences that are emerging after violent police confrontations implicates public health concerns. We argue that several strategies can be used to reduce police violence in the future
Epithelial cell–derived secreted and transmembrane 1a signals to activated neutrophils during pneumococcal pneumonia
Airway epithelial cell responses are critical to the outcome of lung infection. In this study, we aimed to identify unique contributions of epithelial cells during lung infection. To differentiate genes induced selectively in epithelial cells during pneumonia, we compared genome-wide expression profiles from three sorted cell populations: epithelial cells from uninfected mouse lungs, epithelial cells from mouse lungs with pneumococcal pneumonia, and nonepithelial cells from those same infected lungs. Of 1,166 transcripts that were more abundant in epithelial cells from infected lungs compared with nonepithelial cells from the same lungs or from epithelial cells of uninfected lungs, 32 genes were identified as highly expressed secreted products. Especially strong signals included two related secreted and transmembrane (Sectm) 1 genes, Sectm1a and Sectm1b. Refinement of sorting strategies suggested that both Sectm1 products were induced predominantly in conducting airway epithelial cells. Sectm1 was induced during the early stages of pneumococcal pneumonia, and mutation of NF-kB RelA in epithelial cells did not diminish its expression. Instead, type I IFN signaling was necessary and sufficient for Sectm1 induction in lung epithelial cells, mediated by signal transducer and activator of transcription 1. For target cells, Sectm1a bound to myeloid cells preferentially, in particular Ly6GbrightCD11bbright neutrophils in the infected lung. In contrast, Sectm1a did not bind to neutrophils from uninfected lungs. Sectm1a increased expression of the neutrophil-attracting chemokine CXCL2 by neutrophils from the infected lung. We propose that Sectm1a is an epithelial product that sustains a positive feedback loop amplifying neutrophilic inflammation during pneumococcal pneumonia
Identification of single-site gold catalysis in acetylene hydrochlorination
There remains considerable debate over the active form of gold under operating conditions of a recently validated gold catalyst for acetylene hydrochlorination. We have performed an in situ x-ray absorption fine structure study of gold/carbon (Au/C) catalysts under acetylene hydrochlorination reaction conditions and show that highly active catalysts comprise single-site cationic Au entities whose activity correlates with the ratio of Au(I):Au(III) present. We demonstrate that these Au/C catalysts are supported analogs of single-site homogeneous Au catalysts and propose a mechanism, supported by computational modeling, based on a redox couple of Au(I)-Au(III) species.
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Association between developmental milestones and age of schizophrenia onset: Results from the Northern Finland Birth Cohort 1966.
We investigated relationships between early developmental milestones, schizophrenia incidence and variability in its age at onset. We hypothesized that the period of risk for schizophrenia would be longer for those with later development. The Northern Finland Birth Cohort 1966 was followed until 47 years of age, and those members diagnosed with schizophrenia or any other non-affective psychoses identified. Latent profile analysis was used to classify people into homogenous classes with respect to developmental milestones, and subsequently survival analysis explored relationship between classes and age of schizophrenia onset. Results suggest that 4-classes (early, regular, late, and extra late developers) can be identified, but due to few cases in one class (n = 93, <0.01% of 10,501), only 3 classes (early, regular, late) could be meaningfully compared. Schizophrenia incidence until 47 years of age differed systematically between classes: late developers had the highest cumulative incidence (2.39%); regular were intermediate (1.25%); and early developers had the lowest incidence (0.99%). However, age at onset and its variability was similar across classes, suggesting that our hypothesis of a wider 'window' for schizophrenia onset in late developers was not supported
Chiral Extrapolations and Exotic Meson Spectrum
We examine the chiral corrections to exotic meson masses calculated in
lattice QCD. In particular, we ask whether the non-linear chiral behavior at
small quark masses, which has been found in other hadronic systems, could lead
to large corrections to the predictions of exotic meson masses based on linear
extrapolations to the chiral limit. We find that our present understanding of
exotic meson decay dynamics suggests that open channels may not make a
significant contribution to such non-linearities whereas the virtual, closed
channels may be important.Comment: 13 pagers, 2 figure
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