656 research outputs found

    Kinematics of experimentally produced deformation bands in stibnite

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    Using videotape techniques, we have observed the kinematic development of a variety of microstructures during experimental deformation of single crystals of stibnite (Sb2S3). The crystals were deformed by flexure or uniaxial compression at room P-T conditions in a small strain device attached to the stage of a reflecting microscope. In more than 50 experimental runs, the primary microstructures produced in stibnite were deformation bands, not deformation twins as often reported in the literature. Translation gliding along (010) [001] results in visible slipbands and produces two basic types of deformation bands, each with a variety of subtypes. Kink bands form with [phi] (angle of internal rotation) [approximate, equal]70[deg] and perpendicular bands develop with [phi][approximate, equal] 90[deg]. Other optical deformation features seen forming were: breccia fragments, bent and opened cleavages, and microfolds.Four stages could be seen in the kinematic development of deformation bands. During initiation, bands form by nearly instantaneous propagation of a narrow bent zone across the crystal. During later migration, the bands widen at a rate invariably slower than the rate of initiation. Termination of bands occurs when growth is impeded by intersections with grain boundaries or other deformation features. During late modification, previously formed bands with straight boundaries are sheared, bent, and compressed. Unconfined crystals tend to form kinks, whereas the perpendicular bands formed in samples confined in relatively rigid plastic. Naturally deformed stibnites show the same features. Television photomicroscopy has great potential for studying microstructures during deformation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23215/1/0000144.pd

    Quantum Transport in Semiconductor Nanostructures

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    I. Introduction (Preface, Nanostructures in Si Inversion Layers, Nanostructures in GaAs-AlGaAs Heterostructures, Basic Properties). II. Diffusive and Quasi-Ballistic Transport (Classical Size Effects, Weak Localization, Conductance Fluctuations, Aharonov-Bohm Effect, Electron-Electron Interactions, Quantum Size Effects, Periodic Potential). III. Ballistic Transport (Conduction as a Transmission Problem, Quantum Point Contacts, Coherent Electron Focusing, Collimation, Junction Scattering, Tunneling). IV. Adiabatic Transport (Edge Channels and the Quantum Hall Effect, Selective Population and Detection of Edge Channels, Fractional Quantum Hall Effect, Aharonov-Bohm Effect in Strong Magnetic Fields, Magnetically Induced Band Structure).Comment: 111 pages including 109 figures; this review from 1991 has retained much of its usefulness, but it was not yet available electronicall

    Design and methods for a randomized clinical trial comparing three outreach efforts to improve screening mammography adherence

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    <p>Abstract</p> <p>Background</p> <p>Despite the demonstrated need to increase screening mammography utilization and strong evidence that mail and telephone outreach to women can increase screening, most managed care organizations have not adopted comprehensive outreach programs. The uncertainty about optimum strategies and cost effectiveness have retarded widespread acceptance. While 70% of women report getting a mammogram within the prior 2 years, repeat mammography rates are less than 50%. This 5-year study is conducted though a Central Massachusetts healthcare plan and affiliated clinic. All womenhave adequate health insurance to cover the test.</p> <p>Methods/Design</p> <p>This randomized study compares 3 arms: reminder letter alone; reminder letter plus reminder call; reminder letter plus a second reminder and booklet plus a counselor call. All calls provide women with the opportunity to schedule a mammogram in a reasonable time. The invention period will span 4 years and include repeat attempts. The counselor arm is designed to educate, motivate and counsel women in an effort to alleviate PCP burden.</p> <p>All women who have been in the healthcare plan for 24 months and who have a current primary care provider (PCP) and who are aged 51-84 are randomized to 1 of 3 arms. Interventions are limited to women who become ≥18 months from a prior mammogram. Women and their physicians may opt out of the intervention study.</p> <p>Measurement of completed mammograms will use plan billing records and clinic electronic records. The primary outcome is the proportion of women continuously enrolled for ≥24 months who have had ≥1 mammogram in the last 24 months. Secondary outcomes include the number of women who need repeat interventions. The cost effectiveness analysis will measure all costs from the provider perspective.</p> <p>Discussion</p> <p>So far, 18,509 women aged 51-84 have been enrolled into our tracking database and were randomized into one of three arms. At baseline, 5,223 women were eligible for an intervention. We anticipate that the outcome will provide firm data about the maximal effectiveness as well as the cost effectiveness of the interventions both for increasing the mammography rate and the repeat mammography rate.</p> <p>Trial registration</p> <p><url>http://clinicaltrials.gov/</url><a href="http://www.clinicaltrials.gov/ct2/show/NCT01332032">NCT01332032</a></p

    The Efficacy of Exercise in Reducing Depressive Symptoms among Cancer Survivors: A Meta-Analysis

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    INTRODUCTION: The purpose of this meta-analysis was to examine the efficacy of exercise to reduce depressive symptoms among cancer survivors. In addition, we examined the extent to which exercise dose and clinical characteristics of cancer survivors influence the relationship between exercise and reductions in depressive symptoms. METHODS: We conducted a systematic search identifying randomized controlled trials of exercise interventions among adult cancer survivors, examining depressive symptoms as an outcome. We calculated effect sizes for each study and performed weighted multiple regression moderator analysis. RESULTS: We identified 40 exercise interventions including 2,929 cancer survivors. Diverse groups of cancer survivors were examined in seven exercise interventions; breast cancer survivors were examined in 26; prostate cancer, leukemia, and lymphoma were examined in two; and colorectal cancer in one. Cancer survivors who completed an exercise intervention reduced depression more than controls, d(+) = -0.13 (95% CI: -0.26, -0.01). Increases in weekly volume of aerobic exercise reduced depressive symptoms in dose-response fashion (β = -0.24, p = 0.03), a pattern evident only in higher quality trials. Exercise reduced depressive symptoms most when exercise sessions were supervised (β = -0.26, p = 0.01) and when cancer survivors were between 47-62 yr (β = 0.27, p = 0.01). CONCLUSION: Exercise training provides a small overall reduction in depressive symptoms among cancer survivors but one that increased in dose-response fashion with weekly volume of aerobic exercise in high quality trials. Depressive symptoms were reduced to the greatest degree among breast cancer survivors, among cancer survivors aged between 47-62 yr, or when exercise sessions were supervised

    Psychological therapies for women who experience intimate partner violence

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    BACKGROUND: Intimate partner violence (IPV) against women is prevalent and strongly associated with mental health problems. Women experiencing IPV attend health services frequently for mental health problems. The World Health Organization recommends that women who have experienced IPV and have a mental health diagnosis should receive evidence-based mental health treatments. However, it is not known if psychological therapies work for women in the context of IPV and whether they cause harm. OBJECTIVES: To assess the effectiveness of psychological therapies for women who experience IPV on the primary outcomes of depression, self-efficacy and an indicator of harm (dropouts) at six- to 12-months' follow-up, and on secondary outcomes of other mental health symptoms, anxiety, quality of life, re-exposure to IPV, safety planning and behaviours, use of healthcare and IPV services, and social support. SEARCH METHODS: We searched the Cochrane Common Mental Disorders Controlled Trials Register (CCMDCTR), CENTRAL, MEDLINE, Embase, CINAHL, PsycINFO, and three other databases, to the end of October 2019. We also searched international trials registries to identify unpublished or ongoing trials and handsearched selected journals, reference lists of included trials and grey literature. SELECTION CRITERIA: We included randomised controlled trials (RCTs), quasi-RCTs, cluster-RCTs and cross-over trials of psychological therapies with women aged 16 years and older who self-reported recent or lifetime experience of IPV. We included trials if women also experienced co-existing mental health diagnoses or substance abuse issues, or both. Psychological therapies included a wide range of interventions that targeted cognition, motivation and behaviour compared with usual care, no treatment, delayed or minimal interventions. We classified psychological therapies according to Cochrane Common Mental Disorders's psychological therapies list. DATA COLLECTION AND ANALYSIS: Two review authors extracted data and undertook 'Risk of Bias' assessment. Treatment effects were compared between experimental and comparator interventions at short-term (up to six months post-baseline), medium-term (six to under 12 months, primary outcome time point), and long-term follow-up (12 months and above). We used standardised mean difference (SMD) for continuous and odds ratio (OR) for dichotomous outcomes, and used random-effects meta-analysis, due to high heterogeneity across trials. MAIN RESULTS: We included 33 psychological trials involving 5517 women randomly assigned to experimental (2798 women, 51%) and comparator interventions (2719 women, 49%). Psychological therapies included 11 integrative therapies, nine humanistic therapies, six cognitive behavioural therapy, four third-wave cognitive behavioural therapies and three other psychologically-orientated interventions. There were no trials classified as psychodynamic therapies. Most trials were from high-income countries (19 in USA, three in Iran, two each in Australia and Greece, and one trial each in China, India, Kenya, Nigeria, Pakistan, Spain and UK), among women recruited from healthcare, community, shelter or refuge settings, or a combination of any or all of these. Psychological therapies were mostly delivered face-to-face (28 trials), but varied by length of treatment (two to 50 sessions) and staff delivering therapies (social workers, nurses, psychologists, community health workers, family doctors, researchers). The average sample size was 82 women (14 to 479), aged 37 years on average, and 66% were unemployed. Half of the women were married or living with a partner and just over half of the participants had experienced IPV in the last 12 months (17 trials), 6% in the past two years (two trials) and 42% during their lifetime (14 trials). Whilst 20 trials (61%) described reliable low-risk random-sampling strategies, only 12 trials (36%) described reliable procedures to conceal the allocation of participant status. While 19 trials measured women's depression, only four trials measured depression as a continuous outcome at medium-term follow-up. These showed a probable beneficial effect of psychological therapies in reducing depression (SMD -0.24, 95% CI -0.47 to -0.01; four trials, 600 women; moderate-certainty evidence). However, for self-efficacy, there may be no evidence of a difference between groups (SMD -0.12, 95% CI -0.33 to 0.09; one trial with medium-term follow-up data, 346 women; low-certainty evidence). Further, there may be no difference between the number of women who dropped out from the experimental or comparator intervention groups, an indicator of no harm (OR 1.04, 95% CI 0.75 to 1.44; five trials with medium-term follow-up data, 840 women; low-certainty evidence). Although no trials reported adverse events from psychological therapies or participation in the trial, only one trial measured harm outcomes using a validated scale. For secondary outcomes, trials measured anxiety only at short-term follow-up, showing that psychological therapies may reduce anxiety symptoms (SMD -0.96, 95% CI -1.29 to -0.63; four trials, 158 women; low-certainty evidence). However, within medium-term follow-up, low-certainty evidence revealed that there may be no evidence between groups for the outcomes safety planning (SMD 0.04, 95% CI -0.18 to 0.25; one trial, 337 women), post-traumatic stress disorder (SMD -0.24, 95% CI -0.54 to 0.06; four trials, 484 women) or re-exposure to any form of IPV (SMD 0.03, 95% CI -0.14 to 0.2; two trials, 547 women). AUTHORS' CONCLUSIONS: There is evidence that for women who experience IPV, psychological therapies probably reduce depression and may reduce anxiety. However, we are uncertain whether psychological therapies improve other outcomes (self-efficacy, post-traumatic stress disorder, re-exposure to IPV, safety planning) and there are limited data on harm. Thus, while psychological therapies probably improve emotional health, it is unclear if women's ongoing needs for safety, support and holistic healing from complex trauma are addressed by this approach. There is a need for more interventions focused on trauma approaches and more rigorous trials (with consistent outcomes at similar follow-up time points), as we were unable to synthesise much of the research

    Gendering the careers of young professionals: some early findings from a longitudinal study. in Organizing/theorizing: developments in organization theory and practice

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    Wonders whether companies actually have employees best interests at heart across physical, mental and spiritual spheres. Posits that most organizations ignore their workforce – not even, in many cases, describing workers as assets! Describes many studies to back up this claim in theis work based on the 2002 Employment Research Unit Annual Conference, in Cardiff, Wales

    Precocious Natural Mummification in a Temperate Climate (Western Cape, South Africa)

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    The general process and pattern of decomposition is well-documented and understood. However, specific environmental conditions may alter this pattern and prematurely terminate the decay process. An example of this is natural mummification – a preservative process characterized by desiccation, brittleness and shrinkage of the skin and body tissues. It is important to understand how, when, and where such variations may occur, and for this reason environmentally-specific studies of decay are required. The aim of the present study was the establish baseline data on soft-tissue decomposition in two terrestrial habitats in the Western Cape. A total of 16 pig carcasses serving as analogues for humans were deployed in these habitats during two successive winters and summers between 2014 and 2016. The rate and pattern of decomposition were assessed via measurement of weight loss over time and scoring the decomposition process using Megyesi et al. (2005) Total Body Score system and study-specific criteria for mummification. Carcasses typically followed the expected pattern of decay with a few exceptions, most notably instances of rapid natural mummification. Natural mummification, as defined by Megyesi et al. (2005), was observed to occur as early as 17 days postmortem, with five carcasses mummifying in less than one month. The timing of natural mummification varies widely, from a few days to several years, averaging around three months in temperate regions. Natural mummification occurring in less than one month is termed precocious mummification and is rarely observed in temperate regions. With only three reports globally, this study’s findings are globally significant, highlighting the importance of regionally-specific decomposition studies. Two local forensic cases wherein precocious mummification has been observed are also presented and, considered together with the study’s results, a possible mechanism driving this process is proposed

    Comparing Notes: Recording and Criticism

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    This chapter charts the ways in which recording has changed the nature of music criticism. It both provides an overview of the history of recording and music criticism, from the advent of Edison’s Phonograph to the present day, and examines the issues arising from this new technology and the consequent transformation of critical thought and practice

    Genetic mechanisms of critical illness in COVID-19.

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    Host-mediated lung inflammation is present1, and drives mortality2, in the critical illness caused by coronavirus disease 2019 (COVID-19). Host genetic variants associated with critical illness may identify mechanistic targets for therapeutic development3. Here we report the results of the GenOMICC (Genetics Of Mortality In Critical Care) genome-wide association study in 2,244 critically ill patients with COVID-19 from 208 UK intensive care units. We have identified and replicated the following new genome-wide significant associations: on chromosome 12q24.13 (rs10735079, P = 1.65 × 10-8) in a gene cluster that encodes antiviral restriction enzyme activators (OAS1, OAS2 and OAS3); on chromosome 19p13.2 (rs74956615, P = 2.3 × 10-8) near the gene that encodes tyrosine kinase 2 (TYK2); on chromosome 19p13.3 (rs2109069, P = 3.98 ×  10-12) within the gene that encodes dipeptidyl peptidase 9 (DPP9); and on chromosome 21q22.1 (rs2236757, P = 4.99 × 10-8) in the interferon receptor gene IFNAR2. We identified potential targets for repurposing of licensed medications: using Mendelian randomization, we found evidence that low expression of IFNAR2, or high expression of TYK2, are associated with life-threatening disease; and transcriptome-wide association in lung tissue revealed that high expression of the monocyte-macrophage chemotactic receptor CCR2 is associated with severe COVID-19. Our results identify robust genetic signals relating to key host antiviral defence mechanisms and mediators of inflammatory organ damage in COVID-19. Both mechanisms may be amenable to targeted treatment with existing drugs. However, large-scale randomized clinical trials will be essential before any change to clinical practice
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