52 research outputs found

    Change in the magnetic structure of (Bi,Sm)FeO3 thin films at the morphotropic phase boundary probed by neutron diffraction

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    We report on the evolution of the magnetic structure of BiFeO3 thin films grown on SrTiO3 substrates as a function of Sm doping. We determined the magnetic structure using neutron diffraction. We found that as Sm increases, the magnetic structure evolves from a cycloid to a G-type antiferromagnet at the morphotropic phase boundary, where there is a large piezoelectric response due to an electric-field induced structural transition. The occurrence of the magnetic structural transition at the morphotropic phase boundary offers another route towards room temperature multiferroic devices

    The Magnetic Phase Transition and Universality Class of h-YMnO3 and h-(Y0.98Eu0.02)MnO3 Under Zero and Applied Pressure

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    We investigated the antiferromagnetic phase transition in the frustrated and multiferroic hexagonal manganites h-YMnO3 (YMO) and h-(Y0.98Eu0.02)MnO3 (YEMO). Elastic neutron scattering was used to study, in detail, the phase transition in YMO and YEMO under zero pressure and in YMO under a hydrostatic pressure of 1.5 GPa. Under conditions of zero pressure, we found critical temperatures of TN = 71.3(1) K and 72.11(5) K and the critical exponent 0.22(2) and b = 0.206(3), for YMO and YEMO, respectively. This is in agreement with earlier work by Roessli et al. Under an applied hydrostatic pressure of 1.5 GPa, the ordering temperature increased to TN = 75.2(5) K, in agreement with earlier reports, while b was unchanged. Inelastic neutron scattering was used to determine the size of the anisotropy spin wave gap close to the phase transition. From spin wave theory, the gap is expected to close with a critical exponent, b0, identical to the order parameter b. Our results indicate that the gap in YEMO indeed closes at TN = 72.4(3) K with b0 = 0.24(2), while the in-pressure gap in YMO closes at 75.2(5) K with an exponent of b0 = 0.19(3). In addition, the low temperature anisotropy gap was found to have a slightly higher absolute value under pressure. The consistent values obtained for b in the two systems support the likelihood of a new universality class for triangular, frustrated antiferromagnets

    Assessing gender mainstreaming in the education sector: depoliticised technique or a step towards women's rights and gender equality?

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    In 1995 the Beijing Conference on Women identified gender mainstreaming as a key area for action. Policies to effect gender mainstreaming have since been widely adopted. This special issue of Compare looks at research on how gender mainstreaming has been used in government education departments, schools, higher education institutions, international agencies and NGOs .1 In this introduction we first provide a brief history of the emergence of gender mainstreaming and review changing definitions of the term. In the process we outline some policy initiatives that have attempted to mainstream gender and consider some difficulties with putting ideas into practice, particularly the tensions between a technical and transformative interpretations . Much of the literature about experiences with gender mainstreaming tends to look at organizational processes and not any specificities of a particular social sector. However, in our second section, we are concerned to explore whether institutional forms and particular actions associated with education give gender mainstreaming in education sites some distinctive features. In our last section we consider some of the debates about global and local negotiations in discussions of gender policy and education and the light this throws on gender mainstreaming. In so doing, we place the articles that follow in relation to contestations over ownership, political economy, the form and content of education practice and the social complexity of gender equality

    Miscellany

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    Art Literature Roy F. Powell Creditshttps://digitalcommons.georgiasouthern.edu/miscell/1001/thumbnail.jp

    Mesothelioma and Radical Surgery 2 (MARS 2): protocol for a multicentre randomised trial comparing (extended) pleurectomy decortication versus no (extended) pleurectomy decortication for patients with malignant pleural mesothelioma.

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    INTRODUCTION: Mesothelioma remains a lethal cancer. To date, systemic therapy with pemetrexed and a platinum drug remains the only licensed standard of care. As the median survival for patients with mesothelioma is 12.1 months, surgery is an important consideration to improve survival and/or quality of life. Currently, only two surgical trials have been performed which found that neither extensive (extra-pleural pneumonectomy) or limited (partial pleurectomy) surgery improved survival (although there was some evidence of improved quality of life). Therefore, clinicians are now looking to evaluate pleurectomy decortication, the only radical treatment option left. METHODS AND ANALYSIS: The MARS 2 study is a UK multicentre open parallel group randomised controlled trial comparing the effectiveness and cost-effectiveness of surgery-(extended) pleurectomy decortication-versus no surgery for the treatment of pleural mesothelioma. The study will test the hypothesis that surgery and chemotherapy is superior to chemotherapy alone with respect to overall survival. Secondary outcomes include health-related quality of life, progression-free survival, measures of safety (adverse events) and resource use to 2 years. The QuinteT Recruitment Intervention is integrated into the trial to optimise recruitment. ETHICS AND DISSEMINATION: Research ethics approval was granted by London - Camberwell St. Giles Research Ethics Committee (reference 13/LO/1481) on 7 November 2013. We will submit the results for publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBERS: ISRCTN-ISRCTN44351742 and ClinicalTrials.gov-NCT02040272

    Self-help interventions for depressive disorders and depressive symptoms: a systematic review

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    <p>Abstract</p> <p>Background</p> <p>Research suggests that depressive disorders exist on a continuum, with subthreshold symptoms causing considerable population burden and increasing individual risk of developing major depressive disorder. An alternative strategy to professional treatment of subthreshold depression is population promotion of effective self-help interventions that can be easily applied by an individual without professional guidance. The evidence for self-help interventions for depressive symptoms is reviewed in the present work, with the aim of identifying promising interventions that could inform future health promotion campaigns or stimulate further research.</p> <p>Methods</p> <p>A literature search for randomised controlled trials investigating self-help interventions for depressive disorders or depressive symptoms was performed using PubMed, PsycINFO and the Cochrane Database of Systematic Reviews. Reference lists and citations of included studies were also checked. Studies were grouped into those involving participants with depressive disorders or a high level of depressive symptoms, or non-clinically depressed participants not selected for depression. A number of exclusion criteria were applied, including trials with small sample sizes and where the intervention was adjunctive to antidepressants or psychotherapy.</p> <p>Results</p> <p>The majority of interventions searched had no relevant evidence to review. Of the 38 interventions reviewed, the ones with the best evidence of efficacy in depressive disorders were S-adenosylmethionine, St John's wort, bibliotherapy, computerised interventions, distraction, relaxation training, exercise, pleasant activities, sleep deprivation, and light therapy. A number of other interventions showed promise but had received less research attention. Research in non-clinical samples indicated immediate beneficial effects on depressed mood for distraction, exercise, humour, music, negative air ionisation, and singing; while potential for helpful longer-term effects was found for autogenic training, light therapy, omega 3 fatty acids, pets, and prayer. Many of the trials were poor quality and may not generalise to self-help without professional guidance.</p> <p>Conclusion</p> <p>A number of self-help interventions have promising evidence for reducing subthreshold depressive symptoms. Other forms of evidence such as expert consensus may be more appropriate for interventions that are not feasible to evaluate in randomised controlled trials. There needs to be evaluation of whether promotion to the public of effective self-help strategies for subthreshold depressive symptoms could delay or prevent onset of depressive illness, reduce functional impairment, and prevent progression to other undesirable outcomes such as harmful use of substances.</p

    Allele-Specific HLA Loss and Immune Escape in Lung Cancer Evolution

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    Immune evasion is a hallmark of cancer. Losing the ability to present neoantigens through human leukocyte antigen (HLA) loss may facilitate immune evasion. However, the polymorphic nature of the locus has precluded accurate HLA copy-number analysis. Here, we present loss of heterozygosity in human leukocyte antigen (LOHHLA), a computational tool to determine HLA allele-specific copy number from sequencing data. Using LOHHLA, we find that HLA LOH occurs in 40% of non-small-cell lung cancers (NSCLCs) and is associated with a high subclonal neoantigen burden, APOBEC-mediated mutagenesis, upregulation of cytolytic activity, and PD-L1 positivity. The focal nature of HLA LOH alterations, their subclonal frequencies, enrichment in metastatic sites, and occurrence as parallel events suggests that HLA LOH is an immune escape mechanism that is subject to strong microenvironmental selection pressures later in tumor evolution. Characterizing HLA LOH with LOHHLA refines neoantigen prediction and may have implications for our understanding of resistance mechanisms and immunotherapeutic approaches targeting neoantigens. Video Abstract [Figure presented] Development of the bioinformatics tool LOHHLA allows precise measurement of allele-specific HLA copy number, improves the accuracy in neoantigen prediction, and uncovers insights into how immune escape contributes to tumor evolution in non-small-cell lung cancer

    Phylogenetic ctDNA analysis depicts early-stage lung cancer evolution.

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    The early detection of relapse following primary surgery for non-small-cell lung cancer and the characterization of emerging subclones, which seed metastatic sites, might offer new therapeutic approaches for limiting tumour recurrence. The ability to track the evolutionary dynamics of early-stage lung cancer non-invasively in circulating tumour DNA (ctDNA) has not yet been demonstrated. Here we use a tumour-specific phylogenetic approach to profile the ctDNA of the first 100 TRACERx (Tracking Non-Small-Cell Lung Cancer Evolution Through Therapy (Rx)) study participants, including one patient who was also recruited to the PEACE (Posthumous Evaluation of Advanced Cancer Environment) post-mortem study. We identify independent predictors of ctDNA release and analyse the tumour-volume detection limit. Through blinded profiling of postoperative plasma, we observe evidence of adjuvant chemotherapy resistance and identify patients who are very likely to experience recurrence of their lung cancer. Finally, we show that phylogenetic ctDNA profiling tracks the subclonal nature of lung cancer relapse and metastasis, providing a new approach for ctDNA-driven therapeutic studies
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