75 research outputs found

    Defect generation and deconfinement on corrugated topographies

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    We investigate topography-driven generation of defects in liquid crystals films coating frozen surfaces of spatially varying Gaussian curvature whose topology does not automatically require defects in the ground state. We study in particular disclination-unbinding transitions with increasing aspect ratio for a surface shaped as a Gaussian bump with an hexatic phase draped over it. The instability of a smooth ground state texture to the generation of a single defect is also discussed. Free boundary conditions for a single bump are considered as well as periodic arrays of bumps. Finally, we argue that defects on a bump encircled by an aligning wall undergo sharp deconfinement transitions as the aspect ratio of the surface is lowered.Comment: 24 page

    Sex differences in the diagnosis of advanced cancer and subsequent outcome in people with chronic kidney disease: an analysis of a national population cohort

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    Background: In the general population, advanced cancer stage at presentation is associated with poorer health outcomes. People with chronic kidney disease (CKD) have increased incidence and mortality from most cancer types. We sought to determine whether people with CKD were more likely to present with advanced stage cancer, whether this was associated with survival, and whether these associations varied by sex. Methods: Data were from Secure Anonymised Information Linkage Databank (SAIL), a Welsh primary care database with linkage to cancer and death registries. We included patients with a de- novo cancer diagnosis (2011-2017), and at least two kidney function tests in the two years prior to diagnosis. Estimated glomerular filtration rate based on serum creatinine (eGFRcr) was calculated using the CKD-EPI 2009 equation (mL/min/1.73m2). Logistic regression models determined odds of presenting with advanced cancer (stage 3 or 4 at diagnosis) by different values of eGFRcr at baseline. Cox proportional hazards models tested associations between eGFRcr at baseline and all-cause mortality risk (reference eGFR 75 to <90). Findings: There were 66,128 patients: 30,857 (46.7%) were female, mean age was 69.1 (standard deviation [SD] 13.8) years in females and 70.6 (SD 11.1) years in males; median eGFRcr at baseline was 78 (interquartile range [IQR] 63 – 90) mL/min/1.73m2 in both females and males. Over a median follow-up time of 3.1 (IQR 0.5 – 5.7) years in females and 2.9 (IQR 0.5-5.5) years in males, there were 17,303 deaths in females and 20,855 in males. An eGFRcr <30 was associated with higher odds of presenting with advanced cancer in males (OR 1.33 95% CI 1.09-1.62), but not in females (OR 1.17 95% CI 0.92-1.50); positive associations were primarily driven by prostate and breast cancers. With lower eGFRcr, hazards of cancer death increased in both sexes, but lower eGFRcr was associated with greater hazards of cancer death in females (eGFRcr <30: HR 1.71, 95% CI 1.56-1.88, p<0.001; male versus female comparison HR 0.88, 95% CI 0.78-0.90; p=0.037). Interpretation: CKD was not associated with substantially higher odds of presenting with advanced cancer across most cancer sites (except prostate and breast), but was associated with reduced survival. Despite an initial survival advantage compared to males, females with CKD had disproportionately higher hazards of death. Though potential explanations for reduced survival after a cancer diagnosis are manifold, scrutiny of access to, efficacy, and safety of cancer treatments in people with CKD – particularly females with CKD – are warranted

    Safety, feasibility and effects of an individualised walking intervention for women undergoing chemotherapy for ovarian cancer: a pilot study

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    Background: Exercise interventions during adjuvant cancer therapy have been shown to increase functional capacity, relieve fatigue and distress and may assist rates of chemotherapy completion. These studies have been limited to breast, gastric and mixed cancer groups and it is not yet known if a similar intervention is even feasible among women with ovarian cancer. We aimed to assess safety, feasibility and potential effect of a walking intervention in women undergoing chemotherapy for ovarian cancer

    Evidence-informed recommendations on managing breast screening atypia : perspectives from an expert panel consensus meeting reviewing results from the sloane atypia project

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    Evidence-based clinical guidelines are essential to maximise patient benefit and to reduce clinical uncertainty and inconsistency in clinical practice. Gaps in the evidence base can be addressed by data acquired in routine practice. At present, there is no international consensus on management of women diagnosed with atypical lesions in breast screening programmes. Here we describe how routine NHS breast screening data collected by the Sloane atypia project was used to inform a management pathway that maximises early detection of cancer and minimises over investigation of lesions with uncertain malignant potential. A half-day consensus meeting with 11 clinical experts, 1 representative from Independent Cancer Patients’ Voice, 6 representatives from NHS England (NHSE) including from Commissioning, and 2 researchers was held to facilitate discussions of findings from an analysis of the Sloane atypia project. Key considerations of the expert group in terms of the management of women with screen detected atypia were: a) frequency and purpose of follow-up; b) communication to patients; c) generalisability of study results; d) workforce challenges. The group concurred that the new evidence does not support annual surveillance mammography for women with atypia, irrespective of type of lesion, or woman’s age. Continued data collection is paramount to monitor and audit the change in recommendations

    Using a Delphi process to determine optimal care for patients with pancreatic cancer

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    Aim Overall 5-year survival for pancreatic cancer is ~5%. Optimising the care that pancreatic cancer patients receive may be one way of improving outcomes. The objective of this study was to establish components of care which Australian health professionals believe important to optimally manage patients with pancreatic cancer. Methods Using a Delphi process, a multi-disciplinary panel of 250 health professionals were invited to provide a list of factors they considered important for optimal care of pancreatic cancer patients. They were then asked to score and then rescore (from one (no importance/disagree) to 10 (very important/agree) the factors. The mean and coefficient of variation scores were calculated and categorised into three levels of importance. Results Overall 63 (66% of those sent the final questionnaire; 25% of those initially invited) health professionals from 9 disciplines completed the final scoring of 55 statements/factors encompassing themes of presentation/staging, surgery and biliary obstruction, multi-disciplinary team details and oncology. Mean scores ranged from 3.7 to 9.7 with the highest related to communication and patient assessment. There was substantial intra- and inter- disciplinary variation in views about MDT membership and roles. Conclusion Overall the opinions of Australian health professionals reflect international guideline recommended care; however they identified a number of additional factors focusing on where patients should be treated, the importance of clear communication and the need for multi-disciplinary care which were not included in current clinical practice guidelines. Differences in priorities between specialty groups were also identified

    The Psychological Science Accelerator: Advancing Psychology Through a Distributed Collaborative Network

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    Source at https://doi.org/10.1177/2515245918797607.Concerns about the veracity of psychological research have been growing. Many findings in psychological science are based on studies with insufficient statistical power and nonrepresentative samples, or may otherwise be limited to specific, ungeneralizable settings or populations. Crowdsourced research, a type of large-scale collaboration in which one or more research projects are conducted across multiple lab sites, offers a pragmatic solution to these and other current methodological challenges. The Psychological Science Accelerator (PSA) is a distributed network of laboratories designed to enable and support crowdsourced research projects. These projects can focus on novel research questions or replicate prior research in large, diverse samples. The PSA’s mission is to accelerate the accumulation of reliable and generalizable evidence in psychological science. Here, we describe the background, structure, principles, procedures, benefits, and challenges of the PSA. In contrast to other crowdsourced research networks, the PSA is ongoing (as opposed to time limited), efficient (in that structures and principles are reused for different projects), decentralized, diverse (in both subjects and researchers), and inclusive (of proposals, contributions, and other relevant input from anyone inside or outside the network). The PSA and other approaches to crowdsourced psychological science will advance understanding of mental processes and behaviors by enabling rigorous research and systematic examination of its generalizability

    The psychological science accelerator’s COVID-19 rapid-response dataset

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    In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data

    The Psychological Science Accelerator's COVID-19 rapid-response dataset

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