2,793 research outputs found

    Molecular footprints of the Holocene retreat of dwarf birch in Britain

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    © 2014 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited

    Common mental disorders and mortality in the West of Scotland Twenty-07 Study: comparing the General Health Questionnaire and the Hospital Anxiety and Depression Scale

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    Background While various measures of common mental disorders (CMD) have been found to be associated with mortality, a comparison of how different measures predict mortality may improve our understanding of the association. This paper compares how the Hospital Anxiety and Depression Scale (HADS) and the 30-item General Health Questionnaire (GHQ-30) predict all cause and cause-specific mortality. Methods Data on 2547 men and women from two cohorts, aged approximately 39 and 55 years, from the West of Scotland Twenty-07 Study who were followed up for mortality over an average of 18.9 (SD 5.0) years. Scores were calculated for HADS depression (HADS-D), HADS Anxiety (HADS-A) and GHQ-30. Cox Proportional Hazards Models were used to determine how each CMD measure predicted mortality. Results After adjusting for serious physical illness, smoking, social class, alcohol, obesity, pulse rate and living alone, HRs (95% CI) per SD increase in score for all-cause mortality were: 1.15 (1.07 to 1.25) for HADSD; 1.13 (1.04 to 1.23) for GHQ-30 and 1.05 (0.96 to 1.14) for HADS-A. After the same adjustments, cardiovascular disease mortality was also related to HADS-D (HR 1.24 (1.07 to 1.43)), to GHQ-30 (HR 1.24 (1.11 to 1.40)) and to HADS-A (HR 1.15 (1.01 to 1.32)); respiratory mortality to GHQ-30 (HR 1.33 (1.13 to 1.55)) and mortality from other causes, excluding injuries, to HADS-D (HR 1.28 (1.05 to 1.55)). Conclusions There were associations between CMD and both all-cause and cause-specific mortality which were broadly similar for GHQ-30 and HADS-D and were still present after adjustment for important confounders and mediators

    Dynamic modeling of mean-reverting spreads for statistical arbitrage

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    Statistical arbitrage strategies, such as pairs trading and its generalizations, rely on the construction of mean-reverting spreads enjoying a certain degree of predictability. Gaussian linear state-space processes have recently been proposed as a model for such spreads under the assumption that the observed process is a noisy realization of some hidden states. Real-time estimation of the unobserved spread process can reveal temporary market inefficiencies which can then be exploited to generate excess returns. Building on previous work, we embrace the state-space framework for modeling spread processes and extend this methodology along three different directions. First, we introduce time-dependency in the model parameters, which allows for quick adaptation to changes in the data generating process. Second, we provide an on-line estimation algorithm that can be constantly run in real-time. Being computationally fast, the algorithm is particularly suitable for building aggressive trading strategies based on high-frequency data and may be used as a monitoring device for mean-reversion. Finally, our framework naturally provides informative uncertainty measures of all the estimated parameters. Experimental results based on Monte Carlo simulations and historical equity data are discussed, including a co-integration relationship involving two exchange-traded funds.Comment: 34 pages, 6 figures. Submitte

    Comparison of DC Bead-irinotecan and DC Bead-topotecan drug eluting beads for use in locoregional drug delivery to treat pancreatic cancer

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    DC Bead is a drug delivery embolisation system that can be loaded with doxorubicin or irinotecan for the treatment of a variety of liver cancers. In this study we demonstrate that the topoisomerase I inhibitor topotecan hydrochloride can be successfully loaded into the DC Bead sulfonate-modified polyvinyl alcohol hydrogel matrix, resulting in a sustained-release drug eluting bead (DEBTOP) useful for therapeutic purposes. The in vitro drug loading capacity, elution characteristics and the effects on mechanical properties of the beads are described with reference to our previous work with irinotecan hydrochloride (DEBIRI). Results showed that drug loading was faster when the solution was agitated compared to static loading and a maximum loading of ca. 40–45 mg topotecan in 1 ml hydrated beads was achievable. Loading the drug into the beads altered the size, compressibility moduli and colour of the bead. Elution was shown to be reliant on the presence of ions to perform the necessary exchange with the electrostatically bound topotecan molecules. Topotecan was shown by MTS assay to have an IC50 for human pancreatic adenocarcinoma cells (PSN-1) of 0.22 and 0.27 lM compared to 28.1 and 19.2 lM for irinotecan at 48 and 72 h, respectively. The cytotoxic efficacy of DEBTOP on PSN-1 was compared to DEBIRI. DEPTOP loaded at 6 & 30 mg ml-1, like its free drug form, was shown to be more potent than DEBIRI of comparable doses at 24, 48 & 72 h using a slightly modified MTS assay. Using a PSN-1 mouse xenograft model, DEBIRI doses of 3.3–6.6 mg were shown to be well tolerated (even with repeat administration) and effective in reducing the tumour size. DEBTOP however, was lethal after 6 days at doses of 0.83–1.2 mg but demonstrated reasonable efficacy and tolerability (again with repeat injection possible) at 0.2–0.4 mg doses. Care must therefore be taken when selecting the dose of topotecan to be loaded into DC Bead given its greater potency and potential toxicity

    A novel isolator-based system promotes viability of human embryos during laboratory processing

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    In vitro fertilisation (IVF) and related technologies are arguably the most challenging of all cell culture applications. The starting material is a single cell from which one aims to produce an embryo capable of establishing a pregnancy eventually leading to a live birth. Laboratory processing during IVF treatment requires open manipulations of gametes and embryos, which typically involves exposure to ambient conditions. To reduce the risk of cellular stress, we have developed a totally enclosed system of interlinked isolator-based workstations designed to maintain oocytes and embryos in a physiological environment throughout the IVF process. Comparison of clinical and laboratory data before and after the introduction of the new system revealed that significantly more embryos developed to the blastocyst stage in the enclosed isolator-based system compared with conventional open-fronted laminar flow hoods. Moreover, blastocysts produced in the isolator-based system contained significantly more cells and their development was accelerated. Consistent with this, the introduction of the enclosed system was accompanied by a significant increase in the clinical pregnancy rate and in the proportion of embryos implanting following transfer to the uterus. The data indicate that protection from ambient conditions promotes improved development of human embryos. Importantly, we found that it was entirely feasible to conduct all IVF-related procedures in the isolator-based workstations

    Intra-anal imiquimod cream against human papillomavirus infection in men who have sex with men living with hiv: A single-arm, open-label pilot study

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    Men who have sex with men (MSM) living with HIV have a high prevalence and incidence of anal high-risk human papillomavirus (hrHPV) and anal cancer. We conducted an open-label, single-arm pilot study to examine the tolerability of imiquimod cream among MSM aged ≥18 years, living with HIV, who tested positive for anal hrHPV at Melbourne Sexual Health Centre between April 2018 and June 2020. We instructed men to apply 6.25 mg imiquimod intra-anally and peri-anally 3 doses per week for 16 weeks (period 1) and then one dose per week for a further 48 weeks (period 2). Twenty-seven MSM enrolled in period 1 and 24 (86%) applied at least 50% of doses. All men reported adverse events (AEs), including 39.5% grade 1, 39.5% grade 2, and 21% grade 3 AEs on at least one occasion. Eighteen MSM (67%) temporarily stopped using imiquimod during period 1, most commonly due to local AEs (n = 11) such as irritation and itching. Eighteen MSM continued in period 2 and all applied at least 50% of doses with no treatment-limiting AEs reported. Imiquimod 3 doses per week caused local AEs in most men and was not well tolerated. In contrast, once-a-week application was well tolerated over 48-weeks with no treatment-limiting AEs

    PRESENT 2020: Text Expanding on the Checklist for Proper Reporting of Evidence in Sport and Exercise Nutrition Trials.

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    Some readers may not have access to the full paper, so a properly formatted and well-written abstract is imperative. Authors should give priority to information about the current study rather than using the abstract for an extensive background or rationale. 2a Methods: Key information regarding the study design, methods, and population should be summarized to enable broad understanding of the study from the abstract. 2b Results: Readers are interested in extracting key data that reflect the main findings of the study. The abstract should present data (e.g., the absolute magnitude of values and the size/precision of effects—specifying which measures of central tendency and variability are stated) rather than simply stating the presence, absence, or direction of effects. The presentation of p values or similar inferential statistics is no substitute for reporting actual data (Maughan, 2004). 2c Conclusion: Priority should be given to the reporting of results as per the previous section, with only a brief concluding statement thereafter. A concise conclusion based on what was actually measured in the study is preferred to speculative interpretations, with cautious use of language to avoid hyperbole or improper inference of causality (Brown et al., 2013). It is not appropriate or necessary to identify further research priorities here

    Observational study of the development and evaluation of a fertility preservation patient decision aid for teenage and adult women diagnosed with cancer: The Cancer, Fertility and Me research protocol

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    Introduction: Women diagnosed with cancer and facing potentially sterilising cancer treatment have to make time-pressured decisions regarding fertility preservation with specialist fertility services whilst undergoing treatment of their cancer with oncology services. Oncologists identify a need for resources enabling them to support women’s fertility preservation decisions more effectively; women report wanting more specialist information to make these decisions. The overall aim of the ‘Cancer, Fertility and Me’ study is to develop and evaluate a new evidence-based patient decision aid (ptDA) for women with any cancer considering fertility preservation to address this unmet need. Methods and analysis: This is a prospective mixed-method observational study including women of reproductive age (16 years +) with a new diagnosis of any cancer across two regional cancer and fertility centres in Yorkshire, UK. The research involves three stages. In Stage 1 the aim is to develop the ptDA using a systematic method of evidence synthesis and multidisciplinary expert review of current clinical practice and patient information. In Stage 2, the aim is to assess the face validity of the ptDA. Feedback on its content and format will be ascertained using both questionnaires and interviews with patients, user groups and key stakeholders. Finally, in Stage 3 the acceptability of using this resource when integrated into usual cancer care pathways at the point of cancer diagnosis and treatment planning will be evaluated. This will involve a quantitative and qualitative evaluation of the ptDA in clinical practice. Measures chosen include using count data of the ptDAs administered in clinics and accessed online, decisional and patient-reported outcome measures and qualitative feedback. Quantitative data will be analysed using descriptive statistics, paired sample t tests and confidence intervals; interviews will be analysed using thematic analysis. Ethics and dissemination: Research Ethics Committee approval (Ref: 16/EM/0122) and Health Research Authority approval (Ref: 194751) has been granted. Findings will be published in open access peer-reviewed journals, presented at conferences for academic and health professional audiences, with feedback to health professionals and program managers. The Cancer, Fertility and Me ptDA will be disseminated via a diverse range of open-access media, study and charity websites, professional organisations and academic sources. External endorsement will be sought from the International Patient Decision Aid Standards (IPDAS) Collaboration inventory of ptDAs and other relevant professional organisations e.g. the British Fertility Society. Trial registration number: NCT02753296 (www.clinicaltrials.gov); pre-results

    Annual and seasonal movements of migrating short-tailed shearwaters reflect environmental variation in sub-Arctic and Arctic waters

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    The marine ecosystems of the Bering Sea and adjacent southern Chukchi Sea are experiencing rapid changes due to recent reductions in sea ice. Short-tailed shearwaters Puffinus tenuirostris visit this region in huge numbers between the boreal summer and autumn during non-breeding season, and represent one of the dominant top predators. To understand the implications for this species of ongoing environmental change in the Pacific sub-Arctic and Arctic seas, we tracked the migratory movements of 19 and 24 birds in 2010 and 2011, respectively, using light-level geolocators. In both years, tracked birds occupied the western (Okhotsk Sea and Kuril Islands) and eastern (southeast Bering Sea) North Pacific from May to July. In August–September of 2010, but not 2011, a substantial proportion (68 % of the tracked individuals in 2010 compared to 38 % in 2011) moved through the Bering Strait to feed in the Chukchi Sea. Based on the correlation with oceanographic variables, the probability of shearwater occurrence was highest in waters with sea surface temperatures (SSTs) of 8–10 °C over shallow depths. Furthermore, shearwaters spent more time flying when SST was warmer than 9 °C, suggesting increased search effort for prey. We hypothesized that the northward shift in the distribution of shearwaters may have been related to temperature-driven changes in the abundance of their dominant prey, krill (Euphausiacea), as the timing of krill spawning coincides with the seasonal increase in water temperature. Our results indicate a flexible response of foraging birds to ongoing changes in the sub-Arctic and Arctic ecosystems
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