2,427 research outputs found

    A 700 year record of Southern Hemisphere extratropical climate variability

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    Annually dated ice cores from West and East Antarctica provide proxies for past changes in atmospheric circulation over Antarctica and portions of the Southern Ocean, temperature in coastal West and East Antarctica, and the frequency of South Polar penetration of El Niño events. During the period AD 1700–1850, atmospheric circulation over the Antarctic and at least portions of the Southern Hemisphere underwent a mode switch departing from the out-of-phase alternation of multi-decadal long phases of EOF1 and EOF2 modes of the 850 hPa field over the Southern Hemisphere (as defined in the recent record by Thompson and Wallace, 2000; Thompson and Solomon, 2002) that characterizes the remainder of the 700 year long record. From AD 1700 to 1850, lower-tropospheric circulation was replaced by in-phase behavior of the Amundsen Sea Low component of EOF2 and the East Antarctic High component of EOF1. During the first phase of the mode switch, both West and East Antarctic temperatures declined, potentially in response to the increased extent of sea ice surrounding both regions. At the end of the mode switch, West Antarctic coastal temperatures rose and East Antarctic coastal temperatures fell, respectively, to their second highest and lowest of the record. Polar penetration of El Niño events increased during the mode switch. The onset of the AD 1700–1850 mode switch coincides with the extreme state of the Maunder Minimum in solar variability. Late 20th-century West Antarctic coastal temperatures are the highest in the record period, and East Antarctic coastal temperatures close to the lowest. Since AD 1700, extratropical regions of the Southern Hemisphere have experienced significant climate variability coincident with changes in both solar variability and greenhouse gase

    Risk factors for leaving employment due to multiple sclerosis and changes in risk over the past decades: using competing risk survival analysis

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    Background: No studies have assessed changes in employment survival in multiple sclerosis (MS) populations over recent decades, including the introduction of disease-modifying therapies (DMTs). Objectives: To evaluate factors associated with leaving employment due to MS; to assess whether the risk of leaving employment has changed over recent decades in Australia, stratified by MS phenotype. Methods: We included 1240 participants who were working before MS diagnosis. Information on employment status, reasons for leaving employment and year of leaving were collected. Data were analysed using competing risk survival analysis. Results: Males, progressive MS, lower education level and older age at diagnosis were associated with a higher sub-distribution hazard of leaving employment. Compared to the period before 2010, the sub-distribution hazard during 2010-2016 for relapsing-remitting multiple sclerosis (RRMS) was reduced by 43% (sub-distribution hazard ratio (sHR) 0.67, 95% confidence interval (CI): 0.50 to 0.90), while no significant reduction was seen for primary-progressive multiple sclerosis (PPMS) (sHR 1.25, 95% CI: 0.72 to 2.16) or secondary-progressive multiple sclerosis (SPMS) (sHR 1.37, 95% CI: 0.84 to 2.25). Conclusion: Males, people with progressive MS and those of lower education level were at higher risk of leaving employment. The differential changed risk of leaving employment between people with different MS phenotype after 2010 coincides with the increased usage of high-efficacy DMTs for RRMS

    Characterization of extrasolar terrestrial planets from diurnal photometric variability

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    The detection of massive planets orbiting nearby stars has become almost routine, but current techniques are as yet unable to detect terrestrial planets with masses comparable to the Earth's. Future space-based observatories to detect Earth-like planets are being planned. Terrestrial planets orbiting in the habitable zones of stars-where planetary surface conditions are compatible with the presence of liquid water-are of enormous interest because they might have global environments similar to Earth's and even harbor life. The light scattered by such a planet will vary in intensity and colour as the planet rotates; the resulting light curve will contain information about the planet's properties. Here we report a model that predicts features that should be discernible in light curves obtained by low-precision photometry. For extrasolar planets similar to Earth we expect daily flux variations up to hundreds of percent, depending sensitively on ice and cloud cover. Qualitative changes in surface or climate generate significant changes in the predicted light curves. This work suggests that the meteorological variability and the rotation period of an Earth-like planet could be derived from photometric observations. Other properties such as the composition of the surface (e.g., ocean versus land fraction), climate indicators (for example ice and cloud cover), and perhaps even signatures of Earth-like plant life could be constrained or possibly, with further study, even uniquely determined.Comment: Published in Nature. 9 pages including 3 figure

    Universal design for learning in physical education: Overview and critical reflection

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    Universal design for learning (UDL) has been advocated for by adapted physical education scholars as a panacea to the challenges associated with teaching disabled and nondisabled students together in physical education. So much so that UDL currently occupies a privileged and largely unquestioned position in adapted physical education scholarship and practice, until now. To move scholarship forward, this article draws on published theoretical and empirical work relating to UDL generally and in physical education in particular to critically discuss the scientific research supporting, or not, the use of UDL as a so-called inclusive approach. We end this article with a call to action for scholars in this field, ourselves included, to conduct theoretically guided and empirically informed research relating to UDL in physical education, which adheres to established hallmarks of research quality that are tied to the ontological and epistemological assumptions of researchers because, at present, it is conspicuous by its absence

    A randomised controlled trial and cost-effectiveness evaluation of "booster" interventions to sustain increases in physical activity in middle-aged adults in deprived urban neighbourhoods

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    Background: Systematic reviews have identified a range of brief interventions which increase physical activity in previously sedentary people. There is an absence of evidence about whether follow up beyond three months can maintain long term physical activity. This study assesses whether it is worth providing motivational interviews, three months after giving initial advice, to those who have become more active. Methods/Design: Study candidates (n = 1500) will initially be given an interactive DVD and receive two telephone follow ups at monthly intervals checking on receipt and use of the DVD. Only those that have increased their physical activity after three months (n = 600) will be randomised into the study. These participants will receive either a "mini booster" (n = 200), "full booster" (n = 200) or no booster (n = 200). The "mini booster" consists of two telephone calls one month apart to discuss physical activity and maintenance strategies. The "full booster" consists of a face-to-face meeting with the facilitator at the same intervals. The purpose of these booster sessions is to help the individual maintain their increase in physical activity. Differences in physical activity, quality of life and costs associated with the booster interventions, will be measured three and nine months from randomisation. The research will be conducted in 20 of the most deprived neighbourhoods in Sheffield, which have large, ethnically diverse populations, high levels of economic deprivation, low levels of physical activity, poorer health and shorter life expectancy. Participants will be recruited through general practices and community groups, as well as by postal invitation, to ensure the participation of minority ethnic groups and those with lower levels of literacy. Sheffield City Council and Primary Care Trust fund a range of facilities and activities to promote physical activity and variations in access to these between neighbourhoods will make it possible to examine whether the effectiveness of the intervention is modified by access to community facilities. A one-year integrated feasibility study will confirm that recruitment targets are achievable based on a 10% sample.Discussion: The choice of study population, study interventions, brief intervention preceding the study, and outcome measure are discussed

    T1 at 1.5T and 3T compared with conventional T2* at 1.5T for cardiac siderosis

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    Background: Myocardial black blood (BB) T2* relaxometry at 1.5T provides robust, reproducible and calibrated non-invasive assessment of cardiac iron burden. In vitro data has shown that like T2*, novel native Modified Look-Locker Inversion recovery (MOLLI) T1 shortens with increasing tissue iron. The relative merits of T1 and T2* are largely unexplored. We compared the established 1.5T BB T2* technique against native T1 values at 1.5T and 3T in iron overload patients and in normal volunteers. Methods: A total of 73 subjects (42 male) were recruited, comprising 20 healthy volunteers (controls) and 53 patients (thalassemia major 22, sickle cell disease 9, hereditary hemochromatosis 9, other iron overload conditions 13). Single mid-ventricular short axis slices were acquired for BB T2* at 1.5T and MOLLI T1 quantification at 1.5T and 3T. Results: In healthy volunteers, median T1 was 1014 ms (full range 939–1059 ms) at 1.5T and modestly increased to 1165ms (full range 1056–1224 ms) at 3T. All patients with significant cardiac iron overload (1.5T T2* values <20 ms) had T1 values <939 ms at 1.5T, and <1056 ms at 3T. Associations between T2* and T1 were found to be moderate with y =377 · x0.282 at 1.5T (R2 = 0.717), and y =406 · x0.294 at 3T (R2 = 0.715). Measures of reproducibility of T1 appeared superior to T2*. Conclusions: T1 mapping at 1.5T and at 3T can identify individuals with significant iron loading as defined by the current gold standard T2* at 1.5T. However, there is significant scatter between results which may reflect measurement error, but it is also possible that T1 interacts with T2*, or is differentially sensitive to aspects of iron chemistry or other biology. Hurdles to clinical implementation of T1 include the lack of calibration against human myocardial iron concentration, no demonstrated relation to cardiac outcomes, and variation in absolute T1 values between scanners, which makes inter-centre comparisons difficult. The relative merits of T1 at 3T versus T2* at 3T require further consideration

    Patient perspectives on molecular tumor profiling: "why wouldn't you?"

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    © 2019 The Author(s). Aim: This study explored the attitudes of patients with advanced cancer towards MTP and return of results, prior to undergoing genomic testing within a research program. Methods: Participants were recruited as part of the longitudinal PiGeOn (Psychosocial Issues in Genomics in Oncology) study involving patients with advanced/metastatic solid cancer who had exhausted therapeutic options and who were offered MTP in order to identify cognate therapies. Twenty patients, selected by purposive sampling, were interviewed around the time they gave consent to MTP. Interviews were audio recorded, transcribed and analysed using thematic analysis. Themes identified in the transcripts were cross-validated via qualitative responses to the PiGeOn study survey (n = 569; 63%). Results: All interviewed participants gave consent to MTP without reservation. Three themes were identified and further supported via the survey responses: (1) Obvious agreement to participate, primarily because of desire for new treatments and altruism. (2) The black box - while participant knowledge of genomics was generally poor, faith in their oncologists and the scientific process encouraged them to proceed with testing; and (3) Survival is the priority - receiving treatment to prolong life was the priority for all participants, and other issues such as identification of a germline variant were generally seen as ancillary. Conclusion: Having advanced cancer seemed to abrogate any potential concerns about MTP. Participants valued the research for varied reasons, but this was secondary to their priority to survive. While no negative attitudes toward MTP emerged, limitations in understanding of genomics were evident

    Environmental Impact Assessment and Strategic Environmental Assessment in the UK after leaving the European Union

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    The United Kingdom has voted to leave the European Union and, until the terms of the ‘Brexit’ are negotiated, this has led to considerable uncertainty over the future practice of Environmental Impact Assessment (EIA) and Strategic Environmental Assessment (SEA) in the UK. Here we show that multiple obligations exist outside the scope of the EU which mean that EIA and SEA will continue to be required in the long-term, but that their future compliance with the Directives remains unclear. We consider three scenarios for Brexit and present the implications of each; these are: signing up to the European Economic Area (EEA) Agreement; membership of the European Free Trade Association (EFTA), but not EEA, or negotiate a separate agreement. The implications of no longer being subjected to the obligations of the Directives under some scenarios are discussed and include opening the door for increasing diversity of application across the regions of the UK, and the probability of raised screening thresholds so as to reduce the burden of assessment on developers

    Collective Animal Behavior from Bayesian Estimation and Probability Matching

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    Animals living in groups make movement decisions that depend, among other factors, on social interactions with other group members. Our present understanding of social rules in animal collectives is based on empirical fits to observations and we lack first-principles approaches that allow their derivation. Here we show that patterns of collective decisions can be derived from the basic ability of animals to make probabilistic estimations in the presence of uncertainty. We build a decision-making model with two stages: Bayesian estimation and probabilistic matching.&#xd;&#xa;In the first stage, each animal makes a Bayesian estimation of which behavior is best to perform taking into account personal information about the environment and social information collected by observing the behaviors of other animals. In the probability matching stage, each animal chooses a behavior with a probability given by the Bayesian estimation that this behavior is the most appropriate one. This model derives very simple rules of interaction in animal collectives that depend only on two types of reliability parameters, one that each animal assigns to the other animals and another given by the quality of the non-social information. We test our model by obtaining theoretically a rich set of observed collective patterns of decisions in three-spined sticklebacks, Gasterosteus aculeatus, a shoaling fish species. The quantitative link shown between probabilistic estimation and collective rules of behavior allows a better contact with other fields such as foraging, mate selection, neurobiology and psychology, and gives predictions for experiments directly testing the relationship between estimation and collective behavior

    Evaluation of a standard provision versus an autonomy promotive exercise referral programme: rationale and study design

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    Background The National Institute of Clinical Excellence in the UK has recommended that the effectiveness of ongoing exercise referral schemes to promote physical activity should be examined in research trials. Recent empirical evidence in health care and physical activity promotion contexts provides a foundation for testing the utility of a Self Determination Theory (SDT) -based exercise referral consultation. Methods/Design Design: An exploratory cluster randomised controlled trial comparing standard provision exercise on prescription with a Self Determination Theory-based (SDT) exercise on prescription intervention. Participants: 347 people referred to the Birmingham Exercise on Prescription scheme between November 2007 and July 2008. The 13 exercise on prescription sites in Birmingham were randomised to current practice (n=7) or to the SDT-based intervention (n=6). Outcomes measured at 3 and 6-months: Minutes of moderate or vigorous physical activity per week assessed using the 7-day Physical Activity Recall; physical health: blood pressure and weight; health status measured using the Dartmouth CO-OP charts; anxiety and depression measured by the Hospital Anxiety and Depression Scale and vitality measured by the subjective vitality score; motivation and processes of change: perceptions of autonomy support from the advisor, satisfaction of the needs for competence, autonomy, and relatedness via physical activity, and motivational regulations for exercise. Discussion This trial will determine whether an exercise referral programme based on Self Determination Theory increases physical activity and other health outcomes compared to a standard programme and will test the underlying SDT-based process model (perceived autonomy support, need satisfaction, motivation regulations, outcomes) via structural equation modelling. Trial registration The trial is registered as Current Controlled trials ISRCTN07682833
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