5,444 research outputs found

    When Is Domestic Political Unrest Related to International Conflict? Diversionary Theory and Japanese Foreign Policy, 1890–19411

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146888/1/j.1468-2478.2010.00620.x.pd

    Assessing hand osteoarthritis using digital photographs in a community-dwelling population: reliability and associations with radiographic and clinical features

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    Purpose: An atlas for grading hand osteoarthritis (OA) on photographs has been shown to be reliable and associated with clinical examination and radiographic features in a population of older adults (aged ≥69 years) from the AGES-Reykjavik study. The objective of this research was to determine if this atlas was reliable and to assess its association with radiographic and clinical features in a different younger community-dwelling population.Methods: Participants were community-dwelling older adults (≥50 years) in North Staffordshire, UK with self-reported hand pain or hand problems in the last year who attended a research clinic. High quality photographs taken at a set distance in a standardised position were graded for the presence of hand OA using an established atlas. Hand radiographs were graded for OA using the Kellgren Lawrence grading system and the presence of clinical features (nodes, bony enlargement, deformity) was determined on physical examination by trained assessors.Results: Following exclusions 558 participants (mean age 64 years, 62% female) were included in the analyses. Overall reliability for scoring each joint and joint group was good (mean intra-rater ICC =0.79, mean inter-rater ICC =0.71). For each joint and joint group photographic hand OA was positively associated with grade of radiographic OA (rho 0.19-0.57, p<0.001) and the number of clinical features present on an examination (rho 0.36-0.59, p<0.001). At the person level, individuals with higher global photographic hand OA scores had higher summed K&L scores and had higher percentages meeting the ACR clinical hand OA criteria.Conclusions: This photographic scoring system for hand OA has been shown to be reliable and associated with both radiographic and clinical features in a different and younger community-dwelling population to that in which it was developed. This method of data collection offers researchers an feasible alternative to the physical examination and maybe of particular use to large studies and those spread over a wide geographic areas

    Detecting periodicity in experimental data using linear modeling techniques

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    Fourier spectral estimates and, to a lesser extent, the autocorrelation function are the primary tools to detect periodicities in experimental data in the physical and biological sciences. We propose a new method which is more reliable than traditional techniques, and is able to make clear identification of periodic behavior when traditional techniques do not. This technique is based on an information theoretic reduction of linear (autoregressive) models so that only the essential features of an autoregressive model are retained. These models we call reduced autoregressive models (RARM). The essential features of reduced autoregressive models include any periodicity present in the data. We provide theoretical and numerical evidence from both experimental and artificial data, to demonstrate that this technique will reliably detect periodicities if and only if they are present in the data. There are strong information theoretic arguments to support the statement that RARM detects periodicities if they are present. Surrogate data techniques are used to ensure the converse. Furthermore, our calculations demonstrate that RARM is more robust, more accurate, and more sensitive, than traditional spectral techniques.Comment: 10 pages (revtex) and 6 figures. To appear in Phys Rev E. Modified styl

    Physics of Eclipsing Binaries: Heartbeat Stars and Tidally Induced Pulsations

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    Heartbeat stars are a relatively new class of eccentric ellipsoidal variable first discovered by Kepler. An overview of the current field is given with details of some of the interesting objects identified in our current Kepler sample of 135 heartbeats stars. Three objects that have recently been or are undergoing detailed study are described along with suggestions for further avenues of research. We conclude by discussing why heartbeat stars are an interesting new tool to study tidally induced pulsations and orbital dynamics

    Holidays, celebrations, and commiserations: measuring drinking during feasting and fasting to improve national and individual estimates of alcohol consumption

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    BACKGROUND: Accurate measures of alcohol consumption are critical in assessing health harms caused by alcohol. In many countries, there are large discrepancies between survey-based measures of consumption and those based on alcohol sales. In England, surveys measuring typical alcohol consumption account for only around 60% of alcohol sold. Here, using a national survey, we measure both typical drinking and atypical/special occasion drinking (i.e., feasting and fasting) in order to develop more complete measures of alcohol consumption. METHODS: A national random probability telephone survey was implemented (May 2013 to April 2014). Inclusion criteria were resident in England and aged 16 years or over. Respondents (n = 6,085) provided information on typical drinking (amounts per day, drinking frequency) and changes in consumption associated with routine atypical days (e.g., Friday nights) and special dinking periods (e.g., holidays) and events (e.g., weddings). Generalized linear modelling was used to identify additional alcohol consumption associated with atypical/special occasion drinking by age, sex, and typical drinking level. RESULTS: Accounting for atypical/special occasion drinking added more than 120 million UK units of alcohol/week (~12 million bottles of wine) to population alcohol consumption in England. The greatest impact was seen among 25- to 34-year-olds with the highest typical consumption, where atypical/special occasions added approximately 18 units/week (144 g) for both sexes. Those reporting the lowest typical consumption (≤1 unit/week) showed large relative increases in consumption (209.3%) with most drinking associated with special occasions. In some demographics, adjusting for special occasions resulted in overall reductions in annual consumption (e.g., females, 65 to 74 years in the highest typical drinking category). CONCLUSIONS: Typical drinking alone can be a poor proxy for actual alcohol consumption. Accounting for atypical/special occasion drinking fills 41.6% of the gap between surveyed consumption and national sales in England. These additional units are inevitably linked to increases in lifetime risk of alcohol-related disease and injury, particularly as special occasions often constitute heavy drinking episodes. Better population measures of celebratory, festival, and holiday drinking are required in national surveys in order to adequately measure both alcohol consumption and the health harms associated with special occasion drinking

    Electron-electron interaction effects in quantum point contacts

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    We consider electron-electron interaction effects in quantum point contacts on the first quantization plateau, taking into account all scattering processes. We compute the low-temperature linear and nonlinear conductance, shot noise, and thermopower, by perturbation theory and a self-consistent nonperturbative method. On the conductance plateau, the low-temperature corrections are solely due to momentum-nonconserving processes that change the relative number of left- and right-moving electrons. This leads to a suppression of the conductance for increasing temperature or voltage. The size of the suppression is estimated for a realistic saddle-point potential, and is largest in the beginning of the conductance plateau. For large magnetic field, interaction effects are strongly suppressed by the Pauli principle, and hence the first spin-split conductance plateau has a much weaker interaction correction. For the nonperturbative calculations, we use a self-consistent nonequilibrium Green's function approach, which suggests that the conductance saturates at elevated temperatures. These results are consistent with many experimental observations related to the so-called 0.7 anomaly

    Mental Health Admissions to Paediatric Wards Study (MAPS): a protocol for the analysis of Hospital Episode Statistics (HES) data.

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    INTRODUCTION: Children and young people (CYP) presenting with a mental health (MH) crisis are frequently admitted to general acute paediatric wards as a place of safety. Prior to the pandemic, a survey in England showed that CYP occupied 6% of general paediatric inpatient beds due to an MH crisis, and there have been longstanding concerns about the quality of care to support these patients in this setting. Mental Health Admissions to Paediatric Wards Study aims to generate a theory of change (ToC) model to improve the quality of care for CYP admitted to acute paediatric services after presenting in a MH crisis. METHODS AND ANALYSIS: We will undertake a national (England), sequential, mixed methods study to inform a ToC framework alongside a stakeholder group consisting of patients, families/carers and healthcare professionals (HCPs). Our study consists of four work packages (WP) undertaken over 30 months. WP1 is limited to using national routine administrative data to identify and characterise trends in MH admissions in acute paediatric wards in England between 2015- 2022. ETHICS AND DISSEMINATION: WP1 received ethical approval (Ref 23/NW/0192). We will publish the overall synthesis of data and the final ToC to improve care of CYP with MH crisis admitted to general acute paediatric settings. As coproducers of the ToC, we will work with our stakeholder group to ensure wide dissemination of findings. Potential impacts will be on service development, new models of care, training and workforce planning

    Tunneling Between Two-Dimensional Electron Gases in a Strong Magnetic Field

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    We have measured the tunneling between two two-dimensional electron gases at high magnetic fields BB, when the carrier densities of the two electron layers are matched. For filling factors ν<1\nu<1, there is a gap in the current-voltage characteristics centered about V=0V=0, followed by a tunneling peak at 6\sim 6~mV. Both features have been observed before and have been attributed to electron-electron interactions within a layer. We have measured high field tunneling peak positions and fitted gap parameters that are proportional to BB, and independent of the carrier densities of the two layers. This suggests a different origin for the gap to that proposed by current theories, which predict a B\sqrt{B} dependence.Comment: 9 pages, cond-mat/yymmnn

    Atomic Configuration of Nitrogen Doped Single-Walled Carbon Nanotubes

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    Having access to the chemical environment at the atomic level of a dopant in a nanostructure is crucial for the understanding of its properties. We have performed atomically-resolved electron energy-loss spectroscopy to detect individual nitrogen dopants in single-walled carbon nanotubes and compared with first principles calculations. We demonstrate that nitrogen doping occurs as single atoms in different bonding configurations: graphitic-like and pyrrolic-like substitutional nitrogen neighbouring local lattice distortion such as Stone-Thrower-Wales defects. The stability under the electron beam of these nanotubes has been studied in two extreme cases of nitrogen incorporation content and configuration. These findings provide key information for the applications of these nanostructures.Comment: 25 pages, 13 figure
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