132 research outputs found

    The Scottish school leavers cohort: linkage of education data to routinely collected records for mortality, hospital discharge and offspring birth characteristics

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    Purpose: The Scottish school leavers cohort provides population-wide prospective follow-up of local authority secondary school leavers in Scotland through linkage of comprehensive education data with hospital and mortality records. It considers educational attainment as a proxy for socioeconomic position in young adulthood and enables the study of associations and causal relationships between educational attainment and health outcomes in young adulthood. Participants: Education data for 284 621 individuals who left a local authority secondary school during 2006/2007–2010/2011 were linked with birth, death and hospital records, including general/acute and mental health inpatient and day case records. Individuals were followed up from date of school leaving until September 2012. Age range during follow-up was 15 years to 24 years. Findings: to date Education data included all formal school qualifications attained by date of school leaving; sociodemographic information; indicators of student needs, educational or non-educational support received and special school unit attendance; attendance, absence and exclusions over time and school leaver destination. Area-based measures of school and home deprivation were provided. Health data included dates of admission/discharge from hospital; principal/secondary diagnoses; maternal-related, birth-related and baby-related variables and, where relevant, date and cause of death. This paper presents crude rates for all-cause and cause-specific deaths and general/acute and psychiatric hospital admissions as well as birth outcomes for children of female cohort members. Future plans: This study is the first in Scotland to link education and health data for the population of local authority secondary school leavers and provides access to a large, representative cohort with the ability to study rare health outcomes. There is the potential to study health outcomes over the life course through linkage with future hospital and death records for cohort members. The cohort may also be expanded by adding data from future school leavers. There is scope for linkage to the Prescribing Information System and the Scottish Primary Care Information Resource

    A Lagrange-D'Alembert formulation of the equations of motion of a helicopter carrying an externally suspended load

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    The exact nonlinear equations of motion are derived for a helicopter with an extenal load suspended by fore and aft, rigid-link cables. Lagrange's form of D'Alembert's principle is used. Ten degrees of freedom are necessary to represent the motion of this system in an inertial reference frame: six for the helicopter relative to inertial space and four for the load relative to the helicopter

    The Effect of Alcohol Consumption on Mortality: Regression Discontinuity Evidence from the Minimum Drinking Age

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    This paper estimates the effect of alcohol consumption on mortality using the minimum drinking age in a regression discontinuity design. We find that granting legal access to alcohol at age 21 leads to large and immediate increases in several measures of alcohol consumption, including a 21 percent increase in the number of days on which people drink. This increase in alcohol consumption results in a discrete 9 percent increase in the mortality rate at age 21. The overall increase in deaths is due primarily to a 14 percent increase in deaths due to motor vehicle accidents, a 30 percent increase in alcohol overdoses and alcohol-related deaths, and a 15 percent increase in suicides. Combining the reduced-form estimates reveals that a 1 percent increase in the number of days a young adult drinks or drinks heavily results in a .4 percent increase in total mortality. Given that mortality due to external causes peaks at about age 21 and that young adults report very high levels of alcohol consumption, our results suggest that public policy interventions to reduce youth drinking can have substantial public health benefits.

    Major bleeding complications and persistence with oral anticoagulation in non-valvular atrial fibrillation:Contemporary findings in real-life Danish patients

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    Background The nonvitamin K antagonist oral anticoagulants have recently become available as an alternative to warfarin as stroke prophylaxis in atrial fibrillation, but data on real‐life patient experience, including bleeding risk, are lacking. Our objective was to compare major bleeding events and nonpersistence between the nonvitamin K antagonist oral anticoagulant apixaban and other nonvitamin K antagonist oral anticoagulants (dabigatran and rivaroxaban) and warfarin in a contemporary, nation‐wide cohort of patients with nonvalvular atrial fibrillation. Methods and Results Of 54 321 patients (median age, 73 years; 56% male; mean CHA 2 DS 2 ‐ VAS c score, 2.9), 7963, 6715, 15 413, and 24 230 patients initiated apixaban, rivaroxaban, dabigatran, and warfarin, respectively. Apixaban and rivaroxaban initiators were older, less often male, with higher HAS ‐ BLED and CHA 2 DS 2 ‐ VAS c scores compared with dabigatran and warfarin initiators. A total of 2418 patients (4.5%) experienced a major bleeding event over all available follow‐up. In this period, rivaroxaban (hazard ratio [ HR ] [95% CI], 1.49 [1.27–1.77]), dabigatran ( HR , 1.17 [1.00–1.38]), and warfarin ( HR , 1.23 [1.05–1.43]) users were significantly more likely to bleed than apixaban users. Findings were similar when restricted to the first 30 days after OAC initiation. Risk of nonpersistence was higher for dabigatran ( HR , 1.45 [1.33–1.59]) and warfarin initiators ( HR , 1.22 [1.12–1.33]), but not for rivaroxaban initiators ( HR , 1.07 [0.96–1.20]) compared with apixaban initiators. Conclusions In a real‐world cohort of nonvalvular atrial fibrillation patients, apixaban had a lower adjusted major bleeding risk compared with rivaroxaban, dabigatran, and warfarin. Apixaban had a lower risk of nonpersistence compared with dabigatran and warfarin and similar risk compared with rivaroxaban. </jats:sec

    Propagation of acoustic-gravity waves in the atmosphere

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    Homogeneous wave guide theory is used to derive dispersion curves, vertical pressure distributions, and synthetic barograms for atmospheric waves. A complicated mode structure is found involving both gravity and acoustic waves. Various models of the atmosphere are studied to explore seasonal and geographic effects on pulse propagation. The influence of different zones in the atmosphere on the character of the barograms is studied. It is found that the first arriving waves are controlled by the properties of the lower atmospheric channel. Comparison of theoretical results and experimental data from large thermonuclear explosions is made in the time and frequency domains, and the following conclusions are reached: (1) The major features on barograms are due to dispersion; (2) superposition of several modes is needed to explain observed features; (3) scatter of data outside the range permitted by extreme atmospheric models shows the influence of winds for A1; wind effects and higher modes are less important for A_2 waves. A discussion is included on atmospheric terminations and how these affect dispersion curves

    Love Your Library Display

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    We have created a display of works about libraries; included are books on the history of libraries, books on library architecture, books on careers in library and information science, works of library-centric fiction, and even a few DVDs with libraries at the core of their plot

    A Refinement of ``A Key-recovery Attack on 855-round Trivium From CRYPTO 2018

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    At CRYPTO 2018, we proposed a method to reduce the Boolean polynomial of 855-round Trivium. By multiplying a polynomial reduction factor, the output Boolean polynomial is simplified. Based on this method, a 855-round key-recovery attack on Trivium is introduced. In addition, we also give a practical attack on 721-round Trivium to show some rationality and evidence. However, Yonglin Hao et al. find some errors in the 721-round attack recently. As a correction, we propose some new right 721-round example attacks based on our method proposed at CRYPTO 2018

    A Key-recovery Attack on 855-round Trivium

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    In this paper, we propose a key-recovery attack on Trivium reduced to 855 rounds. As the output is a complex Boolean polynomial over secret key and IV bits and it is hard to find the solution of the secret keys, we propose a novel nullification technique of the Boolean polynomial to reduce the output Boolean polynomial of 855-round Trivium. Then we determine the degree upper bound of the reduced nonlinear boolean polynomial and detect the right keys. These techniques can be applicable to most stream ciphers based on nonlinear feedback shift registers (NFSR). Our attack on 855855-round Trivium costs time complexity 2772^{77}. As far as we know, this is the best key-recovery attack on round-reduced Trivium. To verify our attack, we also give some experimental data on 721-round reduced Trivium
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