892 research outputs found

    Coronary heart disease and risk factors as predictors of trajectories of psychological distress from midlife to old age

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    Objective To examine coronary heart disease (CHD) and its risk factors as predictors of long-term trajectories of psychological distress from midlife to old age. Methods In the Whitehall II cohort study, 6890 participants (4814 men, 2076 women; mean age 49.5 years) had up to seven repeat assessments of psychological distress over 21 years (mean follow-up 19 years). CHD and its risk factors (lifestyle-related risk factors, diabetes, hypertension and cholesterol) were assessed at baseline. Group-based trajectory modelling was used to identify clusters of individuals with a similar pattern of psychological distress over time. Results We identified four trajectories of psychological distress over the follow-up: 'persistently low (69% of the participants), 'persistently intermediate' (13%), 'intermediate to low' (12%) and 'persistently high' (7%). The corresponding proportions were 60%, 16%, 13% and 11% among participants with CHD; 63%, 15%, 12% and 10% among smokers and 63%, 16%, 12% and 10% among obese participants. In multivariable adjusted multinomial regression analyses comparing other trajectories to persistently low trajectory, prevalent CHD was associated with intermediate to low (OR 1.70, 95% CI 1.08 to 2.68) and persistently high (OR 1.92, 95% CI 1.16 to 3.19) trajectories. Smoking (OR 1.33, 95% CI 1.07 to 1.64; OR 1.55, 95% CI 1.19 to 2.04) and obesity (OR 1.33, 95% CI 1.04 to 1.70; OR 1.47, 95% CI 1.07 to 2.01) were associated with persistently intermediate and persistently high trajectories, respectively. Conclusion CHD, smoking and obesity may have a role in the development of long-lasting psychological distress from midlife to old age.Peer reviewe

    Non-Markovian Steady States of a Driven Two-Level System

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    We show that an open quantum system in a non-Markovian environment can reach steady states that it cannot reach in a Markovian environment. As these steady states are unique for the non-Markovian regime, they could offer a simple way of detecting non-Markovianity, as no information about the system\u27s transient dynamics is necessary. In particular, we study a driven two-level system (TLS) in a semi-infinite waveguide. Once the waveguide has been traced out, the TLS sees an environment with a distinct memory time. The memory time enters the equations as a time delay that can be varied to compare a Markovian to a non-Markovian environment. We find that some non-Markovian states show exotic behaviors such as population inversion and steady-state coherence beyond 1/8, neither of which is possible for a driven TLS in the Markovian regime, where the time delay is neglected. Additionally, we show how the coherence of quantum interference is affected by time delays in a driven system by extracting the effective Purcell-modified decay rate of a TLS in front of a mirror

    The multifunctional roles of vegetated strips around and within agricultural fields : A systematic map protocol.

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    Background: Agriculture and agricultural intensification can have significant negative impacts on the environment, including nutrient and pesticide leaching, spreading of pathogens, soil erosion and reduction of ecosystem services provided by terrestrial and aquatic biodiversity. The establishment and management of vegetated strips adjacent to farmed fields (including various field margins, buffer strips and hedgerows) are key mitigation measures for these negative environmental impacts and environmental managers and other stakeholders must often make decisions about how best to design and implement vegetated strips for a variety of different outcomes. However, it may be difficult to obtain relevant, accurate and summarised information on the effects of implementation and management of vegetated strips, even though a vast body of evidence exists on multipurpose vegetated strip interventions within and around fields. To improve the situation, we describe a method for assembling a database of relevant research relating to vegetated strips undertaken in boreo-temperate farming systems (arable, pasture, horticulture, orchards and viticulture). Methods: We will search 13 bibliographic databases, 1 search engine and 37 websites for stakeholder organisations using a predefined and tested search string that focuses on a comprehensive list of vegetated strip synonyms. Non-English language searches in Danish, Finnish, German, Spanish, and Swedish will also be undertaken using a web-based search engine. We will screen search results at title, abstract and full text levels, recording the number of studies deemed non-relevant (with reasons at full text). A systematic map database that displays the meta-data (i.e. descriptive summary information about settings and methods) of relevant studies will be produced following full text assessment. The systematic map database will be displayed as a web-based geographical information system (GIS). The nature and extent of the evidence base will be discussed

    Guidelines (1988) for training in clinical laboratory management

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    Trainees in laboratory medicine must develop skills in laboratory management. Guidelines are detailed for laboratory staff in training, directors responsible for staff development and professional bodies wishing to generate material appropriate to their needs. The syllabus delineates the knowledge base required and includes laboratory planning and organization, control of operations, methodology and instrumentation, data management and statistics, financial management, clinical use of tests, communication, personnel management and training and research and development. Methods for achievement of the skills required are suggested. A bibliography of IFCC publications and other material is provided to assist in training in laboratory management

    Simple elbow dislocations: a systematic review of the literature

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    Objective: To identify if functional treatment is the best available treatment for simple elbow dislocations. Search strategy: Electronic databases MEDLINE, EMBASE, LILACS, and the Cochrane Central Register of Controlled Trials. Selection criteria: Studies were eligible for inclusion if they were trials comparing different techniques for the treatment of simple elbow dislocations. Data analysis: Results were expressed as relative risk for dichotomous outcomes and weighted mean difference for continuous outcomes with 95% confidence intervals. Main results: This review has included data from two trials and three observational comparative studies. Important data were missing from three observational comparative studies and the results from these studies were extracted for this review. No difference was found between surgical treatment of the collateral ligaments and plaster immobilisation of the elbow joint. Better range of movement, less pain, better functional scores, shorter disability and shorter treatment time were seen after functional treatment versus plaster immobilisation

    Modeling of negative Poisson’s ratio (auxetic) crystalline cellulose Iβ

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    Energy minimizations for unstretched and stretched cellulose models using an all-atom empirical force field (Molecular Mechanics) have been performed to investigate the mechanism for auxetic (negative Poisson’s ratio) response in crystalline cellulose Iβ from kraft cooked Norway spruce. An initial investigation to identify an appropriate force field led to a study of the structure and elastic constants from models employing the CVFF force field. Negative values of on-axis Poisson’s ratios nu31 and nu13 in the x1-x3 plane containing the chain direction (x3) were realized in energy minimizations employing a stress perpendicular to the hydrogen-bonded cellobiose sheets to simulate swelling in this direction due to the kraft cooking process. Energy minimizations of structural evolution due to stretching along the x3 chain direction of the ‘swollen’ (kraft cooked) model identified chain rotation about the chain axis combined with inextensible secondary bonds as the most likely mechanism for auxetic response

    What is the value of orthodontic treatment?

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    Orthodontic treatment is as popular as ever. Orthodontists frequently have long lists of people wanting treatment and the cost to the NHS in England was £258m in 2010-2011 (approximately 10% of the NHS annual spend on dentistry). It is important that clinicians and healthcare commissioners constantly question the contribution of interventions towards improving the health of the population. In this article, the authors outline some of the evidence for and against the claims that people with a malocclusion are at a disadvantage compared with those without a malocclusion and that orthodontic treatment has significant health benefits. The authors would like to point out that this is not a comprehensive and systematic review of the entire scientific literature. Rather the evidence is presented in order to stimulate discussion and debate

    Towards phonon routing: controlling propagating acoustic waves in the quantum regime

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    We explore routing of propagating phonons in analogy with previous experiments on photons. Surface acoustic waves (SAWs) in the microwave regime are scattered by a superconducting transmon qubit. The transmon can be tuned on or off resonance with the incident SAW field using an external magnetic field or the Autler-Townes effect, and thus the reflection and transmission of the SAW field can be controlled in time. We observe 80% extinction in the transmission of the low power continuous signal and a 40 ns rise time of the router. The slow propagation speed of SAWs on solid surfaces allows for in-flight manipulations of the propagating phonons. The ability to route short, 100 ns, pulses enables new functionality, for instance to catch an acoustic phonon between two qubits and then release it in a controlled direction

    Waveguide-Fed Slot Antennas and Arrays: A Review

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    Conceived in the forties, slot array antennas have reached a state of maturity. However, there are still many problems addressed in the current literature. This paper presents an overview of the significant publications on waveguide-fed slot antennas and arrays.Electromagnetics 19(1), 3-22. (1999)1532-527
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