4,718 research outputs found

    Commensurability oscillations due to pinned and drifting orbits in a two-dimensional lateral surface superlattice

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    We have simulated conduction in a two-dimensional electron gas subject to a weak two-dimensional periodic potential, Vxcos⁥(2πx/a)+Vycos⁥(2πy/a)V_x \cos(2\pi x/a) + V_y \cos(2\pi y/a). The usual commensurability oscillations in ρxx(B)\rho_{xx}(B) are seen with VxV_x alone. An increase of VyV_y suppresses these oscillations, rather than introducing the additional oscillations in ρyy(B)\rho_{yy}(B) expected from previous perturbation theories. We show that this behavior arises from drift of the guiding center of cyclotron motion along contours of an effective potential. Periodic modulation in the magnetic field can be treated in the same way.Comment: 3 pages text, 4 eps figures, revte

    Estimated local economic impacts of BLM land use change on the oil and gas industry: the Little Snake resource area management plan

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    April 2007.PDF masthead has later name: Colorado State University Extension.Includes bibliographical references

    Serum osmolarity and haematocrit do not modify the association between the impedance index (Ht2/Z) and total body water in the very old: The Newcastle 85+ Study

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    Bioelectrical impedance is a non-invasive technique for the assessment of body composition; however, information on its accuracy in the very old (80+ years) is limited. We investigated whether the association between the impedance index and total body water (TBW) was modified by hydration status as assessed by haematocrit and serum osmolarity. This was a cross-sectional analysis of baseline data from the Newcastle 85+ Cohort Study. Anthropometric measurements [weight, height (Ht)] were taken and body mass index (BMI) calculated. Leg-to-leg bioimpedance was used to measure the impedance value (Z) and to estimate fat mass, fat free mass and TBW. The impedance index (Ht2/Z) was calculated. Blood haematocrit, haemoglobin, glucose, sodium, potassium, urea and creatinine concentrations were measured. Serum osmolarity was calculated using a validated prediction equation. 677 men and women aged 85 years were included. The average BMI of the population was 24.3±4.2kg/m2 and the prevalence of overweight and obesity was 32.6% and 9.5%, respectively. The impedance index was significantly associated with TBW in both men (n=274, r=0.76, p<0.001) and women (n=403, r=0.96, p<0.001); in regression models, the impedance index remained associated with TBW after adjustment for height, weight and gender, and further adjustment for serum osmolarity and haematocrit. The impedance index values increased with BMI and the relationship was not modified by hydration status in women (p=0.69) and only marginally in men (p=0.02). The association between the impedance index and TBW was not modified by hydration status, which may support the utilisation of leg-to-leg bioimpedance for the assessment of body composition in the very old

    Exploring the Global Health and Defence Engagement Interface

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    Militaries have an important and inevitable role in global health and will interface with existing health systems on deployments. Whilst the primary concern of militaries is not global health, there are clear, and increasingly frequent, circumstances when global health activities align with the interests of defence. Recognising this link between global health and security warrants thoughtful consideration and action where concerns affecting both intersect. In addition to providing medical support to military personnel on operations, advantageous effects can be achieved directly from military medical activities as part of Defence Engagement. Whilst there are limitations and ethical boundaries to the role of militaries in global health, further training, research and conceptual development are warranted to optimise military medical activity at the intersection of security and global health to deliver advantageous effects. This paper forms part of a special issue of BMJ Military Health dedicated to Defence Engagement

    Predicting the spatial expansion of an animal population with presence-only data

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    Abstract Predictive models can improve the efficiency of wildlife management by guiding actions at the local, landscape and regional scales. In recent decades, a vast range of modelling techniques have been developed to predict species distributions and patterns of population spread. However, data limitations often constrain the precision and biological realism of models, which make them less useful for supporting decision‐making. Complex models can also be challenging to evaluate, and the results are often difficult to interpret for wildlife management practitioners. There is therefore a need to develop techniques that are appropriately robust, but also accessible to a range of end users. We developed a hybrid species distribution model that utilises commonly available presence‐only distribution data and minimal demographic information to predict the spread of roe deer (Capreolus caprelous) in Great Britain. We take a novel approach to representing the environment in the model by constraining the size of habitat patches to the home‐range area of an individual. Population dynamics are then simplified to a set of generic rules describing patch occupancy. The model is constructed and evaluated using data from a populated region (England and Scotland) and applied to predict regional‐scale patterns of spread in a novel region (Wales). It is used to forecast the relative timing of colonisation events and identify important areas for targeted surveillance and management. The study demonstrates the utility of presence‐only data for predicting the spread of animal species and describes a method of reducing model complexity while retaining important environmental detail and biological realism. Our modelling approach provides a much‐needed opportunity for users without specialist expertise in computer coding to leverage limited data and make robust, easily interpretable predictions of spread to inform proactive population management

    Robustness of adiabatic quantum computation

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    We study the fault tolerance of quantum computation by adiabatic evolution, a quantum algorithm for solving various combinatorial search problems. We describe an inherent robustness of adiabatic computation against two kinds of errors, unitary control errors and decoherence, and we study this robustness using numerical simulations of the algorithm.Comment: 11 pages, 5 figures, REVTe

    Protocol for a randomized controlled trial of the Breaking Free Online Health and Justice program for substance misuse in prison settings

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    Background Substance misuse, including problematic drug and alcohol use, are significant issues in society that can have multiple detrimental effects. Many people access support for their substance misuse during prison sentences, due to the associations between substance misuse and offending, and the high proportion of the prison population who have drug and alcohol issues. Breaking Free Online Health and Justice is a computer-assisted therapy program that has been developed to support substance-involved offenders to address their substance misuse and associated offending within prison settings. Methods This will be a parallel-group randomized controlled trial of 4-week Breaking Free Online Health and Justice program as an adjunct to standard treatment for substance misuse, in comparison to standard treatment only, in a male Category D open prison. Interventional and control groups will be compared in terms of the changes in their scores on multiple measures from baseline to post-treatment assessment at 4-weeks, and then 3- and 6-months follow-up. Participants will be adult male offenders serving sentences in prison in England who have demonstrable difficulties with drugs and/or alcohol for at least the past 12-months. The primary outcome measure will be self-reported substance misuse, with secondary outcomes being standardized psychometric assessments of substance dependence, mental health, biopsychosocial functioning, quality of life and post-release offending. Other secondary measures will include frequency of completion of specific intervention strategies in the program. Discussion This study will examine whether Breaking Free Online Health and Justice as an adjunct to standard substance misuse interventions in prisons, improves outcomes for substance-involved offenders receiving interventions in custodial settings. Findings from the study will be used to inform further developments of the program and potential improvements to custodial treatment

    LibertĂ  ed equitĂ  nei processi di scelta. Il capability approach nell'orientamento

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    I processi di scelta che indirizzano la vita di un individuo, quelli che orientano i suoi percorsi formativi e professionali, determinano la qualità del suo benessere personale, del suo star bene esistenziale. Il raggiungimento e il perseguimento di questo star bene, e la valorizzazione della qualità della vita per lo sviluppo umano, sono al centro delle riflessioni del capability approach di Amartya Sen. Nell'articolo si presentano i concetti fondamentali per i processi di scelta: - Functionings come stati “di essere e di fare” (being e doing) costitutivi dell'esistenza personale; - Capability come libertà / opportunità di una persona di acquisire i funzionamenti che reputa rilevanti per la propria esistenza; - Well-being (star-bene) come benessere soggettivo dato dai funzionamenti acquisiti; - Agency (agentività) come possibilità e abilità d’azione della persona nel voler raggiungere qualunque cosa essa decida, in quanto agente responsabile

    Reviews and contestability: new directions for Defence

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    Overview: The First Principles Review of Defence is arguably the most significant review of the defence establishment since the 1973 re-organisation led by Sir Arthur Tange. This Strategic Insights brings together a series of contributions to ASPI’s blog The Strategist written by ten experts with long experience and broad knowledge of Australia’s defence bureaucracy. They bring a wealth of different perspectives and point to significant challenges ahead for Defence if the reforms proposed by the First Principles Review are to succeed
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