1,710 research outputs found
Coherent rotations of a single spin-based qubit in a single quantum dot at fixed Zeeman energy
Coherent rotations of single spin-based qubits may be accomplished
electrically at fixed Zeeman energy with a qubit defined solely within a single
electrostatically-defined quantum dot; the -factor and the external magnetic
field are kept constant. All that is required to be varied are the voltages on
metallic gates which effectively change the shape of the elliptic quantum dot.
The pseudospin-1/2 qubit is constructed from the two-dimensional ,
subspace of three interacting electrons in a two-dimensional
potential well. Rotations are created by altering the direction of the
pseudomagnetic field through changes in the shape of the confinement potential.
By deriving an exact analytic solution to the long-range Coulomb interaction
matrix elements, we calculate explicitly the range of magnitudes and directions
the pseudomagnetic field can take. Numerical estimates are given for {GaAs}.Comment: Restructured manuscript, more details shown (results unchanged); Six
pages, revtex4; More info at http://soliton.phys.dal.c
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Enhancing care for older people living in nursing homes in rural Australia using action learning as a catalyst for change
The implementation of action learning workshops in three nursing homes in rural Victoria, Australia has been critical in the re-visioning of how care can be enhanced for residents. The workshops were designed with the intent of improving quality of care for residents by providing health care staff with opportunities to learn together and effect cultural change. Valuing what was accomplished well in these nursing homes was the starting point. The project was funded by a Commonwealth Government Rural Education Grant and was based on ‘My Home Life’ a popular programme that promotes quality of life and delivers positive change in care homes for older people across the United Kingdom. This paper provides an account of the project including key components of the action learning workshops and subsequent evaluation of the programme conducted in Australia. The lessons learnt throughout this project have provided the impetus to continue using appreciative inquiry and action learning to involve participants in reflecting on their practice, valuing what they do well while identifying areas that require change. Working together in a safe and respectful space provides participants with opportunity to harness their own collective wisdom and as the health professionals in this project experienced, also learn valuable skills that support progressive action that makes a difference to older people’s lives
The waiting time paradox: population based retrospective study of treatment delay and survival of women with endometrial cancer in Scotland
No abstract available
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Home-prepared food, dietary quality and socio-demographic factors: a cross-sectional analysis of the UK National Diet and nutrition survey 2008–16
Abstract: Background: Evidence suggests eating home-prepared food (HPF) is associated with increased dietary quality, while dietary quality varies across socio-demographic factors. Although it has been hypothesised that variation in HPF consumption between population sub-groups may contribute to variation in dietary quality, evidence is inconclusive. This study takes a novel approach to quantifying home-prepared food (HPF) consumption, and describes HPF consumption in a population-representative sample, determining variation between socio-demographic groups. It tests the association between HPF consumption and dietary quality, determining whether socio-demographic characteristics moderate this association. Methods: Cross-sectional analysis of UK survey data (N = 6364, aged≥19; collected 2008–16, analysed 2018). High dietary quality was defined as ‘DASH accordance’: the quintile most accordant with the Dietary Approaches to Stopping Hypertension (DASH) diet. HPF consumption was estimated from 4-day food diaries. Linear regressions were used to determine the association between HPF consumption and socio-demographic variables (household income, education, occupation, age, gender, ethnicity and children in the household). Logistic regression was used to determine the association between HPF consumption and DASH accordance. Interaction terms were introduced, testing for moderation of the association between HPF consumption and DASH accordance by socio-demographic variables. Results: HPF consumption was relatively low across the sample (Mean (SD) % of energy consumption = 26.5%(12.1%)), and lower among white participants (25.9% v 37.8 and 34.4% for black and Asian participants respectively, p < 0.01). It did not vary substantially by age, gender, education, income or occupation. Higher consumption of HPF was associated with greater odds of being in the most DASH accordant quintile (OR = 1.2 per 10% increase in % energy from HPF, 95% CI 1.1–1.3). Ethnicity was the only significant moderator of the association between HPF consumption and DASH accordance, but this should be interpreted with caution due to high proportion of white participants. Conclusions: While an association exists between HPF consumption and higher dietary quality, consumption of HPF or HPF’s association with dietary quality does not vary substantially between socio-demographic groups. While HPF may be a part of the puzzle, it appears other factors drive socio-demographic variation in dietary quality
Engineering Cell–ECM–Material Interactions for Musculoskeletal Regeneration
The extracellular microenvironment regulates many of the mechanical and biochemical cues that direct musculoskeletal development and are involved in musculoskeletal disease. The extracellular matrix (ECM) is a main component of this microenvironment. Tissue engineered approaches towards regenerating muscle, cartilage, tendon, and bone target the ECM because it supplies critical signals for regenerating musculoskeletal tissues. Engineered ECM–material scaffolds that mimic key mechanical and biochemical components of the ECM are of particular interest in musculoskeletal tissue engineering. Such materials are biocompatible, can be fabricated to have desirable mechanical and biochemical properties, and can be further chemically or genetically modified to support cell differentiation or halt degenerative disease progression. In this review, we survey how engineered approaches using natural and ECM-derived materials and scaffold systems can harness the unique characteristics of the ECM to support musculoskeletal tissue regeneration, with a focus on skeletal muscle, cartilage, tendon, and bone. We summarize the strengths of current approaches and look towards a future of materials and culture systems with engineered and highly tailored cell–ECM–material interactions to drive musculoskeletal tissue restoration. The works highlighted in this review strongly support the continued exploration of ECM and other engineered materials as tools to control cell fate and make large-scale musculoskeletal regeneration a reality
How many species of fossil arachnids are there?
The species-level diversity of fossil Chelicerata is summarized for each order. 1952 valid species of fossil\ud
chelicerates are currently recognized, of which 1593 are arachnids. In order of abundance they are: Araneae (979 fossil\ud
species), Actinotrichida (283), Eurypterida (241), Scorpiones (111), Xiphosura (96), Trigonotarbida (71), Pseudoscorpiones\ud
(38), Phalangiotarbida (30), Opiliones (25), Ricinulei (15), and Anactinotrichida (11). Other groups are represented by ten\ud
fossil species or fewer. Based on published descriptions, spiders thus appear to dominate the fossil arachnid species\ud
assemblage, making up a greater proportion of paleodiversity than their Recent diversity would predict. Scorpions are also\ud
overrepresented, particularly in the Paleozoic, compared to their modern diversity. By contrast, groups like mites,\ud
harvestmen, pseudoscorpions and solifuges are noticeably under-represented as fossils when compared to modern patterns\ud
of diversity
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How Does Time Use Differ between Individuals Who Do More versus Less Foodwork? A Compositional Data Analysis of Time Use in the United Kingdom Time Use Survey 2014–2015
Background: Increased time spent on home food preparation is associated with higher diet quality, but a lack of time is often reported as a barrier to this practice. We compared time use in individuals who do more versus less foodwork (tasks required to feed ourselves and our households, including home food preparation). Methods: Cross-sectional analysis of the UK Time Use Survey 2014−15, participants aged 16+ (N = 6143). Time use over 24 h was attributed to seven compositional parts: personal care; sleep; eating; physical activity; leisure screen time; work (paid and unpaid); and socialising and hobbies. Participants were categorised as doing no, ‘some’ (70 min), or ‘more’ foodwork (≥70 min). We used compositional data analysis to test whether time-use composition varied between these participant groups, determine which of the parts varied between groups, and test for differences across population subgroups. Results: Participants who spent more time on foodwork spent less time on sleep, eating, and personal care and more time on work. Women who did more foodwork spent less time on personal care, socialising, and hobbies, which was not the case for men. Conclusion: Those who seek to encourage home food preparation should be aware of the associations between foodwork and other activities and design their interventions to guard against unintended consequences
Study of resonance light scattering for remote optical probing
Enhanced scattering and fluorescence processes in the visible and UV were investigated which will enable improved remote measurements of gas properties. The theoretical relationship between scattering and fluorescence from an isolated molecule in the approach to resonance is examined through analysis of the time dependence of re-emitted light following excitation of pulsed incident light. Quantitative estimates are developed for the relative and absolute intensities of fluorescence and resonance scattering. New results are obtained for depolarization of scattering excited by light at wavelengths within a dissociative continuum. The experimental work was performed in two separate facilities. One of these utilizes argon and krypton lasers, single moded by a tilted etalon, and a 3/4 meter double monochromator. This facility was used to determine properties of the re-emission from NO2, I2 and O3 excited by visible light. The second facility involves a narrow-line dye laser, and a 3/4 meter single monochromator. The dye laser produces pulsed light with 5 nsec pulse duration and 0.005 nm spectral width
Targeting Policy for Obesity Prevention: Identifying the Critical Age for Weight Gain in Women
The obesity epidemic requires the development of prevention policy targeting individuals most likely to benefit. We used self-reported prepregnancy body weight of all women giving birth in Nova Scotia between 1988 and 2006 to define obesity and evaluated socioeconomic, demographic, and temporal trends in obesity using linear regression. There were 172,373 deliveries in this cohort of 110,743 women. Maternal body weight increased significantly by 0.5 kg per year from 1988, and lower income and rural residence were both associated significantly with increasing obesity. We estimated an additional 82,000 overweight or obese women in Nova Scotia in 2010, compared to the number that would be expected from obesity rates of just two decades ago. The critical age for weight gain was identified as being between 20 and 24 years. This age group is an important transition age between adolescence and adulthood when individuals first begin to accept responsibility for food planning, purchasing, and preparation. Policy and public health interventions must target those most at risk, namely, younger women and the socially deprived, whilst tackling the marketing of low-cost energy-dense foods at the expense of healthier options
Cluster derivation of Parisi's RSB solution for disordered systems
We propose a general scheme in which disordered systems are allowed to
sacrifice energy equi-partitioning and separate into a hierarchy of ergodic
sub-systems (clusters) with different characteristic time-scales and
temperatures. The details of the break-up follow from the requirement of
stationarity of the entropy of the slower cluster, at every level in the
hierarchy. We apply our ideas to the Sherrington-Kirkpatrick model, and show
how the Parisi solution can be {\it derived} quantitatively from plausible
physical principles. Our approach gives new insight into the physics behind
Parisi's solution and its relations with other theories, numerical experiments,
and short range models.Comment: 7 pages 5 figure
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