211 research outputs found
Observation of a red-blue detuning asymmetry in matter-wave superradiance
We report the first experimental observations of strong suppression of
matter-wave superradiance using blue-detuned pump light and demonstrate a
pump-laser detuning asymmetry in the collective atomic recoil motion. In
contrast to all previous theoretical frameworks, which predict that the process
should be symmetric with respect to the sign of the pump-laser detuning, we
find that for condensates the symmetry is broken. With high condensate
densities and red-detuned light, the familiar distinctive multi-order,
matter-wave scattering pattern is clearly visible, whereas with blue-detuned
light superradiance is strongly suppressed. In the limit of a dilute atomic
gas, however, symmetry is restored.Comment: Accepted by Phys. Rev. Let
Quantum Computation with Coherent Spin States and the Close Hadamard Problem
We study a model of quantum computation based on the
continuously-parameterized yet finite-dimensional Hilbert space of a spin
system. We explore the computational powers of this model by analyzing a pilot
problem we refer to as the close Hadamard problem. We prove that the close
Hadamard problem can be solved in the spin system model with arbitrarily small
error probability in a constant number of oracle queries. We conclude that this
model of quantum computation is suitable for solving certain types of problems.
The model is effective for problems where symmetries between the structure of
the information associated with the problem and the structure of the unitary
operators employed in the quantum algorithm can be exploited.Comment: RevTeX4, 13 pages with 8 figures. Accepted for publication in Quantum
Information Processing. Article number: s11128-015-1229-
Quantitative trait loci for sensitivity to ethanol intoxication in a C57BL/6J × 129S1/SvImJ inbred mouse cross
Individual variation in sensitivity to acute ethanol (EtOH) challenge is associated with alcohol drinking and is a predictor of alcohol abuse. Previous studies have shown that the C57BL/6J (B6) and 129S1/SvImJ (S1) inbred mouse strains differ in responses on certain measures of acute EtOH intoxication. To gain insight into genetic factors contributing to these differences, we performed quantitative trait locus (QTL) analysis of measures of EtOH-induced ataxia (accelerating rotarod), hypothermia, and loss of righting reflex (LORR) duration in a B6 × S1 F2 population. We confirmed that S1 showed greater EtOH-induced hypothermia (specifically at a high dose) and longer LORR compared to B6. QTL analysis revealed several additive and interacting loci for various phenotypes, as well as examples of genotype interactions with sex. QTLs for different EtOH phenotypes were largely non-overlapping, suggesting separable genetic influences on these behaviors. The most compelling main-effect QTLs were for hypothermia on chromosome 16 and for LORR on chromosomes 4 and 6. Several QTLs overlapped with loci repeatedly linked to EtOH drinking in previous mouse studies. The architecture of the traits we examined was complex but clearly amenable to dissection in future studies. Using integrative genomics strategies, plausible functional and positional candidates may be found. Uncovering candidate genes associated with variation in these phenotypes in this population could ultimately shed light on genetic factors underlying sensitivity to EtOH intoxication and risk for alcoholism in humans
Innocent parties or devious drug users: the views of primary healthcare practitioners with respect to those who misuse prescription drugs
<p>Abstract</p> <p>Background</p> <p>Many health professionals engage in providing health services for drug users; however, there is evidence of stigmatisation by some health professionals. Prescription drug misusers as a specific group, may also be subject to such judgment. This study aimed to understand issues for primary care health practitioners in relation to prescription drug misuse (PDM), by exploring the attitudes and experiences of healthcare professionals with respect to PDM.</p> <p>Methods</p> <p>Tape-recorded interviews were conducted with a purposive sample of general practitioners (17), community pharmacists (16) and 'key experts' (18) in New Zealand. Interviews were transcribed verbatim and a thematic analysis undertaken. Participants were offered vouchers to the value of NZ$30 for their participation.</p> <p>Results</p> <p>A major theme that was identified was that of two different types of patients involved in PDM, as described by participants - the 'abuser' and the 'overuser'. The 'abuser' was believed to acquire prescription medicines through deception for their own use or for selling on to the illicit market, to use the drugs recreationally, for a 'high' or to stave off withdrawal from illicit drugs. 'Overusers' were characterised as having become 'addicted' through inadvertent overuse and over prescribing, and were generally viewed more sympathetically by practitioners. It also emerged that practitioners' attitudes may have impacted on whether any harm reduction interventions might be offered. Furthermore, whilst practitioners might be more willing to offer help to the 'over-user', it seemed that there is a lack of appropriate services for this group, who may also lack a peer support network.</p> <p>Conclusions</p> <p>A binary view of PDM may not be helpful in understanding the issues surrounding PDM, nor in providing appropriate interventions. There is a need for further exploration of 'over users’ whose needs may not be being met by mainstream drug services, and issues of stigma in relation to ‘abusers’.</p
Quality of life: international and domestic students studying medicine in New Zealand
International students form a significant proportion of students studying within universities in Western countries. The quality of life perceptions of international medical students in comparison with domestic medical students has not been well documented. There is some evidence to suggest that international medical students may have different educational and social experiences in relation to their domestic peers. This study investigates the levels of quality of life experienced by international and domestic students studying medicine. A total of 548 medical students completed the abbreviated version of the World Health Organization Quality of Life questionnaire. The focus of the analysis was to evaluate differences between international and domestic students in their early clinical years. The responses were analysed using multivariate analysis of variance methods. International medical students are experiencing lower social and environmental quality of life compared with domestic peers. International medical students in New Zealand have expressed quality of life concerns, which likely have an impact on their academic achievement, feelings of wellness, acculturation, and social adaptation. The findings reinforce the need for creating stronger social networks and accessible accommodation, as well as developing systems to ensure safety, peer mentorship and student support.published_or_final_versio
Gordon Valentine Manley and his contribution to the study of climate change: a review of his life and work
British climatologist and geographer, Gordon Manley (1902–1980), is perhaps best known for his pioneering work on climate variability in the UK, for establishing the Central England Temperature series and, for his pivotal role in demonstrating the powerful relationship between climate, weather, and culture in post-World War II Britain. Yet Manley made many contributions, both professional and popular, to climate change debates in the twentieth century, where climate change is broadly understood to be changes over a range of temporal and spatial scales rather than anthropogenic warming per se. This review first establishes how Manley's work, including that on snow and ice, was influenced by key figures in debates over climatic amelioration around the North Atlantic between 1920s and 1950s. His research exploring historical climate variability in the UK using documentary sources is then discussed. His perspectives on the relationship between climate changes and cultural history are reviewed, paying particular attention to his interpretation of this relationship as it played out in the UK. Throughout, the review aims to show Manley to be a fieldworker and an empiricist and reveals how he remained committed to rigorous scientific investigation despite changing trends within his academic discipline
Duloxetine versus placebo for the treatment of women with stress predominant urinary incontinence in Taiwan: a double-blind, randomized, placebo-controlled trial
Measuring implementation behaviour of menu guidelines in the childcare setting: confirmatory factor analysis of a theoretical domains framework questionnaire (TDFQ)
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