29,072 research outputs found

    State estimation from pair of conjugate qudits

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    We show that, for NN parallel input states, an anti-linear map with respect to a specific basis is essentially a classical operator. We also consider the information contained in phase-conjugate pairs ∣ϕ>∣ϕ∗>|\phi > |\phi^*>, and prove that there is more information about a quantum state encoded in phase-conjugate pairs than in parallel pairs.Comment: 4 pages, 1 tabl

    Structural and electronic properties of the metal-metal intramolecular junctions of single-walled carbon nanotubes

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    Several intramolecular junctions (IMJs) connecting two metallic (11, 8) and (9, 6) carbon nanotubes along their common axis have been realized by using a layer-divided technique to the nanotubes and introducing the topological defects. Atomic structure of each IMJ configuration is optimized with a combination of density-functional theory (DFT) and the universal force field (UFF) method, based upon which a four-orbital tight-binding calculation is made on its electronic properties. Different topological defect structures and their distributions on the IMJ interfaces have been found, showing decisive effects on the localized density of states, while the sigma-pi coupling effect is negligible near Fermi energy (EF). Finally, a new IMJ model has been proposed, which probably reflects a real atomic structure of the M-M IMJ observed in the experiment [Science 291, 97 (2001)].Comment: 11 pages and 3 figure

    Crucial Dependence of ``Precarious'' and ``Autonomous'' phi^4s Upon the Normal-ordering Mass

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    Using the Gaussian wave-functional approach with the normal-ordering renormalization prescription, we show that for the (3+1)-dimensional massive lambda phi^4 theory, ``precarious'' and ``autonomous'' phi^4s can exist if and only if the normal-ordering mass is equal to the classical masses at the symmetrc and asymmetric vacua, respectively.Comment: 6 pages, no figures, Revtex file, accepted for publication in Mod. Phys. Lett.

    Physical accessible transformations on a finite number of quantum states

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    We consider to treat the usual probabilistic cloning, state separation, unambiguous state discrimination, \emph{etc} in a uniform framework. All these transformations can be regarded as special examples of generalized completely positive trace non-increasing maps on a finite number of input states. From the system-ancilla model we construct the corresponding unitary implementation of pure →\to pure, pure →\to mixed, mixed →\to pure, and mixed →\to mixed states transformations in the whole system and obtain the necessary and sufficient conditions on the existence of the desired maps. We expect our work will be helpful to explore what we can do on a finite set of input states.Comment: 7 page

    S-duality and 2d Topological QFT

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    We study the superconformal index for the class of N=2 4d superconformal field theories recently introduced by Gaiotto. These theories are defined by compactifying the (2,0) 6d theory on a Riemann surface with punctures. We interpret the index of the 4d theory associated to an n-punctured Riemann surface as the n-point correlation function of a 2d topological QFT living on the surface. Invariance of the index under generalized S-duality transformations (the mapping class group of the Riemann surface) translates into associativity of the operator algebra of the 2d TQFT. In the A_1 case, for which the 4d SCFTs have a Lagrangian realization, the structure constants and metric of the 2d TQFT can be calculated explicitly in terms of elliptic gamma functions. Associativity then holds thanks to a remarkable symmetry of an elliptic hypergeometric beta integral, proved very recently by van de Bult.Comment: 25 pages, 11 figure

    Sleep and psychological factors are associated with meeting discharge criteria to return to sport following ACL reconstruction in athletes

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    INTRODUCTION: This study aimed to determine if sleep quality and psychological factors were associated with time to meet the discharge criteria to return to sport (RTS) following anterior cruciate ligament reconstruction (ACL-R) among athletes experiencing better quality of sleep and psychological responses returning faster to full activity. METHOD: A cohort-study design included 89 athletes following ACL-R. Each participant completed a battery of questionnaires at 6 different time points: within 3 days of injury occurrence and at post-surgery (1.5m, 3m, 4.5m, 6m and when discharge criteria were met). Assessment included sleep quality and quantity, symptoms of depression, anxiety, stress, psychological readiness to RTS and fear of re-injury. The primary outcome was the time needed to meet all discharge criteria to RTS. RESULTS: Sleep parameters and psychological factors were not associated with time to meet the discharge criteria to RTS. However, athletes that had low anxiety and insomnia scores at baseline and better sleep quality at 3m, 4.5m, 6m and at discharge were more adherent to the rehabilitation program and more likely to meet the RTS discharge criteria OR 1.2 (95% CI 1.0-1.34), 1.3 (95% CI 1.1, 1.7) and 2.0 (95% CI 1.1-3.4) respectively. CONCLUSIONS: Sleep quality and psychological factors were not associated with time to meet the discharge criteria to RTS but impacted whether athletes adhered and completed their rehabilitation program or not. Monitoring sleep quality and psychological factors of athletes before and following ACL-R surgery is important to identify athletes who could have difficulties in adhering to and completing their rehabilitation program to RTS

    Manifestly Supersymmetric RG Flows

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    Renormalisation group (RG) equations in two-dimensional N=1 supersymmetric field theories with boundary are studied. It is explained how a manifestly N=1 supersymmetric scheme can be chosen, and within this scheme the RG equations are determined to next-to-leading order. We also use these results to revisit the question of how brane obstructions and lines of marginal stability appear from a world-sheet perspective.Comment: 22 pages; references added, minor change

    Design and delivery of a national pilot survey of capabilities

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    Understanding the numbers of people with different levels of ability in the population is important for informing design decisions for mainstream products, but a survey dataset for this purpose does not exist. This paper describes a key step towards obtaining such data. It describes a pilot survey of 362 people across England and Wales in preparation for a full national survey. Information was gathered on vision, hearing, hand and arm function, mobility, cognitive function, product use, psychological characteristics, anthropometrics and demographics. An interesting finding is that of those participants who reported any limitations in daily activities due to capability loss, 44% reported limitations due to loss of more than one capability. This finding highlights the importance of measuring multiple capabilities in a single survey. Top-level lessons learnt include: simplifying vision tests; reducing exclusion criteria for some of the tests; adopting a stratified sampling approach; and allocating more training for interviewers.This research was funded by the Engineering and Physical Sciences Research Council grant (Award Number: RG45089).This is the accepted version of the article. The final version is available fro Inderscience at http://inderscience.metapress.com/content/fk41618325n25741/

    Next-to-leading order QCD corrections to electroweak Zjj production in the POWHEGBOX

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    We present an implementation of electroweak Z-boson production in association with two jets at hadron colliders in the POWHEG framework, a method that allows the interfacing of NLO-QCD calculations with parton-shower Monte Carlo programs. We focus on the leptonic decays of the weak gauge boson, and take photonic and non-resonant contributions to the matrix elements fully into account. We provide results for observables of particular importance for the suppression of QCD backgrounds to vector-boson fusion processes by means of central-jet-veto techniques. While parton-shower effects are small for most observables associated with the two hardest jets, they can be more pronounced for distributions that are employed in central-jet-veto studies.Comment: 12 pages, 5 figure

    Oral health behind the bars: oral health seeking behavior among jail prisoners at central jail of Peshawar, Pakistan: a cross-sectional study

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    Background: The oral health care-seeking behavior among prison inmates is an overlooked area, often leading to deteriorating general health due to the prisoners’ limited awareness of oral hygiene practices. It is crucial to address this issue and understand the factors associated with oral healthcare-seeking behavior in prisons. Objective: To assess the oral healthcare-seeking behavior of prison inmates at Central Prisoner Jail, Peshawar Pakistan and to look the factors associated with their dental care utilization. Material and Methods: This cross-sectional study was conducted at Central Prisoner Jail, Peshawar Khyber Pakhtunkhwa, Pakistan from November 2021 to April 2022. A consecutive sampling technique was used to collect data from both convicted and under-trial prisoners by using a pre-tested WHO Basic Oral Health Survey 2013 tool. Our outcome variable was “Visit to a dentist in the last 12 months (Never/Once or more than one visit). Chi-square test was used to determine univariate association with other explanatory variables while multivariable logistic regression was performed to adjust for potential confounders. Result: A total of 225 participants were recruited to the study with a mean (SD) age of 32.9(11.4). More than two-thirds of 200(88.9%) of the participants were males. One-third of the sample never visited the dentist75(33.3). Participants who completed college/university education and never visited the dentist in the last 12 months constituted a smaller proportion (17.6%) compared to those who visited the dentist once or more than once n = 28(82.4%, p-value = 0.003). Individuals who were using toothbrushes were most frequently visiting the dentist n = 130(72.6%=p value = 0.001) as compared to never visitors. Multivariate logistic regression analysis revealed that Participants who experienced teeth pain or discomfort had 0.42 times lower odds of visiting the dentist compared to those who did not experience any pain or discomfort [AOR 0.42 (95% CI 0.17–0.80), p = 0.04]. Similarly, Participants who do not use any denture have 4.06 times higher odds[AOR 4.06(95% CI 1.76–9.36), p = 0.001] of visiting the dentist compared to those who use a denture. Conclusion: Our result demonstrates that those prisoners who were experiencing tooth pain or discomfort and not using dentures were the strong predictors with lower dental visit frequency to seek oral health care
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