524 research outputs found

    q-deformed dynamics and Josephson junction

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    We define a generalized rate equation for an observable in quantum mechanics, that involves a parameter q and whose limit q→1q\to 1 gives the standard Heisenberg equation. The generalized rate equation is used to study dynamics of current biased Josephson junction. It is observed that this toy model incorporates diffraction like effects in the critical current. Physical interpretation for q is provided which is also shown to be q-deformation parameter.Comment: LaTeX 9 pages, submitted Mod. Phys. Lett. B, e-mail: [email protected]

    The impact of orthodontic treatment on a young person's quality of life, esthetics, and self-esteem in hypodontia: A longitudinal study.

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    INTRODUCTION: This research aimed to evaluate the impact of orthodontic treatment on a young person's oral health-related quality of life, self-esteem, and esthetics concerning hypodontia. METHODS: A prospective longitudinal hospital-based study recruited 97 participants with hypodontia, aged 11-18 years. Forty-one participants (42%) originally planned to have space closure and the remainder space opening, with subsequent prosthetic replacement. The following questionnaires were completed before and after orthodontic treatment: the child perception questionnaire, Bristol condition-specific questionnaire for hypodontia (BCSQ), the child health questionnaire, and the Oral Aesthetic Subjective Impact Scale (OASIS). The Wilcoxon and matched pairs t tests approach was applied to compare before and after orthodontic treatment for significant testing (P <0.05). RESULTS: Fifteen participants were lost to follow-up, resulting in 82 participants completing orthodontic treatment, with an average age of 13.8 ± 1.71 years. A total of 282 teeth were missing in the sample. Treatment resulted in significantly lower indexes (P <0.001) to overall BCSQ, OASIS, appearance, and how others would treat them. In comparing the 2 subgroups, those treated with space closure had significantly reduced functional limitations (child perception questionnaire), appearance concerns, self-esteem (child health questionnaire), OASIS, and overall BCSQ scores. CONCLUSIONS: Orthodontic treatment in participants with hypodontia appears to significantly impact a range of psychological and esthetic scales. In particular, space closure appears to significantly improve the quality of life of participants compared with those undergoing space opening

    Ignorance based inference of optimality in thermodynamic processes

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    We derive ignorance based prior distribution to quantify incomplete information and show its use to estimate the optimal work characteristics of a heat engine.Comment: Latex, 10 pages, 3 figure

    Geometry of escort distributions

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    Given an original distribution, its statistical and probabilistic attributs may be scanned by the associated escort distribution introduced by Beck and Schlogl and employed in the formulation of nonextensive statistical mechanics. Here, the geometric structure of the one-parameter family of the escort distributions is studied based on the Kullback-Leibler divergence and the relevant Fisher metric. It is shown that the Fisher metric is given in terms of the generalized bit-variance, which measures fluctuations of the crowding index of a multifractal. The Cramer-Rao inequality leads to the fundamental limit for precision of statistical estimate of the order of the escort distribution. It is also quantitatively discussed how inappropriate it is to use the original distribution instead of the escort distribution for calculating the expectation values of physical quantities in nonextensive statistical mechanics.Comment: 12 pages, no figure

    The HIV-1 long terminal repeat contains an unusual element that induces the synthesis of short RNAs from various mRNA and snRNA promoters

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    We describe an unusual element that activates the synthesis of short transcripts from a wide variety of mRNA and small nuclear RNA (snRNA) promoters, including the U6 RNA polymerase III promoter. This inducer of short transcripts (IST) is located between positions -5 and +82 relative to the cap site in the HIV-1 LTR. In the presence of IST, the total transcriptional activity of the different promoters is greatly increased, but the resulting additional RNA molecules are short, ending around position +60. IST is not the RNA target (TAR) for Tat trans-activation; however, because it relies entirely on cellular factors for activity, IST may serve to provide abundant RNA targets for Tat trans-activation without a requirement for full-length viral mRNA expression

    Performance Evaluation of Multiple Differential Detection for Third Generation Mobile Communication System

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    Third generation mobile communication system is widely used nowadays. One of its parameter standard, which is QPSK modulation has been adopted by International Telecommunication Union (ITU) to be used in IMT-2000. However, due to amplitude variations introduced in QPSK, a rather robust and reliable data modulation technique, namely the p/4-shift Differential QPSK is proposed. For detection purposes, two types of detectors are evaluated for their performance in AWGN and Rayleigh fading channels.A differential detection technique called multiple differential detection technique which uses maximumlikelihood sequence estimation (MLSE) of the transmitted phases is compared with conventional differential detection which uses symbol-by-symbol detection. By using some of the IMT-2000 standard parameters, the simulation results show that multiple differential detection scheme performs much better than conventional differential detection scheme

    Generalized symmetric nonextensive thermostatistics and q-modified structures

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    We formulate a convenient generalization of the q-expectation value, based on the analogy of the symmetric quantum groups and q-calculus, and show that the q->q^{-1} symmetric nonextensive entropy preserves all of the mathematical structure of thermodynamics just as in the case of non-symmetric Tsallis statistics. Basic properties and analogies with quantum groups are discussed.Comment: 9 pages, 1 figure. To appear in Mod. Phys. Lett.

    The Role of Oral Appliance Therapy in Obstructive Sleep Apnoea: a review

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    There is now widespread recognition within the world of sleep medicine of the increasing importance of dental sleep medicine and, in particular, the role of oral appliance therapy (OAT) in the management of adults with obstructive sleep apnoea (OSA). For the purpose of this review, the term OAT refers to a custom-made intra-oral appliance, which acts to posture the mandible in a forward and downward direction, away from its natural resting position. Whilst nasally applied continuous positive airway pressure remains the “gold standard” in nonsurgical OSA management, OAT remains the recognised alternative treatment. This review of OAT aims to provide an evidence-based update on our current understanding of their mode of action, exploring the potential anatomical and physiological impact of their use in preventing collapse of the upper airway; the current clinical practice guidelines, including the recently published National Institute of Clinical Excellence 2021 guidance, in conjunction with the American Academy of Sleep Medicine and American Academy of Dental Sleep Medicine; optimal design features, comparing the role of custom-made versus noncustom OAT devices and the importance of titration in achieving a dose-dependent effect; patient predictors, preference and adherence to OAT; its impact on a range of both patient- and clinician-centred health outcomes, with a comparison with CPAP; the limitations and side-effects of providing OAT; and, finally, a look at future considerations to help optimise the delivery and outcomes of OAT
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