20 research outputs found

    The Association Between Dental Coverage and Self-reported Health in Older Adults jGPHA

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    Background: For the older population of the United States, lack of dental insurance coverage is a substantial health problem. The purpose of the present study was to examine the longitudinal relationship between dental coverage and self-reported health among older adults. Methods: The Health and Retirement Study (HRS), a nationally representative biennial cohort study of community-dwelling individuals, includes 19,595 adults (aged 50 and older) living in the United States. For the 2010, 2012, and 2014 waves, the independent variable of dental coverage and the outcome of self-reported health were examined. Results: At each time point, dental coverage for older adults had a positive association with self-reported health (parameter estimate, Ξ²=0.340, standard error (SE)=0.039, p\u3c0.0001), controlling for sociodemographic variables of age, sex, race/ethnicity, education, and the status of edentulism. There were no significant longitudinal effects for dental coverage associated with selfreported health. Conclusions: At each time point, the results show a positive association between having dental coverage and better self-reported health of older adults. This is relevant, because, in the United States, there is an increasing population of older people

    Quantum metrology timing limits of the Hong-Ou-Mandel interferometer and of general two-photon measurements

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    We examine the precision limits of Hong-Ou-Mandel (HOM) timing measurements, as well as precision limits applying to generalized two-photon measurements. As a special case, we consider the use of two-photon measurements using photons with variable bandwidths and frequency correlations. When the photon bandwidths are not equal, maximizing the measurement precision involves a trade-off between high interference visibility and strong frequency anticorrelations, with the optimal precision occuring when the photons share non-maximal frequency anticorrelations. We show that a generalized measurement has precision limits that are qualitatively similar to those of the HOM measurement whenever the generalized measurement is insensitive to the net delay of both photons. By examining the performance of states with more general frequency distributions, our analysis allows for engineering of the joint spectral amplitude for use in realistic situations, in which both photons may not have ideal spectral properties.Comment: 12 pages, 6 figures; resubmissio

    Properties and Applications of the Kirkwood-Dirac Distribution

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    The most famous quasi-probability distribution, the Wigner function, has played a pivotal role in the development of a continuous-variable quantum theory that has clear analogues of position and momentum. However, the Wigner function is ill-suited for much modern quantum-information research, which is focused on finite-dimensional systems and general observables. Instead, recent years have seen the Kirkwood-Dirac (KD) distribution come to the forefront as a powerful quasi-probability distribution for analysing quantum mechanics. The KD distribution allows tools from statistics and probability theory to be applied to problems in quantum-information processing. A notable difference to the Wigner function is that the KD distribution can represent a quantum state in terms of arbitrary observables. This paper reviews the KD distribution, in three parts. First, we present definitions and basic properties of the KD distribution and its generalisations. Second, we summarise the KD distribution's extensive usage in the study or development of measurement disturbance; quantum metrology; weak values; direct measurements of quantum states; quantum thermodynamics; quantum scrambling and out-of-time-ordered correlators; and the foundations of quantum mechanics, including Leggett-Garg inequalities, the consistent-histories interpretation, and contextuality. We emphasise connections between operational quantum advantages and negative or non-real KD quasi-probabilities. Third, we delve into the KD distribution's mathematical structure. We summarise the current knowledge regarding the geometry of KD-positive states (the states for which the KD distribution is a classical probability distribution), describe how to witness and quantify KD non-positivity, and outline relationships between KD non-positivity and observables' incompatibility.Comment: 37 pages, 13 figure

    Principles of Hand Fracture Management

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    The hand is essential in humans for physical manipulation of their surrounding environment. Allowing the ability to grasp, and differentiated from other animals by an opposing thumb, the main functions include both fine and gross motor skills as well as being a key tool for sensing and understanding the immediate surroundings of their owner

    Bordetella pertussis Infection Exacerbates Influenza Virus Infection through Pertussis Toxin-Mediated Suppression of Innate Immunity

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    Pertussis (whooping cough) is frequently complicated by concomitant infections with respiratory viruses. Here we report the effect of Bordetella pertussis infection on subsequent influenza virus (PR8) infection in mouse models and the role of pertussis toxin (PT) in this effect. BALB/c mice infected with a wild-type strain of B. pertussis (WT) and subsequently (up to 14 days later) infected with PR8 had significantly increased pulmonary viral titers, lung pathology and mortality compared to mice similarly infected with a PT-deficient mutant strain (Ξ”PT) and PR8. Substitution of WT infection by intranasal treatment with purified active PT was sufficient to replicate the exacerbating effects on PR8 infection in BALB/c and C57/BL6 mice, but the effects of PT were lost when toxin was administered 24 h after virus inoculation. PT had no effect on virus titers in primary cultures of murine tracheal epithelial cells (mTECs) in vitro, suggesting the toxin targets an early immune response to increase viral titers in the mouse model. However, type I interferon responses were not affected by PT. Whole genome microarray analysis of gene expression in lung tissue from PT-treated and control PR8-infected mice at 12 and 36 h post-virus inoculation revealed that PT treatment suppressed numerous genes associated with communication between innate and adaptive immune responses. In mice depleted of alveolar macrophages, increase of pulmonary viral titers by PT treatment was lost. PT also suppressed levels of IL-1Ξ², IL-12, IFN-Ξ³, IL-6, KC, MCP-1 and TNF-Ξ± in the airways after PR8 infection. Furthermore PT treatment inhibited early recruitment of neutrophils and NK cells to the airways. Together these findings demonstrate that infection with B. pertussis through PT activity predisposes the host to exacerbated influenza infection by countering protective innate immune responses that control virus titers

    The Association Between Dental Coverage and Self-reported Health in Older Adults jGPHA

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    Background: For the older population of the United States, lack of dental insurance coverage is a substantial health problem. The purpose of the present study was to examine the longitudinal relationship between dental coverage and self-reported health among older adults. Methods: The Health and Retirement Study (HRS), a nationally representative biennial cohort study of community-dwelling individuals, includes 19,595 adults (aged 50 and older) living in the United States. For the 2010, 2012, and 2014 waves, the independent variable of dental coverage and the outcome of self-reported health were examined. Results: At each time point, dental coverage for older adults had a positive association with self-reported health (parameter estimate, Ξ²=0.340, standard error (SE)=0.039, p\u3c0.0001), controlling for sociodemographic variables of age, sex, race/ethnicity, education, and the status of edentulism. There were no significant longitudinal effects for dental coverage associated with selfreported health. Conclusions: At each time point, the results show a positive association between having dental coverage and better self-reported health of older adults. This is relevant, because, in the United States, there is an increasing population of older people

    Weak-value-amplification enhancement of the magneto-optical Kerr effect in nanoscale layered structures

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    The achievement of a larger magneto-optical Kerr effect (MOKE) in nanoscale layered structures is extremely important for both theoretical understandings and practical applications. However, nanoscale layered structures may not always exhibit enhanced MOKE under certain geometries. In this paper, we present a scheme based on weak-value amplification (WVA) for simultaneously detecting and enhancing the Kerr signals in nanoscale layered structures. The Kerr signals can be effectively amplified as the parameters of the preselection in WVA. We numerically investigate the dependence of the thickness d of Co in the sample HfO2(10nm)/Co(d nm)/HfO2(30nm)/Al(40nm)/Si and the sample Co(d nm)/Si in the range of 5 nm < d < 50 nm. Our results indicate that the combination of the cavity and WVA can simultaneously amplify the MOKE signals when compared to the application of WVA on the sample Co(d nm)/Si and the application of traditional MOKEsetup (TMOKES) on the two samples. Importantly, our results highlight that WVA maintains its ability to amplify MOKE signals even in cases where the cavity in the TMOKES scheme fails to enhance the Kerr signals. This signifies the exceptional advantage of WVA in amplifying Kerr signals over TMOKES, regardless of the sample structures and specific MOKE geometries employed
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