533 research outputs found

    Optically excited states in positronium

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    Optical excitation are reported of the 1 3S-2 3P transition in positronium, and a second excitation from n=2 to higher n states. The experiment used light from two pulsed dye lasers. Changes in the positronium annihilation rate during and after the laser pulse were used to deduce the excited state populations. The n=2 level was found to be saturable and excitable to a substantial fraction of n=2 positronium to higher levels. Preliminary spectroscopic measurements were performed on n=14 and n=15 positronium

    Picoradian deflection measurement with an interferometric quasi-autocollimator using weak value amplification

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    We present an "interferometric quasi-autocollimator" that employs weak value amplification to measure angular deflections of a target mirror. The device has been designed to be insensitive to all translations of the target. We present a conceptual explanation of the amplification effect used by the device. An implementation of the device demonstrates sensitivities better than 10 picoradians per root hertz between 10 and 200 hertz.Comment: To be published in Optics Letter

    Variably Transmittive, Electronically-Controlled Eyewear

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    A system and method for flight training and evaluation of pilots comprises electronically activated vision restriction glasses that detect the pilot's head position and automatically darken and restrict the pilot's ability to see through the front and side windscreens when the pilot-in-training attempts to see out the windscreen. Thus, the pilot-in-training sees only within the aircraft cockpit, forcing him or her to fly by instruments in the most restricted operational mode

    The Empirical Foundations of Telemedicine Interventions in Primary Care

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    Introduction: This article presents the scientific evidence for the merits of telemedicine interventions in primary care. Although there is no uniform and consistent definition of primary care, most agree that it occupies a central role in the healthcare system as first contact for patients seeking care, as well as gatekeeper and coordinator of care. It enables and supports patient-centered care, the medical home, managed care, accountable care, and population health. Increasing concerns about sustainability and the anticipated shortages of primary care physicians have sparked interest in exploring the potential of telemedicine in addressing many of the challenges facing primary care in the United States and the world. Materials and Methods: The findings are based on a systematic review of scientific studies published from 2005 through 2015. The initial search yielded 2,308 articles, with 86 meeting the inclusion criteria. Evidence is organized and evaluated according to feasibility/acceptance, intermediate outcomes, health outcomes, and cost. Results: The majority of studies support the feasibility/acceptance of telemedicine for use in primary care, although it varies significantly by demographic variables, such as gender, age, and socioeconomic status, and telemedicine has often been found more acceptable by patients than healthcare providers. Outcomes data are limited but overall suggest that telemedicine interventions are generally at least as effective as traditional care. Cost analyses vary, but telemedicine in primary care is increasingly demonstrated to be cost-effective. Conclusions: Telemedicine has significant potential to address many of the challenges facing primary care in today's healthcare environment. Challenges still remain in validating its impact on clinical outcomes with scientific rigor, as well as in standardizing methods to assess cost, but patient and provider acceptance is increasingly making telemedicine a viable and integral component of primary care around the world.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140293/1/tmj.2016.0045.pd

    Human Immunodeficiency Virus Type 1 Infection of Cells and Tissues from the Upper and Lower Human Female Reproductive Tract

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    Viable tissue sections and isolated cell cultures from the human fallopian tube, uterus, cervix, and vaginal mucosa were examined for susceptibility to infection with human immunodeficiency virus type 1 (HIV-1). We examined infectivity by using the monocytotropic strain HIV-1JR-FLand several primary isolates of HIV-1 obtained from infected neonates. HIV-1 infection was measured by p24 production in short-term culture and by immunofluorescence detection of HIV-1 Nef and p24 proteins by laser scanning confocal microscopy. Three-color immunofluorescence was used to phenotype HIV-infected cells within tissue sections from each site. Our findings indicate that epithelial, stromal, and dendritic cells and cells with CD14+, CD4+, CD14-, CD4-, and CD4+, CD14- phenotypes from the female reproductive tract are infectable with HIV-1. Of importance is the finding that tissues from the upper reproductive tract are susceptible to infection with HIV-1. Moreover, tissue samples from women in all stages of the menstrual cycle, including postmenopausal women (inactive), could be infected with HIV-1. Female reproductive tract cells required a minimum of 60 min of exposure to HIV-1 in order for infection to occur, in contrast to peripheral blood lymphocytes, which became infected after being exposed to HIV-1 for only 1 min. These findings demonstrate that HIV-1 can infect cells and tissues from different sites within the female reproductive tract and suggest that multiple cell types, including epithelial cells, may be targets for the initial infection by HIV-1
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