236 research outputs found

    Gauge dependence of effective action and renormalization group functions in effective gauge theories

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    The Caswell-Wilczek analysis on the gauge dependence of the effective action and the renormalization group functions in Yang-Mills theories is generalized to generic, possibly power counting non renormalizable gauge theories. It is shown that the physical coupling constants of the classical theory can be redefined by gauge parameter dependent contributions of higher orders in ℏ\hbar in such a way that the effective action depends trivially on the gauge parameters, while suitably defined physical beta functions do not depend on those parameters.Comment: 13 pages Latex file, additional comments in section

    A multi-center diabetes eye screening study in community settings: Study design and methodology

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    Purpose: Diabetes is the leading cause of new cases of blindness among adults aged 20-74 years within the United States. The Innovative Network for Sight Research group (INSIGHT) designed the Diabetic Eye Screening Study (DESS) to examine the feasibility and short-term effectiveness of non-mydriatic diabetic retinopathy (DR) screening for adults with diabetes in community-based settings.Methods: Study enrollment began in December 2011 at four sites: an internal medicine clinic at a county hospital in Birmingham, Alabama; a Federally-qualified community healthcare center in Miami-Dade County, Florida; a university-affiliated outpatient pharmacy in Philadelphia, Pennsylvania; and a medical home in Winston-Salem, North Carolina. People 18 years or older with previously diagnosed diabetes were offered free DR screening using non-mydriatic retinal photography that was preceded by a brief questionnaire addressing demographic information and previous eye care use. Visual acuity was also measured for each eye. Images were evaluated at a telemedicine reading center by trained evaluators using the National Health System DR grading classification. Participants and their physicians were sent screening report results and telephoned for a follow-up survey 3 months post-screening to determine whether participants had sought follow-up comprehensive eye care and their experiences with the screening process.Results: Target enrollment at each site was a minimum of 500 persons. Three of the four sites met this enrollment goal.Conclusion: The INSIGHT/DESS is intended to establish the feasibility and short-term effectiveness of DR screening using non-mydriatic retinal photography in persons with diabetes who seek services in community-based clinic and pharmacy settings

    Protocol of a randomised trial of teriparatide followed by zoledronic acid to reduce fracture risk in adults with osteogenesis imperfecta

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    Introduction: Osteogenesis imperfecta (OI) is a rare genetic disease associated with multiple fractures throughout life. It is often treated with osteoporosis medications but their effectiveness at preventing fractures is unknown. The Treatment of Osteogenesis Imperfecta with Parathyroid Hormone and Zoledronic Acid trial will determine if therapy with teriparatide (TPTD) followed by zoledronic acid (ZA) can reduce the risk of clinical fractures in OI. Methods and analysis: Individuals aged ≄18 years with a clinical diagnosis of OI are eligible to take part. At baseline, participants will undergo a spine X-ray, and have bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) at the spine and hip. Information on previous fractures and previous bone targeted treatments will be collected. Questionnaires will be completed to assess pain and other aspects of health-related quality of life (HRQoL). Participants will be randomised to receive a 2-year course of TPTD injections 20 ”g daily followed by a single intravenous infusion of 5 mg ZA, or to receive standard care, which will exclude the use of bone anabolic drugs. Participants will be followed up annually, have a repeat DXA at 2 years and at the end of study. Spine X-rays will be repeated at the end of study. The duration of follow-up will range between 2 and 8 years. The primary endpoint will be new clinical fractures confirmed by X-ray or other imaging. Secondary endpoints will include participant reported fractures, BMD and changes in pain and HRQoL. Ethics and dissemination: The study received ethical approval in December 2016. Following completion of the trial, a manuscript will be submitted to a peer-reviewed journal. The results will inform clinical practice by determining if TPTD/ZA can reduce the risk of fractures in OI compared with standard care. Trial registration number: ISRCTN15313991

    Two-species percolation and Scaling theory of the metal-insulator transition in two dimensions

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    Recently, a simple non-interacting-electron model, combining local quantum tunneling via quantum point contacts and global classical percolation, has been introduced in order to describe the observed ``metal-insulator transition'' in two dimensions [1]. Here, based upon that model, a two-species-percolation scaling theory is introduced and compared to the experimental data. The two species in this model are, on one hand, the ``metallic'' point contacts, whose critical energy lies below the Fermi energy, and on the other hand, the insulating quantum point contacts. It is shown that many features of the experiments, such as the exponential dependence of the resistance on temperature on the metallic side, the linear dependence of the exponent on density, the e2/he^2/h scale of the critical resistance, the quenching of the metallic phase by a parallel magnetic field and the non-monotonic dependence of the critical density on a perpendicular magnetic field, can be naturally explained by the model. Moreover, details such as the nonmonotonic dependence of the resistance on temperature or the inflection point of the resistance vs. parallel magnetic are also a natural consequence of the theory. The calculated parallel field dependence of the critical density agrees excellently with experiments, and is used to deduce an experimental value of the confining energy in the vertical direction. It is also shown that the resistance on the ``metallic'' side can decrease with decreasing temperature by an arbitrary factor in the degenerate regime (Tâ‰ČEFT\lesssim E_F).Comment: 8 pages, 8 figure

    Evaluation of a Web-Based Training in Smoking Cessation Counseling Targeting U.S. Eye-Care Professionals

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    Background. Smoking causes blindness-related diseases. Eye-care providers are uniquely positioned to help their patients quit smoking. Aims. Using a pre-/postevaluation design, this study evaluated a web-based training in smoking cessation counseling targeting eye-care providers. Method. The training was developed based on the 3A1R protocol: “Ask about smoking, Advise to quit, Assess willingness to quit, and Refer to tobacco quitlines,” and made available in the form of a web-based video presentation. Providers (n = 654) at four academic centers were invited to participate. Participants completed pretraining, posttraining, and 3-month follow-up surveys. Main outcomes were self-reported improvement in their motivation, confidence, and counseling practices at 3-month follow-up. Generalized linear mixed models for two time-points (pretraining and 3-month) were conducted for these outcomes. Results. A total of 113 providers (54.0% males) participated in the study (17.7% response rate). At the 3-month evaluation, 9.8% of participants reported improvement in their motivation. With respect to the 3A1R, 8% reported improvement in their confidence for Ask, 15.5% for Advise, 28.6% for Assess, and 37.8% for Refer. Similarly, 25.5% reported improvement in their practices for Ask, 25.5% for Advise, 37.2% for Assess, and 39.4% for Refer to tobacco quitlines (p <.001 for all except for Refer confidence p =.05). Discussion. Although participation rate was low, the program effectively improved providers’ smoking cessation counseling practices. Conclusions. Including training in smoking cessation counseling in ophthalmology curriculums, and integrating the 3A1R protocol into the electronic medical records systems in eye-care settings, might promote smoking cessation practices in these settings

    News from the Muon (g-2) Experiment at BNL

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    The magnetic moment anomaly a_mu = (g_mu - 2) / 2 of the positive muon has been measured at the Brookhaven Alternating Gradient Synchrotron with an uncertainty of 0.7 ppm. The new result, based on data taken in 2000, agrees well with previous measurements. Standard Model evaluations currently differ from the experimental result by 1.6 to 3.0 standard deviations.Comment: Talk presented at RADCOR - Loops and Legs 2002, Kloster Banz, Germany, September 8-13 2002, to be published in Nuclear Physics B (Proc. Suppl.); 5 pages, 3 figure

    Diabetes eye screening in urban settings serving minority populations: Detection of diabetic retinopathy and other ocular findings using telemedicine

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    IMPORTANCE The use of a nonmydriatic camera for retinal imaging combined with the remote evaluation of images at a telemedicine reading center has been advanced as a strategy for diabetic retinopathy (DR) screening, particularly among patients with diabetes mellitus from ethnic/racial minority populations with low utilization of eye care. OBJECTIVE To examine the rate and types of DR identified through a telemedicine screening program using a nonmydriatic camera, as well as the rate of other ocular findings. DESIGN, SETTING, AND PARTICIPANTS A cross-sectional study (Innovative Network for Sight [INSIGHT]) was conducted at 4 urban clinic or pharmacy settings in the United States serving predominantly ethnic/racial minority and uninsured persons with diabetes. Participants included persons aged 18 years or older who had type 1 or 2 diabetes mellitus and presented to the community-based settings. MAIN OUTCOMES AND MEASURES The percentage of DR detection, including type of DR, and the percentage of detection of other ocular findings. RESULTS A total of 1894 persons participated in the INSIGHT screening program across sites, with 21.7%having DR in at least 1 eye. The most common type of DR was background DR, which was present in 94.1%of all participants with DR. Almost half (44.2%) of the sample screened had ocular findings other than DR; 30.7%of the other ocular findings were cataract. CONCLUSIONS AND RELEVANCE In a DR telemedicine screening program in urban clinic or pharmacy settings in the United States serving predominantly ethnic/racial minority populations, DR was identified on screening in approximately 1 in 5 persons with diabetes. The vast majority of DR was background, indicating high public health potential for intervention in the earliest phases of DR when treatment can prevent vision loss. Other ocular conditions were detected at a high rate, a collateral benefit of DR screening programs that may be underappreciated

    Programmable antivirals targeting critical conserved viral RNA secondary structures from influenza A virus and SARS-CoV-2

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    Influenza A virus’s (IAV’s) frequent genetic changes challenge vaccine strategies and engender resistance to current drugs. We sought to identify conserved and essential RNA secondary structures within IAV’s genome that are predicted to have greater constraints on mutation in response to therapeutic targeting. We identified and genetically validated an RNA structure (packaging stem–loop 2 (PSL2)) that mediates in vitro packaging and in vivo disease and is conserved across all known IAV isolates. A PSL2-targeting locked nucleic acid (LNA), administered 3 d after, or 14 d before, a lethal IAV inoculum provided 100% survival in mice, led to the development of strong immunity to rechallenge with a tenfold lethal inoculum, evaded attempts to select for resistance and retained full potency against neuraminidase inhibitor-resistant virus. Use of an analogous approach to target SARS-CoV-2, prophylactic administration of LNAs specific for highly conserved RNA structures in the viral genome, protected hamsters from efficient transmission of the SARS-CoV-2 USA_WA1/2020 variant. These findings highlight the potential applicability of this approach to any virus of interest via a process we term ‘programmable antivirals’, with implications for antiviral prophylaxis and post-exposure therapy

    Parkin-deficient Mice Exhibit Nigrostriatal Deficits but not Loss of Dopaminergic Neurons

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    Loss-of-function mutations in parkin are the major cause of early-onset familial Parkinson's disease. To investigate the pathogenic mechanism by which loss of parkin function causes Parkinson's disease, we generated a mouse model bearing a germline disruption in parkin. Parkin-/- mice are viable and exhibit grossly normal brain morphology. Quantitative in vivo microdialysis revealed an increase in extracellular dopamine concentration in the striatum of parkin-/- mice. Intracellular recordings of medium-sized striatal spiny neurons showed that greater currents are required to induce synaptic responses, suggesting a reduction in synaptic excitability in the absence of parkin. Furthermore, parkin-/- mice exhibit deficits in behavioral paradigms sensitive to dysfunction of the nigrostriatal pathway. The number of dopaminergic neurons in the substantia nigra of parkin-/- mice, however, is normal up to the age of 24 months, in contrast to the substantial loss of nigral neurons characteristic of Parkinson's disease. Steady-state levels of CDCrel-1, synphilin-1, and α-synuclein, which were identified previously as substrates of the E3 ubiquitin ligase activity of parkin, are unaltered in parkin-/- brains. Together these findings provide the first evidence for a novel role of parkin in dopamine regulation and nigrostriatal function, and a non-essential role of parkin in the survival of nigral neurons in mice
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