7,426 research outputs found

    Prospects for detection of ΄(1D)→΄(1S)ππ\Upsilon(1D) \to \Upsilon(1S) \pi \pi via ΄(3S)→΄(1D)+X\Upsilon(3S) \to \Upsilon(1D) + X

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    At least one state in the first family of D-wave bbˉb \bar b quarkonium levels has been discovered near the predicted mass of 10.16 GeV/c2c^2. This state is probably the one with J=2. This state and the ones with J=1 and J=3 may contribute a detectable amount to the decay ΄(1D)→΄(1S)ππ\Upsilon(1D) \to \Upsilon(1S) \pi \pi, depending on the partial widths for these decays for which predictions vary considerably. The prospects for detection of the chain ΄(3S)→΄(1D)+X→΄ππ+X\Upsilon(3S) \to \Upsilon(1D) + X \to \Upsilon \pi \pi + X are discussed.Comment: 4 pages, LaTeX, 1 figure, to be published in Phys. Rev. D, comment added after Eq. (2

    Speckle observations with PISCO in Merate - V. Astrometric measurements of visual binaries in 2006

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    International audienceWe present relative astrometric measurements of visual binaries made during the first semester of 2006, with the Pupil Interferometry Speckle camera and COronagraph at the 102-cm Zeiss telescope of the Brera Astronomical Observatory, in Merate. Our sample contains orbital couples as well as binaries whose motion is still uncertain. We obtained 217 new measurements of 194 objects, with angular separations in the range 0.1-4.2arcsec, and an average accuracy of 0.01arcsec. The mean error on the position angles is 0.5°. About half of those angles could be determined without the usual 180° ambiguity by the application of triple-correlation techniques. We also present a revised orbit for ADS 277 for which the previously published orbit resulted in a large residual from our measurements

    Electroconvulsive Therapy Practice Changes in Older Individuals Due to COVID-19: Expert Consensus Statement

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    © 2020 American Association for Geriatric Psychiatry The ubiquitous coronavirus 2019 (COVID-19) pandemic has required healthcare providers across all disciplines to rapidly adapt to public health guidelines to reduce risk while maintaining quality of care. Electroconvulsive therapy (ECT), which involves an aerosol-generating procedure from manual ventilation with a bag mask valve while under anesthesia, has undergone drastic practice changes in order to minimize disruption of treatment in the midst of COVID-19. In this paper, we provide a consensus statement on the clinical practice changes in ECT specific to older adults based on expert group discussions of ECT practitioners across the country and a systematic review of the literature. There is a universal consensus that ECT is an essential treatment of severe mental illness. In addition, there is a clear consensus on what modifications are imperative to ensure continued delivery of ECT in a manner that is safe for patients and Northwell Health, while maintaining the viability of ECT services. Approaches to modifications in ECT to address infection control, altered ECT procedures, and adjusting ECT operations are almost uniform across the globe. With modified ECT procedures, it is possible to continue to meet the needs of older patients while mitigating risk of transmission to this vulnerable population

    Astrometric Methods and Instrumentation to Identify and Characterize Extrasolar Planets: A Review

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    I present a review of astrometric techniques and instrumentation utilized to search for, detect, and characterize extra-solar planets. First, I briefly summarize the properties of the present-day sample of extrasolar planets, in connection with predictions from theoretical models of planet formation and evolution. Next, the generic approach to planet detection with astrometry is described, with significant discussion of a variety of technical, statistical, and astrophysical issues to be faced by future ground-based as well as space-borne efforts in order to achieve the required degree of measurement precision. After a brief summary of past and present efforts to detect planets via milli-arcsecond astrometry, I then discuss the planet-finding capabilities of future astrometric observatories aiming at micro-arcsecond precision. Lastly, I outline a number experiments that can be conducted by means of high-precision astrometry during the next decade, to illustrate its potential for important contributions to planetary science, in comparison with other indirect and direct methods for the detection and characterization of planetary systems.Comment: 61 pages, 8 figures, PASP, accepted (October 2005 issue

    Spectroscopy at B-factories Using Hard Photon Emission

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    The process of hard photon emission by initial electrons (positrons) at B-factories is discussed. It is shown that studies of the bottomonium spectroscopy will be feasible for the planned integrated luminosity of the B-factory experiments.Comment: 9 pages, Latex, 1 fugure, Submitted to Int.Jour.Mod.Phys.

    The ALMA REBELS Survey: The Cosmic H i Gas Mass Density in Galaxies at z ≈ 7

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    The neutral atomic gas content of individual galaxies at large cosmological distances has until recently been difficult to measure due to the weakness of the hyperfine H I 21 cm transition. Here we estimate the H I gas mass of a sample of main-sequence star-forming galaxies at z similar to 6.5-7.8 surveyed for [C II] 158 mu m emission as part of the Reionization Era Bright Emission Line Survey (REBELS), using a recent calibration of the [C II]-to-H I conversion factor. We find that the H I gas mass excess in galaxies increases as a function of redshift, with an average of M-HI /M-star approximate to 10, corresponding to H I gas mass fractions of f(HI) = M-HI /(M-star + M-HI) = 90%, at z approximate to 7. Based on the [C II] 158 mu m luminosity function (LF) derived from the same sample of galaxies, we further place constraints on the cosmic H I gas mass density in galaxies (rho(HI)) at this redshift, which we measure to be rho(HI) = 7.1(-3.0)(+6.4) x 10(6) M-circle dot Mpc(-3). This estimate is substantially lower by a factor of approximate to 10 than that inferred from an extrapolation of damped Ly alpha absorber (DLA) measurements and largely depends on the exact [C II] LF adopted. However, we find this decrease in rho(HI) to be consistent with recent simulations and argue that this apparent discrepancy is likely a consequence of the DLA sight lines predominantly probing the substantial fraction of H I gas in high-z galactic halos, whereas [C II] traces the H I in the ISM associated with star formation. We make predictions for this buildup of neutral gas in galaxies as a function of redshift, showing that at z greater than or similar to 5, only approximate to 10% of the cosmic H I gas content is confined in galaxies and associated with the star-forming ISM

    Education as Risk Factor of Mild Cognitive Impairment:The Link to the Gut Microbiome

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    Background: With differences apparent in the gut microbiome in mild cognitive impairment (MCI) and dementia, and risk factors of dementia linked to alterations of the gut microbiome, the question remains if gut microbiome characteristics may mediate associations of education with MCI. Objectives: We sought to examine potential mediation of the association of education and MCI by gut microbiome diversity or composition. Design: Cross-sectional study. Setting: Luxembourg, the Greater Region (surrounding areas in Belgium, France, Germany). Participants: Control participants of the Luxembourg Parkinson’s Study. Measurements: Gut microbiome composition, ascertained with 16S rRNA gene amplicon sequencing. Differential abundance, assessed across education groups (0–10, 11–16, 16+ years of education). Alpha diversity (Chao1, Shannon and inverse Simpson indices). Mediation analysis with effect decomposition was conducted with education as exposure, MCI as outcome and gut microbiome metrics as mediators. Results: After exclusion of participants below 50, or with missing data, n=258 participants (n=58 MCI) were included (M [SD] Age=64.6 [8.3] years). Higher education (16+ years) was associated with MCI (Odds ratio natural direct effect=0.35 [95% CI 0.15–0.81]. Streptococcus and Lachnospiraceae-UCG-001 genera were more abundant in higher education. Conclusions: Education is associated with gut microbiome composition and MCI risk without clear evidence for mediation. However, our results suggest signatures of the gut microbiome that have been identified previously in AD and MCI to be reflected in lower education and suggest education as important covariate in microbiome studies

    PHASES High Precision Differential Astrometry of delta Equulei

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    delta Equulei is among the most well-studied nearby binary star systems. Results of its observation have been applied to a wide range of fundamental studies of binary systems and stellar astrophysics. It is widely used to calibrate and constrain theoretical models of the physics of stars. We report 27 high precision differential astrometry measurements of delta Equulei from the Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES). The median size of the minor axes of the uncertainty ellipses for these measurements is 26 micro-arcseconds. These data are combined with previously published radial velocity data and other previously published differential astrometry measurements using other techniques to produce a combined model for the system orbit. The distance to the system is determined to within a twentieth of a parsec and the component masses are determined at the level of a percent. The constraints on masses and distance are limited by the precisions of the radial velocity data; we outline plans improve this deficiency and discuss the outlook for further study of this binary.Comment: Accepted by AJ. Complete versions of tables 2-7 now available at http://stuff.mit.edu/~matthew1/deltaEquTables/ (removed from astroph server
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