253 research outputs found

    Vascular Depression: An Early Warning Sign of Frailty

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    Objectives: Frailty is a common geriatric disorder associated with ADL impairment, hospitalization, and death. Phenomenological evidence suggests that late-life depression (Katz, 2004), particularly vascular depression, may be a risk factor for frailty. This study tests that hypothesis. Methods: We identified a sample of stroke-free women over the age of 80 from the Health and Retirement Survey. The sample included 984 respondents in 2000 (incidence sample). Of these, 459 were non-frail at baseline and still alive in 2004 (prevalence sample). Frail respondents experienced at least three of the following: wasting, exhaustion, weakness, slowness, and falls. Vascular depression was represented using two dummy variables. The first repre-sented respondents with either high CVB (at least two cerebrovascular risk factors) or probable depression (score ≥ 3 on the 8-item CES-D), and the second represented respondents with both high CVB and probable depression. Results: At baseline, the prevalence of frailty was 31.5%. Over 4 years the incidence of frailty was 31.8%. After controlling for age, education, ADL and IADL disability, arthritis, pulmonary disorders, cancer, and self-rated health, respondents with either high CVB or probable depression were more likely to be frail at baseline, and those with both were at even higher risk. Of those who were not frail at the 2000 wave, respondents who reported both high CVB and probable depression were more likely to become frail by 2004. Discussion: These findings suggest that vascular depression is a prodrome for frailty

    EXPERIMENTAL CHARACTERIZATION OF ATMOSPHERIC TURBULENCE SUPPORTED BY ADVANCED PHASE SCREEN SIMULATIONS

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    Characterization of optical propagation through the low turbulent atmosphere has been a topic of scientific investigation for decades, and has important engineering applications in the fields of free space optical communications, remote sensing, and directed energy. Traditional theories, starting with early radio science, have flowed down from the assumption of three dimensional statistical symmetry of so-called fully developed, isotropic turbulence. More recent experimental results have demonstrated that anisotropy and irregular frequency domain characteristics are regularly observed near boundaries of the atmosphere, and similar findings have been reported in computational fluid dynamics literature. We have used a multi-aperture transmissometer in field testing to characterize atmospheric transparency, refractive index structure functions, and turbulence anisotropy near atmospheric boundaries. Additionally, we have fielded arrays of resistive temperature detector probes alongside optical propagation paths to provide direct measurements of temperature and refractive index statistics supporting optical turbulence observations. We are backing up these experimental observations with a modified algorithm for modeling optical propagation through atmospheric turbulence. Our new phase screen approach utilizes a randomized spectral sampling algorithm to emulate the turbulence energy spectrum and improve modeling of low frequency fluctuations and improve convergence with theory. We have used the new algorithm to investigate open theoretical topics, such as the behavior of beam statistics in the strong fluctuation regime as functions of anisotropy parameters, and energy spectrum power law behavior. These results have to be leveraged in order to develop new approaches for characterization of atmospheric optical turbulence

    Successful Aging and Longevity in Older Old Women: The Role of Depression and Cognition

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    Based in successful aging theory and terminal cognitive drop research, this paper investigates cerebrovascular burden (CVB), depressive symptoms, and cognitive decline as threats to longevity. A subsample of stroke-free women over the age of 80 was identified in the Health and Retirement Survey (years 2000–2008). Mortality at 2, 6, and 8 year intervals was predicted using CVB (diabetes, heart disease, hypertension), depressive symptoms (Center for Epidemiological Studies Depression Scale), and cognitive decline (decline of 1 standard deviation or more on the 35-point Telephone Interview for Cognitive Status over 2 years). At most waves (2002, 2004, and 2006) mortality was predicted by CVB, depressive symptoms, and cognitive drop measured 2 years prior. CVB and depressive symptoms at the 2000 wave predicted mortality at 6 and 8 years. Older women with the greatest longevity had low CVB, robust cognitive functioning, and few depression symptoms, supporting successful aging theory and terminal cognitive drop

    A new foundational crisis in mathematics, is it really happening?

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    The article reconsiders the position of the foundations of mathematics after the discovery of HoTT. Discussion that this discovery has generated in the community of mathematicians, philosophers and computer scientists might indicate a new crisis in the foundation of mathematics. By examining the mathematical facts behind HoTT and their relation with the existing foundations, we conclude that the present crisis is not one. We reiterate a pluralist vision of the foundations of mathematics. The article contains a short survey of the mathematical and historical background needed to understand the main tenets of the foundational issues.Comment: Final versio

    Starspot-induced optical and infrared radial velocity variability in T Tauri star Hubble 4

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    We report optical (6150 Ang) and K-band (2.3 micron) radial velocities obtained over two years for the pre-main sequence weak-lined T Tauri star Hubble I 4. We detect periodic and near-sinusoidal radial velocity variations at both wavelengths, with a semi-amplitude of 1395\pm94 m/s in the optical and 365\pm80 m/s in the infrared. The lower velocity amplitude at the longer wavelength, combined with bisector analysis and spot modeling, indicates that there are large, cool spots on the stellar surface that are causing the radial velocity modulation. The radial velocities maintain phase coherence over hundreds of days suggesting that the starspots are long-lived. This is one of the first active stars where the spot-induced velocity modulation has been resolved in the infrared.Comment: Accepted for publication in The Astrophysical Journa

    Precision radial velocities with CSHELL

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    Radial velocity identification of extrasolar planets has historically been dominated by optical surveys. Interest in expanding exoplanet searches to M dwarfs and young stars, however, has motivated a push to improve the precision of near infrared radial velocity techniques. We present our methodology for achieving 58 m/s precision in the K band on the M0 dwarf GJ 281 using the CSHELL spectrograph at the 3-meter NASA IRTF. We also demonstrate our ability to recover the known 4 Mjup exoplanet Gl 86 b and discuss the implications for success in detecting planets around 1-3 Myr old T Tauri stars.Comment: 31 pages, 3 figures, 2 tables, accepted for publication in Ap

    Vulnerable warriors: the atmospheric marketing of military and policing equipment before and after 9/11

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    In this article, we analyse changes in the circulation of advertisements of policing products at security expos between 1995 and 2013. While the initial aim of the research was to evidence shifts in terrorist frames in the marketing of policing equipment before and after 9/11, our findings instead suggested that what we are seeing is the rise of marketing to police as “vulnerable warriors”, law enforcement officers in need of military weapons both for their offensive capabilities and for the protection they can offer to a police force that is always under threat

    Lewy Body Dementia Association\u27s Research Centers of Excellence Program: Inaugural Meeting Proceedings

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    The first Lewy Body Dementia Association (LBDA) Research Centers of Excellence (RCOE) Investigator\u27s meeting was held on December 14, 2017, in New Orleans. The program was established to increase patient access to clinical experts on Lewy body dementia (LBD), which includes dementia with Lewy bodies (DLB) and Parkinson\u27s disease dementia (PDD), and to create a clinical trials-ready network. Four working groups (WG) were created to pursue the LBDA RCOE aims: (1) increase access to high-quality clinical care, (2) increase access to support for people living with LBD and their caregivers, (3) increase knowledge of LBD among medical and allied (or other) professionals, and (4) create infrastructure for a clinical trials-ready network as well as resources to advance the study of new therapeutics

    Aqueductal developmental venous anomaly as an unusual cause of congenital hydrocephalus: a case report and review of the literature

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    <p>Abstract</p> <p>Introduction</p> <p>Aqueductal stenosis may be caused by a number of etiologies including congenital stenosis, tumor, inflammation, and, very rarely, vascular malformation. However, aqueductal stenosis caused by a developmental venous anomaly presenting as congenital hydrocephalus is even more rare, and, to the best of our knowledge, has not yet been reported in the literature. In this study, we review the literature and report the first case of congenital hydrocephalus associated with aqueductal stenosis from a developmental venous anomaly.</p> <p>Case presentation</p> <p>The patient is a three-day-old, African-American baby girl with a prenatal diagnosis of hydrocephalus. She presented with a full fontanelle, splayed sutures, and macrocephaly. Postnatal magnetic resonance imaging showed triventricular hydrocephalus, suggesting aqueductal stenosis. Examination of the T1-weighted sagittal magnetic resonance imaging enhanced with gadolinium revealed a developmental venous anomaly passing through the orifice of the aqueduct. We treated the patient with a ventriculoperitoneal shunt.</p> <p>Conclusions</p> <p>Ten cases of aqueductal stenosis due to venous lesions have been reported and, although these venous angiomas and developmental venous anomalies are usually considered congenital lesions, all 10 cases became symptomatic as older children and adults. Our case is the first in which aqueductal stenosis caused by a developmental venous anomaly presents as congenital hydrocephalus. We hope adding to the literature will improve understanding of this very uncommon cause of hydrocephalus and, therefore, will aid in treatment.</p
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