57 research outputs found

    Compensation Following Bilateral Vestibular Damage

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    Bilateral loss of vestibular inputs affects far fewer patients than unilateral inner ear damage, and thus has been understudied. In both animal subjects and human patients, bilateral vestibular hypofunction (BVH) produces a variety of clinical problems, including impaired balance control, inability to maintain stable blood pressure during postural changes, difficulty in visual targeting of images, and disturbances in spatial memory and navigational performance. Experiments in animals have shown that non-labyrinthine inputs to the vestibular nuclei are rapidly amplified following the onset of BVH, which may explain the recovery of postural stability and orthostatic tolerance that occurs within 10 days. However, the loss of the vestibulo-ocular reflex and degraded spatial cognition appear to be permanent in animals with BVH. Current concepts of the compensatory mechanisms in humans with BVH are largely inferential, as there is a lack of data from patients early in the disease process. Translation of animal studies of compensation for BVH into therapeutic strategies and subsequent application in the clinic is the most likely route to improve treatment. In addition to physical therapy, two types of prosthetic devices have been proposed to treat individuals with bilateral loss of vestibular inputs: those that provide tactile stimulation to indicate body position in space, and those that deliver electrical stimuli to branches of the vestibular nerve in accordance with head movements. The relative efficacy of these two treatment paradigms, and whether they can be combined to facilitate recovery, is yet to be ascertained

    From the CMD of Omega Centauri and (super-)AGB stellar models to a Galactic plane passage gas purging chemical evolution scenario

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    [Abbreviated] We have investigated the color-magnitude diagram of Omega Centauri and find that the blue main sequence (bMS) can be reproduced only by models that have a of helium abundance in the range Y=0.35-0.40.Toexplainthefaintsubgiantbranchofthereddeststars("MSa/RGa"sequence),isochronesfortheobservedmetallicity([Fe/H]0.7)appeartorequirebothahighage( 13Gyr)andenhancedCNOabundances([CNO/Fe]0.90.40. To explain the faint subgiant branch of the reddest stars ("MS-a/RG-a" sequence), isochrones for the observed metallicity ([Fe/H]\approx0.7) appear to require both a high age (~13Gyr) and enhanced CNO abundances ([CNO/Fe]\approx0.9). Y~0.35 must also be assumed in order to counteract the effects of high CNO on turnoff colors, and thereby to obtain a good fit to the relatively blue turnoff of this stellar population. This suggest a short chemical evolution period of time (<1Gyr) for Omega Cen. Our intermediate-mass (super-)AGB models are able to reproduce the high helium abundances, along with [N/Fe]~2 and substantial O depletions if uncertainties in the treatment of convection are fully taken into account. These abundance features distinguish the bMS stars from the dominant [Fe/H] 1.7\approx1.7 population. The most massive super-AGB stellar models (M_zams>=6.8M_sun, M_He,core>=1.245M_sun) predict too large N-enhancements, which limits their role in contributing to the extreme populations. We show quantitatively that highly He- and N-enriched AGB ejecta have particularly efficient cooling properties. Based on these results and on the reconstruction of the orbit of Omega Cen with respect to the Milky Way we propose the galactic plane passage gas purging scenario for the chemical evolution of this cluster. Our model addresses the formation and properties of the bMS population (including their central location in the cluster). We follow our model descriptively through four passage events, which could explain not only some key properties of the bMS, but also of the MS-a/RGB-a and the s-enriched stars.Comment: Accepted for publication in ApJ. 10 figures, 5 tables, 21 page

    Are Voluntary Agreements Better? Evidence from Baseball Arbitration

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    This paper empirically examines the widespread belief that voluntarily negotiated agreements produce better long-run relationships than third-party imposed settlements, such as arbitrator decisions or court judgments. Two key outcomes are analyzed – subsequent player performance and the durability of club-player relationship. Major League Baseball provides a compelling setting for these analyses because individual performance is well measured, there is the possibility of relationship breakdown, and both voluntary and imposed settlements are routinely used. While the results clearly show that a third-party imposed settlement is not better than a voluntary one, the evidence in support of the widespread belief is mixed

    PUSH-ing Construction Communications & Going Viral for Safety

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    Over the past 2 years, the Indiana Toll Road Concession Co. (ITRCC) and its contractors have delivered the 80/90 PUSH project, an ambitious rehabilitation of 70 miles of the Indiana Toll Road. The team developed an aggressive communications program to keep its customers and community stakeholders informed, partnering with the Indiana Motor Truck Association to take its Put the Phone Down campaign to social media. Join us for a discussion

    Assessing the Benefits of Reward Programs: A Recommended Approach and Case Study from the Lodging Industry

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    Two groups of independent hotels experienced an average 50-percent increase in annual revenue when customers joined their loyalty programs, almost entirely due to increased patronage. These guests were already the hotels’ best customers, but the number of annual room-nights they purchased increased by an average of 50 percent after they joined the program. On the other hand, ADR for the loyalty program guests increased modestly (1 percent for one hotel group and 5 percent for the other). The analysis compared customer behavior of matched pairs of hotel guests, where one member of the pair had enrolled in the hotels’ loyalty program and the other had not. By identifying matched pairs of the guests before enrollment, the analysis could record the differential behavior of guests after one member of the pair joined the loyalty program
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