Gravitational Radiation from Rotational Instabilities in Compact Stellar Cores with Stiff Equations of State

We carry out 3-D numerical simulations of the dynamical instability in rapidly rotating stars initially modeled as polytropes with n = 1.5, 1.0, and 0.5. The calculations are done with a SPH code using Newtonian gravity, and the gravitational radiation is calculated in the quadrupole limit. All models develop the global m=2 bar mode, with mass and angular momentum being shed from the ends of the bar in two trailing spiral arms. The models then undergo successive episodes of core recontraction and spiral arm ejection, with the number of these episodes increasing as n decreases: this results in longer-lived gravitational wave signals for stiffer models. This instability may operate in a stellar core that has expended its nuclear fuel and is prevented from further collapse due to centrifugal forces. The actual values of the gravitational radiation amplitudes and frequencies depend sensitively on the radius of the star R_{eq} at which the instability develops.Comment: 39 pages, uses Latex 2.09. To be published in the Dec. 15, 1996 issue of Physical Review D. 21 figures (bitmapped). Originals available in compressed Postscript format at ftp://zonker.drexel.edu/papers/bars

Comparison of advanced gravitational-wave detectors

We compare two advanced designs for gravitational-wave antennas in terms of their ability to detect two possible gravitational wave sources. Spherical, resonant mass antennas and interferometers incorporating resonant sideband extraction (RSE) were modeled using experimentally measurable parameters. The signal-to-noise ratio of each detector for a binary neutron star system and a rapidly rotating stellar core were calculated. For a range of plausible parameters we found that the advanced LIGO interferometer incorporating RSE gave higher signal-to-noise ratios than a spherical detector resonant at the same frequency for both sources. Spheres were found to be sensitive to these sources at distances beyond our galaxy. Interferometers were sensitive to these sources at far enough distances that several events per year would be expected

Harmonic devices employed by Claude Debussy in Hommage a Rameau and L'isle Joyeuse

There is no abstract available for this creative project.Thesis (M.M.)School of Musi

Psychometric properties of selected tests in patients with lumbar spinal stenosis

Background context: The psychometric properties of many outcome tools commonly used with patients with lumbar spinal stenosis have yet to be examined. Purpose: Examine the test-retest reliability, responsiveness, and minimum levels of detectable and clinically important differences for several outcome measures in a cohort of patients with lumbar spinal stenosis. Study design/setting: Cohort secondary analysis of a randomized clinical trial of patients with lumbar spinal stenosis receiving outpatient physical therapy. Patient sample: Fifty-five patients (mean age, 69.5 years; standard deviation, ±7.9 years; 43.1% females) presenting with lumbar spinal stenosis to physical therapy. Outcome measures: The Modified Oswestry Disability Index, Modified Swiss Spinal Stenosis Scale (SSS), Patient Specific Functional Scale, and Numeric Pain Rating Scale (NPRS). Methods: All patients completed the Oswestry Disability Index, SSS, Patient Specific Functional Scale, and NPRS at the baseline examination and at a follow-up. In addition, patients completed a 15-point Global Rating of Change at follow-up, which was used to categorize whether patients experienced clinically meaningful change. Changes in the Oswestry Disability Index, SSS, Patient Specific Functional Scale, and NPRS were then used to assess test-retest reliability, responsiveness, and minimum levels of detectable and clinically important differences. Results: The Oswestry Disability Index was the only outcome measure to exhibit excellent test-retest reliability with an intraclass correlation coefficient of 0.86 (95% confidence interval, 0.63-0.93). All others ranged between fair and moderate. The Oswestry Disability Index, SSS, and Patient Specific Functional Scale exhibited varying levels of responsiveness, each of which was superior to the NPRS. The minimal clinically important difference for the Oswestry Disability Index was five points, the SSS was 0.36 and 0.10 for symptoms subscale and functional subscale, respectively, 1.3 for the Patient Specific Functional Scale, and for the NPRS, 1.25 for back/buttock symptoms and 1.5 for thigh/leg symptoms. Conclusions: The results of our study indicate that the Oswestry Disability Index, SSS, and Patient Specific Functional Scale possess adequate psychometric properties to be used in the outcome assessment of patients with lumbar spinal stenosis. However, further investigation is needed to validate these findings in other samples of patients with lumbar spinal stenosis and nonspecific low back pain. © 2012 Elsevier Inc. All rights reserved

Confirmation of the “disability paradox” among hospice patients: Preservation of quality of life despite physical ailments and psychosocial concerns

Objective: The purpose of this study was to describe quality of life (QOL) and psychosocial and spiritual issues among patients receiving hospice care. Methods: A questionnaire addressing QOL, spirituality, optimism, loss, fears about the terminal process and death anxiety was administered to 66 adults receiving care from 14 hospices. The physical components of QOL (physical symptoms and physical well-being) were rated lower than the psychosocial and spiritual aspects (support, existential well-being, psychological symptoms). Results: Respondents had a strong spiritual connection and a strong sense of hope. Although these individuals did not express anxiety or fear about death, there were concerns about the dying process itself. Also, although most felt at ease with their current situation, respondents were concerned about how their illness was affecting their family. Financial and legal issues did not concern most of these individuals. Significance of results: There were few significant associations between patient characteristics and the QOL or other psychosocial or spiritual issues addressed. Among this older terminally ill population receiving hospice care, whose functional status was fair and for whom physical symptoms were troublesome, QOL persisted and a positive outlook prevailed. © 2003, Cambridge University Press. All rights reserved