50 research outputs found
Longitudinal Effects of Medical Comorbidities on Functional Outcome and Life Satisfaction After Traumatic Brain Injury: An Individual Growth Curve Analysis of NIDILRR Traumatic Brain Injury Model System Data
Objective:
To explore associations of specific physical and neuropsychiatric medical conditions to motor and cognitive functioning and life satisfaction over the first 10 years following traumatic brain injury (TBI).
Setting:
Telephone follow-up through six TBI Model System centers.
Participants:
404 individuals or proxies with TBI enrolled in the TBI Model System longitudinal study participating in 10 year follow-up.
Design:
Individual growth curve analysis.
Main Measures:
FIM™ Motor and Cognitive subscales, Life Satisfaction Scales, Medical and Mental Health Co-Morbidities Interview.
Results:
Hypertension, diabetes, cancers, rheumatoid arthritis, and anxiety negatively affected the trajectory of motor functioning over time. Diabetes, cancers, chronic bronchitis, anxiety, and depression negatively impacted cognitive functioning. Numerous neuropsychiatric conditions (sleep disorder, alcoholism, drug addiction, anxiety, panic attacks, PTSD, depression, bipolar disorder), as well as hypertension, liver disease, and cancers diminished life satisfaction. Other medical conditions had a negative effect on functioning and satisfaction at specific follow-up periods.
Conclusion:
Natural recovery after TBI may include delayed onset of functional decline or early recovery followed by progressive deterioration and is negatively affected by medical comorbidities. Results contribute to the growing evidence that TBI is most appropriately treated as a chronic medical condition complicated by a variety of comorbid conditions
Prevalence of Medical and Psychiatric Comorbidities Following Traumatic Brain Injury
Objective:
To examine the prevalence of selected medical and psychiatric comorbidities that existed prior to, or up to 10 years following, traumatic brain injury (TBI) requiring acute rehabilitation.
Design:
Retrospective cohort.
Setting:
Six TBI Model Systems centers.
Participants:
404 participants in the TBI Model System National Database who experienced TBI 10 years prior.
Interventions:
Not applicable.
Main Outcome Measure:
Self-reported medical and psychiatric comorbidities and the onset time of each endorsed comorbidity.
Results:
At 10 years post-injury, the most common comorbidities developing post-injury, in order, were: back pain, depression, hypertension, anxiety, fractures, high blood cholesterol, sleep disorders, panic attacks, osteoarthritis, and diabetes. Comparing those 50 years and older to those less than 50 years, diabetes (OR = 3.54; p = 0.0016), high blood cholesterol (OR = 2.04; p = 0.0092), osteoarthritis (OR = 2.02; p = 0.0454), and hypertension (OR = 1.84; p = 0.0175) were significantly more prevalent in the older cohort while panic attacks (OR = 0.33; p = 0.0022) were significantly more prevalent in the younger cohort. No significant differences in prevalence rates between the older and younger cohorts were found for back pain, depression, anxiety, fractures, or sleep disorders.
Conclusions:
People with moderate-severe TBI experience other medical and mental health comorbidities during the long-term course of recovery and life after injury. The findings can inform further investigation into comorbidities associated with TBI and the role of medical care, surveillance, prevention, lifestyle, and healthy behaviors in potentially modifying their presence and/or prevalence over the life span
New constraint on cosmological variation of the proton-to-electron mass ratio from Q0528-250
Molecular hydrogen transitions in quasar spectra can be used to constrain
variation in the proton-to-electron mass ratio, , at high
redshifts (). We present here an analysis of a new spectrum of the
quasar Q0528250, obtained on VLT/UVES (the Ultraviolet and Visual Echelle
Spectrograph, on the Very Large Telescope), and analyse the well-known H
absorber at in this spectrum. For the first time we detect HD
(deuterated molecular hydrogen) in this system with a column density of
; HD is sensitive to variation in
, and so we include it in our analysis. Using 76 H and 7 HD
transitions we constrain variation in from the current laboratory value
to be , which is consistent with no cosmological variation in , as well
as with previous results from other H/HD absorbers. The main sources of
systematic uncertainty relate to accurate wavelength calibration of the spectra
and the re-dispersion of multiple telescope exposures onto the one pixel grid.Comment: 30 pages, 6 figures + 14 supplementary figures. Accepted for
publication for MNRA
A prospective evaluation of the safety and efficacy of the TAXUS Element paclitaxel-eluting coronary stent system for the treatment of de novo coronary artery lesions: Design and statistical methods of the PERSEUS clinical program
<p>Abstract</p> <p>Background</p> <p>Paclitaxel-eluting stents decrease angiographic and clinical restenosis following percutaneous coronary intervention compared to bare metal stents. TAXUS Element is a third-generation paclitaxel-eluting stent which incorporates a novel, thinner-strut, platinum-enriched metal alloy platform. The stent is intended to have enhanced radiopacity and improved deliverability compared to other paclitaxel-eluting stents. The safety and efficacy of the TAXUS Element stent are being evaluated in the pivotal PERSEUS clinical trials.</p> <p>Methods/Design</p> <p>The PERSEUS trials include two parallel studies of the TAXUS Element stent in single, de novo coronary atherosclerotic lesions. The PERSEUS Workhorse study is a prospective, randomized (3:1), single-blind, non-inferiority trial in subjects with lesion length ≤28 mm and vessel diameter ≥2.75 mm to ≤4.0 mm which compares TAXUS Element to the TAXUS Express<sup>2 </sup>paclitaxel-eluting stent system. The Workhorse study employs a novel Bayesian statistical approach that uses prior information to limit the number of study subjects exposed to the investigational device and thus provide a safer and more efficient analysis of the TAXUS Element stent. PERSEUS Small Vessel is a prospective, single-arm, superiority trial in subjects with lesion length ≤20 mm and vessel diameter ≥2.25 mm to <2.75 mm that compares TAXUS Element with a matched historical bare metal Express stent control.</p> <p>Discussion</p> <p>The TAXUS PERSEUS clinical trial program uses a novel statistical approach to evaluate whether design and metal alloy iterations in the TAXUS Element stent platform provide comparable safety and improved procedural performance compared to the previous generation Express stent. PERSEUS trial enrollment is complete and primary endpoint data are expected in 2010. PERSEUS Workhorse and Small Vessel are registered at <url>http://www.clinicaltrials.gov</url>, identification numbers NCT00484315 and NCT00489541.</p
Upper limits on the strength of periodic gravitational waves from PSR J1939+2134
The first science run of the LIGO and GEO gravitational wave detectors
presented the opportunity to test methods of searching for gravitational waves
from known pulsars. Here we present new direct upper limits on the strength of
waves from the pulsar PSR J1939+2134 using two independent analysis methods,
one in the frequency domain using frequentist statistics and one in the time
domain using Bayesian inference. Both methods show that the strain amplitude at
Earth from this pulsar is less than a few times .Comment: 7 pages, 1 figure, to appear in the Proceedings of the 5th Edoardo
Amaldi Conference on Gravitational Waves, Tirrenia, Pisa, Italy, 6-11 July
200
Improving the sensitivity to gravitational-wave sources by modifying the input-output optics of advanced interferometers
We study frequency dependent (FD) input-output schemes for signal-recycling
interferometers, the baseline design of Advanced LIGO and the current
configuration of GEO 600. Complementary to a recent proposal by Harms et al. to
use FD input squeezing and ordinary homodyne detection, we explore a scheme
which uses ordinary squeezed vacuum, but FD readout. Both schemes, which are
sub-optimal among all possible input-output schemes, provide a global noise
suppression by the power squeeze factor, while being realizable by using
detuned Fabry-Perot cavities as input/output filters. At high frequencies, the
two schemes are shown to be equivalent, while at low frequencies our scheme
gives better performance than that of Harms et al., and is nearly fully
optimal. We then study the sensitivity improvement achievable by these schemes
in Advanced LIGO era (with 30-m filter cavities and current estimates of
filter-mirror losses and thermal noise), for neutron star binary inspirals, and
for narrowband GW sources such as low-mass X-ray binaries and known radio
pulsars. Optical losses are shown to be a major obstacle for the actual
implementation of these techniques in Advanced LIGO. On time scales of
third-generation interferometers, like EURO/LIGO-III (~2012), with
kilometer-scale filter cavities, a signal-recycling interferometer with the FD
readout scheme explored in this paper can have performances comparable to
existing proposals. [abridged]Comment: Figs. 9 and 12 corrected; Appendix added for narrowband data analysi
Search for gravitational wave bursts in LIGO's third science run
We report on a search for gravitational wave bursts in data from the three
LIGO interferometric detectors during their third science run. The search
targets subsecond bursts in the frequency range 100-1100 Hz for which no
waveform model is assumed, and has a sensitivity in terms of the
root-sum-square (rss) strain amplitude of hrss ~ 10^{-20} / sqrt(Hz). No
gravitational wave signals were detected in the 8 days of analyzed data.Comment: 12 pages, 6 figures. Amaldi-6 conference proceedings to be published
in Classical and Quantum Gravit
Do Market-Level Hospital and Physician Resources Affect Small Area Variation in Hospital Use?
This study evaluates the effect of market-level physician and hospital resources on hospital use. It is anticipated that higher hospital discharges are associated with (1) greater hospital and physician resources, (2) more differentiated hospital and physician resources, and (3) higher levels of teaching intensity in the community. Data on 14 modified diagnostically related groups (DRGs) and 58 hospital market communities in Michigan are analyzed during a 7-year period. Findings indicate that physician resources, hospital resources, differentiation of hospital and physician resources, and teaching intensity contribute only modestly to discharges, holding constant the socioeconomic attributes of the community and adjusting for the variation in hospital use over time. With the inclusion of hospital and physician resource variables, socioeconomic factors remain important determinants of the variation across market communities. Findings are discussed in terms of their implications for health care organizations, managed care programs, and cost control efforts in general.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68450/2/6.pd
Upper limit map of a background of gravitational waves
We searched for an anisotropic background of gravitational waves using data
from the LIGO S4 science run and a method that is optimized for point sources.
This is appropriate if, for example, the gravitational wave background is
dominated by a small number of distinct astrophysical sources. No signal was
seen. Upper limit maps were produced assuming two different power laws for the
source strain power spectrum. For an f^-3 power law and using the 50 Hz to 1.8
kHz band the upper limits on the source strain power spectrum vary between
1.2e-48 Hz^-1 (100 Hz/f)^3 and 1.2e-47 Hz^-1 (100 Hz /f)^3, depending on the
position in the sky. Similarly, in the case of constant strain power spectrum,
the upper limits vary between 8.5e-49 Hz^-1 and 6.1e-48 Hz^-1.
As a side product a limit on an isotropic background of gravitational waves
was also obtained. All limits are at the 90% confidence level. Finally, as an
application, we focused on the direction of Sco-X1, the closest low-mass X-ray
binary. We compare the upper limit on strain amplitude obtained by this method
to expectations based on the X-ray luminosity of Sco-X1.Comment: 11 pages, 9 figures, 2 table
Upper limit map of a background of gravitational waves
We searched for an anisotropic background of gravitational waves using data
from the LIGO S4 science run and a method that is optimized for point sources.
This is appropriate if, for example, the gravitational wave background is
dominated by a small number of distinct astrophysical sources. No signal was
seen. Upper limit maps were produced assuming two different power laws for the
source strain power spectrum. For an f^-3 power law and using the 50 Hz to 1.8
kHz band the upper limits on the source strain power spectrum vary between
1.2e-48 Hz^-1 (100 Hz/f)^3 and 1.2e-47 Hz^-1 (100 Hz /f)^3, depending on the
position in the sky. Similarly, in the case of constant strain power spectrum,
the upper limits vary between 8.5e-49 Hz^-1 and 6.1e-48 Hz^-1.
As a side product a limit on an isotropic background of gravitational waves
was also obtained. All limits are at the 90% confidence level. Finally, as an
application, we focused on the direction of Sco-X1, the closest low-mass X-ray
binary. We compare the upper limit on strain amplitude obtained by this method
to expectations based on the X-ray luminosity of Sco-X1.Comment: 11 pages, 9 figures, 2 table