901 research outputs found
An Improved Measurement of the Hubble Constant from the Sunyaev-Zeldovich Effect
We present a determination of the Hubble constant from measurements of the
Sunyaev-Zeldovich Effect (SZE) in an orientation-unbiased sample of 7 z < 0.1
galaxy clusters. With improved X-ray models and a more accurate 32-GHz
calibration, we obtain H_O = 64+14-11 +/- 14_sys km/s/Mpc. for a standard CDM
cosmology, or 66+14-11 +/- 15_sys km/s/Mpc for a flat LambdaCDM cosmology. In
combination with X-ray cluster measurements and the BBN value for Omega_B, we
find Omega_M = 0.32 +/- 0.05.Comment: 5 pp., Accepted for publication in ApJ
Assessing An Economics Programme: Hansen Proficiencies, ePortfolio, and Undergraduate Research
Numerous sources calling for more accountability in higher education are putting increased pressure on many economics departments to develop assessment plans. This paper discusses a set of principles for programmatic assessment gleaned from the assessment literature, while highlighting one US economic department's journey to develop an assessment of student learning outcomes based on Hansen's proficiencies. We explain the curriculum reforms that culminate with independent undergraduate research as suggested by the highest level of Hansen's proficiencies. We describe ePortfolios which showcase student abilities and integrate evidence of student learning across the curriculum. For departments without direct guidance from accreditation boards or other agencies, we put forth a process of forming programmatic assessment in economics.
Implementing GRACE Team Care in a Veterans Affairs Medical Center: Lessons Learned and Impacts Observed
In a randomized clinical trial, Geriatric Resources for Assessment and Care of Elders (GRACE), a model of care that works in collaboration with primary care providers (PCPs) and patient-centered medical homes to provide home-based geriatric care management focusing on geriatric syndromes and psychosocial problems commonly found in older adults, improved care quality and reduced acute care use for high-risk, low-income older adults. To assess the effect of GRACE at a Veterans Affairs (VA) Medical Center (VAMC), veterans aged 65 and older from Marion County, Indiana, with PCPs from four of five VAMC clinics who were not on hospice or dialysis were enrolled in GRACE after discharge home from an acute hospitalization. After an initial home-based transition visit to GRACE enrollees, the GRACE team returned to conduct a geriatric assessment. Guided by 12 protocols and input from an interdisciplinary panel and the PCP, the GRACE team developed and implemented a veteran-centric care plan. Hospitalized veterans from the fifth clinic, who otherwise met enrollment criteria, served as a usual-care comparison group. Demographic, comorbidity, and usage data were drawn from VA databases. The GRACE and comparison groups were similar in age, sex, and burden of comorbidity, although predicted risk of 1-year mortality in GRACE veterans was higher. Even so, GRACE enrollment was associated with 7.1% fewer emergency department visits, 14.8% fewer 30-day readmissions, 37.9% fewer hospital admissions, and 28.5% fewer total bed days of care, saving the VAMC an estimated $200,000 per year after program costs during the study for the 179 veterans enrolled in GRACE. Having engaged, enthusiastic VA leadership and GRACE staff; aligning closely with the medical home; and accommodating patient acuity were among the important lessons learned during implementation
An Absolute Flux Density Measurement of the Supernova Remnant Casseopia A at 32 GHz
We report 32 GHz absolute flux density measurements of the supernova remnant
Cas A, with an accuracy of 2.5%. The measurements were made with the 1.5-meter
telescope at the Owens Valley Radio Observatory. The antenna gain had been
measured by NIST in May 1990 to be .
Our observations of Cas A in May 1998 yield . We also report absolute flux density measurements of 3C48, 3C147, 3C286,
Jupiter, Saturn and Mars.Comment: 30 pages, 4 figures; accepted for publication by AJ. Revised
systematic error budget, corrected typos, and added reference
Increasing the density of nanomedicines improves their ultrasound-mediated delivery to tumours
AbstractNanomedicines have provided fresh impetus in the fight against cancer due to their selectivity and power. However, these agents are limited when delivered intravenously due to their rapid clearance from the bloodstream and poor passage from the bloodstream into target tumours. Here we describe a novel stealthing strategy which addresses both these limitations and thereby demonstrate that both the passive and mechanically-mediated tumour accumulation of the model nanomedicine adenovirus (Ad) can be substantially enhanced. In our strategy gold nanoparticles were thoroughly modified with 2kDa polyethyleneglycol (PEG) and then linked to Ad via a single reduction-cleavable 5kDa PEG. The resulting AdâgoldâPEG construct was compared to non-modified Ad or conventionally stealthed Adâpoly[N-(2-hydroxypropyl)methacrylamide] (AdâPHPMA). Notably, although AdâgoldâPEG was of similar size and surface charge to AdâPHPMA the increase in density, resulting from the inclusion of the gold nanoparticles, provided a substantial enhancement of ultrasound-mediated transport. In an in vitro tumour mimicking phantom, the level and distance of AdâgoldâPEG transport was shown to be substantially greater than achieved with AdâPHPMA. In in vivo studies 0.1% of an unmodified Ad dose was shown to accumulate in tumours, whereas over 12% of the injected dose was recovered from the tumours of mice treated with AdâgoldâPEG and ultrasound. Ultimately, a significant increase in anti-tumour efficacy resulted from this strategy. This stealthing and density-increasing technology could ultimately enhance clinical utility of intravenously delivered nanoscale medicines including viruses, liposomes and antibodies
Mass Models and Sunyaev-Zeldovich Effect Predictions for a Flux Limited Sample of 22 Nearby X-Ray Clusters
We define a 90% complete, volume-limited sample of 31 z<0.1 x-ray clusters
and present a systematic analysis of public ROSAT PSPC data on 22 of these
objects. Our efforts are undertaken in support of the Penn/OVRO SZE survey, and
to this end we present predictions for the inverse Compton optical depth
towards all 22 of these clusters. We have performed detailed Monte Carlo
simulations to understand the effects of the cluster profile uncertainties on
the SZE predictions given the OVRO 5.5-meter telescope beam and switching
patterns; we find that the profile uncertainties are one of the least
significant components of our error budget for SZE-based distance measurements.
We also present baryonic masses and baryon mass fractions derived under the
assumption of hydrostatic equilibrium for these 22 clusters. The mean baryonic
mass fraction within R_500 \sim 500 h^-1 kpc is (7.02 \pm 0.28) x 10^-2 h^-3/2,
or (19.8 \pm 0.8) x 10^-2 for h=0.5. We confirm the Allen et al. (1993) claim
of an excess absorbing column density towards Abell 478, but do not find
similar anomalies in the other 21 clusters in our sample. We also find some
evidence for an excess of soft counts in the ROSAT PSPC data.
A measurement of H_o using these models and OVRO SZE determinations will be
presented in a second paper.Comment: 51 pages, 6 figures included in text. Added comparison of different
cosmologies; accepted for publication in Ap
Climate vulnerability assessment for Pacific salmon and steelhead in the California Current Large Marine Ecosystem.
Major ecological realignments are already occurring in response to climate change. To be successful, conservation strategies now need to account for geographical patterns in traits sensitive to climate change, as well as climate threats to species-level diversity. As part of an effort to provide such information, we conducted a climate vulnerability assessment that included all anadromous Pacific salmon and steelhead (Oncorhynchus spp.) population units listed under the U.S. Endangered Species Act. Using an expert-based scoring system, we ranked 20 attributes for the 28 listed units and 5 additional units. Attributes captured biological sensitivity, or the strength of linkages between each listing unit and the present climate; climate exposure, or the magnitude of projected change in local environmental conditions; and adaptive capacity, or the ability to modify phenotypes to cope with new climatic conditions. Each listing unit was then assigned one of four vulnerability categories. Units ranked most vulnerable overall were Chinook (O. tshawytscha) in the California Central Valley, coho (O. kisutch) in California and southern Oregon, sockeye (O. nerka) in the Snake River Basin, and spring-run Chinook in the interior Columbia and Willamette River Basins. We identified units with similar vulnerability profiles using a hierarchical cluster analysis. Life history characteristics, especially freshwater and estuary residence times, interplayed with gradations in exposure from south to north and from coastal to interior regions to generate landscape-level patterns within each species. Nearly all listing units faced high exposures to projected increases in stream temperature, sea surface temperature, and ocean acidification, but other aspects of exposure peaked in particular regions. Anthropogenic factors, especially migration barriers, habitat degradation, and hatchery influence, have reduced the adaptive capacity of most steelhead and salmon populations. Enhancing adaptive capacity is essential to mitigate for the increasing threat of climate change. Collectively, these results provide a framework to support recovery planning that considers climate impacts on the majority of West Coast anadromous salmonids
At the intersection of primary pulmonary myxoid sarcoma and pulmonary angiomatoid fibrous histiocytoma: observations from three new cases
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/107555/1/his12354.pd
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