2,945 research outputs found
Opportunities for Non-Degree Executive Education in Taiwan
Few organizations today have remained untouched by globalization. Whether they are in direct competition with multinational businesses or simply experiencing the pressure of operating within a large competitive universe, virtually all firms now operate in a global economy. As a result of this global competition, U.S. and foreign executives alike have been confronted with the need to broaden their conceptualization and understanding of the impacts of these trends. In response to these needs, both universities and independent training organizations have developed innovative programs for executive training and education. Observers predict that demand for this type of education will grow substantially during the next decade, both within the United States and abroad. In anticipation of this demand and in response to the requirements of the global economy, educational institutions of many forms have begun to focus on international opportunities, both in terms of new markets and also in terms of subject material
Single particle characterization using the soot particle aerosol mass spectrometer (SP-AMS)
Understanding the impact of atmospheric black carbon (BC) containing particles on human health and radiative forcing requires knowledge of the mixing state of BC, including the characteristics of the materials with which it is internally mixed. In this study, we demonstrate for the first time the capabilities of the Aerodyne Soot-Particle Aerosol Mass Spectrometer equipped with a light scattering module (LS-SP-AMS) to examine the mixing state of refractory BC (rBC) and other aerosol components in an urban environment (downtown Toronto). K-means clustering analysis was used to classify single particle mass spectra into chemically distinct groups. One resultant cluster is dominated by rBC mass spectral signals (C+1 to C+5) while the organic signals fall into a few major clusters, identified as hydrocarbon-like organic aerosol (HOA), oxygenated organic aerosol (OOA), and cooking emission organic aerosol (COA). A nearly external mixing is observed with small BC particles only thinly coated by HOA ( 28% by mass on average), while over 90% of the HOA-rich particles did not contain detectable amounts of rBC. Most of the particles classified into other inorganic and organic clusters were not significantly associated with BC. The single particle results also suggest that HOA and COA emitted from anthropogenic sources were likely major contributors to organic-rich particles with low to mid-range aerodynamic diameter (dva). The similar temporal profiles and mass spectral features of the organic clusters and the factors from a positive matrix factorization (PMF) analysis of the ensemble aerosol dataset validate the conventional interpretation of the PMF results
Triggered Star Formation in a Massive Galaxy at z=3.8: 4C41.17
Spectropolarimetric observations obtained with the W. M. Keck Telescope of
the z=3.8 radio galaxy 4C41.17 show that the UV continuum emission from this
galaxy, which is aligned with the radio axis, is unpolarized (P[2sigma] <
2.4%). This implies that scattered AGN light, which is generally the dominant
contributor to the rest-frame UV emission in z~1 radio galaxies, is unlikely to
be a major component of the UV flux from 4C41.17. The spectrum shows absorption
lines that are similar to those detected in the spectra of the recently
discovered population of star forming galaxies at z~2-3. A galaxian outflow may
contribute partially to the low ionization absorption lines; however, the high
velocity wings of the high ionization lines are unlikely to be dominated by a
galaxian wind since the implied outflow mass is very large. The detection of
stellar absorption lines, the shape of the SiIV profile, the unpolarized
continuum, the inability of any AGN-related processes to account for the UV
flux, and the similarity of the UV continuum spectra of 4C41.17 and the nearby
starburst region NGC 1741B1 suggest that the UV light in 4C41.17 is dominated
by young stars. If so, the implied star-formation rate is roughly
140-1100Msun/yr. We discuss the possibility that star formation in 4C41.17 was
triggered by the radio source. Our data are consistent with the hypothesis that
4C41.17 is undergoing its major epoch of star formation at z~4, and that by z~1
it will have evolved to have spectral and morphological properties similar to
those observed in known z~1 powerful radio galaxies.Comment: 28 pages (Latex text + figures); Accepted for publication in The
Astrophysical Journal (Dec 1, 1997 issue
Shocked Molecular Hydrogen in the 3C 326 Radio Galaxy System
The Spitzer spectrum of the giant FR II radio galaxy 3C 326 is dominated by
very strong molecular hydrogen emission lines on a faint IR continuum. The H2
emission originates in the northern component of a double-galaxy system
associated with 3C 326. The integrated luminosity in H2 pure-rotational lines
is 8.0E41 erg/s, which corresponds to 17% of the 8-70 micron luminosity of the
galaxy. A wide range of temperatures (125-1000 K) is measured from the H2 0-0
S(0)-S(7) transitions, leading to a warm H2 mass of 1.1E9 Msun. Low-excitation
ionic forbidden emission lines are consistent with an optical LINER
classification for the active nucleus, which is not luminous enough to power
the observed H2 emission. The H2 could be shock-heated by the radio jets, but
there is no direct indication of this. More likely, the H2 is shock-heated in a
tidal accretion flow induced by interaction with the southern companion galaxy.
The latter scenario is supported by an irregular morphology, tidal bridge, and
possible tidal tail imaged with IRAC at 3-9 micron. Unlike ULIRGs, which in
some cases exhibit H2 line luminosities of comparable strength, 3C 326 shows
little star-formation activity (~0.1 Msun/yr). This may represent an important
stage in galaxy evolution. Starburst activity and efficient accretion onto the
central supermassive black hole may be delayed until the shock-heated H2 can
kinematically settle and coolComment: 27 pages, 7 figures, accepted for publication in the Astrophysical
Journa
In-Home Medication Reviews: A Novel Approach to Improving Patient Care Through Coordination of Care
Abstract The use of multiple medications, in persons 65 years and older, has been linked to increased risk for cognitive impairment, falls, hip fractures, hospitalizations, adverse drug reactions, and mortality. The purpose of this study was to determine if trained undergraduate students, in conjunction with pharmacists, could provide in-home medication reviews and demonstrate benefit to the health and welfare of a senior population affiliated with a primary care facility. Students received training in the completion of an in-home medication inventory, assessing a home for fall risk, and performing blood pressures. Once trained and proven proficient students performed the assessments in homes of Decatur Family Medicine Residency patients 65 years and older. Collected medication inventories were reviewed by a hospital pharmacist for fall risk medications, major drug interactions, or duplicate therapy. Changes to patient management were made by the primary care provider as needed. In all, 75 students visited 118 patients in Fall 2010. Findings from the medication review include: 102 (86%) patients were prescribed at least one fall risk medication; 43% were prescribed 3 or more; 14% had the potential for a major drug interaction; and 7% were prescribed duplicate therapies. Fifty-seven patients had a subsequent change made to their clinical medication list. The results demonstrate that an in-home outreach can be successfully performed by student volunteers and provide data of high clinical relevance and use. This application of the patient-centered medical home can readily and directly improve patient safety
Kinetic theory of point vortices: diffusion coefficient and systematic drift
We develop a kinetic theory for point vortices in two-dimensional
hydrodynamics. Using standard projection operator technics, we derive a
Fokker-Planck equation describing the relaxation of a ``test'' vortex in a bath
of ``field'' vortices at statistical equilibrium. The relaxation is due to the
combined effect of a diffusion and a drift. The drift is shown to be
responsible for the organization of point vortices at negative temperatures. A
description that goes beyond the thermal bath approximation is attempted. A new
kinetic equation is obtained which respects all conservation laws of the point
vortex system and satisfies a H-theorem. Close to equilibrium this equation
reduces to the ordinary Fokker-Planck equation.Comment: 50 pages. To appear in Phys. Rev.
WP 2017-372
As workers age, their physical and cognitive abilities tend to decline. This could lead to a mismatch between workers’ resources and the demands of their jobs, restricting future work. We use longitudinal data from the Health and Retirement Study (HRS) linked to detailed occupational characteristics from the O*NET project to investigate how mismatches between job demands and workers’ resources in two physical and two cognitive domains affect retirement outcomes. We estimate how changes in physical and cognitive resources as well as their interactions with occupational job-demands affect changes in 1) subjective reports of work-limiting health problems; 2) mental health; and 3) subjective probabilities of working past age 65. We also estimate hazard models for transitions from full-time work to retirement. We found that declines in physical and cognitive resources are strong predictors of all outcomes: Fewer resources lead to greater reporting of work-limiting health problems; decline in mental health; smaller subjective probabilities of working full-time past age 65; and more transitions from work to retirement. The interaction of resources with job demands, however, is only statistically significant for workers with large-muscle limitations who are more likely to report changes in outcomes when they work in occupations that rely heavily on physical strength. In contrast, the effects of declines in fine motor skills and cognition do not show statistically significant differences by occupational job demands. It appears cognitive and fine motor skills, at least as measured in the HRS, are universally important determinants of working, not specific to certain occupations.Social Security Administration, RRC08098401-09, R-UM17-10https://deepblue.lib.umich.edu/bitstream/2027.42/142346/1/wp372.pd
International Space Station Spacecraft Charging Environments: Modeling, Measurement and Implications for Future Human Space Flight Programs
Spacecraft charging analysis and migration is an interdisciplinary subject combining aspects of electrostatics, plasma physics, ionizing radiation, and materials science, as well as electronic system electromagnetic interference and compatibility (EMI/EMC) effects. Spacecraft charging hazards are caused by the accumulation of electrical charge on spacecraft and spacecraft components produced by interactions with space plasmas, energetic charged particles, and solar UV photons as well as spacecraft electrical power and propulsion systems operations. Spacecraft charging hazard effects include both hard and soft avionics and electrical power system anomalies and have led to the partial or complete loss of numerous spacecraft. The International Space Station (ISS) orbital altitude and inclination (~400 km and 51.6o) determined the dominant natural environment factors affecting ISS spacecraft charging; high speed flight through the geomagnetic field and electrical power system interaction with the cold, high-density ionospheric plasma. In addition ISS is exposed to energetic auroral electrons at high latitude. In this paper we present the results of ISS spacecraft charging modeling and measurements and compare the measurements with numerical modeling of ISS charging processes. ISS is a large metallic structure and flight through the geomagnetic field at orbital speed dominates ISS charging. Collection of ionospheric electrons by the large 160V PV arrays is the next largest contributor. Charging by auroral electrons is detectable but makes a relatively minor contribution. Finally we report the observation of short duration (~ 1 sec) rapid charging peaks associated with shunt/un-shunt operations of the 160V PV arrays, a phenomena not predicted before flight. ISS spacecraft charging environments are radically different from those encountered at higher altitudes in Earth?s magnetosphere and in cis-Lunar space. We present a brief review of those charging environments and an assessment of the applicability of ISS spacecraft charging management and experience to future human spaceflight programs beyond LEO
Noise2Recon: Enabling Joint MRI Reconstruction and Denoising with Semi-Supervised and Self-Supervised Learning
Deep learning (DL) has shown promise for faster, high quality accelerated MRI
reconstruction. However, supervised DL methods depend on extensive amounts of
fully-sampled (labeled) data and are sensitive to out-of-distribution (OOD)
shifts, particularly low signal-to-noise ratio (SNR) acquisitions. To alleviate
this challenge, we propose Noise2Recon, a model-agnostic, consistency training
method for joint MRI reconstruction and denoising that can use both
fully-sampled (labeled) and undersampled (unlabeled) scans in semi-supervised
and self-supervised settings. With limited or no labeled training data,
Noise2Recon outperforms compressed sensing and deep learning baselines,
including supervised networks, augmentation-based training, fine-tuned
denoisers, and self-supervised methods, and matches performance of supervised
models, which were trained with 14x more fully-sampled scans. Noise2Recon also
outperforms all baselines, including state-of-the-art fine-tuning and
augmentation techniques, among low-SNR scans and when generalizing to other OOD
factors, such as changes in acceleration factors and different datasets.
Augmentation extent and loss weighting hyperparameters had negligible impact on
Noise2Recon compared to supervised methods, which may indicate increased
training stability. Our code is available at https://github.com/ad12/meddlr
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