13,145 research outputs found
The Need for An Automated Acuity Tool for Children With Special Health Care Needs
Children with special health care needs (CSHCN) often require extended and continuous contact with health care professionals due to their chronic conditions. Additionally, some of these children have other non-health burdens, including multiple problems with access to care, that make it even more difficult to treat their medical illness. These extra obstacles illustrate that effective care for CSHCN requires proper care coordination among a network of doctors, nurses, and care coordinators. Unfortunately, care coordination has been inadequate due to large caseload assignments. An automated acuity tool that reassesses the child’s acuity (low, medium or high) regularly would help balance the caseloads and improve care coordination. Unique to this design, the tool would not only describe disease needs, but also account for modifiable psychosocial characteristics. It would first be deployed in South Florida where the population of CSHCN mainly consists of low-income, minority back- grounds with language barriers. The implementation of an acuity tool provides a thoughtful way to tackle the new challenges within the established structure of pediatric care
Modified gravity without dark matter
On an empirical level, the most successful alternative to dark matter in
bound gravitational systems is the modified Newtonian dynamics, or MOND,
proposed by Milgrom. Here I discuss the attempts to formulate MOND as a
modification of General Relativity. I begin with a summary of the
phenomenological successes of MOND and then discuss the various covariant
theories that have been proposed as a basis for the idea. I show why these
proposals have led inevitably to a multi-field theory. I describe in some
detail TeVeS, the tensor-vector-scalar theory proposed by Bekenstein, and
discuss its successes and shortcomings. This lecture is primarily pedagogical
and directed to those with some, but not a deep, background in General
RelativityComment: 28 pages, 10 figures, lecture given at Third Aegean Summer School,
The Invisible Universe: Dark Matter and Dark Energy, minor errors corrected,
references update
Stellar and Gaseous Nuclear Disks Observed in Nearby (U)LIRGs
We present near-infrared integral field spectroscopy of the central
kiloparsec of 17 nearby luminous and ultra-luminous infrared galaxies
undergoing major mergers. These observations were taken with OSIRIS assisted by
the Keck I and II Adaptive Optics systems, providing spatial resolutions of a
few tens of parsecs. The resulting kinematic maps reveal gas disks in at least
16 out of 19 nuclei and stellar disks in 11 out of 11 nuclei observed in these
galaxy merger systems. In our late-stages mergers, these disks are young
(stellar ages Myr) and likely formed as gas disks which became unstable
to star formation during the merger. On average, these disks have effective
radii of a few hundred parsecs, masses between and ,
and between 1 and 5. These disks are similar to those created in
high-resolution hydrodynamical simulations of gas-rich galaxy mergers, and
favor short coalescence times for binary black holes. The few galaxies in our
sample in earlier stages of mergers have disks which are larger
( pc) and likely are remnants of the galactic disks that
have not yet been completely disrupted by the merger.Comment: accepted for publication in Ap
Recommended from our members
Information Sharing for Care Coordination
Teamwork and care coordination are of increasing importance to health care delivery and patient safety and health. This paper describes our initial work on developing agents that are able to make intelligent information sharing decisions to support a diverse, evolving team of care providers in constructing and maintaining a shared plan that operates in uncertain environments and over a long time horizon.Engineering and Applied Science
Shocked Gas in IRAS F17207-0014: ISM Collisions and Outflows
We combine optical and near-infrared AO-assisted integral field observations
of the merging ULIRG IRAS F17207-0014 from the Wide-Field Spectrograph (WiFeS)
and Keck/OSIRIS. The optical emission line ratios [N II]/H, [S
II]/H, and [O I]/H reveal a mixing sequence of shocks present
throughout the galaxy, with the strongest contributions coming from large radii
(up to 100% at 5 kpc in some directions), suggesting galactic-scale
winds. The near-infrared observations, which have approximately 30 times higher
spatial resolution, show that two sorts of shocks are present in the vicinity
of the merging nuclei: low-level shocks distributed throughout our
field-of-view evidenced by an H/Br line ratio of 0.6-4, and
strong collimated shocks with a high H/Br line ratio of
4-8, extending south from the two nuclear disks approximately 400 pc
(0.5 arcsec). Our data suggest that the diffuse shocks are caused by the
collision of the interstellar media associated with the two progenitor galaxies
and the strong shocks trace the base of a collimated outflow coming from the
nucleus of one of the two disks.Comment: accepted to MNRA
Following Black Hole Scaling Relations Through Gas-Rich Mergers
We present black hole mass measurements from kinematic modeling of
high-spatial resolution integral field spectroscopy of the inner regions of 9
nearby (ultra-)luminous infrared galaxies in a variety of merger stages. These
observations were taken with OSIRIS and laser guide star adaptive optics on the
Keck I and Keck II telescopes, and reveal gas and stellar kinematics inside the
spheres of influence of these supermassive black holes. We find that this
sample of black holes are overmassive ( M) compared to
the expected values based on black hole scaling relations, and suggest that the
major epoch of black hole growth occurs in early stages of a merger, as opposed
to during a final episode of quasar-mode feedback. The black hole masses
presented are the dynamical masses enclosed in 25pc, and could include
gas which is gravitationally bound to the black hole but has not yet lost
sufficient angular momentum to be accreted. If present, this gas could in
principle eventually fuel AGN feedback or be itself blown out from the system.Comment: accepted to Ap
MOND vs. Newtonian dynamics in early-type galaxies. The case of NGC 4649 (M60)
Context: Regarding the significant interest in both dark matter and the
application of MOND to early-type galaxies, we investigate the MOND theory by
comparing its predictions, for models of constant mass-to-light ratio, with
observational data of the early-type galaxy NGC 4649.
Aims: We study whether measurements for NGC 3379 and NGC 1399 are typical of
early-type systems and we test the assumption of a Newtonian constant M/L ratio
underlying most of the published models.
Methods: We employ the globular clusters of NGC 4649 as a mass tracer. The
Jeans equation is calculated for both MOND and constant mass-to-light ratio
assumptions. Spherical symmetry is assumed and the calculations are performed
for both isotropic and anisotropic cases.
Results: We found that both Jeans models with the assumption of a constant
mass-to-light ratio and different MOND models provide good agreement with the
observed values of the velocity dispersion. The most accurate fits of the
velocity dispersion were obtained for the mass-to-light ratio in the B-band,
which was equal to 7, implying that there is no need for significant amounts of
dark matter in the outer parts (beyond 3 effective radii) of this galaxy. We
also found that tangential anisotropies are most likely present in NGC 4649.Comment: 6 pages, 4 figure
A Survey of Atomic Carbon [C I] in High-redshift Main-Sequence Galaxies
We present the first results of an ALMA survey of the lower fine structure
line of atomic carbon [C I](^3P_1\,-\,^{3}P_0) in far infrared-selected
galaxies on the main sequence at in the COSMOS field. We compare our
sample with a comprehensive compilation of data available in the literature for
local and high-redshift starbursting systems and quasars. We show that the [C
I]() luminosity correlates on global scales with the
infrared luminosity similarly to low- CO transitions. We report
a systematic variation of L'_{\rm [C\,I]^3P_1\,-\, ^3P_0}/ as a
function of the galaxy type, with the ratio being larger for main-sequence
galaxies than for starbursts and sub-millimeter galaxies at fixed .
The L'_{\rm [C\,I]^3P_1\,-\, ^3P_0}/ and / mass ratios are similar for main-sequence galaxies and for
local and high-redshift starbursts within a 0.2 dex intrinsic scatter,
suggesting that [C I] is a good tracer of molecular gas mass as CO and dust. We
derive a fraction of %
of the total carbon mass in the atomic neutral phase. Moreover, we estimate the
neutral atomic carbon abundance, the fundamental ingredient to calibrate [C I]
as a gas tracer, by comparing L'_{\rm [C\,I]^3P_1\,-\, ^3P_0} and available
gas masses from CO lines and dust emission. We find lower [C I] abundances in
main-sequence galaxies than in starbursting systems and sub-millimeter
galaxies, as a consequence of the canonical and gas-to-dust
conversion factors. This argues against the application to different galaxy
populations of a universal standard [C I] abundance derived from highly biased
samples.Comment: 14 pages + Appendix. Accepted for publication in ApJ. All the data
tables in Appendix will be also released in electronic forma
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