1,057 research outputs found
A Systems Approach to Healthcare Efficiency Improvement
AbstractHealthcare patient outcomes and healthcare costs, in the context of the healthcare delivery system, is a prominent societal issue for the U.S. Although improvements have been achieved, they are silo-centric, specific to a single area or discipline. It is clear that improvements need to be transferred across the healthcare delivery system in a broader sense. To that end, the ability to measure a change in the system is paramount in determining progress and in what parts of the system are impacted. The research work presented describes a case of how an Electronic Medical Record (EMR) system implementation can be measured within a systems or systems engineering context. In the first phase, time motion study has been employed to assess physician workflow. In this manner, data collection, analysis, and inferences elicited can be quickly assessed by subject matter experts for effectiveness. The objective of this collaborative work is that it demonstrates a systems engineering driven application of the improvement of an orthopaedic office that may then be generalized to a broader context. This works employs a phased approach which allows for synchronization between one set of tools or methodologies from one phase that inform and provide insight for the next. Additionally it facilitates an iterative effort as each phase will assess and reassess the key stakeholders and take into account the process/product life cycle thus allowing refinement of the previous phase and its results. The progression from one phase to another provides the means of measuring the progress and impact. The partnership between the Department of Orthopaedics and the Department of Systems and Industrial Engineering at the University of Arizona, provides a real-life setting for testing our hypotheses. All of the features described in this implementation make up a methodological framework that will render implications for engineers, physicians, patients, and policy makers
LINER-like Extended Nebulae in ULIRGs: Shocks Generated by Merger Induced Flows
In this work we studied the two-dimensional ionization structure of the
circumnuclear and extranuclear regions in a sample of six low-z Ultraluminous
Infrared Galaxies using Integral Field Spectroscopy. The ionization conditions
in the extranuclear regions of these galaxies (~5-15 kpc) are typical of LINERs
as obtained from the Veilleux-Osterbrock line ratio diagnostic diagrams. The
range of observed line ratios is best explained by the presence of fast shocks
with velocities of 150 to 500 km s^{-1}, while the ionization by an AGN or
nuclear starburst is in general less likely. The comparison of the
two-dimensional ionization level and velocity dispersion in the extranuclear
regions of these galaxies shows a positive correlation, further supporting the
idea that shocks are indeed the main cause of ionization.
The origin of these shocks is also investigated. Despite the likely presence
of superwinds in the circumnuclear regions of these systems, no evidence for
signatures of superwinds such as double velocity components are found in the
extended extranuclear regions. We consider a more likely explanation for the
presence of shocks, the existence of tidally induced large scale gas flows
caused by the merging process itself, as evidenced by the observed velocity
fields characterized by peak-to-peak velocities of 400 km s^{-1}, and velocity
dispersions of up to 200 km s^{-1}.Comment: 21 pages, 5 figures, accepted for publication in The Astrophysical
Journa
Synthesis and Characterization of Three-Coordinate Ni(III)-Imide Complexes
A new family of low-coordinate nickel imides supported by 1,2-bis(di-tert-butylphosphino)ethane was synthesized. Oxidation of nickel(II) complexes led to the formation of both aryl- and alkyl-substituted nickel(III)-imides, and examples of both types have been isolated and fully characterized. The aryl substituent that proved most useful in stabilizing the Ni(III)-imide moiety was the bulky 2,6-dimesitylphenyl. The two Ni(III)-imide compounds showed different variable-temperature magnetic properties but analogous EPR spectra at low temperatures. To account for this discrepancy, a low-spin/high-spin equilibrium was proposed to take place for the alkyl-substituted Ni(III)-imide complex. This proposal was supported by DFT calculations. DFT calculations also indicated that the unpaired electron is mostly localized on the imide nitrogen for the Ni(III) complexes. The results of reactions carried out in the presence of hydrogen donors supported the findings from DFT calculations that the adamantyl substituent was a significantly more reactive hydrogen-atom abstractor. Interestingly, the steric properties of the 2,6-dimesitylphenyl substituent are important not only in protecting the Ni═N core but also in favoring one rotamer of the resulting Ni(III)-imide, by locking the phenyl ring in a perpendicular orientation with respect to the NiPP plane
Oscillatory relaxation of zonal flows in a multi-species stellarator plasma
The low frequency oscillatory relaxation of zonal potential perturbations is
studied numerically in the TJ-II stellarator (where it was experimentally
detected for the first time). It is studied in full global gyrokinetic
simulations of multi-species plasmas. The oscillation frequency obtained is
compared with predictions based on single-species simulations using simplified
analytical relations. It is shown that the frequency of this oscillation for a
multi-species plasma can be accurately obtained from single-species
calculations using extrapolation formulas. The damping of the oscillation and
the influence of the different inter-species collisions is studied in detail.
It is concluded that taking into account multiple kinetic ions and electrons
with impurity concentrations realistic for TJ-II plasmas allows to account for
the values of frequency and damping rate in zonal flows relaxations observed
experimentally.Comment: 11 figures, 22 page
Detection and Mapping of Decoupled Stellar and Ionized Gas Structures in the Ultraluminous Infrared Galaxy IRAS 12112+0305
Integral field optical spectroscopy with the INTEGRAL fiber-fed system and
HST optical imaging are used to map the complex stellar and warm ionized gas
structure in the ultraluminous infrared galaxy IRAS 12112+0305. Images
reconstructed from wavelength-delimited extractions of the integral field
spectra reveal that the observed ionized gas distribution is decoupled from the
stellar main body of the galaxy, with the dominant continuum and emission-line
regions separated by projected distances of up to 7.5 kpc. The two optical
nuclei are detected as apparently faint emission-line regions, and their
optical properties are consistent with being dust-enshrouded weak-[OI] LINERs.
The brightest emission-line region is associated with a faint (m_{I}= 20.4),
giant HII region of 600 pc diameter, where a young (about 5 Myr) massive
cluster of about 2 10 dominates the ionization.
Internal reddening towards the line-emitting regions and the optical nuclei
ranges from 1 to 8 magnitudes, in the visual. Taken the reddening into aacount,
the overall star formation in IRAS 12112+0305 is dominated by starbursts
associated with the two nuclei and corresponding to a star formation rate of 80
yr.Comment: 2 figures, accepted to Ap.J. Letter
Integral Field Spectroscopy based H\alpha\ sizes of local Luminous and Ultraluminous Infrared Galaxies. A Direct Comparison with high-z Massive Star Forming Galaxies
Aims. We study the analogy between local U/LIRGs and high-z massive SFGs by
comparing basic H{\alpha} structural characteristics, such as size, and
luminosity (and SFR) surface density, in an homogeneous way (i.e. same tracer
and size definition, similar physical scales). Methods. We use Integral Field
Spectroscopy based H{\alpha} emission maps for a representative sample of 54
local U/LIRGs (66 galaxies). From this initial sample we select 26 objects with
H{\alpha} luminosities (L(H{\alpha})) similar to those of massive (i.e. M\ast
\sim 10^10 M\odot or larger) SFGs at z \sim 2, and observed on similar physical
scales. Results. The sizes of the H{\alpha} emitting region in the sample of
local U/LIRGs span a large range, with r1/2(H{\alpha}) from 0.2 to 7 kpc.
However, about 2/3 of local U/LIRGs with Lir > 10^11.4 L\odot have compact
H{\alpha} emission (i.e. r1/2 < 2 kpc). The comparison sample of local U/LIRGs
also shows a higher fraction (59%) of objects with compact H{\alpha} emission
than the high-z sample (25%). This gives further support to the idea that for
this luminosity range the size of the star forming region is a distinctive
factor between local and distant galaxies of similar SF rates. However, when
using H{\alpha} as a tracer for both local and high-z samples, the differences
are smaller than the ones recently reported using a variety of other tracers.
Despite of the higher fraction of galaxies with compact H{\alpha} emission, a
sizable group (\sim 1/3) of local U/LIRGs are large (i.e. r1/2 > 2 kpc). These
are systems showing pre-coalescence merger activity and they are
indistinguishable from the massive high-z SFGs galaxies in terms of their
H{\alpha} sizes, and luminosity and SFR surface densities.Comment: Accepted for publication in A&A. (!5 pages, 7 figures, 2 tables
Kinematic modelling of a 3-axis NC machine tool in linear and circular interpolation
Machining time is a major performance criterion when it comes to high-speed
machining. CAM software can help in estimating that time for a given strategy.
But in practice, CAM-programmed feed rates are rarely achieved, especially
where complex surface finishing is concerned. This means that machining time
forecasts are often more than one step removed from reality. The reason behind
this is that CAM routines do not take either the dynamic performances of the
machines or their specific machining tolerances into account. The present
article seeks to improve simulation of high-speed NC machine dynamic behaviour
and machining time prediction, offering two models. The first contributes
through enhanced simulation of three-axis paths in linear and circular
interpolation, taking high-speed machine accelerations and jerks into account.
The second model allows transition passages between blocks to be integrated in
the simulation by adding in a polynomial transition path that caters for the
true machining environment tolerances. Models are based on respect for path
monitoring. Experimental validation shows the contribution of polynomial
modelling of the transition passage due to the absence of a leap in
acceleration. Simulation error on the machining time prediction remains below
1%
Integrated spectra extraction based on signal-to-noise optimization using Integral Field Spectroscopy
We propose and explore the potential of a method to extract high
signal-to-noise (S/N) integrated spectra related to physical and/or
morphological regions on a 2-dimensional field using Integral Field
Spectroscopy (IFS) observations by employing an optimization procedure based on
either continuum (stellar) or line (nebular) emission features. The
optimization method is applied to a set of IFS VLT-VIMOS observations of
(U)LIRG galaxies, describing the advantages of the optimization by comparing
the results with a fixed-aperture, single spectrum case, and by implementing
some statistical tests. We demonstrate that the S/N of the IFS optimized
integrated spectra is significantly enhanced when compared with the single
aperture unprocessed case. We provide an iterative user-friendly and versatile
IDL algorithm that allows the user to spatially integrate spectra following
more standard procedures. This is made available to the community as part of
the PINGSoft IFS software package.Comment: Accepted for publication in Astronomy & Astrophysics, 12 pages, 7
figure
The rationale, design, and methods of a randomized, controlled trial to evaluate the efficacy and safety of an active strategy for the diagnosis and treatment of acute pulmonary embolism during exacerbations of chronic obstructive pulmonary disease.
Introduction: Some previous studies have suggested a high prevalence of pulmonary embolism
(PE) during exacerbations of chronic obstructive pulmonary disease (ECOPD). The SLICE trial
aims to assess the efficacy and safety of an active strategy for the diagnosis and treatment of PE
(vs usual care) in patients hospitalized because of ECOPD.
Methods: SLICE is a phase III, prospective, international, multicenter, randomized, open-label,
and parallel-group trial. A total of 746 patients hospitalized because of ECOPD will be random-
ized in a 1:1 fashion to receive either an active strategy for the diagnosis and anticoagulant
treatment of PE or usual care (ie, standard care without any diagnostic test for diagnosing PE).
The primary outcome is a composite of all-cause death, non-fatal (recurrent) venous thrombo-
embolism (VTE), or readmission for ECOPD within 90 days after enrollment. Secondary out-
comes are (a) death from any cause within 90 days after enrollment, (b) non-fatal (recurrent) VTE within 90 days after enrollment, (c) readmission within 90 days after enrollment, and
(d) length of hospital stay.
Results: Enrollment started in September 2014 and is expected to proceed until 2020. Median
age of the first 443 patients was 71 years (interquartile range, 64-78), and 26% were female.
Conclusions: This multicenter trial will determine the value of detecting PEs in patients with
ECOPD. This has implications for COPD patient morbidity and mortality.Ministerio de Salud, Instituto de Salud Carlos III: PI14/0040
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