1,273 research outputs found
Toward Integration of mHealth in Primary Care in the Netherlands: A Qualitative Analysis of Stakeholder Perspectives
Background: There is a growing need to structurally change the way chronic illness care is organized as health systems struggle to meet the demand for chronic care. mHealth technologies can alter traditional approaches to health care provision by stimulating self-management of chronically ill patients. The aim of this study was to understand the complex environment related to the introduction of mHealth solutions into primary care for chronic disease management while considering health system functioning and stakeholder views. Methods: A transdisciplinary approach was used informed by the Interactive Learning and Action (ILA) methodology. Exploratory interviews (n = 5) were held with representatives of stakeholder groups to identify and position key stakeholders. Subsequently, professionals and chronically ill patients were consulted separately to elaborate on the barriers and facilitators in integration, using semi-structured interviews (n = 17) and a focus group (n = 6). Follow-up interviews (n = 5) were conducted to discuss initial findings of the stakeholder analysis. Results: Most stakeholders, in particular primary care practitioners and patients, seem to have a supporting or mixed attitude toward integration of mHealth. On the other hand, several powerful stakeholders, including primary care information system developers and medical specialists are likely to show resistance or a lack of initiative toward mHealth integration. Main barriers to mHealth integration were a lack of interoperability with existing information systems; difficulties in financing mHealth implementation; and limited readiness in general practices to change. Potential enablers of integration included co-design of mHealth solutions and incentives for pioneers. Conclusion: Stakeholders acknowledge the benefits of integrating mHealth in primary care. However, important barriers perceived by end-users prevent them to fully adopt and use mHealth. This study shows that the complexity of introducing mHealth into primary care calls for strategies encouraging collaboration between multiple stakeholders to enhance successful implementation
Characterizing precursors to stellar clusters with Herschel
Context. Despite their profound effect on the universe, the formation of massive stars and stellar clusters remains elusive. Recent advances in observing facilities and computing power have brought us closer to understanding this formation process. In the past decade, compelling evidence has emerged that suggests infrared dark clouds (IRDCs) may be precursors to stellar clusters. However, the usual method for identifying IRDCs is biased by the requirement that they are seen in absorption against background mid-IR emission, whereas dust continuum observations allow cold, dense pre-stellar-clusters to be identified anywhere. Aims: We aim to understand what dust temperatures and column densities characterize and distinguish IRDCs, to explore the population of dust continuum sources that are not IRDCs, and to roughly characterize the level of star formation activity in these dust continuum sources. Methods: We use Hi-GAL 70 to 500 m bright sources at the warmest. Finally, we identify five candidate IRDC-like sources on the far-side of the Galaxy. These are cold (20 K), high column density (N(H) gt 10 cm) clouds identified with Hi-GAL which, despite bright surrounding mid-IR emission, show little to no absorption at 8 $m. These are the first inner Galaxy far-side candidate IRDCs of which the authors are aware. Herschel in an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation by NASA.The FITS files discussed in the paper would be released publicly WITH the Hi-GAL data (on the Hi-GAL website) when the Hi-GAL data is released publicly.Peer reviewe
A Micro Molecular Bipolar Outflow From HL Tau
We present detailed geometry and kinematics of the inner outflow toward HL
Tau observed using Near Infrared Integral Field Spectograph (NIFS) at the
Gemini-North 8-m Observatory. We analyzed H2 2.122 um emission and [Fe II]
1.644 um line emission as well as the adjacent continuum observed at a <0".2
resolution. The H2 emission shows (1) a bubble-like geometry to the northeast
of the star, as briefly reported in the previous paper, and (2) faint emission
in the southwest counterflow, which has been revealed through careful analysis.
The emission on both sides of the star show an arc 1".0 away from the star,
exhibiting a bipolar symmetry. Different brightness and morphologies in the
northeast and southwest flows are attributed to absorption and obscuration of
the latter by a flattened envelope and a circumstellar disk. The H2 emission
shows a remarkably different morphology from the collimated jet seen in [Fe II]
emission. The positions of some features coincide with scattering continuum,
indicating that these are associated with cavities in the dusty envelope. Such
properties are similar to millimeter CO outflows, although the spatial scale of
the H2 outflow in our image (~150 AU) is strikingly smaller than the mm
outflows, which often extend over 1000-10000 AU scales. The position-velocity
diagram of the H2 and [Fe II] emission do not show any evidence for kinematic
interaction between these flows. All results described above support the
scenario that the jet is surrounded by an unseen wide-angled wind, which
interacts with the ambient gas and produce the bipolar cavity and shocked H2
emission.Comment: 13 pages, 4 figures, accepted for publication in ApJ
Optimal quantization for the pricing of swing options
In this paper, we investigate a numerical algorithm for the pricing of swing
options, relying on the so-called optimal quantization method. The numerical
procedure is described in details and numerous simulations are provided to
assert its efficiency. In particular, we carry out a comparison with the
Longstaff-Schwartz algorithm.Comment: 27
Mapping the column density and dust temperature structure of IRDCs with Herschel
Infrared dark clouds (IRDCs) are cold and dense reservoirs of gas potentially
available to form stars. Many of these clouds are likely to be pristine
structures representing the initial conditions for star formation. The study
presented here aims to construct and analyze accurate column density and dust
temperature maps of IRDCs by using the first Herschel data from the Hi-GAL
galactic plane survey. These fundamental quantities, are essential for
understanding processes such as fragmentation in the early stages of the
formation of stars in molecular clouds. We have developed a simple
pixel-by-pixel SED fitting method, which accounts for the background emission.
By fitting a grey-body function at each position, we recover the spatial
variations in both the dust column density and temperature within the IRDCs.
This method is applied to a sample of 22 IRDCs exhibiting a range of angular
sizes and peak column densities. Our analysis shows that the dust temperature
decreases significantly within IRDCs, from background temperatures of 20-30 K
to minimum temperatures of 8-15 K within the clouds, showing that dense
molecular clouds are not isothermal. Temperature gradients have most likely an
important impact on the fragmentation of IRDCs. Local temperature minima are
strongly correlated with column density peaks, which in a few cases reach NH2 =
1 x 10^{23} cm^{-2}, identifying these clouds as candidate massive prestellar
cores. Applying this technique to the full Hi-GAL data set will provide
important constraints on the fragmentation and thermal properties of IRDCs, and
help identify hundreds of massive prestellar core candidates.Comment: Accepted for publication in A&A Herschel special issu
Spitzer observations of Bow Shocks and Outflows in RCW 38
We report Spitzer observations of five newly identified bow shocks in the
massive star-forming region RCW 38. Four are visible at IRAC wavelengths, the
fifth is visible only at 24 microns. Chandra X-ray emission indicates that
winds from the central O5.5 binary, IRS~2, have caused an outflow to the NE and
SW of the central subcluster. The southern lobe of hot ionised gas is detected
in X-rays; shocked gas and heated dust from the shock-front are detected with
Spitzer at 4.5 and 24 microns. The northern outflow may have initiated the
present generation of star formation, based on the filamentary distribution of
the protostars in the central subcluster. Further, the bow-shock driving star,
YSO 129, is photo-evaporating a pillar of gas and dust. No point sources are
identified within this pillar at near- to mid-IR wavelengths.
We also report on IRAC 3.6 & 5.8 micron observations of the cluster
DBS2003-124, NE of RCW 38, where 33 candidate YSOs are identified. One star
associated with the cluster drives a parsec-scale jet. Two candidate HH objects
associated with the jet are visible at IRAC and MIPS wavelengths. The jet
extends over a distance of ~3 pc. Assuming a velocity of 100 km/s for the jet
material gives an age of about 30,000 years, indicating that the star (and
cluster) are likely to be very young, with a similar or possibly younger age
than RCW 38, and that star formation is ongoing in the extended RCW 38 region.Comment: 27 pages, 6 figures, accepted to Ap
Chandra Orion Ultradeep Project: Observations and Source Lists
We present a description of the data reduction methods and the derived
catalog of more than 1600 X-ray point sources from the exceptionally deep
January 2003 Chandra X-ray Observatory observation of the Orion Nebula Cluster
and embedded populations around OMC-1. The observation was obtained with
Chandra's Advanced CCD Imaging Spectrometer (ACIS) and has been nicknamed the
Chandra Orion Ultradeep Project (COUP). With an 838 ks exposure made over a
continuous period of 13.2 days, the COUP observation provides the most uniform
and comprehensive dataset on the X-ray emission of normal stars ever obtained
in the history of X-ray astronomy.Comment: 52 pages, 11 figures, 12 tables. Accepted for publication in ApJS,
special issue dedicated to Chandra Orion Ultradeep Project. A version with
high quality figures can be found at
http://www.astro.psu.edu/users/gkosta/COUP_Methodology.pd
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