3,241 research outputs found
Lost in translation: a multi-level case study of the metamorphosis of meanings and action in public sector organisational innovation
This paper explores the early implementation of an organisational innovation in the UK National Health Service (NHS) - Treatment Centres (TCs) - designed to dramatically reduce waiting lists for elective care. The paper draws on case studies of eight TCs (each at varying stages of their development) and aims to explore how meanings about TCs are created and evolve, and how these meanings impact upon the development of the organisational innovation. Research on organisational meanings needs to take greater account of the fact that modern organisations like the NHS are complex multi-level phenomena, comprising layers of interlacing networks. To understand the pace, direction and impact of organisational innovation and change we need to study the interconnections between meanings across different organisational levels. The data presented in this paper show how the apparently simple, relatively unformed, concept of a TC framed by central government, is translated and transmuted by subsequent layers in the health service administration, and by players in local health economies and, ultimately in the TCs themselves, picking up new rationales, meanings, and significance as it goes. The developmental histories of TCs reveal a range of significant re-workings of macro policy with the result that there is considerable diversity and variation between local TC schemes. The picture is of important disconnections between meanings, that in many ways mirror Weickâs (1976) âloosely coupled systemsâ. The emergent meanings and the direction of micro-level development of TCs appear more strongly determined by interactions within the local TC environment, notably between what we identify as groups of âidealistsâ, âpragmatistsâ, âopportunistsâ and âscepticsâ than by the framing (Goffman 1974) provided by macro and meso organisational levels. While this illustrates the limitations of top down and policy-driven attempts at change, and highlights the crucial importance of the front-line local âmicro-systemsâ (Donaldson & Mohr, 2000) in the overall scheme of implementing organisational innovations, the space or headroom provided by frames at the macro and meso levels can enable local change, albeit at variable speed and with uncertain outcomes
A stochastic Lagrangian representation of the 3-dimensional incompressible Navier-Stokes equations
In this paper we derive a representation of the deterministic 3-dimensional
Navier-Stokes equations based on stochastic Lagrangian paths. The particle
trajectories obey SDEs driven by a uniform Wiener process; the inviscid Weber
formula for the Euler equations of ideal fluids is used to recover the velocity
field. This method admits a self-contained proof of local existence for the
nonlinear stochastic system, and can be extended to formulate stochastic
representations of related hydrodynamic-type equations, including viscous
Burgers equations and LANS-alpha models.Comment: v4: Minor corrections to bibliography, and final version that will
apear in CPAM. v3: Minor corrections to the algebra in the last section. v2:
Minor changes to introduction and refferences. 14 pages, 0 figure
Clustering of Dust-Obscured Galaxies at z ~ 2
We present the angular autocorrelation function of 2603 dust-obscured
galaxies (DOGs) in the Bootes field of the NOAO Deep Wide-Field Survey. DOGs
are red, obscured galaxies, defined as having R-[24] \ge 14 (F_24/F_R \ga
1000). Spectroscopy indicates that they are located at 1.5 \la z \la 2.5. We
find strong clustering, with r_0 = 7.40^{+1.27}_{-0.84} Mpc/h for the full F_24
> 0.3 mJy sample. The clustering and space density of the DOGs are consistent
with those of submillimeter galaxies, suggestive of a connection between these
populations. We find evidence for luminosity-dependent clustering, with the
correlation length increasing to r_0 = 12.97^{+4.26}_{-2.64} Mpc/h for brighter
(F_24 > 0.6 mJy) DOGs. Bright DOGs also reside in richer environments than
fainter ones, suggesting these subsamples may not be drawn from the same parent
population. The clustering amplitudes imply average halo masses of log M =
12.2^{+0.3}_{-0.2} Msun for the full DOG sample, rising to log M =
13.0^{+0.4}_{-0.3} Msun for brighter DOGs. In a biased structure formation
scenario, the full DOG sample will, on average, evolve into ~ 3 L* present-day
galaxies, whereas the most luminous DOGs may evolve into brightest cluster
galaxies.Comment: ApJL in press; 4 pages, 3 figures, 1 tabl
Dynamic conservation of variability: responses of wheat populations to different selective forces including powdery mildew
CO J=2-1 line emission in cluster galaxies at z~1: fueling star formation in dense environments
We present observations of CO J=2-1 line emission in infrared-luminous
cluster galaxies at z~1 using the IRAM Plateau de Bure Interferometer. Our two
primary targets are optically faint, dust-obscured galaxies (DOGs) found to lie
within 2 Mpc of the centers of two massive (>10^14 Msun) galaxy clusters. CO
line emission is not detected in either DOG. We calculate 3-sigma upper limits
to the CO J=2-1 line luminosities, L'_CO < 6.08x10^9 and < 6.63x10^9 K km/s
pc^2. Assuming a CO-to-H_2 conversion factor derived for ultraluminous infrared
galaxies in the local Universe, this translates to limits on the cold molecular
gas mass of M_H_2 < 4.86x10^9 Msun and M_H_2 < 5.30x10^9 Msun. Both DOGs
exhibit mid-infrared continuum emission that follows a power-law, suggesting
that an AGN contributes to the dust heating. As such, estimates of the star
formation efficiencies in these DOGs are uncertain. A third cluster member with
an infrared luminosity, L_IR < 7.4x10^11 Lsun, is serendipitously detected in
CO J=2-1 line emission in the field of one of the DOGs located roughly two
virial radii away from the cluster center. The optical spectrum of this object
suggests that it is likely an obscured AGN, and the measured CO line luminosity
is L'_CO = (1.94 +/- 0.35)x10^10 K km/s pc^2, which leads to an estimated cold
molecular gas mass M_H_2 = (1.55+/-0.28)x10^10 Msun. A significant reservoir of
molecular gas in a z~1 galaxy located away from the cluster center demonstrates
that the fuel can exist to drive an increase in star-formation and AGN activity
at the outskirts of high-redshift clusters.Comment: 22 pages, 4 figures; accepted for publication in Ap
The evolution of submillimetre galaxies: two populations and a redshift cut-off
We explore the epoch dependence of number density and star-formation rate for
submillimetre galaxies (SMGs) found at 850 um. The study uses a sample of 38
SMG in the GOODS-N field, for which cross-waveband identifications have been
obtained for 35/38 members together with redshift measurements or estimates. A
maximum-likelihood analysis is employed, along with the `single-source-survey'
technique. We find a diminution in both space density and star formation rate
at z > 3, closely mimicking the redshift cut-offs found for QSOs selected in
different wavebands. The diminution in redshift is particularly marked, at a
significance level too small to measure. The data further suggest, at a
significance level of about 0.001, that two separately-evolving populations may
be present, with distinct luminosity functions. These results parallel the
different evolutionary behaviours of LIRGs and ULIRGs, and represent another
manifestation of `cosmic down-sizing', suggesting that differential evolution
extends to the most extreme star-forming galaxies.Comment: 12 pages, 11 figures, MNRAS accepted. The new version, as accepted
for MNRAS, is substantially revised, with more detail on sample selection as
well as extended significance tests of the result
Average Infrared Galaxy Spectra From Spitzer Flux Limited Samples
The mid-infrared spectroscopic analysis of a flux-limited sample of galaxies
with fv(24um) > 10 mJy is presented. Sources observed are taken from the
Spitzer First Look Survey (FLS) catalog and from the NOAO Deep Wide-Field
Survey region in Bootes (NDWFS). The spectroscopic sample includes 60 of the
100 sources in these combined catalogs having fv(24um) > 10 mJy. New spectra
from the Spitzer Infrared Spectrograph are presented for 25 FLS sources and for
11 Bootes AGN; these are combined with 24 Bootes starburst galaxies previously
published to determine the distribution of mid-infrared spectral
characteristics for the total 10 mJy sample. Sources have 0.01 < z < 2.4 and
41.8 < log vLv(15um) < 46.2 (ergs/s). Average spectra are determined as a
function of luminosity; lower luminosity sources (log vLv(15um) < 44.0) are
dominated by PAH features and higher luminosity sources (log vLv(15um) > 44.0)
are dominated by silicate absorption or emission. We find that a rest frame
equivalent width of 0.4um for the 6.2um PAH emission feature provides a well
defined division between lower luminosity, "pure" starbursts and higher
luminosity AGN or composite sources. Using the average spectra, fluxes fv(24um)
which would be observed with the Spitzer MIPS are predicted as a function of
redshift for sources with luminosities that correspond to the average spectra.
AGN identical to those in this 10 mJy sample could be seen to z = 3 with
fv(24um) > 1 mJy, but starbursts fall to fv(24um) < 1 mJy by z ~ 0.5. This
indicates that substantial luminosity evolution of starbursts is required to
explain the numerous starbursts found in other IRS results having fv(24um) > 1
mJy and z ~ 2.Comment: Accepted for publication in The Astrophysical Journa
GOODS-: identification of the individual galaxies responsible for the 80-290m cosmic infrared background
We propose a new method of pushing to its faintest detection
limits using universal trends in the redshift evolution of the far infrared
over 24m colours in the well-sampled GOODS-North field. An extension to
other fields with less multi-wavelength information is presented. This method
is applied here to raise the contribution of individually detected
sources to the cosmic infrared background (CIRB) by a factor 5 close to its
peak at 250m and more than 3 in the 350m and 500m bands. We
produce realistic mock images of the deep PACS and SPIRE images of
the GOODS-North field from the GOODS- Key Program and use them to
quantify the confusion noise at the position of individual sources, i.e.,
estimate a "local confusion noise". Two methods are used to identify sources
with reliable photometric accuracy extracted using 24m prior positions.
The clean index (CI), previously defined but validated here with simulations,
which measures the presence of bright 24m neighbours and the photometric
accuracy index (PAI) directly extracted from the mock images. After
correction for completeness, thanks to our mock images, individually
detected sources make up as much as 54% and 60% of the CIRB in the PACS bands
down to 1.1 mJy at 100m and 2.2 mJy at 160m and 55, 33, and 13% of
the CIRB in the SPIRE bands down to 2.5, 5, and 9 mJy at 250m, 350m,
and 500m, respectively. The latter depths improve the detection limits of
by factors of 5 at 250m, and 3 at 350m and 500m as
compared to the standard confusion limit. Interestingly, the dominant
contributors to the CIRB in all bands appear to be distant siblings
of the Milky Way (0.96 for 300m) with a stellar mass
of 910M.Comment: 22 pages, 16 figures. Accepted for publication by Astronomy and
Astrophysic
A Personalized Self-Management Rehabilitation System with an Intelligent Shoe for Stroke Survivors: A Realist Evaluation
Background: In the United Kingdom, stroke is the most significant cause of adult disability. Stroke survivors are frequently
left with physical and psychological changes that can profoundly affect their functional ability, independence, and social
participation. Research suggests that long-term, intense, task- and context-specific rehabilitation that is goal-oriented and
environmentally enriched improves function, independence, and quality of life after a stroke. It is recommended that rehabilitation
should continue until maximum recovery has been achieved. However, the increasing demand on services and financial constraints
means that needs cannot be met through traditional face-to-face delivery of rehabilitation. Using a participatory design methodology,
we developed an information communication technologyâenhanced Personalized Self-Managed rehabilitation System (PSMrS)
for stroke survivors with integrated insole sensor technology within an âintelligent shoe.â. The intervention model was based
around a rehabilitation paradigm underpinned by theories of motor relearning and neuroplastic adaptation, motivational feedback,
self-efficacy, and knowledge transfer.
Objective: To understand the conditions under which this technology-based rehabilitation solution would most likely have an
impact on the motor behavior of the user, what would work for whom, in what context, and how. We were interested in what
aspects of the system would work best to facilitate the motor behavior change associated with self-managed rehabilitation and
which user characteristics and circumstances of use could promote improved functional outcomes.
Methods: We used a Realist Evaluation (RE) framework to evaluate the final prototype PSMrS with the assumption that the
intervention consists of a series of configurations that include the Context of use, the underlying Mechanisms of change and the
potential Outcomes or impacts (CMOs). We developed the CMOs from literature reviews and engagement with clinicians, users,
and caregivers during a series of focus groups and home visits. These CMOs were then tested in five in-depth case studies with
stroke survivors and their caregivers.
Results: While two new propositions emerged, the second importantly related to the self-management aspects of the system.
The study revealed that the system should also encourage independent use and the setting of personalized goals or activities.
Conclusions: Information communication technology that purports to support the self-management of stroke rehabilitation
should give significant consideration to the need for motivational feedback that provides quantitative, reliable, accurate,
context-specific, and culturally sensitive information about the achievement of personalized goal-based activities
Infrared Luminosities and Dust Properties of z ~ 2 Dust-Obscured Galaxies
We present SHARC-II 350um imaging of twelve 24um-bright (F_24um > 0.8 mJy)
Dust-Obscured Galaxies (DOGs) and CARMA 1mm imaging of a subset of 2 DOGs, all
selected from the Bootes field of the NOAO Deep Wide-Field Survey. Detections
of 4 DOGs at 350um imply IR luminosities which are consistent within a factor
of 2 of expectations based on a warm dust spectral energy distribution (SED)
scaled to the observed 24um flux density. The 350um upper limits for the 8
non-detected DOGs are consistent with both Mrk231 and M82 (warm dust SEDs), but
exclude cold dust (Arp220) SEDs. The two DOGs targeted at 1mm were not detected
in our CARMA observations, placing strong constraints on the dust temperature:
T_dust > 35-60 K. Assuming these dust properties apply to the entire sample, we
find dust masses of ~3x10^8 M_sun. In comparison to other dusty z ~ 2 galaxy
populations such as sub-millimeter galaxies (SMGs) and other Spitzer-selected
high-redshift sources, this sample of DOGs has higher IR luminosities (2x10^13
L_sun vs. 6x10^12 L_sun for the other galaxy populations), warmer dust
temperatures (>35-60 K vs. ~30 K), and lower inferred dust masses (3x10^8 M_sun
vs. 3x10^9 M_sun). Herschel and SCUBA-2 surveys should be able to detect
hundreds of these power-law dominated DOGs. We use HST and Spitzer/IRAC data to
estimate stellar masses of these sources and find that the stellar to gas mass
ratio may be higher in our 24um-bright sample of DOGs than in SMGs and other
Spitzer-selected sources. Although larger sample sizes are needed to provide a
definitive conclusion, the data are consistent with an evolutionary trend in
which the formation of massive galaxies at z~2 involves a sub-millimeter
bright, cold-dust and star-formation dominated phase followed by a 24um-bright,
warm-dust and AGN-dominated phase.Comment: 16 pages, 7 figures, 6 tables; accepted to the Ap
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