641 research outputs found
Informing the design of a randomised controlled trial of an exercise-based programme for long term stroke survivors: lessons from a before-and-after case series study
Background: To inform the design of a randomised controlled trial (RCT) of an exercise-based programme for long
term stroke survivors, we conducted a mixed methods before-and-after case series with assessment at three time
points. We evaluated Action for Rehabilitation from Neurological Injury (ARNI), a personalised, functionally-focussed
programme. It was delivered through 24 hours of one-to-one training by an Exercise Professional (EP), plus at least
2 hours weekly unsupervised exercise, over 12- 14 weeks. Assessment was by patient-rated questionnaires
addressing function, physical activity, confidence, fatigue and health-related quality of life; objective assessment of
gait quality and speed; qualitative individual interviews conducted with participants. Data were collected at
baseline, 3 months and 6 months. Fidelity and acceptability was assessed by participant interviews, audit of
participant and EP records, and observation of training.
Findings: Four of six enrolled participants completed the exercise programme. Quantitative data demonstrated
little change across the sample, but marked changes on some measures for some individuals. Qualitative interviews
suggested that small benefits in physical outcomes could be of great psychological significance to participants.
Participant-reported fatigue levels commonly increased, and non-completers said they found the programme too
demanding. Most key components of the intervention were delivered, but there were several potentially important
departures from intervention fidelity.
Discussion: The study provided data and experience that are helping to inform the design of an RCT of this
intervention. It suggested the need for a broader recruitment strategy; indicated areas that could be explored in
more depth in the qualitative component of the trial; and highlighted issues that should be addressed to enhance
and evaluate fidelity, particularly in the preparation and monitoring of intervention providers. The experience
illustrates the value of even small sample before-and-after studies in the development of trials of complex
interventions.PenCLAHRC; NIH
Testing ecological theories with sequence similarity networks: marine ciliates exhibit similar geographic dispersal patterns as multicellular organisms
International audienceBackground : High-throughput sequencing technologies are lifting major limitations to molecular-based ecological studies of eukaryotic microbial diversity, but analyses of the resulting millions of short sequences remain a major bottleneck for these approaches. Here, we introduce the analytical and statistical framework of sequence similarity networks, increasingly used in evolutionary studies and graph theory, into the field of ecology to analyze novel pyrosequenced V4 small subunit rDNA (SSU-rDNA) sequence data sets in the context of previous studies, including SSU-rDNA Sanger sequence data from cultured ciliates and from previous environmental diversity inventories.Results : Our broadly applicable protocol quantified the progress in the description of genetic diversity of ciliates by environmental SSU-rDNA surveys, detected a fundamental historical bias in the tendency to recover already known groups in these surveys, and revealed substantial amounts of hidden microbial diversity. Moreover, network measures demonstrated that ciliates are not globally dispersed, but are structured by habitat and geographical location at intermediate geographical scale, as observed for bacteria, plants, and animals.Conclusions : Currently available ‘universal’ primers used for local in-depth sequencing surveys provide little hope to exhaust the significantly higher ciliate (and most likely microbial) diversity than previously thought. Network analyses such as presented in this study offer a promising way to guide the design of novel primers and to further explore this vast and structured microbial diversity
The rise of policy coherence for development: a multi-causal approach
In recent years policy coherence for development (PCD) has become a key principle in international development debates, and it is likely to become even more relevant in the discussions on the post-2015 sustainable development goals. This article addresses the rise of PCD on the Western donors’ aid agenda. While the concept already appeared in the work of Organisation for Economic Co-operation and Development (OECD) in the early 1990s, it took until 2007 before PCD became one of the Organisation’s key priorities. We adopt a complexity-sensitive perspective, involving a process-tracing analysis and a multi-causal explanatory framework. We argue that the rise of PCD is not as contingent as it looks. While actors such as the EU, the DAC and OECD Secretariat were the ‘active causes’ of the rise of PCD, it is equally important to look at the underlying ‘constitutive causes’ which enabled policy coherence to thrive well
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The validation of a computer-based food record for older adults: the Novel Assessment of Nutrition and Ageing (NANA) method
Dietary assessment in older adults can be challenging. The Novel Assessment of Nutrition and Ageing (NANA) method is a touch-screen
computer-based food record that enables older adults to record their dietary intakes. The objective of the present study was to assess
the relative validity of the NANA method for dietary assessment in older adults. For this purpose, three studies were conducted in which a
total of ninety-four older adults (aged 65–89 years) used the NANA method of dietary assessment. On a separate occasion, participants
completed a 4 d estimated food diary. Blood and 24 h urine samples were also collected from seventy-six of the volunteers for the analysis
of biomarkers of nutrient intake. The results from all the three studies were combined, and nutrient intake data collected using the NANA
method were compared against the 4 d estimated food diary and biomarkers of nutrient intake. Bland–Altman analysis showed
a reasonable agreement between the dietary assessment methods for energy and macronutrient intake; however, there were small, but
significant, differences for energy and protein intake, reflecting the tendency for the NANA method to record marginally lower energy intakes.
Significant positive correlations were observed between urinary urea and dietary protein intake using both the NANA and the 4 d estimated
food diary methods, and between plasma ascorbic acid and dietary vitamin C intake using the NANA method. The results demonstrate the
feasibility of computer-based dietary assessment in older adults, and suggest that the NANA method is comparable to the 4 d estimated
food diary, and could be used as an alternative to the food diary for the short-term assessment of an individual’s dietary intake
The SINS/zC-SINF Survey of z~2 Galaxy Kinematics: The Nature of Dispersion Dominated Galaxies
We analyze the spectra, spatial distributions and kinematics of Ha, [NII] and
[SII] emission in a sample of 42, z~2.2 UV/optically selected star forming
galaxies (SFGs) from the SINS & zC-SINF surveys, 35 of which were observed in
the adaptive optics mode of SINFONI. This is supplemented by kinematic data
from 48 z~1-2.5 galaxies from the literature. We find that the kinematic
classification of the high-z SFGs as `dispersion dominated' or `rotation
dominated' correlates most strongly with their intrinsic sizes. Smaller
galaxies are more likely `dispersion-dominated' for two main reasons: 1) The
rotation velocity scales linearly with galaxy size but intrinsic velocity
dispersion does not depend on size, and as such, their ratio is systematically
lower for smaller galaxies, and 2) Beam smearing strongly decreases large-scale
velocity gradients and increases observed dispersion much more for galaxies
with sizes at or below the resolution. Dispersion dominated SFGs may thus have
intrinsic properties similar to `rotation dominated' SFGs, but are primarily
more compact, lower mass, less metal enriched and may have higher gas
fractions, plausibly because they represent an earlier evolutionary state.Comment: 13 pages, 9 figures, accepted by Ap
Dependence of climate response on meridional structure of external thermal forcing
This study shows that the magnitude of global surface warming greatly depends on the meridional distribution of surface thermal forcing. An atmospheric model coupled to an aquaplanet slab mixed layer ocean is perturbed by prescribing heating to the ocean mixed layer. The heating is distributed uniformly globally or confined to narrow tropical or polar bands, and the amplitude is adjusted to ensure that the global mean remains the same for all cases. Since the tropical temperature is close to a moist adiabat, the prescribed heating leads to a maximized warming near the tropopause, whereas the polar warming is trapped near the surface because of strong atmospheric stability. Hence, the surface warming is more effectively damped by radiation in the tropics than in the polar region. As a result, the global surface temperature increase is weak (strong) when the given amount of heating is confined to the tropical (polar) band. The degree of this contrast is shown to depend on water vapor-and cloud-radiative feedbacks that alter the effective strength of prescribed thermal forcing.open0
The WiggleZ Dark Energy Survey: Star-formation in UV-luminous galaxies from their luminosity functions
We present the ultraviolet (UV) luminosity function of galaxies from the
GALEX Medium Imaging Survey with measured spectroscopic redshifts from the
first data release of the WiggleZ Dark Energy Survey. This sample selects
galaxies with high star formation rates: at 0.6 < z < 0.9 the median star
formation rate is at the upper 95th percentile of optically-selected (r<22.5)
galaxies and the sample contains about 50 per cent of all NUV < 22.8, 0.6 < z <
0.9 starburst galaxies within the volume sampled.
The most luminous galaxies in our sample (-21.0>M_NUV>-22.5) evolve very
rapidly with a number density declining as (1+z)^{5\pm 1} from redshift z = 0.9
to z = 0.6. These starburst galaxies (M_NUV<-21 is approximately a star
formation rate of 30 \msuny) contribute about 1 per cent of cosmic star
formation over the redshift range z=0.6 to z=0.9. The star formation rate
density of these very luminous galaxies evolves rapidly, as (1+z)^{4\pm 1}.
Such a rapid evolution implies the majority of star formation in these large
galaxies must have occurred before z = 0.9.
We measure the UV luminosity function in 0.05 redshift intervals spanning
0.1<z<0.9, and provide analytic fits to the results. At all redshifts greater
than z=0.55 we find that the bright end of the luminosity function is not well
described by a pure Schechter function due to an excess of very luminous
(M_NUV<-22) galaxies. These luminosity functions can be used to create a radial
selection function for the WiggleZ survey or test models of galaxy formation
and evolution. Here we test the AGN feedback model in Scannapieco et al.
(2005), and find that this AGN feedback model requires AGN feedback efficiency
to vary with one or more of the following: stellar mass, star formation rate
and redshift.Comment: 27 pages; 13 pages without appendices. 22 figures; 11 figures in the
main tex
The WiggleZ Dark Energy Survey: the selection function and z=0.6 galaxy power spectrum
We report one of the most accurate measurements of the three-dimensional
large-scale galaxy power spectrum achieved to date, using 56,159 redshifts of
bright emission-line galaxies at effective redshift z=0.6 from the WiggleZ Dark
Energy Survey at the Anglo-Australian Telescope. We describe in detail how we
construct the survey selection function allowing for the varying target
completeness and redshift completeness. We measure the total power with an
accuracy of approximately 5% in wavenumber bands of dk=0.01 h/Mpc. A model
power spectrum including non-linear corrections, combined with a linear galaxy
bias factor and a simple model for redshift-space distortions, provides a good
fit to our data for scales k < 0.4 h/Mpc. The large-scale shape of the power
spectrum is consistent with the best-fitting matter and baryon densities
determined by observations of the Cosmic Microwave Background radiation. By
splitting the power spectrum measurement as a function of tangential and radial
wavenumbers we delineate the characteristic imprint of peculiar velocities. We
use these to determine the growth rate of structure as a function of redshift
in the range 0.4 < z < 0.8, including a data point at z=0.78 with an accuracy
of 20%. Our growth rate measurements are a close match to the self-consistent
prediction of the LCDM model. The WiggleZ Survey data will allow a wide range
of investigations into the cosmological model, cosmic expansion and growth
history, topology of cosmic structure, and Gaussianity of the initial
conditions. Our calculation of the survey selection function will be released
at a future date via our website wigglez.swin.edu.au.Comment: 21 pages, 22 figures, accepted for publication in MNRA
The WiggleZ Dark Energy Survey: Survey Design and First Data Release
The WiggleZ Dark Energy Survey is a survey of 240,000 emission line galaxies
in the distant universe, measured with the AAOmega spectrograph on the 3.9-m
Anglo-Australian Telescope (AAT). The target galaxies are selected using
ultraviolet photometry from the GALEX satellite, with a flux limit of NUV<22.8
mag. The redshift range containing 90% of the galaxies is 0.2<z<1.0. The
primary aim of the survey is to precisely measure the scale of baryon acoustic
oscillations (BAO) imprinted on the spatial distribution of these galaxies at
look-back times of 4-8 Gyrs. Detailed forecasts indicate the survey will
measure the BAO scale to better than 2% and the tangential and radial acoustic
wave scales to approximately 3% and 5%, respectively.
This paper provides a detailed description of the survey and its design, as
well as the spectroscopic observations, data reduction, and redshift
measurement techniques employed. It also presents an analysis of the properties
of the target galaxies, including emission line diagnostics which show that
they are mostly extreme starburst galaxies, and Hubble Space Telescope images,
which show they contain a high fraction of interacting or distorted systems. In
conjunction with this paper, we make a public data release of data for the
first 100,000 galaxies measured for the project.Comment: Accepted by MNRAS; this has some figures in low resolution format.
Full resolution PDF version (7MB) available at
http://www.physics.uq.edu.au/people/mjd/pub/wigglez1.pdf The WiggleZ home
page is at http://wigglez.swin.edu.au
The WiggleZ Dark Energy Survey: the transition to large-scale cosmic homogeneity
We have made the largest-volume measurement to date of the transition to
large-scale homogeneity in the distribution of galaxies. We use the WiggleZ
survey, a spectroscopic survey of over 200,000 blue galaxies in a cosmic volume
of ~1 (Gpc/h)^3. A new method of defining the 'homogeneity scale' is presented,
which is more robust than methods previously used in the literature, and which
can be easily compared between different surveys. Due to the large cosmic depth
of WiggleZ (up to z=1) we are able to make the first measurement of the
transition to homogeneity over a range of cosmic epochs. The mean number of
galaxies N(<r) in spheres of comoving radius r is proportional to r^3 within
1%, or equivalently the fractal dimension of the sample is within 1% of D_2=3,
at radii larger than 71 \pm 8 Mpc/h at z~0.2, 70 \pm 5 Mpc/h at z~0.4, 81 \pm 5
Mpc/h at z~0.6, and 75 \pm 4 Mpc/h at z~0.8. We demonstrate the robustness of
our results against selection function effects, using a LCDM N-body simulation
and a suite of inhomogeneous fractal distributions. The results are in
excellent agreement with both the LCDM N-body simulation and an analytical LCDM
prediction. We can exclude a fractal distribution with fractal dimension below
D_2=2.97 on scales from ~80 Mpc/h up to the largest scales probed by our
measurement, ~300 Mpc/h, at 99.99% confidence.Comment: 21 pages, 16 figures, accepted for publication in MNRA
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