267 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
Target prediction for small, noncoding RNAs in bacteria
Many small, noncoding RNAs in bacteria act as post-transcriptional regulators by basepairing with target mRNAs. While the number of characterized small RNAs (sRNAs) has steadily increased, only a limited number of the corresponding mRNA targets have been identified. Here we present a program, TargetRNA, that predicts the targets of these bacterial RNA regulators. The program was evaluated by assessing whether previously known targets could be identified. The program was then used to predict targets for the Escherichia coli RNAs RyhB, OmrA, OmrB and OxyS, and the predictions were compared with changes in whole genome expression patterns observed upon expression of the sRNAs. Our results show that TargetRNA is a useful tool for finding mRNA targets of sRNAs, although its rate of success varies between sRNAs
The SAMI Galaxy Survey: mass-kinematics scaling relations
We use data from the Sydney-AAO Multi-object Integral-field spectroscopy
(SAMI) Galaxy Survey to study the dynamical scaling relation between galaxy
stellar mass and the general kinematic parameter that combines rotation velocity and velocity dispersion
. We show that the relation: (1)~is linear above
limits set by properties of the samples and observations; (2)~has slightly
different slope when derived from stellar or gas kinematic measurements;
(3)~applies to both early-type and late-type galaxies and has smaller scatter
than either the Tully-Fisher relation () for late
types or the Faber-Jackson relation () for early types;
and (4)~has scatter that is only weakly sensitive to the value of , with
minimum scatter for in the range 0.4 and 0.7. We compare to the
aperture second moment (the `aperture velocity dispersion') measured from the
integrated spectrum within a 3-arcsecond radius aperture
(). We find that while and
are in general tightly correlated, the relation has less scatter than the relation.Comment: 14 pages, 8 figures, Accepted 2019 May 22. Received 2019 May 18; in
original form 2019 January
The SAMI Galaxy Survey: Revising the Fraction of Slow Rotators in IFS Galaxy Surveys
The fraction of galaxies supported by internal rotation compared to galaxies
stabilized by internal pressure provides a strong constraint on galaxy
formation models. In integral field spectroscopy surveys, this fraction is
biased because survey instruments typically only trace the inner parts of the
most massive galaxies. We present aperture corrections for the two most widely
used stellar kinematic quantities and . Our
demonstration involves integral field data from the SAMI Galaxy Survey and the
ATLAS Survey. We find a tight relation for both and
when measured in different apertures that can be used as a linear
transformation as a function of radius, i.e., a first-order aperture
correction. We find that and radial growth curves are
well approximated by second order polynomials. By only fitting the inner
profile (0.5), we successfully recover the profile out to one
if a constraint between the linear and quadratic parameter in the
fit is applied. However, the aperture corrections for and
derived by extrapolating the profiles perform as well as applying
a first-order correction. With our aperture-corrected
measurements, we find that the fraction of slow rotating galaxies increases
with stellar mass. For galaxies with 11, the fraction
of slow rotators is percent, but is underestimated if galaxies
without coverage beyond one are not included in the sample
( percent). With measurements out to the largest aperture radius
the slow rotator fraction is similar as compared to using aperture corrected
values ( percent). Thus, aperture effects can significantly bias
stellar kinematic IFS studies, but this bias can now be removed with the method
outlined here.Comment: Accepted for Publication in the Monthly Notices of the Royal
Astronomical Society. 16 pages and 11 figures. The key figures of the paper
are: 1, 4, 9, and 1
The SAMI Galaxy Survey: gravitational potential and surface density drive stellar populations -- I. early-type galaxies
The well-established correlations between the mass of a galaxy and the
properties of its stars are considered evidence for mass driving the evolution
of the stellar population. However, for early-type galaxies (ETGs), we find
that color and stellar metallicity [Z/H] correlate more strongly with
gravitational potential than with mass , whereas stellar population
age correlates best with surface density . Specifically, for our sample
of 625 ETGs with integral-field spectroscopy from the SAMI Galaxy Survey,
compared to correlations with mass, the color--, [Z/H]--, and
age-- relations show both smaller scatter and less residual trend with
galaxy size. For the star formation duration proxy [/Fe], we find
comparable results for trends with and , with both being
significantly stronger than the [/Fe]- relation. In determining the
strength of a trend, we analyze both the overall scatter, and the observational
uncertainty on the parameters, in order to compare the intrinsic scatter in
each correlation. These results lead us to the following inferences and
interpretations: (1) the color-- diagram is a more precise tool for
determining the developmental stage of the stellar population than the
conventional color--mass diagram; and (2) gravitational potential is the
primary regulator of global stellar metallicity, via its relation to the gas
escape velocity. Furthermore, we propose the following two mechanisms for the
age and [/Fe] relations with : (a) the age-- and
[/Fe]-- correlations arise as results of compactness driven
quenching mechanisms; and/or (b) as fossil records of the
relation in their disk-dominated progenitors.Comment: 9 pages, 4 figures, 1 table Accepted to Ap
The Sydney-AAO Multi-object Integral field spectrograph (SAMI)
We demonstrate a novel technology that combines the power of the multi-object
spectrograph with the spatial multiplex advantage of an integral field
spectrograph (IFS). The Sydney-AAO Multi-object IFS (SAMI) is a prototype
wide-field system at the Anglo-Australian Telescope (AAT) that allows 13
imaging fibre bundles ("hexabundles") to be deployed over a 1-degree diameter
field of view. Each hexabundle comprises 61 lightly-fused multimode fibres with
reduced cladding and yields a 75 percent filling factor. Each fibre core
diameter subtends 1.6 arcseconds on the sky and each hexabundle has a field of
view of 15 arcseconds diameter. The fibres are fed to the flexible AAOmega
double-beam spectrograph, which can be used at a range of spectral resolutions
(R=lambda/delta(lambda) ~ 1700-13000) over the optical spectrum (3700-9500A).
We present the first spectroscopic results obtained with SAMI for a sample of
galaxies at z~0.05. We discuss the prospects of implementing hexabundles at a
much higher multiplex over wider fields of view in order to carry out
spatially--resolved spectroscopic surveys of 10^4 to 10^5 galaxies.Comment: 24 pages, 16 figures. Accepted by MNRA
A Video-based End-to-end Pipeline for Non-nutritive Sucking Action Recognition and Segmentation in Young Infants
We present an end-to-end computer vision pipeline to detect non-nutritive
sucking (NNS) -- an infant sucking pattern with no nutrition delivered -- as a
potential biomarker for developmental delays, using off-the-shelf baby monitor
video footage. One barrier to clinical (or algorithmic) assessment of NNS stems
from its sparsity, requiring experts to wade through hours of footage to find
minutes of relevant activity. Our NNS activity segmentation algorithm solves
this problem by identifying periods of NNS with high certainty -- up to 94.0\%
average precision and 84.9\% average recall across 30 heterogeneous 60 s clips,
drawn from our manually annotated NNS clinical in-crib dataset of 183 hours of
overnight baby monitor footage from 19 infants. Our method is based on an
underlying NNS action recognition algorithm, which uses spatiotemporal deep
learning networks and infant-specific pose estimation, achieving 94.9\%
accuracy in binary classification of 960 2.5 s balanced NNS vs. non-NNS clips.
Tested on our second, independent, and public NNS in-the-wild dataset, NNS
recognition classification reaches 92.3\% accuracy, and NNS segmentation
achieves 90.8\% precision and 84.2\% recall
'Keeping busy' as agency in early desistance
Agency in desistance research has often been understood as deliberate action
undertaken in pursuit of a desisting identity. Through a micro-longitudinal
approach, this research focuses on the early desistance experiences of a
number of mainly white British female participants. Agency was exhibited not
with a new identity in mind, but instead through 'keeping busy'. The surprising
lack of identity concerns may be due to the early stages of the participants'
desistance experiences, with new identities emerging later in the process.
Alternatively, it may indicate a fundamental difference to the classic desistance
narrative, linked to the differences between this sample and the frequently
researched, Western, male, high-frequency offender. Finally, important aspects
of the cultures surrounding desistance research may have shaped the
narratives of desisters and the biases of researchers towards finding a concern
for identity when this is not necessarily experienced in the everyday lives of
desisters
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