264 research outputs found
Varied response to mirror gait retraining of gluteus medius control, hip kinematics, pain, and function in 2 female runners with patellofemoral pain.
STUDY DESIGN:
Case report.
BACKGROUND:
The underlying mechanism of the changes in running mechanics after gait retraining is presently unknown. This case report assesses changes in muscle coordination and kinematics during treadmill running and step ascent in 2 female runners with patellofemoral pain after mirror gait retraining.
CASE DESCRIPTION:
Two female runners with chronic patellofemoral pain underwent 8 sessions of mirror gait retraining during treadmill running. Subjective measures and hip abductor strength were recorded at baseline and after the retraining phase. Changes in hip mechanics and electromyography data of the gluteus medius during treadmill running and step ascent were also assessed.
OUTCOMES:
Both runners reported improvements in pain and function that were maintained for at least 3 months. During running, peak contralateral pelvic drop (baseline-postretraining difference: runner 1, 2.6° less; runner 2, 1.7° less) and peak hip adduction (baseline-postretraining difference: runner 1, 5.2° less; runner 2, 6.3° less) were reduced after retraining. Kinematic reductions accompanied earlier activation of the gluteus medius relative to foot strike (baseline-postretraining difference: runner 1, 12.6 milliseconds earlier; runner 2, 37.3 milliseconds earlier) and longer duration of gluteus medius activity (runner 1, 55.8 milliseconds longer; runner 2, 44.4 milliseconds longer). Runner 1 transferred reduced contralateral pelvic drop to step ascent, whereas runner 2 did not (contralateral pelvic drop baseline-postretraining difference: runner 1, 3.6° less; runner 2, 1.5° more; hip adduction baseline-postretraining difference: runner 1, 3.0° less; runner 2, 0.5° more). Both runners demonstrated earlier onset of gluteus medius activity during step ascent (baseline-postretraining difference: runner 1, 48.0 milliseconds earlier; runner 2, 28.3 milliseconds earlier), but only runner 1 demonstrated longer activation duration (runner 1, 25.0 milliseconds longer; runner 2, 69.4 milliseconds shorter).
DISCUSSION:
While changes in hip mechanics and gluteus medius activity during running were consistent with those noted during step ascent for runner 1, runner 2 failed to demonstrate similar consistency between the tasks. Earlier onset and longer duration of gluteus medius activity may have been necessary to alter step mechanics for runner 2.
LEVEL OF EVIDENCE:
Therapy, level 4.
NOTE: This is a non-final version of an article published in final form in Willy, R. W., & Davis, I. S. (2013). Varied response to mirror gait retraining of gluteus medius control, hip kinematics, pain, and function in 2 female runners with patellofemoral pain. The Journal of Orthopaedic and Sports Physical Therapy, 43(12), 864-874. doi:10.2519/jospt.2013.451
Sparse aperture masking interferometry survey of transitional discs: Search for substellar-mass companions and asymmetries in their parent discs
This is the author accepted manuscript. The final version is available from EDP Sciences via the DOI in this record.Context. Transitional discs are a class of circumstellar discs around young stars with extensive clearing of dusty material within their
inner regions on 10s of au scales. One of the primary candidates for this kind of clearing is the formation of planet(s) within the disc
that then accrete or clear their immediate area as they migrate through the disc.
Aims. The goal of this survey was to search for asymmetries in the brightness distribution around a selection of transitional disc
targets. We then aimed to determine whether these asymmetries trace dynamically-induced structures in the disc or the gap-opening
planets themselves.
Methods. Our sample included eight transitional discs. Using the Keck/NIRC2 instrument we utilised the Sparse Aperture Masking
(SAM) interferometry technique to search for asymmetries indicative of ongoing planet formation. We searched for close-in companions
using both model fitting and interferometric image reconstruction techniques. Using simulated data, we derived diagnostics that
helped us to distinguish between point sources and extended asymmetric disc emission. In addition, we investigated the degeneracy
between the contrast and separation that appear for marginally resolved companions.
Results. We found FP Tau to contain a previously unseen disc wall, and DM Tau, LkHα330, and TW Hya to contain an asymmetric
signal indicative of point source-like emission. We placed upper limits on the contrast of a companion in RXJ1842.9-3532 and
V2246 Oph. We ruled the asymmetry signal in RXJ1615.3-3255 and V2062 Oph to be false positives. In the cases where our data
indicated a potential companion we computed estimates for the value of McMË™
c and found values in the range of 10−5 − 10−3M2
J
yr−1
.
Conclusions. We found significant asymmetries in four targets. Of these, three were consistent with companions. We resolved a
previously unseen gap in the disc of FP Tau extending inwards from approximately 10 au.We acknowledge support from a STFC Rutherford Fellowship
and Grant (ST/J004030/1, ST/K003445/1), Marie Sklodowska-Curie CIG
grant (Ref. 618910), and Philip Leverhulme Prize (PLP-2013-110). We additionally
acknowledge support from NASA KPDA grants (JPL-1452321, 1474717,
1485953, 1496788). The authors wish to recognise and acknowledge the very
significant cultural role and reverence that the summit of Mauna Kea has always
had within the indigenous Hawaiian community. We are most fortunate to have
the opportunity to conduct observations from this mountain. Some of the data
presented herein were obtained at the W.M. Keck Observatory, which is operated
as a scientific partnership among the California Institute of Technology, the
University of California and the National Aeronautics and Space Administration.
The Observatory was made possible by the generous financial support of
the W.M. Keck Foundatio
Sparse aperture masking interferometry survey of transitional discs. Search for substellar-mass companions and asymmetries in their parent discs
This is the author accepted manuscript. The final version is available from EDP Sciences via the DOI in this record.Context. Transitional discs are a class of circumstellar discs around young stars with extensive clearing of dusty material within their inner regions on 10s of au scales. One of the primary candidates for this kind of clearing is the formation of planet(s) within the disc that then accrete or clear their immediate area as they migrate through the disc.
Aims. The goal of this survey was to search for asymmetries in the brightness distribution around a selection of transitional disc targets. We then aimed to determine whether these asymmetries trace dynamically-induced structures in the disc or the gap-opening planets themselves.
Methods. Our sample included eight transitional discs. Using the Keck/NIRC2 instrument we utilised the Sparse Aperture Masking (SAM) interferometry technique to search for asymmetries indicative of ongoing planet formation. We searched for close-in companions using both model fitting and interferometric image reconstruction techniques. Using simulated data, we derived diagnostics that helped us to distinguish between point sources and extended asymmetric disc emission. In addition, we investigated the degeneracy between the contrast and separation that appear for marginally resolved companions.
Results. We found FP Tau to contain a previously unseen disc wall, and DM Tau, LkHα330, and TW Hya to contain an asymmetric signal indicative of point source-like emission. We placed upper limits on the contrast of a companion in RXJ 1842.9-3532 and V2246 Oph. We ruled the asymmetry signal in RXJ 1615.3-3255 and V2062 Oph to be false positives. In the cases where our data indicated a potential companion we computed estimates for the value of McṀc and found values in the range of 10−5−10−3 M2J yr−1.
Conclusions. We found significant asymmetries in four targets. Of these, three were consistent with companions. We resolved a previously unseen gap in the disc of FP Tau extending inwards from approximately 10 au.We acknowledge support from a STFC Rutherford Fellowship and Grant (ST/J004030/1, ST/K003445/1), Marie Sklodowska-Curie CIG grant (Ref. 618910), and Philip Leverhulme Prize (PLP-2013-110). We additionally acknowledge support from NASA KPDA grants (JPL-1452321, 1474717, 1485953, 1496788). The authors wish to recognise and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation
Tiny grains shining bright in the gaps of Herbig Ae transitional discs
This is the final version. Available from the publisher via the DOI in this record.This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement.This work presents a study of two Herbig Ae transitional discs, Oph IRS 48 and HD 169142; which both have reported rings in their dust density distributions. We use Keck-II/NIRC2 adaptive optics imaging observations in the L' filter (3.8 micron) to probe the regions of these discs inwards of ~20AU from the star. We introduce our method for investigating these transitional discs, which takes a forward modelling approach: making a model of the disc (using the Monte Carlo radiative transfer code RADMC), convolving it with point-spread functions of calibrator stars, and comparing the convolved models with the observational data. The disc surface density parameters are explored with a Monte Carlo Markov Chain technique. Our analysis recovers emission from both of the discs interior to the well known optically thick walls, modelled as a ring of emission at ~15AU in Oph IRS 48, and ~7AU for HD 169142, and identifies asymmetries in both discs. Given the brightness of the near-symmetric rings compared to the reported companion candidates, we suggest that the reported companion candidates can be interpreted as slightly asymmetric disc emission or illumination.European Research Council (ERC)Science and Technology Facilities Council Rutherford Fellowshi
Imaging the disc rim and a moving close-in companion candidate in the pre-transitional disc of V1247 Orionis
This is the author accepted manuscript. The final version is available from EDP Sciences via the DOI in this record.Context. V1247 Orionis harbours a pre-transitional disc with a partially cleared gap. Earlier interferometric and polarimetric observations
revealed strong asymmetries both in the gap region and in the outer disc. The presence of a companion was inferred to explain
these asymmetric structures and the ongoing disc clearing.
Aims. Using an extensive set of multi-wavelength and multi-epoch observations we aimed to identify the origin of the previously
detected asymmetries.
Methods. We observed V1247 Ori at three epochs spanning ∼ 678 days using sparse aperture masking interferometry with
Keck/NIRC2 and VLT/NACO. In addition, we search for signs of accretion through VLT/SPHERE-ZIMPOL spectral differential
imaging in Hα and R-band continuum. Our SMA sub-millimetre interferometry in 880 µm continuum and in the CO(3-2) line allows
us to constrain the orientation and direction of rotation of the outer disc.
Results. We find the L’-band emission to be dominated by static features which trace forward-scattered dust emission from the
inner edge of the outer disc located to the north-east. In H- and K-band, we see evidence for a companion candidate that moved
systematically by 45◦ within the first ∼345 days. The separation of the companion candidate is not well constrained, but the observed
position angle change is consistent with Keplerian motion of a body located on a 6 au orbit. From the SMA CO moment map, the
location of the disc rim, and the detected orbital motion, we deduced the 3-dimensional orientation of the disc. We see no indication
of accretion in Hα and set upper limits for an accreting companion.
Conclusions. The measured contrast of the companion candidate in H and K is consistent with an actively accreting protoplanet.
Hence, we identify V1247 Ori as a unique laboratory for studying companion-disc interactions and disc clearing.We acknowledge support from an ERC
Starting Grant (Grant Agreement No. 639889), STFC Rutherford Fellowship
Article number, page 14 of 17
M. Willson et al.: Imaging the disc rim and companion candidate in V1247 Ori
(ST/J004030/1), STFC Rutherford Grant (ST/K003445/1), Marie SklodowskaCurie
CIG grant (Ref. 618910), and Philip Leverhulme Prize (PLP-2013-110).
We additionally acknowledge support from NASA KPDA grants (JPL-1452321,
1474717, 1485953, 1496788). The Submillimeter Array is a joint project between
the Smithsonian Astrophysical Observatory and the Academia Sinica Institute
of Astronomy and Astrophysics and is funded by the Smithsonian Institution
and the Academia Sinica. The authors wish to recognize and acknowledge
the very significant cultural role and reverence that the summit of Mauna Kea
has always had within the indigenous Hawaiian community. We are most fortunate
to have the opportunity to conduct observations from this mountain.Some
of the data presented herein were obtained at the W.M. Keck Observatory, which
is operated as a scientific partnership among the California Institute of Technology,
the University of California and the National Aeronautics and Space
Administration. The Observatory was made possible by the generous financial
support of the W.M. Keck Foundation. J. Kluska acknowledges support from the
research council of the KU Leuven under grant number C14/17/082. M. Curé
and S. Kanaan acknowledge financial support from Centro de AstrofÃsica de Valparaiso.
S. Kanaan thank the support of Fondecyt iniciacÃon grant No. 11130702.
T. Muto is partially supported by JSPS KAKENHI grant No. 26800106
Clusters of galaxies : observational properties of the diffuse radio emission
Clusters of galaxies, as the largest virialized systems in the Universe, are
ideal laboratories to study the formation and evolution of cosmic
structures...(abridged)... Most of the detailed knowledge of galaxy clusters
has been obtained in recent years from the study of ICM through X-ray
Astronomy. At the same time, radio observations have proved that the ICM is
mixed with non-thermal components, i.e. highly relativistic particles and
large-scale magnetic fields, detected through their synchrotron emission. The
knowledge of the properties of these non-thermal ICM components has increased
significantly, owing to sensitive radio images and to the development of
theoretical models. Diffuse synchrotron radio emission in the central and
peripheral cluster regions has been found in many clusters. Moreover
large-scale magnetic fields appear to be present in all galaxy clusters, as
derived from Rotation Measure (RM) studies. Non-thermal components are linked
to the cluster X-ray properties, and to the cluster evolutionary stage, and are
crucial for a comprehensive physical description of the intracluster medium.
They play an important role in the cluster formation and evolution. We review
here the observational properties of diffuse non-thermal sources detected in
galaxy clusters: halos, relics and mini-halos. We discuss their classification
and properties. We report published results up to date and obtain and discuss
statistical properties. We present the properties of large-scale magnetic
fields in clusters and in even larger structures: filaments connecting galaxy
clusters. We summarize the current models of the origin of these cluster
components, and outline the improvements that are expected in this area from
future developments thanks to the new generation of radio telescopes.Comment: Accepted for the publication in The Astronomy and Astrophysics
Review. 58 pages, 26 figure
CACHE (Critical Assessment of Computational Hit-finding Experiments): A public–private partnership benchmarking initiative to enable the development of computational methods for hit-finding
One aspirational goal of computational chemistry is to predict potent and drug-like binders for any protein, such that only those that bind are synthesized. In this Roadmap, we describe the launch of Critical Assessment of Computational Hit-finding Experiments (CACHE), a public benchmarking project to compare and improve small-molecule hit-finding algorithms through cycles of prediction and experimental testing. Participants will predict small-molecule binders for new and biologically relevant protein targets representing different prediction scenarios. Predicted compounds will be tested rigorously in an experimental hub, and all predicted binders as well as all experimental screening data, including the chemical structures of experimentally tested compounds, will be made publicly available and not subject to any intellectual property restrictions. The ability of a range of computational approaches to find novel binders will be evaluated, compared and openly published. CACHE will launch three new benchmarking exercises every year. The outcomes will be better prediction methods, new small-molecule binders for target proteins of importance for fundamental biology or drug discovery and a major technological step towards achieving the goal of Target 2035, a global initiative to identify pharmacological probes for all human proteins. [Figure not available: see fulltext.
Towards the reconstruction of integrated genome-scale models of metabolism and gene expression
The reconstruction of integrated genome-scale models of metabolism and gene expression has been a challenge for a while now. In fact, various methods that allow integrating reconstructions of Transcriptional Regulatory Networks, gene expression data or both into Genome-Scale Metabolic Models have been proposed. Several of these methods are surveyed in this article, which allowed identifying their strengths and weaknesses concerning the reconstruction of integrated models for multiple prokaryotic organisms. Additionally, the main resources of regulatory information were also surveyed, as the existence of novel sources of regulatory information and gene expression data may contribute for the improvement of methodologies referred herein.This study was supported by the Portuguese Foundation for Science andTechnology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit andBioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European RegionalDevelopment Fund under the scope of Norte2020-Programa Operacional Regional do Norte. Fernando Cruz holds a doctoral fellowship (SFRH/BD/139198/2018) funded by the FCT. The authors thank project SHIKIFACTORY100 - Modular cell factories for the production of 100 compounds from the shikimate pathway (814408) funded by the European Commission.info:eu-repo/semantics/publishedVersio
The quest for the solar g modes
Solar gravity modes (or g modes) -- oscillations of the solar interior for
which buoyancy acts as the restoring force -- have the potential to provide
unprecedented inference on the structure and dynamics of the solar core,
inference that is not possible with the well observed acoustic modes (or p
modes). The high amplitude of the g-mode eigenfunctions in the core and the
evanesence of the modes in the convection zone make the modes particularly
sensitive to the physical and dynamical conditions in the core. Owing to the
existence of the convection zone, the g modes have very low amplitudes at
photospheric levels, which makes the modes extremely hard to detect. In this
paper, we review the current state of play regarding attempts to detect g
modes. We review the theory of g modes, including theoretical estimation of the
g-mode frequencies, amplitudes and damping rates. Then we go on to discuss the
techniques that have been used to try to detect g modes. We review results in
the literature, and finish by looking to the future, and the potential advances
that can be made -- from both data and data-analysis perspectives -- to give
unambiguous detections of individual g modes. The review ends by concluding
that, at the time of writing, there is indeed a consensus amongst the authors
that there is currently no undisputed detection of solar g modes.Comment: 71 pages, 18 figures, accepted by Astronomy and Astrophysics Revie
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