1,645 research outputs found
Integrin-independent movement of immune cells
Cell motility requires the temporal and spatial coordination of the actin cytoskeleton with cell-matrix adhesions. Since their discovery more than 20 years ago, integrins have been at the center of cell-matrix adhesion research. Integrin-mediated adhesions link the actin network to the extracellular matrix and are commonly observed as cells migrate across rigid two-dimensional substrates. However, as more cell motility studies are being conducted in three-dimensional (3D) culture systems and in vivo, the role of integrins has become less clear. Recent work has shown that leukocyte migration in 3D contexts can be integrin-independent and that alternative mechanisms of cell adhesion are employed
First Evidence of a Precessing Jet Excavating a Protostellar Envelope
We present new, sensitive, near-infrared images of the Class I protostar,
Elias 29, in the Ophiuchus cloud core. To explore the relationship between the
infall envelope and the outflow, narrowband H2 1-0 S(1), Br-gamma, and
narrowband K-continuum filters were used to image the source with the
Wide-Field Infrared Camera on the Hale 5m telescope and with Persson's
Auxiliary Nasmyth Infrared Camera on the Baade 6.5 m telescope. The source
appears as a bipolar, scattered light nebula, with a wide opening angle in all
filters, as is typical for late-stage protostars. However, the pure H2
emission-line images point to the presence of a heretofore undetected
precessing jet. It is argued that high-velocity, narrow, precessing jets
provide the mechanism for creating the observed wide-angled outflow cavity in
this source.Comment: 11 pages, 1 figure, 1 tabl
Application of digital pathology-based advanced analytics of tumour microenvironment organisation to predict prognosis and therapeutic response.
In recent years, the application of advanced analytics, especially artificial intelligence (AI), to digital H&E images, and other histological image types, has begun to radically change how histological images are used in the clinic. Alongside the recognition that the tumour microenvironment (TME) has a profound impact on tumour phenotype, the technical development of highly multiplexed immunofluorescence platforms has enhanced the biological complexity that can be captured in the TME with high precision. AI has an increasingly powerful role in the recognition and quantitation of image features and the association of such features with clinically important outcomes, as occurs in distinct stages in conventional machine learning. Deep-learning algorithms are able to elucidate TME patterns inherent in the input data with minimum levels of human intelligence and, hence, have the potential to achieve clinically relevant predictions and discovery of important TME features. Furthermore, the diverse repertoire of deep-learning algorithms able to interrogate TME patterns extends beyond convolutional neural networks to include attention-based models, graph neural networks, and multimodal models. To date, AI models have largely been evaluated retrospectively, outside the well-established rigour of prospective clinical trials, in part because traditional clinical trial methodology may not always be suitable for the assessment of AI technology. However, to enable digital pathology-based advanced analytics to meaningfully impact clinical care, specific measures of 'added benefit' to the current standard of care and validation in a prospective setting are important. This will need to be accompanied by adequate measures of explainability and interpretability. Despite such challenges, the combination of expanding datasets, increased computational power, and the possibility of integration of pre-clinical experimental insights into model development means there is exciting potential for the future progress of these AI applications. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland
A close look into the carbon disk at the core of the planetary nebula CPD-568032
We present high spatial resolution observations of the dusty core of the
Planetary Nebula with Wolf-Rayet central star CPD-568032. These observations
were taken with the mid-infrared interferometer VLTI/MIDI in imaging mode
providing a typical 300 mas resolution and in interferometric mode using
UT2-UT3 47m baseline providing a typical spatial resolution of 20 mas. The
visible HST images exhibit a complex multilobal geometry dominated by faint
lobes. The farthest structures are located at 7" from the star. The mid-IR
environment of CPD-568032 is dominated by a compact source, barely resolved by
a single UT telescope in a 8.7 micron filter. The infrared core is almost fully
resolved with the three 40-45m projected baselines ranging from -5 to 51 degree
but smooth oscillating fringes at low level have been detected in spectrally
dispersed visibilities. This clear signal is interpreted in terms of a ring
structure which would define the bright inner rim of the equatorial disk.
Geometric models allowed us to derive the main geometrical parameters of the
disk. For instance, a reasonably good fit is reached with an achromatic and
elliptical truncated Gaussian with a radius of 97+/-11 AU, an inclination of
28+/-7 degree and a PA for the major axis at 345+/-7 degree. Furthermore, we
performed some radiative transfer modeling aimed at further constraining the
geometry and mass content of the disk, by taking into account the MIDI
dispersed visibilities, spectra, and the large aperture SED of the source.
These models show that the disk is mostly optically thin in the N band and
highly flared.Comment: Paper accepted in A&
Equatorial ozone characteristics as measured at Natal (5.9 deg S, 35.2 deg W)
Ozone density profiles obtained through electrochemical concentration cell (ECC) sonde measurements at Natal were analyzed. Time variations, as expected, are small. Outstanding features of the data are tropospheric densities substantially higher than those measured at other stations, and also a total ozone content that is higher than the averages given by satellite measurements
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FARS2 mutations presenting with pure spastic paraplegia and lesions of the dentate nuclei.
Mutations in FARS2, the gene encoding the mitochondrial phenylalanine-tRNA synthetase (mtPheRS), have been linked to a range of phenotypes including epileptic encephalopathy, developmental delay, and motor dysfunction. We report a 9-year-old boy with novel compound heterozygous variants of FARS2, presenting with a pure spastic paraplegia syndrome associated with bilateral signal abnormalities in the dentate nuclei. Exome sequencing identified a paternal nonsense variant (Q216X) lacking the catalytic core and anticodon-binding regions, and a maternal missense variant (P136H) possessing partial enzymatic activity. This case confirms and expands the phenotype related to FARS2 mutations with regards to clinical presentation and neuroimaging findings
Hydrodynamical simulations of the jet in the symbiotic star MWC 560 III. Application to X-ray jets in symbiotic stars
In papers I and II in this series, we presented hydrodynamical simulations of
jet models with parameters representative of the symbiotic system MWC 560.
These were simulations of a pulsed, initially underdense jet in a high density
ambient medium. Since the pulsed emission of the jet creates internal shocks
and since the jet velocity is very high, the jet bow shock and the internal
shocks are heated to high temperatures and should therefore emit X-ray
radiation. In this paper, we investigate in detail the X-ray properties of the
jets in our models. We have focused our study on the total X-ray luminosity and
its temporal variability, the resulting spectra and the spatial distribution of
the emission. Temperature and density maps from our hydrodynamical simulations
with radiative cooling presented in the second paper are used together with
emissivities calculated with the atomic database ATOMDB. The jets in our models
show extended and variable X-ray emission which can be characterized as a sum
of hot and warm components with temperatures that are consistent with
observations of CH Cyg and R Aqr. The X-ray spectra of our model jets show
emission line features which correspond to observed features in the spectra of
CH Cyg. The innermost parts of our pulsed jets show iron line emission in the
6.4 - 6.7 keV range which may explain such emission from the central source in
R Aqr. We conclude that MWC 560 should be detectable with Chandra or
XMM-Newton, and such X-ray observations will provide crucial for understanding
jets in symbiotic stars.Comment: 10 pages, 12 figures, accepted for publication in ApJ, uses
emulateap
Observational Study of the Multistructured Planetary Nebula NGC 7354
We present an observational study of the planetary nebula (PN) NGC 7354
consisting of narrowband Halpha and [NII]6584 imaging as well as low- and
high-dispersion long-slit spectroscopy and VLA-D radio continuum. According to
our imaging and spectroscopic data, NGC 7354 has four main structures: a quite
round outer shell and an elliptical inner shell, a collection of low-excitation
bright knots roughly concentrated on the equatorial region of the nebula, and
two symmetrical jet-like features, not aligned either with the shells' axes, or
with each other. We have obtained physical parameters like electron temperature
and electron density as well as ionic and elemental abundances for these
different structures. Electron temperature and electron density slightly vary
throughout the nebula. The local extinction coefficient c_Hbeta shows an
increasing gradient from south to north and a decreasing gradient from east to
west consistent with the number of equatorial bright knots present in each
direction. Abundance values show slight internal variations but most of them
are within the estimated uncertainties. In general, abundance values are in
good agreement with the ones expected for PNe. Radio continuum data are
consistent with optically thin thermal emission. We have used the interactive
three-dimensional modeling tool SHAPE to reproduce the observed morphokinematic
structures in NGC 7354 with different geometrical components. Our SHAPE model
is in very good agreement with our imaging and spectroscopic observations.
Finally, after modeling NGC 7354 with SHAPE, we suggest a possible scenario for
the formation of the nebula.Comment: Accepted for publication in AJ, 12 pages, 8 figure
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