665 research outputs found
KRAS mutation and Consensus Molecular Subtypes 2 and 3 are independently associated with reduced immune infiltration and reactivity in colorectal cancer
Abstract
Purpose: KRAS mutation is a common canonical mutation in colorectal cancer, found at differing frequencies in all consensus molecular subtypes (CMS). The independent immunobiological impacts of RAS mutation and CMS are unknown. Thus, we explored the immunobiological effects of KRAS mutation across the CMS spectrum.
Experimental Design: Expression analysis of immune genes/signatures was performed using The Cancer Genome Atlas (TCGA) RNA-seq and the KFSYSCC microarray datasets. Multivariate analysis included KRAS status, CMS, tumor location, MSI status, and neoantigen load. Protein expression of STAT1, HLA-class II, and CXCL10 was analyzed by digital IHC.
Results: The Th1-centric co-ordinate immune response cluster (CIRC) was significantly, albeit modestly, reduced in KRAS-mutant colorectal cancer in both datasets. Cytotoxic T cells, neutrophils, and the IFNγ pathway were suppressed in KRAS-mutant samples. The expressions of STAT1 and CXCL10 were reduced at the mRNA and protein levels. In multivariate analysis, KRAS mutation, CMS2, and CMS3 were independently predictive of reduced CIRC expression. Immune response was heterogeneous across KRAS-mutant colorectal cancer: KRAS-mutant CMS2 samples have the lowest CIRC expression, reduced expression of the IFNγ pathway, STAT1 and CXCL10, and reduced infiltration of cytotoxic cells and neutrophils relative to CMS1 and CMS4 and to KRAS wild-type CMS2 samples in the TCGA. These trends held in the KFSYSCC dataset.
Conclusions: KRAS mutation is associated with suppressed Th1/cytotoxic immunity in colorectal cancer, the extent of the effect being modulated by CMS subtype. These results add a novel immunobiological dimension to the biological heterogeneity of colorectal cancer. Clin Cancer Res; 24(1); 224–33. ©2017 AACR.</jats:p
Photometric Estimates of Stellar Masses in High-Redshift Galaxies
We present a new tool for the photometric estimate of stellar masses in
distant galaxies. The observed SEDs are fitted by combining single stellar
populations, with different SFRs and amounts of dust extinction. This approach
gives us the best flexibility when dealing with the widest variety of physical
situation for the target galaxies. In particular we tested the code on three
classes of sources: dusty ISO-selected starbursts, K-band selected
ellipticals/S0s and z=2-3 Lyman-break galaxies. We pay particular attention in
evaluating the uncertainties in the stellar mass estimate, due to degeneracies
in the physical parameters, different SFHs or metallicities. Based on
optical-NIR photometric data, the stellar masses are found to have overall
uncertainties of a factor of ~2 for E/S0s, ~2-5 for the starbursts population,
and up to 10 for Ly-break galaxies. In any case the latter appear to correspond
to a galaxy population significantly less massive than those observed at lower
redshifts, possibly indicating substantial stellar build-up at z~1-2 in the
field galaxy population. Using simulated deep SIRTF/IRAC observations of
starbursts and Lyman-break galaxies, we investigate how an extension of the
wavelength dynamic range will decrease the uncertainties in the stellar mass
estimate, and find that they will reduce for both classes to factors of 2-3,
good enough for statistically reliable determinations of the galaxy
evolutionary mass functions.Comment: 14 pages; 3 jpg figures; A&A, in pres
ImpZ: a new photometric redshift code for galaxies and quasars
We present a combined galaxy-quasar approach to template-fitting photometric
redshift techniques and show the method to be a powerful one. The code (ImpZ)
is presented, developed and applied to two spectroscopic redshift catalogues,
namely the Isaac Newton Telescope Wide Angle Survey ELAIS N1 and N2 fields and
the Chandra Deep Field North. In particular, optical size information is used
to improve the redshift determination. The success of the code is shown to be
very good with Delta z/(1+z) constrained to within 0.1 for 92 per cent of the
galaxies in our sample. The extension of template-fitting to quasars is found
to be reasonable with Delta z/(1+z) constrained to within 0.25 for 68 per cent
of the quasars in our sample. Various template extensions into the far-UV are
also tested.Comment: 21 pages. MNRAS in press. Minor alterations to match MNRAS final
proo
H alpha emitting galaxies and the star formation rate density at z~0.24
We have carried out a survey searching for H alpha emitting galaxies at
z~0.24 using a narrow band filter tuned with the redshifted line. The total sky
area covered was 0.19 square degrees within the redshift range 0.228 to 0.255
in a set of four fields in the ELAIS-N1 zone. This corresponds to a volume of
9.8 10^3 Mpc^3 and a look-back time of 3.6 Gyr when H0=50 km s^{-1} Mpc^{-1}
and q=0.5 are assumed. A total of 52 objects are selected as candidates for a
broad band limiting magnitude of I~22.9, plus 16 detected only in the narrow
band image for a narrow band limiting magnitude for object detection of 21.0.
The threshold detection corresponds to about 20 A equivalent width with an
uncertainty of ~ 10 AA. Point-like objects (15) were excluded from our analysis
using CLASS_STAR parameter from SExtractor}. The contamination from other
emission lines such as O[II] 3727, H beta and [OIII] 4959,5007 at redshifts
1.2, 0.66 and 0.61 respectively is estimated, and found to be negligible at the
flux limits of our sample. We find an extinction-corrected H alpha luminosity
density of 5.4 10^39 erg s^{-1} Mpc^{-3}. This uncertainty takes into account
the photometric and Poissonian errors only. Assuming a constant relation
between the H alpha luminosity and star formation rate, the SFR density in the
covered volume is 0.043 M_sun yr^{-1} Mpc^{-3}. This translates to 0.037 M_sun
yr^{-1} Mpc^{-3} when the total density is corrected for the AGN contribution
as estimated in the local Universe. This value is a factor ~4 higher than the
local SFR density. This result needs to be confirmed by future spectroscopic
follow-up observations.Comment: 10 pages, 7 figures. To be published in Astronomy & Astrophysics.
Corrected astrometry in Table 2, field b4. Corrected luminosity funcion from
Tresse & Maddox on figure 6. Corrected mismatched logL axis on figure
The ESO-Spitzer Imaging extragalactic Survey (ESIS) I: WFI B,V,R deep observations of ELAIS-S1 and comparison to Spitzer and GALEX data
The ESO-Spitzer extragalactic Imaging Survey (ESIS) is the optical follow up
of the Spitzer Wide-Area InfraRed Extragalactic (SWIRE) survey in the ELAIS-S1
area. This paper presents B, V, R Wide Field Imager observations of the first
1.5 square degree of the ESIS survey. Data reduction is described including
astrometric calibration, illumination and color corrections, completeness and
photometric accuracy estimates. Number counts and color distributions are
compared to literature observational and theoretical data, including
non-evolutionary, PLE, evolutionary and semi-analytic Lambda-CDM galaxy models,
as well as Milky Way stellar predictions. ESIS data are in good agreement with
previous works and are best reproduced by evolutionary and hierarchical
Lambda-CDM scenarios. The ELAIS-S1 area benefits from extensive follow-up from
X-ray to radio frequencies: some potential uses of the multi-wavelength
observations are illustrated. Optical-Spitzer color-color plots promise to be
very powerful tools to disentangle different classes of sources (e.g. AGNs,
starbursts, quiescent galaxies). Ultraviolet GALEX data are matched to optical
and Spitzer samples, leading to a discussion of galaxy properties in the
UV-to-24 microns color space. The spectral energy distribution of a few
objects, from the X-rays to the far-IR are presented as examples of the
multi-wavelength study of galaxy emission components in different spectral
domains.Comment: Accepted for publication in A&A. 24 pages, quality of some figures
have been degrade
Measurement of the cross-section and charge asymmetry of bosons produced in proton-proton collisions at TeV with the ATLAS detector
This paper presents measurements of the and cross-sections and the associated charge asymmetry as a
function of the absolute pseudorapidity of the decay muon. The data were
collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with
the ATLAS experiment at the LHC and correspond to a total integrated luminosity
of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements
varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the
1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured
with an uncertainty between 0.002 and 0.003. The results are compared with
predictions based on next-to-next-to-leading-order calculations with various
parton distribution functions and have the sensitivity to discriminate between
them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables,
submitted to EPJC. All figures including auxiliary figures are available at
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13
Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector
A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13 TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139 fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
Chemical vapour deposition synthetic diamond: materials, technology and applications
Substantial developments have been achieved in the synthesis of chemical
vapour deposition (CVD) diamond in recent years, providing engineers and
designers with access to a large range of new diamond materials. CVD diamond
has a number of outstanding material properties that can enable exceptional
performance in applications as diverse as medical diagnostics, water treatment,
radiation detection, high power electronics, consumer audio, magnetometry and
novel lasers. Often the material is synthesized in planar form, however
non-planar geometries are also possible and enable a number of key
applications. This article reviews the material properties and characteristics
of single crystal and polycrystalline CVD diamond, and how these can be
utilized, focusing particularly on optics, electronics and electrochemistry. It
also summarizes how CVD diamond can be tailored for specific applications,
based on the ability to synthesize a consistent and engineered high performance
product.Comment: 51 pages, 16 figure
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