163 research outputs found
The shadow knows: using shadows to investigate the structure of the pretransitional disk of HD 100453
We present GPI polarized intensity imagery of HD 100453 in Y-, J-, and K1
bands which reveals an inner gap ( au), an outer disk ( au) with
two prominent spiral arms, and two azimuthally-localized dark features also
present in SPHERE total intensity images (Wagner 2015). SED fitting further
suggests the radial gap extends to au. The narrow, wedge-like shape of the
dark features appears similar to predictions of shadows cast by a inner disk
which is misaligned with respect to the outer disk. Using the Monte Carlo
radiative transfer code HOCHUNCK3D (Whitney 2013), we construct a model of the
disk which allows us to determine its physical properties in more detail. From
the angular separation of the features we measure the difference in inclination
between the disks 45, and their major axes, PA = 140 east
of north for the outer disk and 100for the inner disk. We find an
outer disk inclination of from face-on in broad agreement
with the Wagner 2015 measurement of 34. SPHERE data in J- and H-bands
indicate a reddish disk which points to HD 100453 evolving into a young debris
disk
D-particles on T^4/Z_n orbifolds and their resolutions
We formulate the effective field theory of a D-particle on orbifolds of
by a cyclic group as a gauge theory in a -bundle over the dual orbifold. We
argue that this theory admits Fayet-Iliopoulos terms analogous to those present
in the case of noncompact orbifolds. In the case, we present some
evidence that turning on such terms resolves the orbifold singularities and may
lead to a surface realized as a blow up of the fixed points of the cyclic
group action.Comment: 34 pages, 3 figures; very minor typos corrected, 2 references adde
Differences in the gas and dust distribution in the transitional disk of a sun-like young star, PDS 70
We present ALMA 0.87 mm continuum, HCO+ J=4--3 emission line, and CO J=3--2
emission line data of the disk of material around the young, Sun-like star PDS
70. These data reveal the existence of a possible two component transitional
disk system with a radial dust gap of 0."2 +/- 0."05, an azimuthal gap in the
HCO+ J=4--3 moment zero map, as well as two bridge-like features in the gas
data. Interestingly these features in the gas disk have no analogue in the dust
disk making them of particular interest. We modeled the dust disk using the
Monte Carlo radiative transfer code HOCHUNK3D (Whitney et al. 2013) using a two
disk components. We find that there is a radial gap that extends from 15-60 au
in all grain sizes which differs from previous work
Tongue bite in a patient with tracheostomy after prone position -A case report-
A 22-year-old man underwent an operation for posterolateral fusion of the lumbar spine at L3-5. He was ventilated via a tracheostomy site in a prone position for 210 minutes. Ventilator function and eyeballs were checked periodically. After changing his position to supine for the wake-up test, it was noticed that his tongue was self-inflicted and looked to be cut unless immediate decompression was applied. After several manual attempts to open the mouth failed, anesthesia depth was deepened with thiopental sodium and neuromuscular blocker to decompress and reposition the tongue into the intraoral cavity. Minimal teeth marks and scarring remained after seven months without any complications
Subaru/HiCIAO imaging of LkH 330 - multi-band detection of the gap and spiral-like structures
We present - and -bands observations of the LkH 330
disk with a multi-band detection of the large gap and spiral-like structures.
The morphology of the outer disk (0\farcs3) at PA=0--45 and
PA=180--290 are likely density wave-induced spirals and comparison
between our observational results and simulations suggests a planet formation.
We have also investigated the azimuthal profiles at the ring and the outer-disk
regions as well as radial profiles in the directions of the spiral-like
structures and semi-major axis. Azimuthal analysis shows a large variety in
wavelength and implies that the disk has non-axisymmetric dust distributions.
The radial profiles in the major-axis direction (PA=) suggest that
the outer region (r\geq0\farcs25) may be influenced by shadows of the inner
region of the disk. The spiral-like directions (PA=10 and 230)
show different radial profiles, which suggests that the surfaces of the
spiral-like structures are highly flared and/or have different dust properties.
Finally, a color-map of the disk shows a lack of an outer eastern region in the
-band disk, which may hint the presence of an inner object that casts a
directional shadow onto the disk.Comment: 12pages, 16 figures, 2 tables, accepted for publication in A
A Possible Substellar Companion to the Intermediate-mass Giant HD 175679
We report the discovery of a substellar companion around the intermediatemass
giant HD 175679. Precise radial velocity data of the star from Xinglong Station
and Okayama Astrophysical Observatory (OAO) revealed a Keplerian velocity
variation with an orbital period of 1366.8 \pm 5.7 days, a semiamplitude of
380.2 \pm 3.2m s.1, and an eccentricity of 0.378 \pm 0.008. Adopting a stellar
mass of 2.7 \pm 0.3 M\odot, we obtain the minimum mass of the HD 175679 b is
37.3 \pm 2.8 MJ, and the semimajor axis is 3.36 \pm 0.12 AU. This discovery is
the second brown dwarf companion candidate from a joint planet-search program
between China and Japan.Comment: 10 pages, 3 figures, RAA accepte
Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context
Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts
Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas
Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN
Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas
This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing
molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin
Spatial Organization and Molecular Correlation of Tumor-Infiltrating Lymphocytes Using Deep Learning on Pathology Images
Beyond sample curation and basic pathologic characterization, the digitized H&E-stained images
of TCGA samples remain underutilized. To highlight this resource, we present mappings of tumorinfiltrating lymphocytes (TILs) based on H&E images from 13 TCGA tumor types. These TIL
maps are derived through computational staining using a convolutional neural network trained to
classify patches of images. Affinity propagation revealed local spatial structure in TIL patterns and
correlation with overall survival. TIL map structural patterns were grouped using standard
histopathological parameters. These patterns are enriched in particular T cell subpopulations
derived from molecular measures. TIL densities and spatial structure were differentially enriched
among tumor types, immune subtypes, and tumor molecular subtypes, implying that spatial
infiltrate state could reflect particular tumor cell aberration states. Obtaining spatial lymphocytic
patterns linked to the rich genomic characterization of TCGA samples demonstrates one use for
the TCGA image archives with insights into the tumor-immune microenvironment
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