2,627 research outputs found
Strong late-time circumstellar interaction in the peculiar supernova iPTF14hls
We present a moderate-resolution spectrum of the peculiar Type II supernova
iPTF14hls taken on day 1153 after discovery. This spectrum reveals the clear
signature of shock interaction with dense circumstellar material (CSM). We
suggest that this CSM interaction may be an important clue for understanding
the extremely unusual photometric and spectroscopic evolution seen over the
first 600 days of iPTF14hls. The late-time spectrum shows a double-peaked
intermediate-width H-alpha line indicative of expansion speeds around 1000
km/s, with the double-peaked shape hinting at a disc-like geometry in the CSM.
If the CSM was highly asymmetric, perhaps in a disc or torus that was ejected
from the star 3-6 years prior to explosion, then the CSM interaction could have
been overrun and hidden below the SN ejecta photosphere from a wide range of
viewing angles. In that case, CSM interaction luminosity would have been
thermalized well below the photosphere, possibly sustaining the high luminosity
without exhibiting the traditional observational signatures of strong CSM
interaction (narrow H-alpha emission and X-rays). Variations in density
structure of the CSM could account for the multiple rebrightenings of the
lightcurve. We propose that enveloped CSM interaction as seen in some recent
SNe, rather than an entirely new explosion mechanism, may be adequate to
explain the peculiar evolution of iPTF14hls.Comment: 6 pages, 5 figures, submitted to MNRAS with referee respons
Massive stars dying alone: The extremely remote environment of SN 2009ip
We present late-time HST images of the site of supernova (SN) 2009ip taken
almost 3 yr after its bright 2012 luminosity peak. SN 2009ip is now slightly
fainter in broad filters than the progenitor candidate detected by HST in 1999.
The current source continues to be dominated by ongoing late-time CSM
interaction that produces strong H-alpha emission and a weak pseudo-continuum,
as found previously for 1-2 yr after explosion. The intent of these
observations was to search for evidence of recent star formation in the local
(1kpc; 10 arcsec) environment around SN 2009ip, in the remote outskirts of its
host spiral galaxy NGC 7259. We can rule out the presence of any massive
star-forming complexes like 30 Dor or the Carina Nebula at the SN site or
within a few kpc. If the progenitor of SN 2009ip was really a 50-80 Msun star
as archival HST images suggested, then it is strange that there is no sign of
this type of massive star formation anywhere in the vicinity. A possible
explanation is that the progenitor was the product of a merger or binary mass
transfer, rejuvenated after a lifetime that was much longer than 4-5 Myr,
allowing its natal H II region to have faded. A smaller region like the Orion
Nebula would be an unresolved but easily detected point source. This is ruled
out within 1.5 kpc around SN 2009ip, but a small H II region could be hiding in
the glare of SN 2009ip itself. Later images after a few more years have passed
are needed to confirm that the progenitor candidate is truly gone and to test
for the presence of a small H II region or cluster at the SN position.Comment: 8 pages, 5 figs. submitted to MNRA
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Outcomes of Physicians' Communication Goals During Patient Interactions.
During healthcare visits, physicians may set communication goals such as providing their patient with information about treatment; however, no recommendations exist regarding which goals physicians should prioritize during their often-brief interactions with patients. Two studies examined five communication goals (providing information, reducing distress, increasing patient satisfaction, increasing patient adherence, and encouraging hope) in the context of physician-patient interactions and their relationship with patient and physician outcomes. In Study 1, audio-recordings of physician-patient interactions were coded by research assistants for goal-related content. In Study 2, patients reported their physician's use of each goal during the interaction. In both studies, patients and physicians reported visit outcomes. Within-study meta-analyses suggested that the goal of reducing distress, but not the other goals, was consistently related to improved outcomes in Study 1. All goals were related to improved outcomes in Study 2. We then computed sample-size-weighted meta-analytic effects of each goal on each outcome across both studies. These results suggested that all of the goals had similar-sized positive relationships with patient and physician outcomes across studies. These findings suggest that physicians should generally approach consultations with communication goals in mind, but prioritizing efforts to reduce distress may be particularly beneficial
Novel cell adhesion/migration pathways are predictive markers of HDAC inhibitor resistance in cutaneous T cell lymphoma
BACKGROUND: Treatment for Cutaneous T Cell Lymphoma (CTCL) is generally not curative. Therefore, selecting therapy that is effective and tolerable is critical to clinical decision-making. Histone deacetylase inhibitors (HDACi), epigenetic modifier drugs, are commonly used but effective in only ~30% of patients. There are no predictive markers of HDACi response and the CTCL histone acetylation landscape remains unmapped. We sought to identify pre-treatment molecular markers of resistance in CTCL that progressed on HDACi therapy.
METHODS: Purified T cells from 39 pre/post-treatment peripheral blood samples and skin biopsies from 20 patients were subjected to RNA-seq and ChIP-seq for histone acetylation marks (H3K14/9 ac, H3K27ac). We correlated significant differences in histone acetylation with gene expression in HDACi-resistant/sensitive CTCL. We extended these findings in additional CTCL patient cohorts (RNA-seq, microarray) and using ELISA in matched CTCL patient plasma.
FINDINGS: Resistant CTCL exhibited high levels of histone acetylation, which correlated with increased expression of 338 genes (FDR \u3c 0·05), including some novel to CTCL: BIRC5 (anti-apoptotic); RRM2 (cell cycle); TXNDC5, GSTM1 (redox); and CXCR4, LAIR2 (cell adhesion/migration). Several of these, including LAIR2, were elevated pre-treatment in HDACi-resistant CTCL. In CTCL patient plasma (n = 6), LAIR2 protein was also elevated (p \u3c 0·01) compared to controls.
INTERPRETATION: This study is the first to connect genome-wide differences in chromatin acetylation and gene expression to HDACi-resistance in primary CTCL. Our results identify novel markers with high pre-treatment expression, such as LAIR2, as potential prognostic and/or predictors of HDACi-resistance in CTCL.
FUNDING: NIH:CA156690, CA188286; NCATS: WU-ICTS UL1 TR000448; Siteman Cancer Center: CA091842
Thirty years of SN 1980K: Evidence for light echoes
We report optical and mid-infrared photometry of SN 1980K between 2004 and
2010, which show slow monotonic fading consistent with previous spectroscopic
and photometric observations made 8 to 17 years after outburst. The slow
rate-of-change over two decades suggests that this evolution may result from
scattered and thermal light echoes off of extended circumstellar material. We
present a semi- analytic dust radiative-transfer model that uses an empirically
corrected effective optical depth to provide a fast and robust alternative to
full Monte-Carlo radiative transfer modeling for homogenous dust at low to
intermediate optical depths. We find that unresolved echoes from a thin
circumstellar shell 14-15 lt-yr from the progenitor, and containing about 0.02
Msun of carbon-rich dust, can explain the broadband spectral and temporal
evolution. The size, mass and dust composition are in good agreement with the
contact discontinuity observed in scattered echoes around SN 1987A. The origin
of slowly-changing high-velocity [O I] and Halpha lines is also considered. We
propose an origin in shocked high-velocity metal-rich clumps of ejecta, rather
than arising in the impact of ejecta on slowly-moving circumstellar material,
as is the case with hot spots in SN 1987A.Comment: Accepted 2/14/12 to be published in ApJ. 15 pages, 10 figure
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SN 2017gmr: An Energetic Type II-P Supernova with Asymmetries
We present high-cadence UV, optical, and near-infrared data on the luminous Type II-P supernova SN 2017gmr from hours after discovery through the first 180 days. SN 2017gmr does not show signs of narrow, high-ionization emission lines in the early optical spectra, yet the optical light-curve evolution suggests that an extra energy source from circumstellar medium (CSM) interaction must be present for at least 2 days after explosion. Modeling of the early light curve indicates a ~500 R ⊙ progenitor radius, consistent with a rather compact red supergiant, and late-time luminosities indicate that up to 0.130 ± 0.026 M ⊙ of 56Ni are present, if the light curve is solely powered by radioactive decay, although the 56Ni mass may be lower if CSM interaction contributes to the post-plateau luminosity. Prominent multipeaked emission lines of Hα and [O i] emerge after day 154, as a result of either an asymmetric explosion or asymmetries in the CSM. The lack of narrow lines within the first 2 days of explosion in the likely presence of CSM interaction may be an example of close, dense, asymmetric CSM that is quickly enveloped by the spherical supernova ejecta.NSFNational Science Foundation (NSF) [AST-1813825, AST-1515559, AST-1821987, 1821967, AST-1813176, AST-1313484, 1829740]; Department of Science and Technology (DST), Govt. of IndiaDepartment of Science & Technology (India); Indo-US Science and Technology Forum (IUSSTF); LSSTC Data Science Fellowship Program - LSSTC; Brinson Foundation; Moore FoundationGordon and Betty Moore Foundation; project "Transient Astrophysical Objects" of the National Research, Development and Innovation Office (NKFIH), Hungary - European Union [GINOP-2-3-2-15-2016-00033]; Chinese Academy of Sciences (CAS)Chinese Academy of Sciences; Swedish Research Council (Vetenskapsradet)Swedish Research Council; Swedish National Space Board; research environment grant "Gravitational Radiation and Electromagnetic Astrophysical Transients (GREAT)"; Packard FoundationThe David & Lucile Packard Foundation; "Millennium Institute of Astrophysics (MAS)" of the Iniciativa Cientifica Milenio del Ministerio Economia, Fomento y Turismo de Chile [IC120009]; CONICYT PAI/INDUSTRIA [79090016]; Science and Engineering Research Board (SERB) under the Department of Science AMP; Technology, Govt. of India [PDF/2016/001563]; Ministry of Economy, Development, and Tourism's Millennium Science Inititative [IC120009]; H2020 through an ERC Starting Grant [758638]; FONDECYTComision Nacional de Investigacion Cientifica y Tecnologica (CONICYT)CONICYT FONDECYT [11170953]; Polish NCN MAESTRO grant [2014/14/A/ST9/00121]; PRIN INAF 2017 "Towards the SKA and CTA era: discovery, localisation and physics of transient sources (PI M. Giroletti)"; Independent Research Fund Denmark [8021-00170B]; VILLUM FONDEN [13261, 16599]; Spanish MICINN grant [ESP2017-82674-R]; FEDER fundsEuropean Union (EU); National Science FoundationNational Science Foundation (NSF) [AST-1613472]; National Natural Science Foundation of China (NSFC)National Natural Science Foundation of China [11325313, 11633002, 11761141001]; National Program on Key Research and Development Project [2016YFA0400803]; Open Project Program of the Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences; IDA (Instrumentation center for Danish Astrophysics); Gemini Observatory [GN-2017B-Q-52]; European Southern Observatory [099.D-0543(A)]; W. M. Keck FoundationW.M. Keck Foundation [NNH14CK55B]; National Aeronautics and Space AdministrationNational Aeronautics & Space Administration (NASA); National Science FoundationNational Science Foundation (NSF); NASAs Astrophysics Data Analysis Program [NNX13AF35G]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
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