1,018 research outputs found
CHILES: HI morphology and galaxy environment at z=0.12 and z=0.17
We present a study of 16 HI-detected galaxies found in 178 hours of
observations from Epoch 1 of the COSMOS HI Large Extragalactic Survey (CHILES).
We focus on two redshift ranges between 0.108 <= z <= 0.127 and 0.162 <= z <=
0.183 which are among the worst affected by radio frequency interference (RFI).
While this represents only 10% of the total frequency coverage and 18% of the
total expected time on source compared to what will be the full CHILES survey,
we demonstrate that our data reduction pipeline recovers high quality data even
in regions severely impacted by RFI. We report on our in-depth testing of an
automated spectral line source finder to produce HI total intensity maps which
we present side-by-side with significance maps to evaluate the reliability of
the morphology recovered by the source finder. We recommend that this become a
common place manner of presenting data from upcoming HI surveys of resolved
objects. We use the COSMOS 20k group catalogue, and we extract filamentary
structure using the topological DisPerSE algorithm to evaluate the \hi\
morphology in the context of both local and large-scale environments and we
discuss the shortcomings of both methods. Many of the detections show disturbed
HI morphologies suggesting they have undergone a recent interaction which is
not evident from deep optical imaging alone. Overall, the sample showcases the
broad range of ways in which galaxies interact with their environment. This is
a first look at the population of galaxies and their local and large-scale
environments observed in HI by CHILES at redshifts beyond the z=0.1 Universe.Comment: 23 pages, 12 figures, 1 interactive 3D figure, accepted to MNRA
Microscopic Realization of the Kerr/CFT Correspondence
Supersymmetric M/string compactifications to five dimensions contain BPS
black string solutions with magnetic graviphoton charge P and near-horizon
geometries which are quotients of AdS_3 x S^2. The holographic duals are
typically known 2D CFTs with central charges c_L=c_R=6P^3 for large P. These
same 5D compactifications also contain non-BPS but extreme Kerr-Newman black
hole solutions with SU(2)_L spin J_L and electric graviphoton charge Q obeying
Q^3 \leq J_L^2. It is shown that in the maximally charged limit Q^3 -> J_L^2,
the near-horizon geometry coincides precisely with the right-moving temperature
T_R=0 limit of the black string with magnetic charge P=J_L^{1/3}. The known
dual of the latter is identified as the c_L=c_R=6J_L CFT predicted by the
Kerr/CFT correspondence. Moreover, at linear order away from maximality, one
finds a T_R \neq 0 quotient of the AdS_3 factor of the black string solution
and the associated thermal CFT entropy reproduces the linearly sub-maximal
Kerr-Newman entropy. Beyond linear order, for general Q^3<J_L^2, one has a
finite-temperature quotient of a warped deformation of the magnetic string
geometry. The corresponding dual deformation of the magnetic string CFT
potentially supplies, for the general case, the c_L=c_R=6J_L CFT predicted by
Kerr/CFT.Comment: 18 pages, no figure
Comparison of Evaluations for Heart Transplant Before Durable Left Ventricular Assist Device and Subsequent Receipt of Transplant at Transplant vs Nontransplant Centers
IMPORTANCE: In 2020, the Centers for Medicare & Medicaid Services revised its national coverage determination, removing the requirement to obtain review from a Medicare-approved heart transplant center to implant a durable left ventricular assist device (LVAD) for bridge-to-transplant (BTT) intent at an LVAD-only center. The association between center-level transplant availability and access to heart transplant, the gold-standard therapy for advanced heart failure (HF), is unknown.
OBJECTIVE: To investigate the association of center transplant availability with LVAD implant strategies and subsequent heart transplant following LVAD implant before the Centers for Medicare & Medicaid Services policy change.
DESIGN, SETTING, AND PARTICIPANTS: A retrospective cohort study of the Society of Thoracic Surgeons Intermacs multicenter US registry database was conducted from April 1, 2012, to June 30, 2020. The population included patients with HF receiving a primary durable LVAD.
EXPOSURES: LVAD center transplant availability (LVAD/transplant vs LVAD only).
MAIN OUTCOMES AND MEASURES: The primary outcomes were implant strategy as BTT and subsequent transplant by 2 years. Covariates that might affect listing strategy and outcomes were included (eg, patient demographic characteristics, comorbidities) in multivariable models. Parameters for BTT listing were estimated using logistic regression with center-level random effects and for receipt of a transplant using a Cox proportional hazards regression model with death as a competing event.
RESULTS: The sample included 22 221 LVAD recipients with a median age of 59.0 (IQR, 50.0-67.0) years, of whom 17 420 (78.4%) were male and 3156 (14.2%) received implants at LVAD-only centers. Receiving an LVAD at an LVAD/transplant center was associated with a 79% increased adjusted odds of BTT LVAD designation (odds ratio, 1.79; 95% CI, 1.35-2.38; P \u3c .001). The 2-year transplant rate following LVAD implant was 25.6% at LVAD/transplant centers and 11.9% at LVAD-only centers. There was an associated 33% increased rate of transplant at LVAD/transplant centers compared with LVAD-only centers (adjusted hazard ratio, 1.33; 95% CI, 1.17-1.51) with a similar hazard for death at 2 years (adjusted hazard ratio, 0.99; 95% CI, 0.90-1.08).
CONCLUSIONS AND RELEVANCE: Receiving an LVAD at an LVAD-transplant center was associated with increased odds of BTT intent at implant and subsequent transplant receipt for patients at 2 years. The findings of this study suggest that Centers for Medicare & Medicaid Services policy change may have the unintended consequence of further increasing inequities in access to transplant among patients at LVAD-only centers
\u3ci\u3eTrans\u3c/i\u3e-ancestry Fine Mapping and Molecular Assays Identify Regulatory Variants at the ANGPTL8 HDL-C GWAS Locus
Recent genome-wide association studies (GWAS) have identified variants associated with highdensity lipoprotein cholesterol (HDL-C) located in or near the ANGPTL8 gene. Given the extensive sharing of GWAS loci across populations, we hypothesized that at least one shared variant at this locus affects HDL-C. The HDL-C–associated variants are coincident with expression quantitative trait loci for ANGPTL8 and DOCK6 in subcutaneous adipose tissue; however, only ANGPTL8 expression levels are associated with HDL-C levels. We identified a 400-bp promoter region of ANGPTL8 and enhancer regions within 5 kb that contribute to regulating expression in liver and adipose. To identify variants functionally responsible for the HDL-C association, we performed fine-mapping analyses and selected 13 candidate variants that overlap putative regulatory regions to test for allelic differences in regulatory function. Of these variants, rs12463177-G increased transcriptional activity (1.5-fold, P = 0.004) and showed differential protein binding. Six additional variants (rs17699089, rs200788077, rs56322906, rs3760782, rs737337, and rs3745683) showed evidence of allelic differences in transcriptional activity and/or protein binding. Taken together, these data suggest a regulatory mechanism at the ANGPTL8 HDL-C GWAS locus involving tissue-selective expression and at least one functional variant
An 800-million-solar-mass black hole in a significantly neutral Universe at redshift 7.5
Quasars are the most luminous non-transient objects known and as a result
they enable studies of the Universe at the earliest cosmic epochs. Despite
extensive efforts, however, the quasar ULAS J1120+0641 at z=7.09 has remained
the only one known at z>7 for more than half a decade. Here we report
observations of the quasar ULAS J134208.10+092838.61 (hereafter J1342+0928) at
redshift z=7.54. This quasar has a bolometric luminosity of 4e13 times the
luminosity of the Sun and a black hole mass of 8e8 solar masses. The existence
of this supermassive black hole when the Universe was only 690 million years
old---just five percent of its current age---reinforces models of early
black-hole growth that allow black holes with initial masses of more than about
1e4 solar masses or episodic hyper-Eddington accretion. We see strong evidence
of absorption of the spectrum of the quasar redwards of the Lyman alpha
emission line (the Gunn-Peterson damping wing), as would be expected if a
significant amount (more than 10 per cent) of the hydrogen in the intergalactic
medium surrounding J1342+0928 is neutral. We derive a significant fraction of
neutral hydrogen, although the exact fraction depends on the modelling.
However, even in our most conservative analysis we find a fraction of more than
0.33 (0.11) at 68 per cent (95 per cent) probability, indicating that we are
probing well within the reionization epoch of the Universe.Comment: Updated to match the final journal versio
A Phase 1b Study of Telisotuzumab Vedotin in Combination With Nivolumab in Patients With NSCLC
Introduction: Telisotuzumab vedotin (Teliso-V) is an anti-c-Met-directed antibody-drug conjugate that has exhibited antitumor activity as monotherapy in NSCLC. Its potential activity combined with programmed cell death protein-1 inhibitors has not been previously evaluated.
Methods: In a phase 1b study (NCT02099058), adult patients (≥18 y) with advanced NSCLC received combination therapy with Teliso-V (1.6, 1.9, or 2.2 mg/kg, every 2 wk) plus nivolumab (3 mg/kg, 240 mg, or per locally approved label). The primary objective was to assess safety and tolerability; secondary objectives included the evaluation of antitumor activity.
Results: As of January 2020, a total of 37 patients received treatment with Teliso-V (safety population) in combination with nivolumab; 27 patients (efficacy population) were c-Met immunohistochemistry-positive. Programmed death-ligand 1 (PD-L1) status was evaluated in the efficacy population (PD-L1-positive [PD-L1+]: n = 15; PD-L1-negative [PD-L1-]: n = 9; PD-L1-unknown: n = 3). The median age was 67 years and 74% (20 of 27) of patients were naive to immune checkpoint inhibitors. The most common any-grade treatment-related adverse events were fatigue (27%) and peripheral sensory neuropathy (19%). The pharmacokinetic profile of Teliso-V plus nivolumab was similar to Teliso-V monotherapy. The objective response rate was 7.4%, with two patients (PD-L1+, c-Met immunohistochemistry H-score 190, n = 1; PD-L1-, c-Met H-score 290, n = 1) having a confirmed partial response. Overall median progression-free survival was 7.2 months (PD-L1+: 7.2 mo; PD-L1-: 4.5 mo; PD-L1-unknown: not reached).
Conclusions: Combination therapy with Teliso-V plus nivolumab was well tolerated in patients with c-Met+ NSCLC with limited antitumor activity
Measurement of the Lifetime Difference Between B_s Mass Eigenstates
We present measurements of the lifetimes and polarization amplitudes for B_s
--> J/psi phi and B_d --> J/psi K*0 decays. Lifetimes of the heavy (H) and
light (L) mass eigenstates in the B_s system are separately measured for the
first time by determining the relative contributions of amplitudes with
definite CP as a function of the decay time. Using 203 +/- 15 B_s decays, we
obtain tau_L = (1.05 +{0.16}/-{0.13} +/- 0.02) ps and tau_H = (2.07
+{0.58}/-{0.46} +/- 0.03) ps. Expressed in terms of the difference DeltaGamma_s
and average Gamma_s, of the decay rates of the two eigenstates, the results are
DeltaGamma_s/Gamma_s = (65 +{25}/-{33} +/- 1)%, and DeltaGamma_s = (0.47
+{0.19}/-{0.24} +/- 0.01) inverse ps.Comment: 8 pages, 3 figures, 2 tables; as published in Physical Review Letters
on 16 March 2005; revisions are for length and typesetting only, no changes
in results or conclusion
Arctic change and possible influence on mid-latitude climate and weather: a US CLIVAR White Paper
The Arctic has warmed more than twice as fast as the global average since the mid 20th century,
a phenomenon known as Arctic amplification (AA). These profound changes to the Arctic system
have coincided with a period of ostensibly more frequent events of extreme weather across the
Northern Hemisphere (NH) mid-latitudes, including extreme heat and rainfall events and recent
severe winters. Though winter temperatures have generally warmed since 1960 over mid-to-high
latitudes, the acceleration in the rate of warming at high-latitudes, relative to the rest of the NH,
started approximately in 1990. Trends since 1990 show cooling over the NH continents, especially
in Northern Eurasia.
The possible link between Arctic change and mid-latitude climate and weather has spurred a rush
of new observational and modeling studies. A number of workshops held during 2013-2014 have
helped frame the problem and have called for continuing and enhancing efforts for improving
our understanding of Arctic-mid-latitude linkages and its attribution to the occurrence of extreme
climate and weather events. Although these workshops have outlined some of the major challenges
and provided broad recommendations, further efforts are needed to synthesize the diversified
research results to identify where community consensus and gaps exist.
Building upon findings and recommendations of the previous workshops, the US CLIVAR Working
Group on Arctic Change and Possible Influence on Mid-latitude Climate and Weather convened an
international workshop at Georgetown University in Washington, DC, on February 1-3, 2017. Experts
in the fields of atmosphere, ocean, and cryosphere sciences assembled to assess the rapidly evolving
state of understanding, identify consensus on knowledge and gaps in research, and develop specific
actions to accelerate progress within the research community. With more than 100 participants,
the workshop was the largest and most comprehensive gathering of climate scientists to address
the topic to date. In this white paper, we synthesize and discuss outcomes from this workshop and
activities involving many of the working group members
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