In patients at risk of cancer therapy-related cardiac dysfunction (CTRCD), initiation of cardioprotective therapy (CPT) is constrained by the low sensitivity of ejection fraction (EF) for minor ...changes in left ventricular (LV) function. Global longitudinal strain (GLS) is a robust and sensitive marker of LV dysfunction, but existing observational data have been insufficient to support a routine GLS-guided strategy for CPT.
This study sought to identify whether GLS-guided CPT prevents reduction in LVEF and development of CTRCD in high-risk patients undergoing potentially cardiotoxic chemotherapy, compared with usual care.
In this international, multicenter, prospective, randomized controlled trial, 331 anthracycline-treated patients with another heart failure risk factor were randomly allocated to CPT initiation guided by either ≥12% relative reduction in GLS (n = 166) or >10% absolute reduction of LVEF (n = 165). Patients were followed for EF and development of CTRCD (symptomatic EF reduction of >5% or >10% asymptomatic to <55%) over 1 year.
Of 331 randomized patients, 2 died, and 22 withdrew consent or were lost to follow-up. Among 307 patients (age: 54 ± 12 years; 94% women; baseline LVEF: 59 ± 6%; GLS: –20.6 ± 2.4%) with a median (interquartile range) follow-up of 1.02 years (0.98 to 1.07 years), most (n = 278) had breast cancer. Heart failure risk factors were prevalent: 29% had hypertension, and 13% had diabetes mellitus. At the 1-year follow-up, although the primary outcome of change in LVEF was not significantly different between the 2 arms, there was significantly greater use of CPT, and fewer patients met CTRCD criteria in the GLS-guided than the EF-guided arm (5.8% vs. 13.7%; p = 0.02), and the 1-year EF was 57 ± 6% versus 55 ± 7% (p = 0.05). Patients who received CPT in the EF-guided arm had a larger reduction in LVEF at follow-up than in the GLS-guided arm (9.1 ± 10.9% vs. 2.9 ± 7.4%; p = 0.03).
Although the change in LVEF was not different between the 2 arms as a whole, when patients who received CPT were compared, those in the GLS-guided arm had a significantly lower reduction in LVEF at 1 year follow-up. Furthermore, GLS-guided CPT significantly reduced a meaningful fall of LVEF to the abnormal range. The results support the use of GLS in surveillance for CTRCD. (Strain Surveillance of Chemotherapy for Improving Cardiovascular Outcomes SUCCOUR; ACTRN12614000341628)
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Current and upcoming wide-field, ground-based, broad-band imaging surveys promise to address a wide range of outstanding problems in galaxy formation and cosmology. Several such uses of ground-based ...data, especially weak gravitational lensing, require highly precise measurements of galaxy image statistics with careful correction for the effects of the point spread function (PSF). In this paper, we introduce the shera (SHEar Reconvolution Analysis) software to simulate ground-based imaging data with realistic galaxy morphologies and observing conditions, starting from space-based data (from the Cosmological Evolution Survey, COSMOS) and accounting for the effects of the space-based PSF. This code simulates ground-based data, optionally with a weak lensing shear applied, in a model-independent way using a general Fourier space formalism. The utility of this pipeline is that it allows for a precise, realistic assessment of systematic errors due to the method of data processing, for example in extracting weak lensing galaxy shape measurements or galaxy radial profiles, given user-supplied observational conditions and real galaxy morphologies. Moreover, the simulations allow for the empirical test of error estimates and determination of parameter degeneracies, via generation of many noise maps. The public release of this software, along with a large sample of cleaned COSMOS galaxy images (corrected for charge transfer inefficiency), should enable upcoming ground-based imaging surveys to achieve their potential in the areas of precision weak lensing analysis, galaxy profile measurement and other applications involving detailed image analysis.
ABSTRACT
Motivated by discovering strongly lensed supernovae, gravitational waves, and kilonovae in the 2020s, we investigate whether to build a watchlist of clusters based on observed cluster ...properties (i.e. lens-plane selection) or on the detectability of strongly lensed background galaxies (i.e. source-plane selection). First, we estimate the fraction of high-redshift transient progenitors that reside in galaxies that are themselves too faint to be detected as being strongly lensed. We find ∼15–50 per cent of transient progenitors reside in z = 1 − 2 galaxies too faint to be detected in surveys that reach AB ≃ 23, such as the Dark Energy Survey. This falls to ≲10 per cent at depths that will be probed by early data releases of LSST (AB ≃ 25). Secondly, we estimate a conservative lower limit on the fraction of strong-lensing clusters that will be missed by magnitude-limited searches for multiply imaged galaxies and giant arcs due to the faintness of such images. We find that DES-like surveys will miss ∼75 per cent of 1015 M⊙ strong-lensing clusters, rising to ∼100 per cent of 1014 M⊙ clusters. Deeper surveys, such as LSST, will miss ∼40 per cent at 1015 M⊙ and ∼95 per cent at 1014 M⊙. Our results motivate building a cluster watchlist for strongly lensed transients that includes those found by the lens-plane selection.
We present a weak-lensing analysis of the merging Frontier Fields (FF) cluster Abell 2744 using new Subaru/Suprime-Cam imaging. The wide-field lensing mass distribution reveals this cluster is ...comprised of four distinct substructures. Simultaneously modeling the two-dimensional reduced shear field using a combination of a Navarro-Frenk-White (NFW) model for the main core and truncated NFW models for the subhalos, we determine their masses and locations. The total mass of the system is constrained as M sub(200c) = (2.06 + or - 0.42) x 10 super(15)M sub(middot in circle). The most massive clump is the southern component with M sub(200c) = (7.7 + or - 3.4) x 10 super(14)M sub(middot in circle) followed by the western substructure M sub(200c) = (4.5 + or - 2.0) x 10 super(14)M sub(middot in circle) and two smaller substructures to the northeast M sub(200c) = (2.8 + or - 1.6) x 10 super(14)M sub(middot in circle) and northwest M sub(200c) = (1.9 + or - 1.2) x 10 super(14)M sub(middot in circle). The presence of the four substructures supports the picture of multiple mergers. Using a composite of hydrodynamical binary simulations we explain this complicated system without the need for a "slingshot" effect to produce the northwest X-ray interloper, as previously proposed. The locations of the substructures appear to be offset from both the gas ((ProQuest: Formulae and/or non-USASCII text omitted) arcsec, 90% CL) and the galaxies ((ProQuest: Formulae and/or non-USASCII text omitted) arcsec, 90% CL) in the case of the northwestern and western subhalos. To confirm or refute these findings, high resolution space-based observations extending beyond the current FF limited coverage to the west and northwestern area are essential.
The first half of this paper explores the origin of systematic biases in the measurement of weak gravitational lensing. Compared to previous work, we expand the investigation of point spread function ...instability and fold in for the first time the effects of non-idealities in electronic imaging detectors and imperfect galaxy shape measurement algorithms. Together, these now explain the additive
and multiplicative
systematics typically reported in current lensing measurements. We find that overall performance is driven by a product of a telescope/camera's absolute performance, and our knowledge about its performance.
The second half of this paper propagates any residual shear measurement biases through to their effect on cosmological parameter constraints. Fully exploiting the statistical power of Stage IV weak lensing surveys will require additive biases
and multiplicative biases
. These can be allocated between individual budgets in hardware, calibration data and software, using results from the first half of the paper.
If instrumentation is stable and well calibrated, we find extant shear measurement software from Gravitational Lensing Accuracy Testing 2010 (GREAT10) already meet requirements on galaxies detected at signal-to-noise ratio = 40. Averaging over a population of galaxies with a realistic distribution of sizes, it also meets requirements for a 2D cosmic shear analysis from space. If used on fainter galaxies or for 3D cosmic shear tomography, existing algorithms would need calibration on simulations to avoid introducing bias at a level similar to the statistical error. Requirements on hardware and calibration data are discussed in more detail in a companion paper. Our analysis is intentionally general, but is specifically being used to drive the hardware and ground segment performance budget for the design of the European Space Agency's recently selected Euclid mission.
ABSTRACT
Supermassive black holes (SMBHs) are a key catalyst of galaxy formation and evolution, leading to an observed correlation between SMBH mass MBH and host galaxy velocity dispersion σe. ...Outside the local Universe, measurements of MBH are usually only possible for SMBHs in an active state: limiting sample size and introducing selection biases. Gravitational lensing makes it possible to measure the mass of non-active SMBHs. We present models of the $z$ = 0.169 galaxy-scale strong lens Abell 1201. A cD galaxy in a galaxy cluster, it has sufficient ‘external shear’ that a magnified image of a $z$ = 0.451 background galaxy is projected just ∼1 kpc from the galaxy centre. Using multiband Hubble Space Telescope imaging and the lens modelling software PYAUTOLENS, we reconstruct the distribution of mass along this line of sight. Bayesian model comparison favours a point mass with MBH = 3.27 ± 2.12 × 1010 M⊙ (3σ confidence limit); an ultramassive black hole. One model gives a comparable Bayesian evidence without an SMBH; however, we argue this model is nonphysical given its base assumptions. This model still provides an upper limit of MBH ≤ 5.3 × 1010 M⊙, because an SMBH above this mass deforms the lensed image ∼1 kpc from Abell 1201’s centre. This builds on previous work using central images to place upper limits on MBH, but is the first to also place a lower limit and without a central image being observed. The success of this method suggests that surveys during the next decade could measure thousands more SMBH masses, and any redshift evolution of the MBH−σe relation. Results are available at https://github.com/Jammy2211/autolens_abell_1201.
Second-order rate constants have been determined for deuteroxide ion-catalyzed exchange of the C(3)-proton for deuterium, k DO (M–1 s–1), of a series of 20 triazolium salts in aqueous solution at 25 ...°C and ionic strength I = 1.0 (KCl). Evidence is presented that the rate constant for the reverse protonation of the triazol-3-ylidenes by solvent water is close to that for dielectric relaxation of solvent (1011 s–1). These data enabled the calculation of carbon acid pK a values in the range 16.5–18.5 for the 20 triazolium salts. pD rate profiles for deuterium exchange of the triazolium salts reveal that protonation at nitrogen to give dicationic triazolium species occurs under acidic conditions, with estimates of pK a N1 = −0.2 to 0.5.
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Steady-state kinetic and structure-activity studies of a series of six triazolium-ion pre-catalysts
2a-2f
were investigated for the benzoin condensation. These data provide quantitative insight into ...the role of triazolium
N
-aryl substitution under synthetically relevant catalytic conditions in a polar solvent environment. Kinetic behaviour was significantly different to that previously reported for a related thiazolium-ion pre-catalyst
1
, with the observed levelling of initial rate constants to
ν
max
at high aldehyde concentrations for all triazolium catalysts. Values for
ν
max
for
2a-2f
increase with electron withdrawing
N
-aryl substituents, in agreement with reported optimal synthetic outcomes under catalytic conditions, and vary by 75-fold across the series. The levelling of rate constants supports a change in rate-limiting step and evidence supports the assignment of the Breslow-intermediate forming step to the plateau region. Correlation of
ν
max
reaction data yielded a positive Hammett
ρ
-value (
ρ
= +1.66) supporting the build up of electron density adjacent to the triazolium
N
-Ar in the rate-limiting step favoured by electron withdrawing
N
-aryl substituents. At lower concentrations of aldehyde, both Breslow-intermediate and benzoin formation are partially rate-limiting.
An initial rate evaluation of the triazolium-catalysed benzoin condensation permitted a Hammett structure-activity analysis providing insight into the rate-limiting step.
Abstract
The statistical power of weak lensing measurements is principally driven by the number of high-redshift galaxies whose shapes are resolved. Conventional wisdom and physical intuition suggest ...this is optimized by deep imaging at long (red or near-IR) wavelengths, to avoid losing redshifted Balmer-break and Lyman-break galaxies. We use the synthetic Emission Line (“EL”)-COSMOS catalog to simulate lensing observations using different filters, from various altitudes. Here were predict the number of exposures to achieve a target
z
≳ 0.3 source density, using off-the-shelf and custom filters. Ground-based observations are easily better at red wavelengths, as (more narrowly) are space-based observations. However, we find that
SuperBIT
, a diffraction-limited observatory operating in the stratosphere, should instead perform its lensing-quality observations at blue wavelengths.
Context. Scaling properties of galaxy cluster observables with cluster mass provide central insights into the processes shaping clusters. Calibrating proxies for cluster mass that are relatively ...cheap to observe will moreover be crucial to harvest the cosmological information available from the number and growth of clusters with upcoming surveys like eROSITA and Euclid. The recent Planck results led to suggestions that X-ray masses might be biased low by ~40%, more than previously considered. Aims. We aim to extend knowledge of the weak lensing - X-ray mass scaling towards lower masses (as low as 1 x 10 super(14)M sub(middot in circle)) in a sample representative of the z ~ 0.4-0.5 population. Thus, we extend the direct calibration of cluster mass estimates to higher redshifts. Methods. We investigate the scaling behaviour of MMT/Megacam weak lensing (WL) masses for 8 clusters at 0.39 < or = z < or = 0.80 as part of the 400d WL programme with hydrostatic Chandra X-ray masses as well as those based on the proxies, e.g. Y sub(X) = T sub(X)M sub(gas). Results. Overall, we find good agreement between WL and X-ray masses, with different mass bias estimators all consistent with zero. When subdividing the sample into a low-mass and a high-mass subsample, we find the high-mass subsample to show no significant mass bias while for the low-mass subsample, there is a bias towards overestimated X-ray masses at the ~2sigma level for some mass proxies. The overall scatter in the mass-mass scaling relations is surprisingly low. Investigating possible causes, we find that neither the greater range in WL than in X-ray masses nor the small scatter can be traced back to the parameter settings in the WL analysis. Conclusions. We do not find evidence for a strong (~40%) underestimate in the X-ray masses, as suggested to reconcile recent Planck cluster counts and cosmological constraints. For high-mass clusters, our measurements are consistent with other studies in the literature. The mass dependent bias, significant at ~2sigma, may hint at a physically different cluster population (less relaxed clusters with more substructure and mergers); or it may be due to small number statistics. Further studies of low-mass high-z lensing clusters will elucidate their mass scaling behaviour.
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