43 research outputs found
Discrepancies between CFHTLenS cosmic shear and Planck: new physics or systematic effects?
There is currently a discrepancy in the measured value of the amplitude of
matter clustering, parameterised using , inferred from galaxy weak
lensing, and cosmic microwave background data, which could be an indication of
new physics, such as massive neutrinos or a modification to the gravity law, or
baryon feedback. In this paper we make the assumption that the cosmological
parameters are well determined by Planck, and use weak lensing data to
investigate the implications for baryon feedback and massive neutrinos, as well
as possible contributions from intrinsic alignments and biases in photometric
redshifts. We apply a non-parametric approach to model the baryonic feedback on
the dark matter clustering, which is flexible enough to reproduce the OWLS and
Illustris simulation results. The statistic we use, 3D cosmic shear, is a
method that extracts cosmological information from weak lensing data using a
spherical-Bessel function power spectrum approach. We analyse the CFHTLenS weak
lensing data and, assuming best fit cosmological parameters from the Planck CMB
experiment, find that there is no evidence for baryonic feedback on the dark
matter power spectrum, but there is evidence for a bias in the photometric
redshifts in the CFHTLenS data, consistent with a completely independent
analysis by Choi et al. (2015), based on spectroscopic redshifts; and that
these conclusions are robust to assumptions about the intrinsic alignment
systematic. We also find an upper limit on the sum of neutrino masses
conditional on other CDM parameters being fixed, of eV
().Comment: 13 pages, 6 figures, accepted to MNRA
The limits of cosmic shear
In this paper we discuss the commonly-used limiting cases, or approximations, for two-point cosmic shear statistics. We discuss the most prominent assumptions in this statistic: the flat-sky (small angle limit), the Limber (Bessel-to-delta function limit) and the Hankel transform (large l-mode limit) approximations; that the vast majority of cosmic shear results to date have used simultaneously. We find that the combined effect of these approximations can suppress power by >1% on scales of l<40. A fully non-approximated cosmic shear study should use a spherical-sky, non-Limber-approximated power spectrum analysis; and a transform involving Wigner small-d matrices in place of the Hankel transform. These effects, unaccounted for, would constitute at least 11% of the total budget for systematic effects for a power spectrum analysis of a Euclid-like experiment; but they are unnecessary
Distinct HR expression patterns significantly affect the clinical behavior of metastatic HER2+ breast cancer and degree of benefit from novel anti-HER2 agents in the real world setting
We analyzed data from 738 HER2\u2010positive metastatic breast cancer (mbc) patients treated with pertuzumab\u2010based regimens and/or T\u2010DM1 at 45 Italian centers. Outcomes were explored in relation to tumor subtype assessed by immunohistochemistry (IHC). The median progression free survival at first\u2010line (mPFS1) was 12 months. Pertuzumab as first\u2010line conferred longer mPFS1 compared to other first\u2010line treatments (16 vs 9 months, p=0.0001), regardless of IHC subtype. Median PFS in second\u2010line (mPFS2) was 7 months, with no difference by IHC subtype, but it was more favorable with T\u2010DM1 compared to other agents (7 vs 6 months, p=0.03). There was no PFS2 gain in patients with tumors expressing both hormonal receptors (HRs) (p=0.17), while a trend emerged for tumors with one HR (p=0.05). Conversely, PFS2 gain was significant in HRs\u2010negative tumors (p=0.04). Median overall survival (mOS) was 74 months, with no significant differences by IHC subtypes. Survival rates at 2 and 3 years in patients treated with T\u2010DM1 in second\u2010line following pertuzumab were significantly lower compared to pertuzumab\u2010na\uefve patients(p=0.01). When analyzed by IHC subtype, the outcome was confirmed if both HRs or no HRs were expressed (p=0.02 and p=0.006, respectively). Our results confirm that HRs expression impacts the clinical behavior and novel treatment\u2010related outcomes of HER2\u2010positive tumors when treatment sequences are considered. Moreover, multivariate analysis showed that HRs expression had no effect on PFS and OS. Further studies are warranted to confirm our findings and clarify the interplay between HER2 and estrogen receptor (ER) pathways in HER2\u2010positive (mbc) patients