94 research outputs found
Adverse drug events in patients with dementia and neuropsychiatric/behavioral, and psychological symptoms, a one-year prospective study
Older people usually present with adverse drug events (ADEs) with nonspecific symptoms such as cognitive decline, recurrent falls, reduced mobility, and/or major deterioration. The aims of this study were to assess the ADEs of patients with dementia and presenting neuropsychiatric/behavioral, and psychological symptoms in dementia (BPSD) and to categorize and identify the principal factors that allow to prevent ADEs, and separately ADEs that result in falls. To that end, a one-year prospective study in a psychogeriatric ward (July 2015 to July 2016) was performed. All patients admitted to this ward were eligible for enrolment. Patients who met any of the following criteria were excluded from the study: Patients without cognitive impairment, a length of stay under 7 days, and palliative or previous psychiatric pathology. We included 65 patients (60% women, 84.9 years ± 6.7) with mild to moderate cognitive impairment, moderate to severe functional dependence, and a high prevalence of geriatric syndromes and comorbidity. A total of 87.7% were taking five or more drugs (mean 9.0 ± 3.1). ADEs were identified during the interdisciplinary meeting and the follow up by clinical record. Sixty-eight ADEs (81.5% patients) were identified, of which 73.5% were not related to falls. From these, 80% were related to drugs of the nervous system. The Naranjo algorithm determined that 90% of ADEs were probable. The severity of the ADEs was Category E in 34 patients (68%). The number of preventable ADE according to the Schumork⁻Thornton test was 58%. The main ADE was drowsiness/somnolence (27.7%). ADEs related to falls represented a 26.5%. The balance between effective treatment and safety is complex in these patients. A medication review in interdisciplinary teams is an essential component to optimize safety prevention
Detection of the significant impact of source clustering on higher-order statistics with DES Year 3 weak gravitational lensing data
We demonstrate and measure the impact of source galaxy clustering on
higher-order summary statistics of weak gravitational lensing data. By
comparing simulated data with galaxies that either trace or do not trace the
underlying density field, we show this effect can exceed measurement
uncertainties for common higher-order statistics for certain analysis choices.
Source clustering effects are larger at small scales and for statistics applied
to combinations of low and high redshift samples, and diminish at high
redshift. We evaluate the impact on different weak lensing observables, finding
that third moments and wavelet phase harmonics are more affected than peak
count statistics. Using Dark Energy Survey Year 3 data we construct null tests
for the source-clustering-free case, finding a -value of
(2.6 ) using third-order map moments and (6.5
) using wavelet phase harmonics. The impact of source clustering on
cosmological inference can be either be included in the model or minimized
through \textit{ad-hoc} procedures (e.g. scale cuts). We verify that the
procedures adopted in existing DES Y3 cosmological analyses (using map moments
and peaks) were sufficient to render this effect negligible. Failing to account
for source clustering can significantly impact cosmological inference from
higher-order gravitational lensing statistics, e.g. higher-order N-point
functions, wavelet-moment observables (including phase harmonics and scattering
transforms), and deep learning or field level summary statistics of weak
lensing maps. We provide recipes both to minimise the impact of source
clustering and to incorporate source clustering effects into forward-modelled
mock data.Comment: 5 pages, 2 figures, submitted to MNRAS Letter
Beyond the 3rd moment: A practical study of using lensing convergence CDFs for cosmology with DES Y3
Widefield surveys of the sky probe many clustered scalar fields -- such as
galaxy counts, lensing potential, gas pressure, etc. -- that are sensitive to
different cosmological and astrophysical processes. Our ability to constrain
such processes from these fields depends crucially on the statistics chosen to
summarize the field. In this work, we explore the cumulative distribution
function (CDF) at multiple scales as a summary of the galaxy lensing
convergence field. Using a suite of N-body lightcone simulations, we show the
CDFs' constraining power is modestly better than that of the 2nd and 3rd
moments of the field, as they approximately capture the information from all
moments of the field in a concise data vector. We then study the practical
aspects of applying the CDFs to observational data, using the first three years
of the Dark Energy Survey (DES Y3) data as an example, and compute the impact
of different systematics on the CDFs. The contributions from the point spread
function are 2-3 orders of magnitude below the cosmological signal, while those
from reduced shear approximation contribute to the signal.
Source clustering effects and baryon imprints contribute . Enforcing
scale cuts to limit systematics-driven biases in parameter constraints degrades
these constraints a noticeable amount, and this degradation is similar for the
CDFs and the moments. We also detect correlations between the observed
convergence field and the shape noise field at . We find that the
non-Gaussian correlations in the noise field must be modeled accurately to use
the CDFs, or other statistics sensitive to all moments, as a rigorous cosmology
tool.Comment: 21 pages, 12 figure
Cosmology from Cross-Correlation of ACT-DR4 CMB Lensing and DES-Y3 Cosmic Shear
Cross-correlation between weak lensing of the Cosmic Microwave Background
(CMB) and weak lensing of galaxies offers a way to place robust constraints on
cosmological and astrophysical parameters with reduced sensitivity to certain
systematic effects affecting individual surveys. We measure the angular
cross-power spectrum between the Atacama Cosmology Telescope (ACT) DR4 CMB
lensing and the galaxy weak lensing measured by the Dark Energy Survey (DES) Y3
data. Our baseline analysis uses the CMB convergence map derived from ACT-DR4
and data, where most of the contamination due to the thermal
Sunyaev Zel'dovich effect is removed, thus avoiding important systematics in
the cross-correlation. In our modelling, we consider the nuisance parameters of
the photometric uncertainty, multiplicative shear bias and intrinsic alignment
of galaxies. The resulting cross-power spectrum has a signal-to-noise ratio and passes a set of null tests. We use it to infer the amplitude of the
fluctuations in the matter distribution () with informative but well-motivated priors on
the nuisance parameters. We also investigate the validity of these priors by
significantly relaxing them and checking the consistency of the resulting
posteriors, finding them consistent, albeit only with relatively weak
constraints. This cross-correlation measurement will improve significantly with
the new ACT-DR6 lensing map and form a key component of the joint 6x2pt
analysis between DES and ACT.Comment: 26 pages, 30 figures (including appendices). Data associated with
this article is available at
https://github.com/itrharrison/actdr4kappa-x-desy3gamma-dat
Dark Energy Survey Year 3 results: Curved-sky weak lensing mass map reconstruction
We present reconstructed convergence maps, mass maps, from the Dark Energy Survey (DES) third year (Y3) weak gravitational lensing data set. The mass maps are weighted projections of the density field (primarily dark matter) in the foreground of the observed galaxies. We use four reconstruction methods, each is a maximum a posteriori estimate with a different model for the prior probability of the map: Kaiser-Squires, null B-mode prior, Gaussian prior, and a sparsity prior. All methods are implemented on the celestial sphere to accommodate the large sky coverage of the DES Y3 data. We compare the methods using realistic \u39bCDM simulations with mock data that are closely matched to the DES Y3 data. We quantify the performance of the methods at the map level and then apply the reconstruction methods to the DES Y3 data, performing tests for systematic error effects. The maps are compared with optical foreground cosmic-web structures and are used to evaluate the lensing signal from cosmic-void profiles. The recovered dark matter map covers the largest sky fraction of any galaxy weak lensing map to date
Cosmological shocks around galaxy clusters: A coherent investigation with DES, SPT & ACT
We search for signatures of cosmological shocks in gas pressure profiles of
galaxy clusters using the cluster catalogs from three surveys: the Dark Energy
Survey (DES) Year 3, the South Pole Telescope (SPT) SZ survey, and the Atacama
Cosmology Telescope (ACT) data releases 4, 5, and 6, and using thermal
Sunyaev-Zeldovich (SZ) maps from SPT and ACT. The combined cluster sample
contains around clusters with mass and redshift ranges and , and the total sky coverage
of the maps is . We find a clear pressure
deficit at in SZ profiles around both ACT and SPT
clusters, estimated at significance, which is qualitatively
consistent with a shock-induced thermal non-equilibrium between electrons and
ions. The feature is not as clearly determined in profiles around DES clusters.
We verify that measurements using SPT or ACT maps are consistent across all
scales, including in the deficit feature. The SZ profiles of optically selected
and SZ-selected clusters are also consistent for higher mass clusters. Those of
less massive, optically selected clusters are suppressed on small scales by
factors of 2-5 compared to predictions, and we discuss possible interpretations
of this behavior. An oriented stacking of clusters -- where the orientation is
inferred from the SZ image, the brightest cluster galaxy, or the surrounding
large-scale structure measured using galaxy catalogs -- shows the normalization
of the one-halo and two-halo terms vary with orientation. Finally, the location
of the pressure deficit feature is statistically consistent with existing
estimates of the splashback radius.Comment: [v2]: Version accepted to MNRA
The Dark Energy Survey Year 3 and eBOSS: constraining galaxy intrinsic alignments across luminosity and colour space
We present direct constraints on galaxy intrinsic alignments using the Dark
Energy Survey Year 3 (DES Y3), the Extended Baryon Oscillation Spectroscopic
Survey (eBOSS) and its precursor, the Baryon Oscillation Spectroscopic Survey
(BOSS). Our measurements incorporate photometric red sequence (redMaGiC)
galaxies from DES with median redshift , luminous red galaxies
(LRGs) from eBOSS at , and also a SDSS-III BOSS CMASS sample at
. We measure two point intrinsic alignment correlations, which we fit
using a model that includes lensing, magnification and photometric redshift
error. Fitting on scales Mpc, we make a detection of
intrinsic alignments in each sample, at (assuming a simple
one parameter model for IAs). Using these red samples, we measure the
IA-luminosity relation. Our results are statistically consistent with previous
results, but offer a significant improvement in constraining power,
particularly at low luminosity. With this improved precision, we see detectable
dependence on colour between broadly defined red samples. It is likely that a
more sophisticated approach than a binary red/blue split, which jointly
considers colour and luminosity dependence in the IA signal, will be needed in
future. We also compare the various signal components at the best fitting point
in parameter space for each sample, and find that magnification and lensing
contribute of the total signal. As precision continues to improve,
it will certainly be necessary to account for these effects in future direct IA
measurements. Finally, we make equivalent measurements on a sample of Emission
Line Galaxies (ELGs) from eBOSS at . We report a null detection,
constraining the IA amplitude (assuming the nonlinear alignment model) to be
( at CL).Comment: Submitted to MNRAS; 22 pages, 11 figure
SPT Clusters with DES and HST Weak Lensing. I. Cluster Lensing and Bayesian Population Modeling of Multi-Wavelength Cluster Datasets
We present a Bayesian population modeling method to analyze the abundance of
galaxy clusters identified by the South Pole Telescope (SPT) with a
simultaneous mass calibration using weak gravitational lensing data from the
Dark Energy Survey (DES) and the Hubble Space Telescope (HST). We discuss and
validate the modeling choices with a particular focus on a robust,
weak-lensing-based mass calibration using DES data. For the DES Year 3 data, we
report a systematic uncertainty in weak-lensing mass calibration that increases
from 1\% at to 10\% at , to which we add 2\% in quadrature to
account for uncertainties in the impact of baryonic effects. We implement an
analysis pipeline that joins the cluster abundance likelihood with a
multi-observable likelihood for the SZ, optical richness, and weak-lensing
measurements for each individual cluster. We validate that our analysis
pipeline can recover unbiased cosmological constraints by analyzing mocks that
closely resemble the cluster sample extracted from the SPT-SZ, SPTpol~ECS, and
SPTpol~500d surveys and the DES Year~3 and HST-39 weak-lensing datasets. This
work represents a crucial prerequisite for the subsequent cosmological analysis
of the real dataset.Comment: submitted to PR
Consistent lensing and clustering in a low-S8 Universe with BOSS, DES Year 3, HSC Year 1, and KiDS-1000
We evaluate the consistency between lensing and clustering based on measurements from Baryon Oscillation Spectroscopic Survey combined with galaxy-galaxy lensing from Dark Energy Survey (DES) Year 3, Hyper Suprime-Cam Subaru Strategic Program (HSC) Year 1, and Kilo-Degree Survey (KiDS)-1000. We find good agreement between these lensing data sets. We model the observations using the DARK EMULATOR and fit the data at two fixed cosmologies: Planck (S8 = 0.83), and a Lensing cosmology (S8 = 0.76). For a joint analysis limited to large scales, we find that both cosmologies provide an acceptable fit to the data. Full utilization of the higher signal-to-noise small-scale measurements is hindered by uncertainty in the impact of baryon feedback and assembly bias, which we account for with a reasoned theoretical error budget. We incorporate a systematic inconsistency parameter for each redshift bin, A, that decouples the lensing and clustering. With a wide range of scales, we find different results for the consistency between the two cosmologies. Limiting the analysis to the bins for which the impact of the lens sample selection is expected to be minimal, for the Lensing cosmology, the measurements are consistent with A = 1; A = 0.91 ± 0.04 (A = 0.97 ± 0.06) using DES+KiDS (HSC). For the Planck case, we find a discrepancy: A = 0.79 ± 0.03 (A = 0.84 ± 0.05) using DES+KiDS (HSC). We demonstrate that a kinematic Sunyaev-Zeldovich-based estimate for baryonic effects alleviates some of the discrepancy in the Planck cosmology. This analysis demonstrates the statistical power of small-scale measurements; however, caution is still warranted given modelling uncertainties and foreground sample selection effects
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