We present a tomographic weak lensing analysis of the Kilo Degree Survey Data Release 4 (KiDS-1000), using a new pseudo angular power spectrum estimator (pseudo-
C
ℓ
) under development for the ESA
...Euclid
mission. Over 21 million galaxies with shape information are divided into five tomographic redshift bins, ranging from 0.1 to 1.2 in photometric redshift. We measured pseudo-
C
ℓ
using eight bands in the multipole range 76 <
ℓ
< 1500 for auto- and cross-power spectra between the tomographic bins. A series of tests were carried out to check for systematic contamination from a variety of observational sources including stellar number density, variations in survey depth, and point spread function properties. While some marginal correlations with these systematic tracers were observed, there is no evidence of bias in the cosmological inference.
B
-mode power spectra are consistent with zero signal, with no significant residual contamination from
E
/
B
-mode leakage. We performed a Bayesian analysis of the pseudo-
C
ℓ
estimates by forward modelling the effects of the mask. Assuming a spatially flat ΛCDM cosmology, we constrained the structure growth parameter
S
8
=
σ
8
(Ω
m
/0.3)
1/2
= 0.754
−0.029
+0.027
. When combining cosmic shear from KiDS-1000 with baryon acoustic oscillation and redshift space distortion data from recent Sloan Digital Sky Survey (SDSS) measurements of luminous red galaxies, as well as the Lyman-
α
forest and its cross-correlation with quasars, we tightened these constraints to
S
8
= 0.771
−0.032
+0.006
. These results are in very good agreement with previous KiDS-1000 and SDSS analyses and confirm a ∼3
σ
tension with early-Universe constraints from cosmic microwave background experiments.
We present here the cosmo-SLICS, a new suite of simulations specially designed for the analysis of current and upcoming weak lensing data beyond the standard two-point cosmic shear. We sampled the Ω
...m
,
σ
8
,
h
,
w
0
parameter space at 25 points organised in a Latin hyper-cube, spanning a range that contains most of the 2
σ
posterior distribution from ongoing lensing surveys. At each of these nodes we evolved a pair of
N
-body simulations in which the sampling variance is highly suppressed, and ray-traced the volumes 800 times to further increase the effective sky coverage. We extracted a lensing covariance matrix from these pseudo-independent light-cones and show that it closely matches a brute-force construction based on an ensemble of 800 truly independent
N
-body runs. More precisely, a Fisher analysis reveals that both methods yield marginalized two-dimensional constraints that vary by less than 6% in area, a result that holds under different survey specifications and that matches to within 15% the area obtained from an analytical covariance calculation. Extending this comparison with our 25
w
CDM models, we probed the cosmology dependence of the lensing covariance directly from numerical simulations, reproducing remarkably well the Fisher results from the analytical models at most cosmologies. We demonstrate that varying the cosmology at which the covariance matrix is evaluated in the first place might have an order of magnitude greater impact on the parameter constraints than varying the choice of covariance estimation technique. We present a test case in which we generate fast predictions for both the lensing signal and its associated variance with a flexible Gaussian process regression emulator, achieving an accuracy of a few percent on the former and 10% on the latter.
We present a bright galaxy sample with accurate and precise photometric redshifts (photo-zs), selected using ugriZYJHKs photometry from the Kilo-Degree Survey (KiDS) Data Release 4. The highly pure ...and complete dataset is flux-limited at r < 20 mag, covers ∼1000 deg2, and contains about 1 million galaxies after artifact masking. We exploit the overlap with Galaxy And Mass Assembly spectroscopy as calibration to determine photo-zs with the supervised machine learning neural network algorithm implemented in the ANNz2 software. The photo-zs have a mean error of |⟨δz⟩|∼5 × 10−4 and low scatter (scaled mean absolute deviation of ∼0.018(1 + z)); they are both practically independent of the r-band magnitude and photo-z at 0.05 < zphot < 0.5. Combined with the 9-band photometry, these allow us to estimate robust absolute magnitudes and stellar masses for the full sample. As a demonstration of the usefulness of these data, we split the dataset into red and blue galaxies, used them as lenses, and measured the weak gravitational lensing signal around them for five stellar mass bins. We fit a halo model to these high-precision measurements to constrain the stellar-mass–halo-mass relations for blue and red galaxies. We find that for high stellar mass (M⋆ > 5 × 1011 M⊙), the red galaxies occupy dark matter halos that are much more massive than those occupied by blue galaxies with the same stellar mass.
High pulmonary vascular resistance index (PVRI) can lead to right ventricular dysfunction and failure of the donor heart early after pediatric heart transplantation. Oral pulmonary vasodilators such ...as sildenafil have been shown to be effective modifiers of pulmonary vascular tone. We performed a retrospective, observational study comparing patients treated with sildenafil (“sildenafil group”) to those not treated with sildenafil (“nonsildenafil group”) after heart transplantation from 2007 to 2012. Pre‐ and posttransplant data were obtained, including hemodynamic data from right heart catheterizations. Twenty‐four of 97 (25%) transplant recipients were transitioned to sildenafil from other systemic vasodilators. Pretransplant PVRI was higher in the sildenafil group (6.8 ± 3.9 indexed Woods units WU) as compared to the nonsildenafil group (2.5 ± 1.7 WU, p = 0.002). In the sildenafil group posttransplant, there were significant decreases in systolic pulmonary artery pressure, mean pulmonary artery pressure, transpulmonary gradient and PVRI (4.7 ± 2.9 WU before sildenafil initiation to 2.7 ± 1 WU on sildenafil, p = 0.0007). While intubation time, length of inotrope use and time to hospital discharge were longer in the sildenafil group, survival was similar between both groups. Oral sildenafil was associated with a significant improvement in right ventricular dysfunction and invasive hemodynamic measurements in pediatric heart transplant recipients with high PVRI early after transplant.
In this retrospective cohort study of pediatric heart transplant recipients, the authors demonstrate that oral sildenafil is associated with an improvement in right ventricular dysfunction, pulmonary vascular resistance, and other invasive hemodynamic measurements early after transplant.
We present a bright galaxy sample with accurate and precise photometric redshifts (photo-
z
s), selected using
ugriZYJHK
s
photometry from the Kilo-Degree Survey (KiDS) Data Release 4. The highly ...pure and complete dataset is flux-limited at
r
< 20 mag, covers ∼1000 deg
2
, and contains about 1 million galaxies after artifact masking. We exploit the overlap with Galaxy And Mass Assembly spectroscopy as calibration to determine photo-
z
s with the supervised machine learning neural network algorithm implemented in the ANNz2 software. The photo-
z
s have a mean error of |⟨
δz
⟩|∼5 × 10
−4
and low scatter (scaled mean absolute deviation of ∼0.018(1 +
z
)); they are both practically independent of the
r
-band magnitude and photo-
z
at 0.05 <
z
phot
< 0.5. Combined with the 9-band photometry, these allow us to estimate robust absolute magnitudes and stellar masses for the full sample. As a demonstration of the usefulness of these data, we split the dataset into red and blue galaxies, used them as lenses, and measured the weak gravitational lensing signal around them for five stellar mass bins. We fit a halo model to these high-precision measurements to constrain the stellar-mass–halo-mass relations for blue and red galaxies. We find that for high stellar mass (
M
⋆
> 5 × 10
11
M
⊙
), the red galaxies occupy dark matter halos that are much more massive than those occupied by blue galaxies with the same stellar mass.
Aims. This study aims to help nurses and nurse practitioners identify and manage paediatric patients with upper airway resistance syndrome. A review of upper airway resistance syndrome is provided, ...including the signs and symptoms of upper airway resistance syndrome, criteria for diagnosis, recommendations for treatment and implications for nursing in paediatric primary care.
Background. Nurses often encounter sleep‐related problems in the paediatric primary care setting. Commonly, these problems are well known and include snoring and obstructive sleep apnoea. Upper airway resistance syndrome is a relatively new diagnosis among sleep‐related breathing disorders with which nurses and nurse practitioners should be familiar. Upper airway resistance syndrome is characterised by incomplete obstruction of the airway during sleep, leading to increased respiratory efforts and frequent arousals despite normal oxygen saturations.
Design. Systematic review.
Method. A review of the sleep literature identified articles regarding sleep and/or sleep‐related breathing disorders and paediatrics, and upper airway resistance syndrome. Articles published since 2002 were prioritised; however, all articles describing upper airway resistance syndrome since 1993 were considered.
Conclusion. Timely recognition of sleep‐disordered breathing is crucial to ensuring that patients receive effective and appropriate treatment. Upper airway resistance syndrome should be a part of the differential diagnosis when assessing a child with a sleep‐related breathing disorder.
Relevance to clinician practice. Nurses and nurse practitioners should become comfortable and skilled in performing a thorough sleep history and physical examination to help identify when a child should receive a sleep study or referral to a specialist.
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