We present a new application of deep learning to infer the masses of galaxy clusters directly from images of the microwave sky. Effectively, this is a novel approach to determining the scaling ...relation between a cluster's Sunyaev-Zel'dovich (SZ) effect signal and mass. The deep-learning algorithm used is mResUNet, which is a modified feed-forward deep-learning algorithm that broadly combines residual learning, convolution layers with different dilation rates, image regression activation, and a U-Net framework. We train and test the deep-learning model using simulated images of the microwave sky that include signals from the cosmic microwave background, dusty and radio galaxies, and instrumental noise as well as the cluster's own SZ signal. The simulated cluster sample covers the mass range 1 × 1014 M < M200c < 8 × 1014 M at z = 0.7. The trained model estimates the cluster masses with a 1 uncertainty ΔM/M ≤ 0.2, consistent with the input scatter on the SZ signal of 20%. We verify that the model works for realistic SZ profiles even when trained on azimuthally symmetric SZ profiles by using the Magneticum hydrodynamical simulations.
Gamma-ray bursts (GRBs) are flashes of high-energy radiation arising from energetic cosmic explosions. Bursts of long (greater than two seconds) duration are produced by the core-collapse of massive ...stars
, and those of short (less than two seconds) duration by the merger of compact objects, such as two neutron stars
. A third class of events with hybrid high-energy properties was identified
, but never conclusively linked to a stellar progenitor. The lack of bright supernovae rules out typical core-collapse explosions
, but their distance scales prevent sensitive searches for direct signatures of a progenitor system. Only tentative evidence for a kilonova has been presented
. Here we report observations of the exceptionally bright GRB 211211A, which classify it as a hybrid event and constrain its distance scale to only 346 megaparsecs. Our measurements indicate that its lower-energy (from ultraviolet to near-infrared) counterpart is powered by a luminous (approximately 10
erg per second) kilonova possibly formed in the ejecta of a compact object merger.
IMPORTANCE: Midlife vascular risk factors have been associated with late-life dementia. Whether these risk factors directly contribute to brain amyloid deposition is less well understood. OBJECTIVE: ...To determine if midlife vascular risk factors are associated with late-life brain amyloid deposition, measured using florbetapir positron emission tomography (PET). DESIGN, SETTING, AND PARTICIPANTS: The Atherosclerosis Risk in Communities (ARIC)–PET Amyloid Imaging Study, a prospective cohort study among 346 participants without dementia in 3 US communities (Washington County, Maryland; Forsyth County, North Carolina; and Jackson, Mississippi) who have been evaluated for vascular risk factors and markers since 1987-1989 with florbetapir PET scans in 2011-2013. Positron emission tomography image analysis was completed in 2015. EXPOSURES: Vascular risk factors at ARIC baseline (age 45-64 years; risk factors included body mass index ≥30, current smoking, hypertension, diabetes, and total cholesterol ≥200 mg/dL) were evaluated in multivariable models including age, sex, race, APOE genotype, and educational level. MAIN OUTCOMES AND MEASURES: Standardized uptake value ratios (SUVRs) were calculated from PET scans and a mean global cortical SUVR was calculated. Elevated florbetapir (defined as a SUVR >1.2) was the dependent variable. RESULTS: Among 322 participants without dementia and with nonmissing midlife vascular risk factors at baseline (mean age, 52 years; 58% female; 43% black), the SUVR (elevated in 164 50.9% participants) was measured more than 20 years later (median follow-up, 23.5 years; interquartile range, 23.0-24.3 years) when participants were between 67 and 88 (mean, 76) years old. Elevated body mass index in midlife was associated with elevated SUVR (odds ratio OR, 2.06; 95% CI, 1.16-3.65). At baseline, 65 participants had no vascular risk factors, 123 had 1, and 134 had 2 or more; a higher number of midlife risk factors was associated with elevated amyloid SUVR at follow-up (30.8% n = 20, 50.4% n = 62, and 61.2% n = 82, respectively). In adjusted models, compared with 0 midlife vascular risk factors, the OR for elevated SUVR associated with 1 vascular risk factor was 1.88 (95% CI, 0.95-3.72) and for 2 or more vascular risk factors was 2.88 (95% CI, 1.46-5.69). No significant race × risk factor interactions were found. Late-life vascular risk factors were not associated with late-life brain amyloid deposition (for ≥2 late-life vascular risk factors vs 0: OR, 1.66; 95% CI, 0.75-3.69). CONCLUSIONS AND RELEVANCE: An increasing number of midlife vascular risk factors was significantly associated with elevated amyloid SUVR; this association was not significant for late-life risk factors. These findings are consistent with a role of vascular disease in the development of Alzheimer disease.
Abstract
We present a new application of deep learning to reconstruct the cosmic microwave background (CMB) temperature maps from images of the microwave sky and to use these reconstructed maps to ...estimate the masses of galaxy clusters. We use a feed-forward deep-learning network, mResUNet, for both steps of the analysis. The first deep-learning model, mResUNet-I, is trained to reconstruct foreground and noise-suppressed CMB maps from a set of simulated images of the microwave sky that include signals from the CMB, astrophysical foregrounds like dusty and radio galaxies, instrumental noise as well as the cluster’s own thermal Sunyaev–Zel’dovich signal. The second deep-learning model, mResUNet-II, is trained to estimate cluster masses from the gravitational-lensing signature in the reconstructed foreground and noise-suppressed CMB maps. For SPTpol-like noise levels, the trained mResUNet-II model recovers the mass for 10
4
galaxy cluster samples with a 1
σ
uncertainty
Δ
M
200
c
est
/
M
200
c
est
=
0.108 and 0.016 for input cluster mass
M
200
c
true
=
10
14
M
⊙
and 8 × 10
14
M
⊙
, respectively. We also test for potential bias on recovered masses, finding that for a set of 10
5
clusters the estimator recovers
M
200
c
est
=
2.02
×
10
14
M
⊙
, consistent with the input at 1% level. The 2
σ
upper limit on potential bias is at 3.5% level.
Previous studies suggest physical activity improves cognition and lowers Alzheimer's disease (AD) risk. However, key AD pathogenic factors that are thought to be influenced by physical activity, ...particularly plasma amyloid-β (Aβ) and Aβ brain load, have yet to be thoroughly investigated. The objective of this study was to determine if plasma Aβ and amyloid brain deposition are associated with physical activity levels, and whether these associations differed between carriers and non-carriers of the apolipoprotein E (APOE) ε4 allele. Five-hundred and forty six cognitively intact participants (aged 60-95 years) from the Australian Imaging, Biomarkers and Lifestyle Study of Ageing (AIBL) were included in these analyses. Habitual physical activity levels were measured using the International Physical Activity Questionnaire (IPAQ). Serum insulin, glucose, cholesterol and plasma Aβ levels were measured in fasting blood samples. A subgroup (n=116) underwent (11)C-Pittsburgh compound B (PiB) positron emission tomography (PET) scanning to quantify brain amyloid load. Higher levels of physical activity were associated with higher high density lipoprotein (HDL) (P=0.037), and lower insulin (P<0.001), triglycerides (P=0.019) and Aβ1-42/1-40 ratio (P=0.001). After stratification of the cohort based on APOE ε4 allele carriage, it was evident that only non-carriers received the benefit of reduced plasma Aβ from physical activity. Conversely, lower levels of PiB SUVR (standardised uptake value ratio) were observed in higher exercising APOE ε4 carriers. Lower plasma Aβ1-42/1-40 and brain amyloid was observed in those reporting higher levels of physical activity, consistent with the hypothesis that physical activity may be involved in the modulation of pathogenic changes associated with AD.
The pathology of glaucoma has been extensively studied at the level of the retina and optic nerve head. Here the first clinicopathological case of human glaucoma is reported demonstrating ...degenerative changes in the brain involving the intracranial optic nerve, lateral geniculate nucleus, and visual cortex. Pathological evidence of neural degeneration in this patient is correlated with clinical, optic nerve head, visual field, and neuroradiology findings. Neuropathology in the glaucoma brain is compared to age matched controls. In the presence of advanced human glaucoma with 50% visual field loss, neural damage is evident in multiple vision stations within the brain.
Abstract
We show the improvement to cosmological constraints from galaxy cluster surveys with the addition of cosmic microwave background (CMB)-cluster lensing data. We explore the cosmological ...implications of adding mass information from the 3.1
σ
detection of gravitational lensing of the CMB by galaxy clusters to the Sunyaev–Zel’dovich (SZ) selected galaxy cluster sample from the 2500 deg
2
SPT-SZ survey and targeted optical and X-ray follow-up data. In the ΛCDM model, the combination of the cluster sample with the Planck power spectrum measurements prefers
σ
8
Ω
m
/
0.3
0.5
=
0.831
±
0.020
. Adding the cluster data reduces the uncertainty on this quantity by a factor of 1.4, which is unchanged whether the 3.1
σ
CMB-cluster lensing measurement is included or not. We then forecast the impact of CMB-cluster lensing measurements with future cluster catalogs. Adding CMB-cluster lensing measurements to the SZ cluster catalog of the ongoing SPT-3G survey is expected to improve the expected constraint on the dark energy equation of state
w
by a factor of 1.3 to
σ
(
w
) = 0.19. We find the largest improvements from CMB-cluster lensing measurements to be for
σ
8
, where adding CMB-cluster lensing data to the cluster number counts reduces the expected uncertainty on
σ
8
by respective factors of 2.4 and 3.6 for SPT-3G and CMB-S4.
In this cardiovascular safety trial, lorcaserin facilitated sustained weight loss without a higher risk of major adverse cardiovascular events than that with placebo in a high-risk population of ...overweight or obese patients.
Objectives
The contribution of depression to mortality in adults with and without HIV infection is unclear. We hypothesized that depression increases mortality risk and that this association is ...stronger among those with HIV infection.
Methods
Veterans Aging Cohort Study (VACS) data were analysed from the first clinic visit on or after 1 April 2003 (baseline) to 30 September 2015. Depression definitions were: (1) major depressive disorder defined using International Classification of Diseases, Ninth Revision (ICD‐9) codes; (2) depressive symptoms defined as Patient Health Questionnaire (PHQ)‐9 scores ≥ 10. The outcome was all‐cause mortality. Covariates were demographics, comorbid conditions and health behaviours.
Results
Among 129 140 eligible participants, 30% had HIV infection, 16% had a major depressive disorder diagnosis, and 24% died over a median follow‐up time of 11 years. The death rate was 25.3 95% confidence interval (CI) 25.0–25.6 deaths per 1000 person‐years. Major depressive disorder was associated with mortality hazard ratio (HR) 1.04; 95% CI 1.01, 1.07. This association was modified by HIV status (interaction P‐value = 0.02). In HIV‐stratified analyses, depression was significantly associated with mortality among HIV‐uninfected veterans but not among those with HIV infection. Among those with PHQ‐9 data (n = 7372), 50% had HIV infection, 22% had PHQ‐9 scores ≥ 10, and 28% died over a median follow‐up time of 12 years. The death rate was 27.3 (95% CI 26.1–28.5) per 1000 person‐years. Depressive symptoms were associated with mortality (HR 1.16; 95% CI 1.04, 1.28). This association was modified by HIV status (interaction P‐value = 0.05). In HIV‐stratified analyses, depressive symptoms were significantly associated with mortality among veterans with HIV infection but not among those without HIV infection.
Conclusions
Depression was associated with all‐cause mortality. This association was modified by HIV status and method of depression ascertainment.
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