Context.
X-ray selected samples are known to miss galaxy clusters that are gas poor and have a low surface brightness. This is different for the optically selected samples such as the X-ray Unbiased ...Selected Sample (XUCS).
Aims.
We characterise the origin of galaxy clusters that are gas poor and have a low surface-brightness by studying covariances between various cluster properties at fixed mass using hydrodynamic cosmological simulations.
Methods.
We extracted ≈1800 galaxy clusters from a high-resolution Magneticum hydrodynamic cosmological simulation and computed covariances at fixed mass of the following properties: core-excised X-ray luminosity, gas fraction, hot gas temperature, formation redshift, matter density profile concentration, galaxy richness, fossilness parameter, and stellar mass of the bright central galaxy. We also compared the correlation between concentration and gas fractions in non-radiative simulations, and we followed the trajectories of particles inside galaxy clusters to assess the role of AGN depletion on the gas fraction.
Results.
In simulations and in observational data, differences in surface brightness are related to differences in gas fraction. Simulations show that the gas fraction strongly correlates with assembly time, in the sense that older clusters are gas poor. Clusters that formed earlier have lower gas fractions because the feedback of the active galactic nucleus ejected a significant amount of gas from the halo. When the X-ray luminosity is corrected for the gas fraction, it shows little or no covariance with other quantities.
Conclusions.
Older galaxy clusters tend to be gas poor and possess a low X-ray surface brightness because the feedback mechanism removes a significant fraction of gas from these objects. Moreover, we found that most of the
L
X
covariance with the other quantities is explained by differences in the gas fraction.
Myocardial conditioning is actually an essential strategy in the management of ischaemia-reperfusion injury. The concept of anaesthetic post-conditioning is intriguing, its action occurring at a ...pivotal moment (that of reperfusion when ischaemia reperfusion lesions are initiated) where the activation of these cardio-protective mechanisms could overpower the mechanisms leading to ischaemia reperfusion injuries. Desflurane and sevoflurane are volatile anaesthetics frequently used during cardiac surgery. This review focuses on the efficacy of desflurane and sevoflurane administered during early reperfusion as a potential cardio-protective strategy. In the context of experimental studies in animal models and in human atrial tissues in vitro, the mechanisms underlying the cardio-protective effect of these agents and their capacity to induce post-conditioning have been reviewed in detail, underlining the role of reactive oxygen species generation, the activation of the cellular signalling pathways, and the actions on mitochondria along with the translatable actions in humans; this might well be sufficient to set the basis for launching randomized clinical studies, actually needed to confirm this strategy as one of real impact.
Aims.
We present a cosmological analysis of abundances and stacked weak lensing profiles of galaxy clusters, exploiting the AMICO KiDS-DR3 catalogue. The sample consists of 3652 galaxy clusters with ...intrinsic richness
λ
*
≥ 20, over an effective area of 377 deg
2
, in the redshift range
z
∈ 0.1, 0.6.
Methods.
We quantified the purity and completeness of the sample through simulations. The statistical analysis has been performed by simultaneously modelling the co-moving number density of galaxy clusters and the scaling relation between the intrinsic richnesses and the cluster masses, assessed through stacked weak lensing profile modelling. The fluctuations of the matter background density, caused by super-survey modes, have been taken into account in the likelihood. Assuming a flat Λ cold dark matter (ΛCDM) model, we constrained Ω
m
,
σ
8
,
S
8
≡
σ
8
(Ω
m
/0.3)
0.5
, and the parameters of the mass-richness scaling relation.
Results.
We obtained Ω
m
= 0.24
−0.04
+0.03
,
σ
8
= 0.86
−0.07
+0.07
, and
S
8
= 0.78
−0.04
+0.04
. The constraint on
S
8
is consistent within 1
σ
with the results from WMAP and Planck. Furthermore, we got constraints on the cluster mass scaling relation in agreement with those obtained from a previous weak lensing only analysis.
To investigate whether marital status is associated to long-term major fatal and non-fatal cardiovascular events in men and women from the Gubbio Population Study. The incidence of cardiovascular ...disease (CVD), including stroke and coronary heart disease (CHD) and CVD death together with all-cause mortality were analyzed. The analysis included 2832 persons (44% men, 54 ± 11 years old). Marital status was defined at entry as married (married or living conjugally) versus unmarried subjects (widowed, separated, divorced or single). Married and unmarried subjects did not differ concerning socio-demographic, anthropometric and biological variables at baseline. Over 191 months median follow-up, the incidence of CHD was lower among married versus unmarried women HR: 0.63 (95% CI 0.41-0.96) only; the same was true for CHD mortality HR: 0.43 (95% CI 0.22-0.84) and all-cause mortality HR: 0.75 (95% CI 0.59-0.96) independently of traditional risk factors (age, SBP, total and HDL cholesterol, cigarette smoke and BMI). In men, marital status was not associated to any of the investigated outcomes. In primary care, marital status should be investigated as it can be associated with long-term CHD and all-cause incidence and mortality risks among women.
Aims.
By means of the
r
-band luminosity function (LF) of galaxies in a sample of about 4000 clusters detected by the cluster finder AMICO in the KiDS-DR3 area of about 400 deg
2
, we studied the ...evolution with richness and redshift of the passive evolving (red), star-forming (blue), and total galaxy populations. This analysis was performed for clusters in the redshift range 0.1, 0.8 and in the mass range 10
13
M
⊙
, 10
15
M
⊙
.
Methods.
To compute LFs, we binned the luminosity distribution in magnitude and statistically subtracted the background. Then, we divided the cluster sample in bins of both redshift and richness/mass. We stacked LF counts in each 2D bin for the total, red, and blue galaxy populations; finally, we fitted the stacked LF with a Schechter function and studied the trend of its parameters with redshift and richness/mass.
Results.
We found a passive evolution with
z
for the bright part of the LF for the red and total populations and no significant trends for the faint galaxies. The mass/richness dependence is clear for the density parameter Φ
⋆
, increasing with richness, and for the total population faint end, which is shallower in the rich clusters.
ABSTRACT
We constrain the ΛCDM cosmological parameter σ8 by applying the extreme value statistics for galaxy cluster mass on the AMICO KiDS-DR3 catalogue. We sample the posterior distribution of the ...parameters by considering the likelihood of observing the largest cluster mass value in a sample of Nobs = 3644 clusters with intrinsic richness λ* > 20 in the redshift range z ∈ 0.10, 0.60. We obtain $\sigma _{8}=0.90_{-0.18}^{+0.20}$, consistent within 1σ with the measurements obtained by the Planck collaboration and with previous results from cluster cosmology exploiting AMICO KiDS-DR3. The constraints could improve by applying this method to forthcoming missions, such as Euclid and LSST, which are expected to deliver thousands of distant and massive clusters.
We study the tomographic clustering properties of the photometric cluster catalogue derived from the third data release of the Kilo Degree Survey (KiDS), focusing on the angular correlation function ...and its spherical harmonic counterpart: the angular power spectrum. We measured the angular correlation function and power spectrum from a sample of 5162 clusters, with an intrinsic richness of
λ
*
≥ 15, in the photometric redshift range of
z
∈ 0.1, 0.6. We compared our measurements with theoretical models, within the framework of the Λ cold dark matter cosmology. We performed a Markov chain Monte Carlo (MCMC) analysis to constrain the cosmological parameters, Ω
m
and
σ
8
, as well as the structure growth parameter,
S
8
≡
σ
8
√Ω
m
/0.3. We adopted Gaussian priors on the parameters of the mass-richness relation, based on the posterior distributions derived from a previous joint analysis of cluster counts and weak-lensing mass measurements carried out on the basis of the same catalogue. From the angular correlation function, we obtained Ω
m
= 0.32
−0.04
+0.05
,
σ
8
= 0.77
−0.09
+0.13
, and
S
8
= 0.80
−0.06
+0.08
, which are in agreement, within 1
σ
, with the 3D clustering result based on the same cluster sample and with existing complementary studies on other data sets. For the angular power spectrum, we checked the validity of the Poissonian shot noise approximation, also considering the mode-mode coupling induced by the mask. We derived statistically consistent results, in particular, Ω
m
= 0.24
−0.04
+0.05
and
S
8
= 0.93
−0.12
+0.11
; while the constraint on
σ
8
alone is weaker with respect to the one provided by the angular correlation function,
σ
8
= 1.01
−0.17
+0.25
. Our results show that the 2D clustering from photometric cluster surveys can provide competitive cosmological constraints with respect to the full 3D clustering statistics. We also demonstrate that they can be successfully applied to ongoing and forthcoming spectrometric and photometric surveys.
The function of left atrium (LA) is closely related to LA remodeling and one of the most important mechanisms is an increased deposition of fibrous tissue that often is the basis for LA ...electro-mechanical changes before the onset of atrial fibrillation (AF). This study evaluated LA shape and function, by investigating standard and novel strain parameters calculated by a new approach based on homologous times derived from 3D speckle tracking echocardiography (3DSTE) in hypertensive (HT) and paroxysmal atrial fibrillation (PAF) patients with or without left ventricular hypertrophy (LVH), compared to control (C) subjects. LA function was assessed using homologous times to compare strain variables among different individuals, acquired at different physiological time periods. Standard global longitudinal (GLS) and circumferential (GCS) strains were measured at peak of atrial diastole, while longitudinal and circumferential strains (GLSh, GCSh), strain rate (GLSr, GCSr), volume (Vh) and volume rate (Vr) were measured during the atrial telediastolic phase (fifth homologous time) and atrial pre-active phase (tenth homologous time). Using ANOVA, we found an impaired LA deformation detected by standard, interpolated strains and strain rates in both HT and PAF groups compared to C. We also performed ROC analysis to identify different performances of each parameter to discriminate groups (GLSr10 + GCSr10: C vs PAF 0.935; C vs PAF_LVH 0.924; C vs HT_LVH 0.844; C vs HT 0.756). Our study showed anatomical and functional LA remodeling in patients with PAF and HT. 3D strains and strain rates derived from the homologous times approach provide more functional information with improved performance to identify among the explored groups, in particular PAF patients.
Abstract The Seven Countries Study of Cardiovascular Diseases was started at the end of the 1950s and it continues to be run after >50 years. It enrolled, at entry, 16 population cohorts in eight ...nations of seven countries for a total of 12,763 middle-aged men. It was the prototype of epidemiological studies seeking cultural contrasts and the first to compare cardiovascular disease (CVD) rates related to diet differences. The study has shown that populations suffer widely different incidence and mortality rates from coronary heart disease (CHD) as well as from other CVDs and overall mortality. Higher rates were found in North America and northern Europe, and lower rates in southern Europe – Mediterranean countries – and Japan. These differences in CHD rates were strongly associated with different levels of saturated fat consumption and average serum cholesterol levels, with lowest rates in Greece and Japan where the total fat intake was very different. The cohorts were also different in dietary patterns defined by the ratio of calories derived from plant foods and fish on the one hand and calories derived from animal foods and sugar on the other. These findings pointed to the so-called Mediterranean diet, which is characterized by large values of that plant/animal ratio, a pattern associated with lower incidence and mortality from CHD and also with the lowest death rates and the greatest survival rates. More recent studies have refined these concepts and documented on a larger scale the virtues of these eating habits.
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