34 research outputs found
Effects of cardiac resynchronization therapy on systemic inflammation and neurohormonal pathways in heart failure
Background: The effect of cardiac resynchronization therapy (CRT) on systemic inflammation
and neurohormonal alterations associated with heart failure is not well characterized.
Accordingly, we aimed to assess the long term effects of CRT on systemic inflammation and
neurohormonal factors in heart failure patients.
Methods and results: In 47 HF patients (NYHA III–IV) we evaluated, at baseline and after
one year of CRT: TNF-α, TNF soluble receptors (sTNFR1 and sTNFR2), insulin-like growth
factor-1α (IGF-1α), adiponectin, norepinephrine, pro-atrial natriuretic peptide (pro-ANP),
N-terminal-pro-brain natriuretic peptide (NT-proBNP) and angiotensin II, NYHA functional
class, quality of life (the Minnesota Living with Heart Failure questionnaire), a 6-minute walk
test and an echocardiogram. Long-term CRT decreased activation of renin–angiotensin system
(RAS) only in patients with reverse remodelling. It failed to prevent a decline in adiponectin
levels, regardless of reverse remodelling. NT-proBNP remained unchanged in patients with
reverse remodelling, whereas its levels increased in those without reverse remodelling. IGF-1α
increased with CRT, whereas CRT had no effect on pro-ANP and inflammatory markers.
Conclusions: Long-term CRT is associated with decreased RAS activation and stabilization
of NT-proBNP in heart failure patients with reverse remodelling. Long-term CRT, with or
without reverse remodelling, does not affect systemic inflammation and fails to prevent
a decline in adiponectin
Le abitudini al tempo del Coronavirus
Introduction: The COVID-19 pandemic that hit the humankind in December 2019, is steering quick and drastic changes to our habits. The goal of our research is the analysis of the emotional, healthy and physiological effects of this radical routine disruption, in a sample of 3000 Italian people.
Methods: We made use of a 5-days flash survey in an anonymous way, available from April the 5th until April the 10th.
Results: As expected, results show a healthy decrease, after just one month of lockdown, at several stages: emotional, relational, nutritional and physical.
Conclusions: This quarantine period can be considered as an extreme example of immediate sedentary and isolation effects on people. Home habits such as basic physical activity, circadian rhythm routine, proper diet, and correct information consumption can be useful to increase our resilience in difficult times like the current one, but also in our next future
Compact object coalescence rate estimation from short gamma-ray burst observations
Recent observational and theoretical results suggest that Short-duration
Gamma-Ray Bursts (SGRBs) are originated by the merger of compact binary systems
of two neutron stars or a neutron star and a black hole. The observation of
SGRBs with known redshifts allows astronomers to infer the merger rate of these
systems in the local universe. We use data from the SWIFT satellite to estimate
this rate to be in the range -1500 Gpcyr. This result
is consistent with earlier published results which were obtained through
alternative approaches. We estimate the number of coincident observations of
gravitational-wave signals with SGRBs in the advanced gravitational-wave
detector era. By assuming that all SGRBs are created by neutron star-neutron
star (neutron star-black hole) mergers, we estimate the expected rate of
coincident observations to be in the range to 1 ( to 3)
yr.Comment: 23 pages, 3 figures, version accepted for publicatio
The zCOSMOS 10k-Bright Spectroscopic Sample
We present spectroscopic redshifts of a large sample of galaxies with I_(AB) < 22.5 in the COSMOS field, measured from spectra of 10,644 objects that have been obtained in the first two years of observations in the zCOSMOS-bright redshift survey. These include a statistically complete subset of 10,109 objects. The average accuracy of individual redshifts is 110 km s^(–1), independent of redshift. The reliability of individual redshifts is described by a Confidence Class that has been empirically calibrated through repeat spectroscopic observations of over 600 galaxies. There is very good agreement between spectroscopic and photometric redshifts for the most secure Confidence Classes. For the less secure Confidence Classes, there is a good correspondence between the fraction of objects with a consistent photometric redshift and the spectroscopic repeatability, suggesting that the photometric redshifts can be used to indicate which of the less secure spectroscopic redshifts are likely right and which are probably wrong, and to give an indication of the nature of objects for which we failed to determine a redshift. Using this approach, we can construct a spectroscopic sample that is 99% reliable and which is 88% complete in the sample as a whole, and 95% complete in the redshift range 0.5 < z < 0.8. The luminosity and mass completeness levels of the zCOSMOS-bright sample of galaxies is also discussed
Fast diffusing p75NTR monomers support apoptosis and growth cone collapse by neurotrophin ligands
The p75 neurotrophin (NT) receptor (p75NTR) plays a crucial role in balancing survival-versus-death decisions in the nervous system. Yet, despite 2 decades of structural and biochemical studies, a comprehensive, accepted model for p75NTR activation by NT ligands is still missing. Here, we present a single-molecule study of membrane p75NTR in living cells, demonstrating that the vast majority of receptors are monomers before and after NT activation. Interestingly, the stoichiometry and diffusion properties of the wild-type (wt) p75NTR are almost identical to those of a receptor mutant lacking residues previously believed to induce oligomerization. The wt p75NTR and mutated (mut) p75NTR differ in their partitioning in cholesterol-rich membrane regions upon nerve growth factor (NGF) stimulation: We argue that this is the origin of the ability of wt p75NTR , but not of mut p75NTR, to mediate immature NT (proNT)-induced apoptosis. Both p75NTR forms support proNT-induced growth cone retraction: We show that receptor surface accumulation is the driving force for cone collapse. Overall, our data unveil the multifaceted activity of the p75NTR monomer and let us provide a coherent interpretative frame of existing conflicting data in the literature
Optical afterglows of gamma-ray bursts: a bimodal distribution?"
The luminosities of the optical afterglows of Gamma Ray Bursts, 12 hours
(rest frame time) after the trigger, show a surprising clustering, with a
minority of events being at a significant smaller luminosity. If real, this
dichotomy would be a crucial clue to understand the nature of optically dark
afterglows, i.e. bursts that are detected in the X-ray band, but not in the
optical. We investigate this issue by studying bursts of the pre-Swift era,
both detected and undetected in the optical. The limiting magnitudes of the
undetected ones are used to construct the probability that a generic bursts is
observed down to a given magnitude limit. Then, by simulating a large number of
bursts with pre-assigned characteristics, we can compare the properties of the
observed optical luminosity distribution with the simulated one. Our results
suggest that the hints of bimodality present in the observed distribution
reflects a real bimodality: either the optical luminosity distributions of
bursts is intrinsically bimodal, or there exists a population of bursts with a
quite significant grey absorption, i.e. wavelength independent extinction. This
population of intrinsically weak or grey-absorbed events can be associated to
dark bursts.Comment: 10 pages, 5 figures, accepted for publication in MNRA
Mass and environment as drivers of galaxy evolution in SDSS and zCOSMOS and the origin of the Schechter function
We explore the inter-relationships between mass, star-formation rate and
environment in the SDSS, zCOSMOS and other surveys. The differential effects of
mass and environment are completely separable to z ~ 1, indicating that two
distinct processes are operating, "mass-quenching" and "environment-quenching".
Environment-quenching, at fixed over-density, evidently does not change with
epoch to z ~ 1, suggesting that it occurs as large-scale structure develops in
the Universe. The observed constancy of the mass-function shape for
star-forming galaxies, demands that the mass-quenching of galaxies around and
above M*, must be proportional to their star-formation rates at all z < 2. We
postulate that this simple mass-quenching law also holds over a much broader
range of stellar mass and epoch. These two simple quenching processes, plus
some additional quenching due to merging, then naturally produce (a) a
quasi-static Schechter mass function for star-forming galaxies with a value of
M* that is set by the proportionality between the star-formation and
mass-quenching rates, (b) a double Schechter function for passive galaxies with
two components: the dominant one is produced by mass-quenching and has exactly
the same M* as the star-forming galaxies but an alpha shallower by +1, while
the other is produced by environment effects and has the same M* and alpha as
the star-forming galaxies, and is larger in high density environments.
Subsequent merging of quenched galaxies modifies these predictions somewhat in
the denser environments, slightly increasing M* and making alpha more negative.
All of these detailed quantitative relationships between the Schechter
parameters are indeed seen in the SDSS, lending strong support to our simple
empirically-based model. The model naturally produces for passive galaxies the
"anti-hierarchical" run of mean ages and alpha-element abundances with mass.Comment: 66 pages, 19 figures, 1 movie, accepted for publication in ApJ. The
movie is also available at
http://www.exp-astro.phys.ethz.ch/zCOSMOS/MF_simulation_d1_d4.mo