232 research outputs found
On the distance of the Magellanic Clouds using Cepheid NIR and optical-NIR Period Wesenheit Relations
We present the largest near-infrared (NIR) data sets, , ever collected
for classical Cepheids in the Magellanic Clouds (MCs). We selected fundamental
(FU) and first overtone (FO) pulsators, and found 4150 (2571 FU, 1579 FO)
Cepheids for Small Magellanic Cloud (SMC) and 3042 (1840 FU, 1202 FO) for Large
Magellanic Cloud (LMC). Current sample is 2--3 times larger than any sample
used in previous investigations with NIR photometry. We also discuss optical
photometry from OGLE-III. NIR and optical--NIR Period-Wesenheit (PW)
relations are linear over the entire period range () and their slopes are, within the intrinsic dispersions, common between the
MCs. These are consistent with recent results from pulsation models and
observations suggesting that the PW relations are minimally affected by the
metal content. The new FU and FO PW relations were calibrated using a sample of
Galactic Cepheids with distances based on trigonometric parallaxes and Cepheid
pulsation models. By using FU Cepheids we found a true distance moduli of
mag (LMC) and
mag (SMC). These estimates
are the weighted mean over ten PW relations and the systematic errors account
for uncertainties in the zero-point and in the reddening law. We found similar
distances using FO Cepheids
( mag [LMC] and
mag [SMC]). These new MC
distances lead to the relative distance, mag (FU, ) and mag (FO, ),which agrees quite
well with previous estimates based on robust distance indicators.Comment: 17 pages, 7 figure
New variable stars in the Galactic Bulge: I. The bright regime
We report the detection of 1143 variable stars towards the Galactic bulge,
including 320 previously uncatalogued variables, using time-series photometry
extracted from data obtained with the VIMOS imager at the Very Large Telescope.
Observations of the Sagittarius Window Eclipsing Extrasolar Planet Search
(SWEEPS) field in the Galactic Bulge were taken over 2 years between March and
October at a cadence of 4 days, enabling the detection of variables with
periods up to 100 days. Many of these were already known, but we detected
a significant number of new variables, including 26 Cepheids, a further 18
Cepheid candidates, and many contact binaries. Here we publish the catalog of
the new variables, containing coordinates, mean magnitudes as well as periods
and classification; full light curves for these variables are also made
available electronically.Comment: 14 pages, 9 figures; submitted to MNRA
On the alpha-element gradients of the Galactic thin disk using Cepheids
We present new homogeneous measurements of Na, Al and three alpha-elements
(Mg, Si, Ca) for 75 Galactic Cepheids. The abundances are based on high
spectral resolution (R ~ 38,000) and high signal-to-noise ratio (S/N ~ 50-300)
spectra collected with UVES at ESO VLT. The current measurements were
complemented with Cepheid abundances either provided by our group (75) or
available in the literature, for a total of 439 Galactic Cepheids. Special
attention was given in providing a homogeneous abundance scale for these five
elements plus iron (Genovali et al. 2013, 2014). In addition, accurate
Galactocentric distances (RG) based on near-infrared photometry are also
available for all the Cepheids in the sample (Genovali et al. 2014). They cover
a large fraction of the Galactic thin disk (4.1 <= RG <= 18.4 kpc). We found
that the above five elements display well defined linear radial gradients and
modest standard deviations over the entire range of RG. Moreover, the
[element/Fe] abundance ratios are constant across the entire thin disk; only
the Ca radial distribution shows marginal evidence of a positive slope. These
results indicate that the chemical enrichment history of iron and of the quoted
five elements has been quite similar across the four quadrants of the Galactic
thin disk. The [element/Fe] ratios are also constant over the entire period
range. This empirical evidence indicates that the chemical enrichment of
Galactic Cepheids has also been very homogenous during the range in age that
they cover (~10-300 Myr). Once again, [Ca/Fe] vs. log(P) shows a (negative)
gradient, being underabundant among youngest Cepheids. Finally, we also found
that Cepheid abundances agree quite well with similar abundances for thin and
thick disk dwarf stars and they follow the typical Mg-Al and Na-O correlations.Comment: 25 pages, 11 figures, 5 table
Gender influence on professional satisfaction and gender issue perception among young oncologists. A survey of the Young Oncologists Working Group of the Italian Association of Medical Oncology (AIOM)
Background The professional gender gap is increasingly recognised in oncology. We explored gender issues perception and gender influence on professional satisfaction/gratification among young Italian oncologists. Methods Italian oncologists aged ≤40 years and members of the Italian Association of Medical Oncology were invited to participate in an online survey addressing workload/burnout, satisfaction in professional abilities and relations, relevant factors for professional gratification, and gender barriers. ‡ 2 test for general association or ‡ 2 test for trend was used to analyse the data. Results 201 young oncologists participated in the survey: 67% female, 71% aged 30-40 years, 41% still in training and 82% without children. Women and men were equally poorly satisfied by the relations with people occupying superior hierarchical positions. There was heterogeneity between women and men in current (p=0.011) and expected future (p=0.007) satisfaction in professional abilities: women were more satisfied by current empathy and relations with colleagues and were more confident in their future managerial and team leader skills. The most important elements for professional gratification indicated by all participants were, in general, work-life balance (36%) and intellectual stimulation/research (32%); specifically for women, work-life balance (48%) and intellectual stimulation/research (20%); and specifically for men, career (29%) and social prestige/recognition (26%). Heterogeneity within the same gender emerged. For example, the elements indicated by men as the most important were intellectual stimulation/research (39%) and work-life balance (21%) in general, versus social prestige/recognition (24%) and career (24%), respectively, specifically for men (p<0.0001). More women versus men perceived gender issue as an actual problem (60% vs 38%, p=0.03); men underestimated gender barriers to women's career (p=0.011). Conclusions Satisfaction in professional abilities varied by gender. Work-life balance is important for both women and men. Stereotypes about gender issues may be present. Gender issue is an actual problem for young oncologists, mostly perceived by women
Addressing Post-Acute COVID-19 Syndrome in Cancer Patients, from Visceral Obesity and Myosteatosis to Systemic Inflammation: Implications in Cardio-Onco-Metabolism
Cardiovascular disease and cancer are the two leading causes of morbidity and mortality in the world. The emerging field of cardio-oncology described several shared risk factors that predispose patients to both cardiovascular disease and cancer. Post-acute COVID-19 syndrome is a chronic condition that occurs in many patients who have experienced a SARS-CoV-2 infection, mainly based on chronic fatigue, sedentary lifestyle, cramps, breathing difficulties, and reduced lung performance. Post-acute COVID-19 exposes patients to increased visceral adiposity, insulin resistance, myosteatosis, and white adipose tissue content (surrounded by M1 macrophages and characterized by a Th1/Th17 phenotype), which increases the risk of cardiovascular mortality and cancer recurrence. In this review, the main metabolic affections of post-acute COVID-19 syndrome in cancer patients at low and high risk of cardiomyopathies will be summarized. Furthermore, several non-pharmacological strategies aimed at reducing atherosclerotic and cardiac risk will be provided, especially through anti-inflammatory nutrition with a low insulin and glycemic index, appropriate physical activity, and immune-modulating bioactivities able to reduce visceral obesity and myosteatosis, improving insulin-related signaling and myocardial metabolism
First metallicity determination from Near-Infrared spectra for five obscured Cepheids discovered in the inner Disk
We report the discovery of five new classical Cepheids located in the inner Galactic Disk at longitude l ≃ −40° in our IRSF/SIRIUS Near-Infrared (NIR) variability survey. The new Cepheids are unique in probing the kinematics and metallicity of young stars at the transition between the inner Disk and the minor axis of the central Bar, where they are expected to be less affected by its dynamical influence. This is also the first time that metallicity of Cepheids is estimated on the basis of medium-resolution (R ∼ 3, 000) NIR spectra, and we validated our results with data in the literature, finding a minimal dependence on the adopted spectroscopic diagnostics. This result is very promising for using Cepheids as stellar proxy of the present-time chemical content of the obscured regions in the Disk. We found that the three Cepheids within 8–10 kpc from us have metallicities consistent with the mean radial metallicity gradient, and kinematics consistent with the Galactic rotation curve. Instead, the closest (∼4 kpc)/farthest (∼12 kpc) Cepheids have significant negative/positive residuals, both in velocity and in iron content. We discuss the possibility that such residuals are related to large-scale dynamical instabilities, induced by the bar/spiral-arm pattern, but the current sample is too limited to reach firm conclusion
Stellar Populations in the Galactic Center
We discuss the stellar content of the Galactic Center, and in particular,
recent estimates of the star formation rate (SFR). We discuss pros and cons of
the different stellar tracers and focus our attention on the SFR based on the
three classical Cepheids recently discovered in the Galactic Center. We also
discuss stellar populations in field and cluster stars and present some
preliminary results based on near-infrared photometry of a field centered on
the young massive cluster Arches. We also provide a new estimate of the true
distance modulus to the Galactic Center and we found
14.490.02(standard)0.10(systematic) mag (7.91 kpc).
Current estimate agrees quite well with similar photometric and kinematic
distance determinations available in the literature. We also discuss the
metallicity gradient of the thin disk and the sharp change in the slope when
moving across the edge of the inner disk, the Galactic Bar and the Galactic
Center. The difference becomes even more compelling if we take into account
that metal abundances are based on young stellar tracers (classical Cepheids,
Red Supergiants, Luminous Blue Variables). Finally, we briefly outline the
possible mechanisms that might account for current empirical evidence.Comment: To be published in the Astrophysics and Space Science Proceeding
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