113 research outputs found
The Evolution of Ideology, Fairness and Redistribution
Ideas about what is "fair" above and beyond the individual's position in the income ladder influence preferences for redistribution. We study the dynamic evolution of different economies in which redistributive policies, perceptions of fairness, inequality and growth are jointly determined. We show how including fairness explains various observed correlations between inequality, redistribution and growth. We also show how different beliefs about fairness can keep two otherwise identical countries in different development paths for a very long time.
Minimal fluoroscopy approach for right-sided supraventricular tachycardia ablation with a novel ablation technology: Insights from the multicenter CHARISMA clinical registry
Role of B diffusion in the interfacial Dzyaloshinskii-Moriya interaction in Ta / Co₂₀ Fe₆₀B₂₀/MgO nanowires
We report on current-induced domain wall motion in Ta/Co20Fe60B20/MgO nanowires. Domain walls are observed to move against the electron flow when no magnetic field is applied, while a field along the nanowires strongly affects the domain wall motion velocity. A symmetric effect is observed for up-down and down-up domain walls. This indicates the presence of right-handed domain walls, due to a Dzyaloshinskii-Moriya interaction (DMI) with a DMI coefficient D=+0.06mJ/m2. The positive DMI coefficient is interpreted to be a consequence of B diffusion into the Ta buffer layer during annealing, which was observed by chemical depth profiling measurements. The experimental results are compared to one-dimensional model simulations including the effects of pinning. This modeling allows us to reproduce the experimental outcomes and reliably extract a spin-Hall angle θSH=-0.11 for Ta in the nanowires, showing the importance of an analysis that goes beyond the model for perfect nanowires
The GAPS programme at TNG: XLIII. A massive brown dwarf orbiting the active M dwarf TOI-5375
Context. Massive substellar companions orbiting active low-mass stars are rare. They, however, offer an excellent opportunity to study the main mechanisms involved in the formation and evolution of substellar objects.
Aims: We aim to unravel the physical nature of the transit signal observed by the TESS space mission on the active M dwarf TOI-5375.
Methods: We analysed the available TESS photometric data as well as high-resolution (R ~ 115 000) HARPS-N spectra. We combined these data to characterise the star TOI-5375 and to disentangle signals related to stellar activity from the companion transit signal in the light-curve data. We ran a Markov chain Monte Carlo analysis to derive the orbital solution and applied state-of-the-art Gaussian process regression to deal with the stellar activity signal.
Results: We reveal the presence of a companion in the boundary between the brown dwarfs and the very-low-mass stars orbiting around the star TOI-5375. The best-fit model corresponds to a companion with an orbital period of 1.721564 ± 10−6 d, a mass of 77 ± 8 MJ, and a radius of 0.99 ± 0.16 RJ.
Conclusions: We derive a rotation period for the host star of 1.9692 ± 0.0004 d, and we conclude that the star is very close to synchronising its rotation with the orbital period of the companion
The GAPS programme at TNG XLV. A massive brown dwarf orbiting the active M dwarf TOI-5375
Context. Massive substellar companions orbiting active low-mass stars are
rare. They, however, offer an excellent opportunity to study the main
mechanisms involved in the formation and evolution of substellar objects. Aims.
We aim to unravel the physical nature of the transit signal observed by the
TESS space mission on the active M dwarf TOI-5375. Methods. We analysed the
available TESS photometric data as well as high-resolution (R 115000)
HARPS-N spectra. We combined these data to characterise the star TOI-5375 and
to disentangle signals related to stellar activity from the companion transit
signal in the light-curve data. We ran an MCMC analysis to derive the orbital
solution and apply state-of-the-art Gaussian process regression to deal with
the stellar activity signal. Results. We reveal the presence of a companion in
the brown dwarf / very-low-mass star boundary orbiting around the star
TOI-5375. The best-fit model corresponds to a companion with an orbital period
of 1.721564 10 d, a mass of 77 8 and a
radius of 0.99 0.16 . We derive a rotation period for the host
star of 1.9692 0.0004 d, and we conclude that the star is very close to
synchronising its rotation with the orbital period of the companion.Comment: Submitted to Astronomy & Astrophysics (under review
Structural and functional papez circuit integrity in amyotrophic lateral sclerosis
Cognitive impairment in amyotrophic lateral sclerosis (ALS) is heterogeneous but now recognized as a feature in non-demented patients and no longer exclusively attributed to executive dysfunction. However, despite common reports of temporal lobe changes and memory deficits in ALS, episodic memory has been less explored. In the current study, we examined how the Papez circuit—a circuit known to participate in memory processes—is structurally and functionally affected in ALS patients (n = 20) compared with healthy controls (n = 15), and whether these changes correlated with a commonly used clinical measure of episodic memory. Our multimodal MRI approach (cortical volume, voxel-based morphometry, diffusion tensor imaging and resting state functional magnetic resonance) showed reduced gray matter in left hippocampus, left entorhinal cortex and right posterior cingulate as well as increased white matter fractional anisotropy and decreased mean diffusivity in the left cingulum bundle (hippocampal part) of ALS patients compared with controls. Interestingly, thalamus, mammillary bodies and fornix were preserved. Finally, we report a decreased functional connectivity in ALS patients in bilateral hippocampus, bilateral anterior and posterior parahippocampal gyrus and posterior cingulate. The results revealed that ALS patients showed statistically significant structural changes, but more important, widespread prominent functional connectivity abnormalities across the regions comprising the Papez circuit. The decreased functional connectivity found in the Papez network may suggest these changes could be used to assess risk or assist early detection or development of memory symptoms in ALS patients even before structural changes are established
The GAPS Programme at TNG : XLVII. A conundrum resolved: HIP 66074b/Gaia-3b characterised as a massive giant planet on a quasi-face-on and extremely elongated orbit
The nearby mid-K dwarf HIP 66074 was recently identified as host to a candidate super-Jupiter companion on a similar to 300 day, almost edge-on, orbit, based on Gaia Data Release 3 (DR3) astrometry. Initial attempts at confirming the planetary nature of the signal based on publicly available radial-velocity (RV) observations uncovered an intriguing conundrum: the inferred RV semi-amplitude appears to be a factor of 15 smaller than the one predicted based on the Gaia solution (corresponding to a 7-M-Jup companion on a close to edge-on orbit). We present the results of intensive RV monitoring of HIP 66074 with the HARPS-N spectrograph. We detected the companion at the Gaia period, but with an extremely eccentric orbit (e = 0:948 +/- 0:004), a semi-amplitude K = 93.9(-7.0)(+9.4) m s(-1), and a minimum mass mb sin i(b) = 0.79 +/- 0.05 M-Jup. We used detailed simulations of Gaia astrometry with the DR3 time-span to show that the conundrum can be fully resolved by taking into account the combination of the initially sub-optimal RV sampling and systematic biases in the Gaia astrometric solution, which include an underestimation of the eccentricity and incorrect identification of orbital inclination, which has turned out to correspond to a close to face-on configuration (i less than or similar to 13 degrees). With an estimated mass in the approximate range of 3-7 M-Jup, we find that HIP 66074b (equivalent to Gaia-3b) is the first exoplanet candidate astrometrically detected by Gaia to be successfully confirmed based on RV follow-up observations
Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays
Average charged multiplicities have been measured separately in , and
light quark () events from decays measured in the SLD experiment.
Impact parameters of charged tracks were used to select enriched samples of
and light quark events, and reconstructed charmed mesons were used to select
quark events. We measured the charged multiplicities:
,
, from
which we derived the differences between the total average charged
multiplicities of or quark events and light quark events: and . We compared
these measurements with those at lower center-of-mass energies and with
perturbative QCD predictions. These combined results are in agreement with the
QCD expectations and disfavor the hypothesis of flavor-independent
fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters
The GAPS programme at TNG XLIX. TOI-5398, the youngest compact multi-planet system composed of an inner sub-Neptune and an outer warm Saturn
Short-period giant planets are frequently found to be solitary compared to
other classes of exoplanets. Small inner companions to giant planets with 15 days are known only in five compact systems: WASP-47, Kepler-730,
WASP-132, TOI-1130, and TOI-2000. Here, we report the confirmation of TOI-5398,
the youngest compact multi-planet system composed of a hot sub-Neptune
(TOI-5398 c, = 4.77271 days) orbiting interior to a short-period
Saturn (TOI-5398 b, = 10.590547 days) planet, both transiting
around a 650 150 Myr G-type star. As part of the GAPS Young Object
project, we confirmed and characterised this compact system, measuring the
radius and mass of both planets, thus constraining their bulk composition.
Using multidimensional Gaussian processes, we simultaneously modelled stellar
activity and planetary signals from TESS Sector 48 light curve and our HARPS-N
radial velocity time series. We have confirmed the planetary nature of both
planets, TOI-5398 b and TOI-5398 c, alongside a precise estimation of stellar
parameters. Through the use of astrometric, photometric, and spectroscopic
observations, our findings indicate that TOI-5398 is a young, active G dwarf
star (650 150 Myr), with a rotational period of = 7.34
days. The transit photometry and radial velocity measurements enabled us to
measure both the radius and mass of planets b, ,
, and c, , . TESS observed TOI-5398 during sector 48 and no further
observations are planned in the current Extended Mission, making our
ground-based light curves crucial for ephemeris improvement. With a
Transmission Spectroscopy Metric value of around 300, TOI-5398 b is the most
amenable warm giant (10 < < 100 days) for JWST atmospheric
characterisation.Comment: 29 pages, Paper accepted for publication in Astronomy & Astrophysic
Clinical Learning Quality Evaluation Index per la valutazione della qualità dell’apprendimento clinico degli studenti infermieri e raccomandazioni di utilizzo
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