5,190 research outputs found
Youth guarantee and the Italian PES: insights from ISFOL PLUS Survey data
This paper uses data from the ISFOL PLUS Survey to focus on the specific features of the Italian labour market and of the Italian Public Employment Services (PESs) so as to analyse the difficulties that they face in responding to the challenges posed by the Youth Guarantee (YG), both in terms of reorganisation and of strengthened financial effort
Follow-up after curative resection for gastric cancer. Is it time to tailor it?
There is still no consensus on the follow-up frequency and regimen after curative resection for gastric cancer. Moreover, controversy exists regarding the utility of follow-up in improving survival, and the recommendations of experts and societies vary considerably. The main reason to establish surveillance programs is to diagnose tumor recurrence or metachronous cancers early and to thereby provide prompt treatment and prolong survival. In the setting of gastric malignancies, other reasons have been put forth: (1) the detection of adverse effects of a previous surgery, such as malnutrition or digestive sequelae; (2) the collection of data; and (3) the identification of psychological and/or social problems and provision of appropriate support to the patients. No randomized controlled trials on the role of follow-up after curative resection of gastric carcinoma have been published. Herein, the primary retrospective series and systematic reviews on this subject are analyzed and discussed. Furthermore, the guidelines from international and national scientific societies are discussed. Follow-up is recommended by the majority of institutions; however, there is no real evidence that follow-up can improve long-term survival rates. Several studies have demonstrated that it is possible to stratify patients submitted to curative gastrectomy into different classes according to the risk of recurrence. Furthermore, promising studies have identified several molecular markers that are related to the risk of relapse and to prognosis. Based on these premises, a promising strategy will be to tailor follow-up in relation to the patient and tumor characteristics, molecular marker status, and individual risk of recurrence
A population study of type II bursts in the Rapid Burster
Type II bursts are thought to arise from instabilities in the accretion flow
onto a neutron star in an X-ray binary. Despite having been known for almost 40
years, no model can yet satisfactorily account for all their properties. To
shed light on the nature of this phenomenon and provide a reference for future
theoretical work, we study the entire sample of Rossi X-ray Timing Explorer
data of type II bursts from the Rapid Burster (MXB 1730-335). We find that type
II bursts are Eddington-limited in flux, that a larger amount of energy goes in
the bursts than in the persistent emission, that type II bursts can be as short
as 0.130 s, and that the distribution of recurrence times drops abruptly below
15-18 s. We highlight the complicated feedback between type II bursts and the
NS surface thermonuclear explosions known as type I bursts, and between type II
bursts and the persistent emission. We review a number of models for type II
bursts. While no model can reproduce all the observed burst properties and
explain the source uniqueness, models involving a gating role for the magnetic
field come closest to matching the properties of our sample. The uniqueness of
the source may be explained by a special combination of magnetic field
strength, stellar spin period and alignment between the magnetic field and the
spin axis.Comment: Accepted 2015 February 12. Received 2015 February 10; in original
form 2014 December 1
EXONEST: The Bayesian Exoplanetary Explorer
The fields of astronomy and astrophysics are currently engaged in an
unprecedented era of discovery as recent missions have revealed thousands of
exoplanets orbiting other stars. While the Kepler Space Telescope mission has
enabled most of these exoplanets to be detected by identifying transiting
events, exoplanets often exhibit additional photometric effects that can be
used to improve the characterization of exoplanets. The EXONEST Exoplanetary
Explorer is a Bayesian exoplanet inference engine based on nested sampling and
originally designed to analyze archived Kepler Space Telescope and CoRoT
(Convection Rotation et Transits plan\'etaires) exoplanet mission data. We
discuss the EXONEST software package and describe how it accommodates
plug-and-play models of exoplanet-associated photometric effects for the
purpose of exoplanet detection, characterization and scientific hypothesis
testing. The current suite of models allows for both circular and eccentric
orbits in conjunction with photometric effects, such as the primary transit and
secondary eclipse, reflected light, thermal emissions, ellipsoidal variations,
Doppler beaming and superrotation. We discuss our new efforts to expand the
capabilities of the software to include more subtle photometric effects
involving reflected and refracted light. We discuss the EXONEST inference
engine design and introduce our plans to port the current MATLAB-based EXONEST
software package over to the next generation Exoplanetary Explorer, which will
be a Python-based open source project with the capability to employ third-party
plug-and-play models of exoplanet-related photometric effects.Comment: 30 pages, 8 figures, 5 tables. Presented at the 37th International
Workshop on Bayesian Inference and Maximum Entropy Methods in Science and
Engineering (MaxEnt 2017) in Jarinu/SP Brasi
Role of the flat-designed surface in improving the cyclic fatigue resistance of endodontic NiTi rotary instruments
The aim of this study was to investigate the role of the flat-designed surface in improving the resistance to cyclic fatigue by comparing heat-treated F-One (Fanta Dental, Shanghai, China) nickel-titanium (NiTi) rotary instruments and similar prototypes, differing only by the absence of the flat side. The null hypothesis was that there were no differences between the two tested instruments in terms of cyclic fatigue lifespan. A total of 40 new NiTi instruments (20 F-One and 20 prototypes) were tested in the present study. The instruments were rotated with the same speed (500 rpm) and torque (2 N) using an endodontic motor (Elements Motor, Kerr, Orange, CA, USA) in the same stainless steel, artificial canal (90° angle of curvature and 5 mm radius). A Wilcoxon-Mann-Whitney test was performed to assess the differences in terms of time to fracture and the length of the fractured segment between the flat- and non-flat-sided instruments. Significance was set at p = 0.05. The differences in terms of time to fracture between non-flat and flat were statistically significant (p < 0.001). In addition, the differences in terms of fractured segment length were statistically significant (p = 0.034). The results of this study highlight the importance of flat-sided design in increasing the cyclic fatigue lifespan of NiTi rotary instruments
Micro-photogrammetry as a tool for characterisation of dissolution behaviour of pharmaceutical dosage forms
The aim of this project is to develop an innovative analytical technique for the 3D
chemical mapping of pharmaceutical dosage forms, via simultaneous topographic
characterisation and dissolution analysis of solid drug delivery systems. The
developed apparatus was optimised using the results obtained from the application
of micro-photogrammetry to the analysis of commercial solid drug delivery systems.
Results of the application of the developed method on the dissolution of a sugarcoated
tablet sample are here presented
Chiral spin texture in the charge-density-wave phase of the correlated metallic Pb/Si(111) monolayer
We investigate the 1/3 monolayer -Pb/Si(111) surface by scanning
tunneling spectroscopy (STS) and fully relativistic first-principles
calculations. We study both the high-temperature and
low-temperature reconstructions and show that, in both phases, the
spin-orbit interaction leads to an energy splitting as large as of the
valence-band bandwidth. Relativistic effects, electronic correlations and
Pb-substrate interaction cooperate to stabilize a correlated low-temperature
paramagnetic phase with well-developed lower and upper Hubbard bands coexisting
with periodicity. By comparing the Fourier transform of STS
conductance maps at the Fermi level with calculated quasiparticle interference
from non-magnetic impurities, we demonstrate the occurrence of two large
hexagonal Fermi sheets with in-plane spin polarizations and opposite
helicities.Comment: 5 pages, 3 figure
Final model independent result of DAMA/LIBRA-phase1
The results obtained with the total exposure of 1.04 ton x yr collected by
DAMA/LIBRA-phase1 deep underground at the Gran Sasso National Laboratory (LNGS)
of the I.N.F.N. during 7 annual cycles (i.e. adding a further 0.17 ton x yr
exposure) are presented. The DAMA/LIBRA-phase1 data give evidence for the
presence of Dark Matter (DM) particles in the galactic halo, on the basis of
the exploited model independent DM annual modulation signature by using highly
radio-pure NaI(Tl) target, at 7.5 sigma C.L.. Including also the first
generation DAMA/NaI experiment (cumulative exposure 1.33 ton x yr,
corresponding to 14 annual cycles), the C.L. is 9.3 sigma and the modulation
amplitude of the single-hit events in the (2-6) keV energy interval is: (0.0112
\pm 0.0012) cpd/kg/keV; the measured phase is (144 \pm 7) days and the measured
period is (0.998 \pm 0.002) yr, values well in agreement with those expected
for DM particles. No systematic or side reaction able to mimic the exploited DM
signature has been found or suggested by anyone over more than a decade.Comment: 20 pages, 13 figures, 6 tables; in publication on Eur. Phys. J.
Investigating Earth shadowing effect with DAMA/LIBRA-phase1
In the present paper the results obtained in the investigation of possible
diurnal effects for low-energy single-hit scintillation events of
DAMA/LIBRA-phase1 (1.04 ton yr exposure) have been analysed in terms
of an effect expected in case of Dark Matter (DM) candidates inducing nuclear
recoils and having high cross-section with ordinary matter, which implies low
DM local density in order to fulfill the DAMA/LIBRA DM annual modulation
results. This effect is due to the different Earth depths crossed by those DM
candidates during the sidereal day.Comment: 22 pages, 9 figures, 1 table; in publication on Eur. Phys. J.
Model independent result on possible diurnal effect in DAMA/LIBRA-phase1
The results obtained in the search for possible diurnal effect in the
single-hit low energy data collected by DAMA/LIBRA-phase1 (total exposure: 1.04
ton x yr) deep underground at the Gran Sasso National Laboratory (LNGS) of the
I.N.F.N. are presented. At the present level of sensitivity the presence of any
significant diurnal variation and of diurnal time structures in the data can be
excluded for both the cases of solar and sidereal time. In particular, the
diurnal modulation amplitude expected, because of the Earth diurnal motion, on
the basis of the DAMA Dark Matter annual modulation results is below the
present sensitivity.Comment: 14 pages, 5 figures, 2 tables; in publication on Eur. Phys. J.
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