8,515 research outputs found
The duration of the school-to-work transition in Italy and in other European countries: a flexible baseline hazard interpretation
Purpose: The Italian school-to-work transition (STWT) is astonishingly slow and long in comparison to the other EU countries. We analyze its determinants comparing the Italian case with Austria, Poland and the UK. Design/methodology/approach: The analysis is based on a Cox survival model with proportional hazard. The smoothed hazard estimates allow us to identify the nonlinear path of the hazard function. Findings: The authors reckon that the actual length of the transition to a stable job is around 30 months in Italy. Conversely, it is less than one year in the other countries. Women are particularly penalized, despite being on average more educated than men. Tertiary or vocational education at high secondary school strongly increases the hazard rate to a regular job. The smoothed hazard estimates suggest positive duration dependence at the beginning of the transition and slightly negative thereafter. Practical implications: Stimulating economic growth and investing in education and training are important pre-conditions for shortening the transition. Originality/value: Despite the duration of the STWT is one of the most important indicators to measure the efficiency of the STWT, it is not easy to measure. The authors build on their previous research work on this topic, but relaxing the assumption of a monotonic hazard rate and using the flexible baseline hazard approach to test for the existence of nonlinear duration dependence. Furthermore, they extend the analysis by including student-workers who attended a vocational path of education, in order to detect its effectiveness in allowing young people finding a job sooner
Import substitution and implicit taxation of agriculture in Brazil.
The industrialization that Brazil experienced prior to World War II was not induced by the government It had its origin in the relative profitability of the agricultura1 and industrial sectors, which favored a shift in resources to the indup trial sector. During the period from the end of World War II until the early sixties, a deliberate import-substitution policy was pursued. The factors that gave rise to that policy were the diff iculty that the country encountered in foreign trade during. the Depression and the two world wars, the influente of the Prebish thesis, and the dominance of two sector models (Rannis & Fei 1961 and Jorgenson 1969) as the basis for development policies
Impact of pairing correlations on the chemical composition of the inner crust of a neutron star
We investigate the impact of the role of pairing correlation on the energy per particles of Wigner-Seitz cells in the inner crust of a neutron star. In particular, we compare some common approximations done to treat pairing effects and we estimate the possible error. To reduce the computational cost of the calculations required to determine the chemical composition of the crust, we present a new numerical method based on Gaussian Emulator Process
Near-infrared spectroscopy study of tourniquet-induced forearm ischaemia in patients with coronary artery disease
Near-Infrared Spectroscopy (NIR) can be employed to monitor local changes in haemodynamics and oxygenation of human tissues. A preliminary study has been performed in order to evaluate the NIRS transmittance response to induced forearm ischaemia in patients with coronary artery disease (CAD). The population consists in 40 patients with cardiovascular risk factors and angiographically documented CAD, compared to a group of 13 normal subjects. By inflating and subsequently deflating a cuff placed around the patient arm, an ischaemia has been induced and released, and the patients have been observed until recovery of the basal conditions. A custom LAIRS spectrometer (IRIS) has been used to collect the backscattered light intensities from the patient forearm throughout the ischaemic and the recovery phase. The time dependence of the near-infrared transmittance on the control group is consistent with the available literature. On the contrary, the magnitude and dynamics of the NIRS signal on the CAD patients show deviations from the documented normal behavior, which can be tentatively attributed to abnormal vessel stiffness. These preliminary results, while validating the performance of the IRIS spectrometer, are strongly conducive towards the applicability of the NIRS technique to ischaemia analysis and to endothelial dysfunction characterization in CAD patients with cardiovascular risk factors.Publisher PD
Radiogenomics in clear cell renal cell carcinoma: correlations between advanced CT imaging (texture analysis) and microRNAs expression
Purpose: A relevant challenge for the improvement of clear cell renal cell carcinoma management could derive from the identification of novel molecular biomarkers that could greatly improve the diagnosis, prognosis, and treatment choice of these neoplasms. In this study, we investigate whether quantitative parameters obtained from computed tomography texture analysis may correlate with the expression of selected oncogenic microRNAs. Methods: In a retrospective single-center study, multiphasic computed tomography examination (with arterial, portal, and urographic phases) was performed on 20 patients with clear cell renal cell carcinoma and computed tomography texture analysis parameters such as entropy, kurtosis, skewness, mean, and standard deviation of pixel distribution were measured using multiple filter settings. These quantitative data were correlated with the expression of selected microRNAs (miR-21-5p, miR-210-3p, miR-185-5p, miR-221-3p, miR-145-5p). Both the evaluations (microRNAs and computed tomography texture analysis) were performed on matched tumor and normal corticomedullar tissues of the same patients cohort. Results: In this pilot study, we evidenced that computed tomography texture analysis has robust parameters (eg, entropy, mean, standard deviation) to distinguish normal from pathological tissues. Moreover, a higher coefficient of determination between entropy and miR-21-5p expression was evidenced in tumor versus normal tissue. Interestingly, entropy and miR-21-5p show promising correlation in clear cell renal cell carcinoma opening to a radiogenomic strategy to improve clear cell renal cell carcinoma management. Conclusion: In this pilot study, a promising correlation between microRNAs and computed tomography texture analysis has been found in clear cell renal cell carcinoma. A clear cell renal cell carcinoma can benefit from noninvasive evaluation of texture parameters in adjunction to biopsy results. In particular, a promising correlation between entropy and miR-21-5p was found
Linear response of light deformed nuclei investigated by self-consistent quasiparticle random-phase-approximation
We present a calculation of the properties of vibrational states in deformed,
axially--symmetric even--even nuclei, within the framework of a fully
self--consistent Quasparticle Random Phase Approximation (QRPA). The same
Skyrme energy density and density-dependent pairing functionals are used to
calculate the mean field and the residual interaction in the particle-hole and
particle-particle channels. We have tested our software in the case of
spherical nuclei against fully self consistent calculations published in the
literature, finding excellent agreement. We investigate the consequences of
neglecting the spin-orbit and Coulomb residual interactions in QRPA.
Furthermore we discuss the improvement obtained in the QRPA result associated
with the removal of spurious modes. Isoscalar and isovector responses in the
deformed Mg, Mg isotopes are presented and compared to
experimental findings
Local chiral interactions and magnetic structure of few-nucleon systems
The magnetic form factors of H, H, and He, deuteron
photodisintegration cross sections at low energies, and deuteron threshold
electrodisintegration cross sections at backward angles in a wide range of
momentum transfers, are calculated with the chiral two-nucleon (and
three-nucleon) interactions including intermediate states that have
recently been constructed in configuration space. The =3 wave
functions are obtained from hyperspherical-harmonics solutions of the
Schr\"odinger equation. The electromagnetic current includes one- and two-body
terms, the latter induced by one- and two-pion exchange (OPE and TPE,
respectively) mechanisms and contact interactions. The contributions associated
with intermediate states are only retained at the OPE level, and are
neglected in TPE loop (tree-level) corrections to two-body (three-body) current
operators. Expressions for these currents are derived and regularized in
configuration space for consistency with the interactions. The low-energy
constants that enter the contact few-nucleon systems. The predicted form
factors and deuteron electrodisintegration cross section are in excellent
agreement with experiment for momentum transfers up to 2--3 fm. However,
the experimental values for the deuteron photodisintegration cross section are
consistently underestimated by theory, unless use is made of the Siegert form
of the electric dipole transition operator. A complete analysis of the results
is provided, including the clarification of the origin of the aforementioned
discrepancy.Comment: 24 pages, 13 figure
Are there localized saddles behind the heterogeneous dynamics of supercooled liquids?
We numerically study the interplay between heterogeneous dynamics and
properties of negatively curved regions of the potential energy surface in a
model glassy system. We find that the unstable modes of saddles and
quasi-saddles undergo a localization transition close to the Mode-Coupling
critical temperature. We also find evidence of a positive spatial correlation
between clusters of particles having large displacements in the unstable modes
and dynamical heterogeneities.Comment: 7 pages, 3 figures, submitted to Europhys. Let
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