Exploration and confirmation of the latent variable structure of the Jefferson scale of empathy.

OBJECTIVE: To reaffirm the underlying components of the JSE by using exploratory factor analysis (EFA), and to confirm its latent variable structure by using confirmatory factor analysis (CFA). METHODS: Research participants included 2,612 medical students who entered Jefferson Medical College between 2002 and 2012. This sample was divided into two groups: Matriculants between 2002 and 2007 (n=1,380) and be-tween 2008 and 2012 (n=1,232). Data for 2002-2007 matriculants were subjected to EFA (principal component factor extraction), and data for matriculants of 2008-2012 were used for CFA (structural equation modeling, and root mean square error for approximation. RESULTS: The EFA resulted in three factors: perspective-taking, compassionate care and walking in patient\u27s shoes replicating the 3-factor model reported in most of the previous studies. The CFA showed that the 3-factor model was an acceptable fit, thus confirming the latent variable structure emerged in the EFA. Corrected item-total score correlations for the total sample were all positive and statistically significant, ranging from 0.13 to 0.61 with a median of 0.44 (p=0.01). The item discrimination effect size indices (contrasting item mean scores for the top-third versus bottom-third JSE scorers) ranged from 0.50 to 1.4 indicating that the differences in item mean scores between top and bottom scorers on the JSE were of practical importance. Cronbach\u27s alpha coefficient of the JSE for the total sample was 0.80, ranging from 0.75 to 0.84 for matriculatnts of different years. CONCLUSIONS: Findings provided further support for under-lying constructs of the JSE, adding to its credibility

Validation of the World Health Organization-5 well-being index; assessment of maternal well-being and its associated factors

Objective: The aim of this study was to validate the World Health Organization-5 Well-Being Index (WHO-5) in a sample of pregnant Iranian women, to explore the changes in maternal well-being from pregnancy to postpartum, and to determine the factors associated with maternal well-being. Materials and Methods: This study included 341 pregnant women that presented to healthcare centers affiliated with Shahroud University of Medical Sciences, Iran, in 2011. The participants completed the General Health Questionnaire (GHQ-28) and Farsi version of WHO-5 during the third trimester of pregnancy and at 2 months postpartum. Results: Cronbach's alpha coefficient for WHO-5 items was 0.85. The correlation coefficient between WHO-5 and GHQ-28 was -0.64 (P < 0.001). Exploratory factor analysis yielded 1 factor with an eigen value equal to 3.15, which explained 63.1% of the total variance. Confirmatory factor analysis confirmed the 1-factor structure. The area under ROC curve was 0.82. A WHO-5 cut-off score of <50 exhibited optimal sensitivity (0.84) and specificity (0.59) for identifying psychological symptoms (GHQ-28 score ≥24). There was a significant difference between third trimester (58.4 ± 22) and postpartum (64.1 ± 22.3) mean WHO-5 scores (P < 0.001). Maternal level of education (OR = 1.130; 95% CI: 1.307, 1.232) was the only predictor of maternal well-being during third trimester. Breastfeeding difficulty (OR = 0.923; 95% CI: 0.882, 0.965) and maternal well-being scores during third trimester (OR = 1.038; 95% CI: 1.019, 1.058) were predictors of maternal well-being during the postpartum period. Conclusions: The Farsi version of WHO-5 was observed to be a reliable and valid instrument for screening psychological symptoms in pregnant Iranian women. The present findings show that maternal well-being improved following childbirth

Third quantization of f(R)f(R)-type gravity

We examine the third quantization of $f(R)$-type gravity, based on its effective Lagrangian in the case of a flat Friedmann-Lemaitre-Robertson-Walker metric. Starting from the effective Lagrangian, we execute a suitable change of variable and the second quantization, and we obtain the Wheeler-DeWitt equation. The third quantization of this theory is considered. And the uncertainty relation of the universe is investigated in the example of $f(R)$-type gravity, where $f(R)=R^2$. It is shown, when the time is late namely the scale factor of the universe is large, the spacetime does not contradict to become classical, and, when the time is early namely the scale factor of the universe is small, the quantum effects are dominating.Comment: 9 pages, Arbitrary constants in (4.19) are changed to arbitrary functions of $\varphi$. Conclusions are not changed. References are added. Typos are correcte

Third-order relativistic dissipative hydrodynamics

Following the procedure introduced by Israel and Stewart, we expand the entropy current up to the third order in the shear stress tensor $\pi^{\alpha\beta}$ and derive a novel third-order evolution equation for $\pi^{\alpha\beta}$. This equation is solved for the one-dimensional Bjorken boost-invariant expansion. The scaling solutions for various values of the shear viscosity to the entropy density ratio $\eta/s$ are shown to be in very good agreement with those obtained from kinetic transport calculations. For the pressure isotropy starting with 1 at $\tau_0=0.4 fm/c$, the third-order corrections to Israel-Stewart theory are approximately 10\% for $\eta/s=0.2$ and more than a factor of 2 for $\eta/s=3$. We also estimate all higher-order corrections to Israel-Stewart theory and demonstrate their importance in describing highly viscous matters.Comment: Version published in Phys.Rev.C. 5 pages, 1 figur

Quantum detectors for the third cumulant of current fluctuations

We consider the measurement of the third cumulant of current fluctuations arising from a point contact, employing the transitions that they cause in a quantum detector connected to the contact. We detail two generic detectors: a quantum two-level system and a harmonic oscillator. In these systems, for an arbitrary relation between the voltage driving the point contact and the energy scales of the detectors, the results can be expressed in terms of an effective detector temperature T_eff. The third cumulant can be found from the dependence of T_eff on the sign of the driving voltage. We find that proper ordering of the fluctuation operators is relevant in the analysis of the transition rates. This is reflected in the effective Fano factor for the third cumulant measured in such setups: it depends on the ratio of the voltage and an energy scale describing the circuit where the fluctuations are produced.Comment: 12+ pages, 8 figure

A 2-MHz 2-kW voltage-source inverter for low-temperature plasma generators: implementation of fast switching with a third-order resonant circuit

This paper presents a specially designed third-order resonant circuit intended to achieve fast switching operation for a voltage-source series-resonant inverter using four MOSFETs. The third-order resonant current superimposed on a sinusoidal load current helps to quickly charge or discharge the output capacitance of each MOSFET. This results not only in a reduction of the commutation period which is required to turn the MOSFET on and off, but also in an improvement of the displacement factor at the output of the inverter. Moreover, the third-order resonant circuit acts as a low-pass filter to suppress the parasitic oscillation between line inductance and stray capacitance. The viability and effectiveness of the third-order resonant circuit is verified by a 2 MHz 2 kW prototype inverter developed for a low-temperature plasma generator </p