3,208 research outputs found
Complete factorization of equations of motion for generalized scalar field theories
We demonstrate that the complete factorization of equations of motion into
first-order differential equations can be obtained for real and complex scalar
field theories with non-canonical dynamics.Comment: 5 pages; version published in EP
Health status and retirement decisions for older European couples
In this paper we use data the European Community Household Panel (ECHP) to describe and analyse the dynamics of joint labour force behaviour of older couples for the EU12 countries. We focus on three main issues: the relevance of joint retirement across EU12 countries, the existence of complementarities in leisure and/or assortative matting and the effects of health variables. Concerning the evidence, we first find that a working spouse is more likely to retire the more recently the other spouse has retired; this effect is stronger if the wife is the working spouse. Second, there is evidence of assortative mating and/or complementarities in leisure; the effects of all relevant factors on the retirement decision of one spouse depend strongly on whether the other one is working, unemployed, or retired. Third, besides the standard evidence that poor health increases the retirement probability, we find that the husband's health affects the couple's retirement decisions much more strongly than the wife's health does. Additional asymmetric effects are detected with respect to income related variables.joint retirement decisions ; labour force transitions ; health variables ; asymmetric effects
Slow light in molecular aggregates nanofilms
We study slow light performance of molecular aggregates arranged in nanofilms
by means of coherent population oscillations (CPO). The molecular cooperative
behavior inside the aggregate enhances the delay of input signals in the GHz
range in comparison with other CPO-based devices. Moreover, the problem of
residual absorption present in CPO processes, is removed. We also propose an
optical switch between different delays by exploiting the optical bistability
of these aggregates.Comment: 4 pages, 4 figure
An Empirical Analysis of the Demand for Physician Services Across the European Union
This paper presents parameter estimates for physician services equations using the European Community Household Panel for 12 countries covering the period 1994-1996. The focus is on two specific points: i) the identification of behavioural similarities and differences in the demand for health across the countries; ii) the variability of the demand for health captured through a joint model for all the countries. We find that there are significant differences across countries, although there are also similarities in the effect of variables such as the health stock, labour situation or family structure. An important fraction of the variability of the demand of health services across countries could be explained from differences in age, income, and the role of General Practitioners (GP) as a gatekeepers in the public health system. We also find some evidence of induced demand effects in both the decision to visit and the number of visits to specialists.count data; demand; physician services; latent class model; two-part model
Health status and retirement decisison for older european couples.
In this paper we use data the European Community Household Panel (ECHP) to describe and analyse the dynamics of joint labour force behaviour of older couples for the EUI2 countries. We focus on three main issues: the relanvance of joint retirement across EUI2 countries, the existence of complementarities in leisure and/or assortative matting and the effects of health variables. Concerning the evidence, we first find that a working spouse is more likely to retire the more recently the other spouse has retired; this effect is stronger if the wife is the working spouse. Second, there is evidence of assortative mating and/or complementarities in leisure; the effects of all relevant factors on the retirement decision of one spouse depend strongly on whether the other one is working, unemployed, or retired. Third, besides the standard evidence that poor health increases the retirement probabiliby, we find that the husband's health affects the couple's retirement decisions much more strongly than the wife's health does. Additional asymmetric effects are detected with respect to income related variables.Joint retirement decisions; Labour force transitions; Health variables; Asymmetric effects;
Investigation of element-specific and bulk magnetism, electronic and crystal structures of La{0.70}Ca{0.30}Mn{1-x}Cr{x}O{3}
The magnetic interactions in La{0.70}Ca{0.30}Mn{1-x}Cr{x}O{3} (x = 0.15, 0.50
and 0.70) are investigated by x-ray absorption spectroscopy (XAS), x-ray
magnetic circular dichroism (XMCD), high-resolution x-ray powder diffraction,
and bulk magnetization measurements. XAS in the Mn and Cr L{2,3} edges support
stable single valent Cr{3+} ions and a varying Mn valence state with x, while
the O K edge XAS spectrum reveals local maxima in the O 2p density of states
close to the Fermi level due to mixing with Mn and Cr 3d states. A robust
antiferromagnetic state is found for x=0.70 below TN = 258 K. For x=0.15,
combined XMCD and bulk magnetization measurements indicate a fully polarized
ferrimagnetic state for the Mn and Cr spins below Tc=224 K. For x=0.50, a
reduced ferrimagnetic component dominated by Mn spins is present below Tc=154
K. No evidence of lattice anomalies due to cooperative charge and orbital
orderings is found by x-ray diffraction for all samples. The magnetic
properties of this system are rationalized in terms of a competition of
ferromagnetic Mn-Mn double exchange and antiferromagnetic Cr-Cr and Cr-Mn
superexchange interactions.Comment: 25 pages, 9 figure
Renormalization aspects of N=1 Super Yang-Mills theory in the Wess-Zumino gauge
The renormalization of N=1 Super Yang-Mills theory is analysed in the
Wess-Zumino gauge, employing the Landau condition. An all orders proof of the
renormalizability of the theory is given by means of the Algebraic
Renormalization procedure. Only three renormalization constants are needed,
which can be identified with the coupling constant, gauge field and gluino
renormalization. The non-renormalization theorem of the gluon-ghost-antighost
vertex in the Landau gauge is shown to remain valid in N=1 Super Yang-Mills.
Moreover, due to the non-linear realization of the supersymmetry in the
Wess-Zumino gauge, the renormalization factor of the gauge field turns out to
be different from that of the gluino. These features are explicitly checked
through a three loop calculation.Comment: 15 pages, minor text improvements, references added. Version accepted
for publication in the EPJ
Parenting style: influence on gifted children psychological adjustment
Este trabajo se centra en las influencias positivas y negativas de la práctica educativa que los padres ejercen sobre el desarrollo de los niños con altas capacidades. El resultado de este estudio teĂłrico muestra que las familias cuyas caracterĂsticas esenciales están basadas en una dinámica de funcionamiento en la que priman la armonĂa y la coherencia se asocian tanto al desarrollo Ăłptimo intelectual y de la autoestima como al adecuado funcionamiento emocional e intelectual. En contraste, las familias en las que la falta de coherencia y la existencia de una dinámica de funcionamiento caracterizada por bajos niveles de comunicaciĂłn, afecto y control del comportamiento se asocian a la apariciĂłn de comportamientos de riesgo. De acuerdo con la literatura existente, las prácticas educativas más efectivas para el ajuste y bienestar de niños y adolescentes son las autoritativas. En el caso de los niños con altas capacidades, la mayorĂa de los padres se muestran acordes con estas prácticas de crianza aunque en algunos casos se han encontrado diferencias en las pautas de actuaciĂłn de madres y padres. Los determinantes parentales que potencian el ajuste positivo de los hijos con altas capacidades son: nivel intelectual, nivel educativo y rendimiento acadĂ©mico alto, y en ausencia de estas caracterĂsticas, interĂ©s de los padres hacia la educaciĂłn y el aprendizaje.This paper focused on influence of parenting practice on gifted children´s development. The result of this study showed that harmony and coherent families are associated both to self-stem, effective intellectual development and social and emotional functioning. In contrast, family discord relates to risk behaviour. According to literature, the most effective parenting practice for children development is authoritative, In gifted children case, most of the parents showed educative patterns framed in the authoritative parenting style although in some cases it was found differences between mother and father. Parents determinants making possible positive adjustement in their gifted children are: high intellectual level, high school achievement and high level of school performance. In absence of this, parent´s high interest on education and learning act as a substitute of these last cognitive and educational characteristics.peerReviewe
Implementing the Gribov-Zwanziger framework in N=1 Super Yang-Mills in the Landau gauge
The Gribov-Zwanziger framework accounting for the existence of Gribov copies
is extended to N=1 Super Yang--Mills theories quantized in the Landau gauge. We
show that the restriction of the domain of integration in the Euclidean
functional integral to the first Gribov horizon can be implemented in a way to
recover non-perturbative features of N=1 Super Yang--Mills theories, namely:
the existence of the gluino condensate as well as the vanishing of the vacuum
energy.Comment: 19 pages, no figure
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