A satisfação vital: sua relação com o preconceito, a identidade nacional, a autoestima e o bem-estar material, em imigrantes

El propósito de esta investigación fue estudiar la relación de la satisfacción vital con varios factores psicosociales corrientemente vinculados a los procesos de migración internacional. En concreto, este estudio exploró la relación de la satisfacción vital - componente cognitivo del bienestar subjetivo - con las variables prejuicio grupal percibido, discriminación personal percibida, autoestima global personal, identidad nacional y bienestar material percibido. La investigación, de tipo empírico y cuantitativo, se realizó a través de un muestreo no probabilístico con inmigrantes colombianos en varias ciudades del Ecuador (N = 185). Confirmando las hipótesis, se halló una relación positiva entre la satisfacción vital, el bienestar material percibido y la autoestima. Se confirmó así mismo una relación negativa entre la satisfacción vital, la discriminación personal percibida y la identidad nacional. Estas mismas variables; la autoestima, el bienestar material percibido, la discriminación personal percibida y la identidad nacional, emergieron como predictoras de la satisfacción vital. No se confirmó, en cambio, la relación negativa hipotetizada entre la satisfacción vital y el prejuicio grupal percibido. Se hace un análisis de dichos resultados desde la literatura psicosocial.O propósito desta pesquisa foi estudar a relação da satisfação vital com vários fatores psicossociais correntemente vinculados aos processos de migração internacional. Em concreto, este estudo explorou a relação da satisfação vital - componente cognitivo do bem-estar subjetivo - com as variáveis preconceito grupal percebido, discriminação pessoal percebida, autoestima global pessoal, identidade nacional e bem-estar material percebido. A pesquisa, de tipo empírica e quantitativa, foi realizada através de um amostra não probabilística com imigrantes colombianos em várias cidades do Equador (N = 185). Confirmando as hipóteses, foi encontrada uma relação positiva entre a satisfação vital, o bem-estar material percebido e a autoestima. Foi confirmada assim uma relação negativa entre a satisfação vital, a discriminação pessoal percebida e a identidade nacional. Estas mesmas variáveis; a autoestima, o bem-estar material percebido, a discriminação pessoal percebida e a identidade nacional, emergiram como preditoras da satisfação vital. Contudo, não foi confirmada a relação negativa hipotética entre a satisfação vital e o preconceito grupal percebido. É feita uma análise desses resultados desde a literatura psicossocial.The aim of this research was to study the relationship between life satisfaction and various psychosocial variables usually linked to international migration processes. Specifically, this study explored the relationship between life satisfaction-a cognitivedimension of subjective well-being- and perceived group prejudice, perceived personal discrimination, global personal self-esteem, national identity and perceived material well- being. The research, of empirical quantitative type, was conducted with a non-probabilistic sample of Colombian migrants at several cities of Ecuador. As expected, the hypothesis that life satisfaction was positively related to self -esteem and perceived material well-being was confirmed. Also, a negative correlation was confirmed between life satisfaction, perceived personal discrimination and national identity. Results show that the variables self-esteem, perceived material well-being, perceived personal discrimination and national identity are significant predictors of life satisfaction. Findings didn´t confirm the expected negative association between life satisfaction and perceived group prejudice. Results are analyzed from a psychosocial perspective

UNITED STATES-LATIN AMERICAN TRADE RELATIONS: IMPORTANCE TO U.S. AGRICULTURAL POLICY DECISIONS

International Relations/Trade,

The Role of Regional Connections in Planning for Future Power System Operations Under Climate Extremes

Identifying the sensitivity of future power systems to climate extremes must consider the concurrent effects of changing climate and evolving power systems. We investigated the sensitivity of a Western U.S. power system to isolated and combined heat and drought when it has low (5%) and moderate (31%) variable renewable energy shares, representing historic and future systems. We used an electricity operational model combined with a model of historically extreme drought (for hydropower and freshwater-reliant thermoelectric generators) over the Western U.S. and a synthetic, regionally extreme heat event in Southern California (for thermoelectric generators and electricity load). We found that the drought has the highest impact on summertime production cost (+10% to +12%), while temperature-based deratings have minimal effect (at most +1%). The Southern California heat wave scenario impacting load increases summertime regional net imports to Southern California by 10–14%, while the drought decreases them by 6–12%. Combined heat and drought conditions have a moderate effect on imports to Southern California (−2%) in the historic system and a stronger effect (+8%) in the future system. Southern California dependence on other regions decreases in the summertime with the moderate increase in variable renewable energy (−34% imports), but hourly peak regional imports are maintained under those infrastructure changes. By combining synthetic and historically driven conditions to test two infrastructures, we consolidate the importance of considering compounded heat wave and drought in planning studies and suggest that region-to-region energy transfers during peak periods are key to optimal operations under climate extremes

Cosmological Magnetic Fields from Primordial Helicity

Primordial magnetic fields may account for all or part of the fields observed in galaxies. We consider the evolution of the magnetic fields created by pseudoscalar effects in the early universe. Such processes can create force-free fields of maximal helicity; we show that for such a field magnetic energy inverse cascades to larger scales than it would have solely by flux freezing and cosmic expansion. For fields generated at the electroweak phase transition, we find that the predicted wavelength today can in principle be as large as 10 kpc, and the field strength can be as large as 10^{-10} G.Comment: 13 page

The Cosmic Microwave Background and Helical Magnetic Fields: the tensor mode

We study the effect of a possible helicity component of a primordial magnetic field on the tensor part of the cosmic microwave background temperature anisotropies and polarization. We give analytical approximations for the tensor contributions induced by helicity, discussing their amplitude and spectral index in dependence of the power spectrum of the primordial magnetic field. We find that an helical magnetic field creates a parity odd component of gravity waves inducing parity odd polarization signals. However, only if the magnetic field is close to scale invariant and if its helical part is close to maximal, the effect is sufficiently large to be observable. We also discuss the implications of causality on the magnetic field spectrum.Comment: We have corrected a normalisation error which was pointed out to us by Antony Lewis. It enhances our limits on the magnetic fields by (2\pi)^{3/4} ~

On the variation of the gauge couplings during inflation

It is shown that the evolution of the (Abelian) gauge coupling during an inflationary phase of de Sitter type drives the growth of the two-point function of the magnetic inhomogeneities. After examining the constraints on the variation of the gauge coupling arising in a standard model of inflationary and post-inflationary evolution, magnetohydrodynamical equations are generalized to the case of time evolving gauge coupling. It is argued that large scale magnetic fields can be copiously generated. Other possible implications of the model are outlined.Comment: 5 pages in RevTex style, one figur

Large-scale magnetic fields from inflation in dilaton electromagnetism

The generation of large-scale magnetic fields is studied in dilaton electromagnetism in inflationary cosmology, taking into account the dilaton's evolution throughout inflation and reheating until it is stabilized with possible entropy production. It is shown that large-scale magnetic fields with observationally interesting strength at the present time could be generated if the conformal invariance of the Maxwell theory is broken through the coupling between the dilaton and electromagnetic fields in such a way that the resultant quantum fluctuations in the magnetic field has a nearly scale-invariant spectrum. If this condition is met, the amplitude of the generated magnetic field could be sufficiently large even in the case huge amount of entropy is produced with the dilution factor $\sim 10^{24}$ as the dilaton decays.Comment: 28 pages, 5 figures, the version accepted for publication in Phys. Rev. D; some references are adde

Equation of State of Oscillating Brans-Dicke Scalar and Extra Dimensions

We consider a Brans-Dicke scalar field stabilized by a general power law potential with power index $n$ at a finite equilibrium value. Redshifting matter induces oscillations of the scalar field around its equilibrium due to the scalar field coupling to the trace of the energy momentum tensor. If the stabilizing potential is sufficiently steep these high frequency oscillations are consistent with observational and experimental constraints for arbitrary value of the Brans-Dicke parameter $\omega$. We study analytically and numerically the equation of state of these high frequency oscillations in terms of the parameters $\omega$ and $n$ and find the corresponding evolution of the universe scale factor. We find that the equation of state parameter can be negative and less than -1 but it is not related to the evolution of the scale factor in the usual way. Nevertheless, accelerating expansion is found for a certain parameter range. Our analysis applies also to oscillations of the size of extra dimensions (the radion field) around an equilibrium value. This duality between self-coupled Brans-Dicke and radion dynamics is applicable for $\omega= -1 + 1/D$ where D is the number of extra dimensions.Comment: 10 two-column pages, RevTex4, 8 figures. Added clarifying discussions, new references. Accepted in Phys. Rev. D (to appear

Large scale magnetogenesis from a non-equilibrium phase transition in the radiation dominated era

We study the generation of large scale primordial magnetic fields by a cosmological phase transition during the radiation dominated era. The setting is a theory of N charged scalar fields coupled to an abelian gauge field, that undergoes a phase transition at a critical temperature much larger than the electroweak scale. The dynamics after the transition features two distinct stages: a spinodal regime dominated by linear long-wavelength instabilities, and a scaling stage in which the non-linearities and backreaction of the scalar fields are dominant. This second stage describes the growth of horizon sized domains. We implement a recently introduced formulation to obtain the spectrum of magnetic fields that includes the dissipative effects of the plasma. We find that large scale magnetogenesis is very efficient during the scaling regime. The ratio between the energy density on scales larger than L and that in the background radiation r(L,T) = rho_B(L,T)/rho_{cmb}(T) is r(L,T) \sim 10^{-34} at the Electroweak scale and r(L,T) \sim 10^{-14} at the QCD scale for L \sim 1 Mpc. The resulting spectrum is insensitive to the magnetic diffusion length. We conjecture that a similar mechanism could be operative after the QCD chiral phase transition.Comment: LaTex, 25 pages, no figures, to appear in Phys. Rev.

Magnetic field generation from non-equilibrium phase transitions

We study the generation of magnetic fields during the stage of particle production resulting from spinodal instabilities during phase transitions out of equilibrium. The main premise is that long-wavelength instabilities that drive the phase transition lead to strong non-equilibrium charge and current fluctuations which generate electromagnetic fields. We present a formulation based on the non-equilibrium Schwinger-Dyson equations that leads to an exact expression for the spectrum of electromagnetic fields valid for general theories and cosmological backgrounds and whose main ingredient is the transverse photon polarization out of equilibrium. This formulation includes the dissipative effects of the conductivity in the medium. As a prelude to cosmology we study magnetogenesis in Minkowski space-time in a theory of N charged scalar fields to lowest order in the gauge coupling and to leading order in the large N within two scenarios of cosmological relevance. The long-wavelength power spectrum for electric and magnetic fields at the end of the phase transition is obtained explicitly. It follows that equipartition between electric and magnetic fields does not hold out of equilibrium. In the case of a transition from a high temperature phase, the conductivity of the medium severely hinders the generation of magnetic fields, however the magnetic fields generated are correlated on scales of the order of the domain size, which is much larger than the magnetic diffusion length. Implications of the results to cosmological phase transitions driven by spinodal unstabilities are discussed.Comment: Preprint no. LPTHE 02-55, 30 pages, latex, 2 eps figures. Added one reference. To appear in Phys. Rev.