1,007 research outputs found
Consumption and habits : evidence from panel data
The purpose of this paper is to test for the presence of habit formation in consumption decisions using household panel data. We use the test proposed by Meghir and Weber (1996) and estimate the within -period marginal rate of substitution between commodities, which is robust to the presence of liquidity constraints. To that end, we use a Spanish panel data set in which households are observed up to eight consecutive quarters. This temporal dimension is crucial, since it allows us to take into account time invariant unobserved heterogeneity across households ("fixed effects") and, therefore, to investigate if the relationship between current and past consumption reflects habits or heterogeneity. Our results conf irm the importance of accounting for fixed effects when analyzing intertemporal consumption decisions allowing for time non-separabilities. Once fixed effects are controlled for and a proper set of instruments is used, the results yield supporting evidence of habit formation in the demand system of food at home, transport and services
CONSUMPTION AND HABITS: EVIDENCE FROM PANEL DATA
The purpose of this paper is to test for the presence of habit formation in consumption decisions using household panel data. We use the test proposed by Meghir and Weber (1996) and estimate the within -period marginal rate of substitution between commodities, which is robust to the presence of liquidity constraints. To that end, we use a Spanish panel data set in which households are observed up to eight consecutive quarters. This temporal dimension is crucial, since it allows us to take into account time invariant unobserved heterogeneity across households (âfixed effectsâ) and, therefore, to investigate if the relationship between current and past consumption reflects habits or heterogeneity. Our results conf irm the importance of accounting for fixed effects when analyzing intertemporal consumption decisions allowing for time non-separabilities. Once fixed effects are controlled for and a proper set of instruments is used, the results yield supporting evidence of habit formation in the demand system of food at home, transport and services.
Necropolitics in Sinan Antoonâs The Corpse Washer
Sinan Antoonâs The Corpse Washer (2013) constitutes an account of post-war Iraq narrated by an Iraqi youth and authored by an Iraqi Ă©migrĂ©. It is thus a valuable alternative to American fiction on the conflict and its aftermath. From this premise, this article explores how the myth of the trauma hero, which has whitewashed the American invasion in redemptive terms, is here replaced by a more nuanced discourse. Mbembeâs necropoliticsâi.e. the âsubjugation of life to the power of deathâ (2003: 39)âhelps explain the story of Jawad, the corpse washer of the title, and of Iraq as one of dehumanization, wounding and spatialization inflicted by Western supremacy and alleged ârationality.â The novel challenges Western necropolitics in two main ways: Iraqi stereotypes are questioned, especially their identification with terrorism and martyrdom. On the other hand, surrealism and gothic elements help the protagonist and his country to sublimate the trauma derived from American neocolonial politics
Femtosecond time-resolved phase-change microscopy and ablation threshold calculations to understand ultrafast laser ablation
El trabajo recoge experimentos realizados en una configuraciĂłn sonda-prueba haciendo uso de un lĂĄser de femtosegundos, con el objetivo de comprender los fenĂłmenos de ablaciĂłn de materiales sĂłlidos ras irradiaciĂłn con lĂĄseres de pulso ultracorto.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tech
Novel approaches to determine residual stresses by ultramicroindentation techniques: application to sand blasted austenitic stainless steel
This research addresses the determination of residual stresses in sandblasted austenitic steel by ultramicroindentation techniques using a sharp indenter, whose sensitivity to residual stress effects is said to be inferior to that for spherical ones. We propose the introduction of an angular correction in the model of Wang et al. that relates variations in the maximum load to the presence of residual stresses. Likewise, the contribution to hardness of grain size refinement and work hardening, developed as a consequence of the severe plastic deformation during blasting, is determined to avoid overestimation of the residual stresses. Measurements were performed on polished cross sections along a length of several microns, thus obtaining a profile of the residual stresses. Results show a good agreement with those obtained by synchrotron radiation on the same specimens, which validates the method and demonstrates that microindentation using sharp indenters may be sensitive to the residual stress effect.Peer Reviewe
Analytic description of the scattering of electrons by molecules
The scattering of electrons by molecules is considered. The structure of the molecule is described in terms of the vibron model, which is an algebraic approach to the description of rotational and vibrational molecular excitations. The dynamics of electron-molecule collision is discussed in terms of coupled-channel calculations, where we assume an isocentrifugal approximation. In the sudden limit, where the excitation energies of the molecule are neglected, the coupled-channel system decouples into eigenchannels. The scattering amplitudes of the eigenchannels, characterized by 1/r2 potentials, are obtained analytically. The resulting probabilities of excitation of the molecular states and the limiting values of the quasielastic cross sections are evaluated in the U(3) and the O(4) limits. A comparison of the results for the differential cross sections with experimental data and other calculations is made for LiF and KI.DirecciĂłn General de InvestigaciĂłn CientĂfica y TĂ©cnica PB92-06
A Multiple System of Radio Sources at the Core of the L723 Multipolar Outflow
We present high angular resolution Very Large Array multi-epoch continuum
observations at 3.6 cm and 7 mm towards the core of the L723 multipolar outflow
revealing a multiple system of four radio sources suspected to be YSOs in a
region of only ~4 arcsecs (1200 AU) in extent. The 3.6 cm observations show
that the previously detected source VLA 2 contains a close (separation ~0.29
arcsecs or ~90 AU) radio binary, with components (A and B) along a position
angle of ~150 degrees. The northern component (VLA 2A) of this binary system is
also detected in the 7 mm observations, with a positive spectral index between
3.6 cm and 7 mm. In addition, the source VLA 2A is associated with extended
emission along a position angle of ~115 degrees, that we interpret as
outflowing shock-ionized gas that is exciting a system of HH objects with the
same position angle. A third, weak 3.6 cm source, VLA 2C, that is detected also
at 7 mm, is located ~0.7 arcsecs northeast of VLA 2A, and is possibly
associated with the water maser emission in the region. The 7 mm observations
reveal the presence of an additional source, VLA 2D, located ~3.5 arcsecs
southeast of VLA 2A, and with a 1.35 mm counterpart. All these radio continuum
sources have a positive spectral index, compatible with them being YSOs. We
also propose that the high velocity CO emission observed in the region could be
the superposition of multiple outflows (at least three independent bipolar
outflows) excited by the YSOs located at the core, instead of the previous
interpretations in terms of only one or two outflows.Comment: Accepted for publication in The Astrophysical Journal (2007 December
6
Spain and the crisis: housing prices, credit, and macroprudential policies
In this paper, we propose a two-country, two sector monetary union DSGE model with housing. One of the countries is calibrated to represent the Spanish economy while the other one is the rest of the European monetary union. First, we illustrate how looser credit conditions coming from the Euro area, together with increases in housing demand, lead to an increase in house prices and credit in Spain. Then, we analyze to what extent, macroprudential policies could have avoided the excess in credit that triggered the financial crisis in Spain. We find that a countercyclical loan-to-value rule that mainly responds to house prices would have mitigated the credit boom in Spain. These results can also be applied to other countries facing similar problems in the housing sector and thinking about implementing macroprudential policies
RNA nuclear export is blocked by poliovirus 2A protease and is concomitant with nucleoporin cleavage
Cytopathic viruses have developed successful strategies to block
or, at least, to attenuate host interference with their replication.
Here, we have analyzed the effects of poliovirus 2A protease on
RNA nuclear export. 2A protease interferes with trafficking of
mRNAs, rRNAs and U snRNAs from the nucleus to the
cytoplasm, without any apparent effect on tRNA transport.
Traffic of newly produced mRNAs is more strongly affected than
traffic of other mRNAs over-represented in the cytoplasm, such
as mRNA encoding ïą-actin. Inhibition of RNA nuclear export
in HeLa cells expressing 2A protease is concomitant with the
cleavage of Nup98, Nup153, Nup62 and their subsequent
subcellular redistribution. The expression of an inactive 2A
protease failed to interfere with RNA nuclear export. In
addition, other related proteases, such as poliovirus 3C or foot
and mouth disease virus Lpro did not affect mRNA distribution
or Nup98 integrity. Treatment of HeLa cells with interferon
(IFN)-ï§ increased the relative amount of Nup98. Under such
conditions, the cleavage of Nup98 induced by 2A protease is
partial, and thus IFN-ï§ prevents the inhibition of RNA nuclear
export. Taken together, these results are consistent with a
specific proteolysis of Nup98 by 2A protease to prevent de novo
mRNA traffic in poliovirus-infected cells.Peer reviewe
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