12,012 research outputs found
BIRTH OUTCOMES AND EARLY-LIFE SOCIAL CHARACTERISTICS PREDICT UNEQUAL EDUCATIONAL OUTCOMES ACROSS THE LIFECOURSE AND ACROSS GENERATIONS. DATA FROM A SWEDISH COHORT BORN 1915-1929 AND THEIR GRANDCHILDREN BORN 1973-1980
Birth characteristics and early-life social characteristics predict unequal educational outcomes across the lifecourse and across generations: Data from a Swedish cohort born 1915-1929 and their grandchildren born 1973-1980
We investigated the effects of adverse birth characteristics and social disadvantage upon educational outcomes over the lifecourse and across generations. Our subjects were 12,674 Swedish infants born 1915-1929 and 9,706 of their grandchildren born 1973-1980. Within both cohorts, better school achievement (schoolmarks in elementary school) was predicted by: heavier birthweight, lower birth order, older mother, married mother and higher family social class. These effects persisted after mutual-adjustment, and birth characteristics and family composition did not play a major role in explaining social class effects. There were no independent effects of pre-term or twin status, but weak evidence of a disadvantage to post-term infants. The predictors of education continuation (secondary school attendance and entrance to tertiary education) were very similar, with family composition and social class effects persisting even after adjusting for school achievement. In cross-generational analyses, better educational outcomes in the grandchildren were predicted by heavier birthweight, lower birth order and higher social class in the grandparents. These associations became non-significant and/or were substantially attenuated after adjusting for grandchild socio-economic position in childhood, suggesting that this was the major mechanism for this effect. We conclude that multiple early-life characteristics predict educational outcomes across the lifecourse and across generations. This includes birth characteristics and family composition effects which typically receive far less attention than socio-economic influences. Most effects were remarkably stable across the half-century separating our cohorts, suggesting their potential relevance for understanding educational inequalities in populations around the world
Anisotropic multi-gap superfluid states in nuclear matter
It is shown that under changing density or temperature a nucleon Fermi
superfluid can undergo a phase transition to an anisotropic superfluid state,
characterized by nonvanishing gaps in pairing channels with singlet-singlet
(SS) and triplet-singlet (TS) pairing of nucleons (in spin and isospin spaces).
In the SS pairing channel nucleons are paired with nonzero orbital angular
momentum. Such two-gap states can arise as a result of branching from the
one-gap solution of the self-consistent equations, describing SS or TS pairing
of nucleons, that depends on the relationship between SS and TS coupling
constants at the branching point. The density/temperature dependence of the
order parameters and the critical temperature for transition to the anisotropic
two-gap state are determined in a model with the SkP effective interaction. It
is shown that the anisotropic SS-TS superfluid phase corresponds to a
metastable state in nuclear matter.Comment: Prepared with RevTeX4, 7p., 5 fi
Systematic study of the PDC speckle structure for quantum imaging applications
Sub shot noise imaging of weak object by exploiting Parametric Down Converted
light represents a very interesting technological development. A precise
characterization of PDC speckle structure in dependence of pump beam parameters
is a fundamental tool for this application. In this paper we present a first
set of data addressed to this purpose
Density of states in an optical speckle potential
We study the single particle density of states of a one-dimensional speckle
potential, which is correlated and non-Gaussian. We consider both the repulsive
and the attractive cases. The system is controlled by a single dimensionless
parameter determined by the mass of the particle, the correlation length and
the average intensity of the field. Depending on the value of this parameter,
the system exhibits different regimes, characterized by the localization
properties of the eigenfunctions. We calculate the corresponding density of
states using the statistical properties of the speckle potential. We find good
agreement with the results of numerical simulations.Comment: 11 pages, 11 figures, revtex
Generalized Lyapunov Exponent and Transmission Statistics in One-dimensional Gaussian Correlated Potentials
Distribution of the transmission coefficient T of a long system with a
correlated Gaussian disorder is studied analytically and numerically in terms
of the generalized Lyapunov exponent (LE) and the cumulants of lnT. The effect
of the disorder correlations on these quantities is considered in weak,
moderate and strong disorder for different models of correlation. Scaling
relations between the cumulants of lnT are obtained. The cumulants are treated
analytically within the semiclassical approximation in strong disorder, and
numerically for an arbitrary strength of the disorder. A small correlation
scale approximation is developed for calculation of the generalized LE in a
general correlated disorder. An essential effect of the disorder correlations
on the transmission statistics is found. In particular, obtained relations
between the cumulants and between them and the generalized LE show that, beyond
weak disorder, transmission fluctuations and deviation of their distribution
from the log-normal form (in a long but finite system) are greatly enhanced due
to the disorder correlations. Parametric dependence of these effects upon the
correlation scale is presented.Comment: 18 pages, 11 figure
Pmp27 Promotes Peroxisomal Proliferation
Peroxisomes perform many essential functions in eukaryotic cells. The weight of evidence indicates that these organelles divide by budding from preexisting peroxisomes. This process is not understood at the molecular level. Peroxisomal proliferation can be induced in Saccharomyces cerevisiae by oleate. This growth substrate is metabolized by peroxisomal enzymes. We have identified a protein, Pmp27, that promotes peroxisomal proliferation. This protein, previously termed Pmp24, was purified from peroxisomal membranes, and the corresponding gene, PMP27, was isolated and sequenced. Prop27 shares sequence similarity with the Pmp30 family in Candida boidinii. Pmp27 is a hydrophobic peroxisomal membrane protein but it can be extracted by high pH, suggesting that it does not fully span the bilayer. Its expression is regulated by oleate. The function of Pmp27 was probed by observing the phenotype of strains in which the protein was eliminated by gene disruption or overproduced by expression from a multicopy plasmid. The strain containing the disruption (3B) was able to grow on all carbon sources tested, including oleate, although growth on oleate, glycerol, and acetate was slower than wild type. Strain 3B contained peroxisomes with all of the enzymes of β-oxidation. However, in addition to the presence of a few modestly sized peroxisomes seen in a typical thin section of a cell growing on oleate-containing medium, cells of strain 3B also contained one or two very large peroxisomes. In contrast, cells in a strain in which Pmp27 was overexpressed contained an increased number of normal-sized peroxisomes. We suggest that Pmp27 promotes peroxisomal proliferation by participating in peroxisomal elongation or fission.
Dust emission from the Perseus molecular cloud
Using far-infrared emission maps taken by IRAS and Spitzer and a near-infrared extinction map derived from 2MASS data, we have made dust temperature and column density maps of the Perseus molecular cloud. We show that the emission from transiently heated very small grains (VSGs) and the big grain dust emissivity vary as a function of extinction and dust temperature, with higher dust emissivities for colder grains. This variable emissivity cannot be explained by temperature gradients along the line of sight or by noise in the emission maps, but it is consistent with grain growth in the higher density and lower temperature regions. By accounting for the variations in the dust emissivity and VSG emission, we are able to map the temperature and column density of a nearby molecular cloud with better accuracy than has previously been possible
Competition of different coupling schemes in atomic nuclei
Shell model calculations reveal that the ground and low-lying yrast states of
the nuclei Pd and Cd are mainly built upon isoscalar
spin-aligned neutron-proton pairs each carrying the maximum angular momentum
J=9 allowed by the shell which is dominant in this nuclear region.
This mode of excitation is unique in nuclei and indicates that the spin-aligned
pair has to be considered as an essential building block in nuclear structure
calculations. In this contribution we will discuss this neutron-proton pair
coupling scheme in detail. In particular, we will explore the competition
between the normal monopole pair coupling and the spin-aligned coupling
schemes. Such a coupling may be useful in elucidating the structure properties
of and neighboring nuclei.Comment: 10 pages, 7 figures, 1 table. Proceedings of the Conference on
Advanced Many-Body and Statistical Methods in Mesoscopic Systems, Constanta,
Romania, June 27th - July 2nd 2011. To appear in Journal of Physics:
Conference Serie
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