133 research outputs found
Forced migration and human capital : evidence from post- WWII population transfers
We exploit a unique historical setting to study the long-run effects of forced migration on investment in education. After World War II, the Polish borders were redrawn, resulting in large-scale migration. Poles were forced to move from the Kresy territories in the East (taken over by the USSR) and were resettled mostly to the newly acquired Western Territories, from which Germans were expelled. We combine historical censuses with newly collected survey data to show that, while there were no pre-WWII differences in education, Poles with a family history of forced migration are significantly more educated today. Descendants of forced migrants have on average one extra year of schooling, driven by a higher propensity to finish secondary or higher education. This result holds when we restrict ancestral locations to a subsample around the former Kresy border and include fixed effects for the destination of migrants. As Kresy migrants were of the same ethnicity and religion as other Poles, we bypass confounding factors of other cases of forced migration. We show that labor market competition with natives and selection of migrants are also unlikely to drive our results. Survey evidence suggests that forced migration led to a shift in preferences, away from material possessions and towards investment in a mobile asset – human capital. The effects persist over three generations
Growth and magnetism of self-organized arrays of Fe(110) wires formed by deposition on kinetically grooved W(110)
Homoepitaxy of W(110) and Mo(110) is performed in a kinetically-limited
regime to yield a nanotemplate in the form of a uniaxial array of hills and
grooves aligned along the [001] direction. The topography and organization of
the grooves were studied with RHEED and STM. The nanofacets, of type {210}, are
tilted 18° away from (110). The lateral period could be varied from 4 to
12nm by tuning the deposition temperature. Magnetic nanowires were formed in
the grooves by deposition of Fe at 150°C on such templates. Fe/W wires
display an easy axis along [001] and a mean blocking temperature Tb=100KComment: Proceedings of ECOSS 2006 (Paris
Structure of self-organized Fe clusters grown on Au(111) analyzed by Grazing Incidence X-Ray Diffraction
We report a detailed investigation of the first stages of the growth of
self-organized Fe clusters on the reconstructed Au(111) surface by grazing
incidence X-ray diffraction. Below one monolayer coverage, the Fe clusters are
in "local epitaxy" whereas the subsequent layers adopt first a strained fcc
lattice and then a partly relaxed bcc(110) phase in a Kurdjumov-Sachs epitaxial
relationship. The structural evolution is discussed in relation with the
magnetic properties of the Fe clusters.Comment: 7 pages, 6 figures, submitted to Physical Review B September 200
Continuous and correlated nucleation during nonstandard island growth at Ag/Si(111)-7x7 heteroepitaxy
We present a combined experimental and theoretical study of submonolayer
heteroepitaxial growth of Ag on Si(111)-7x7 at temperatures from 420 K to 550 K
when Ag atoms can easily diffuse on the surface and the reconstruction 7x7
remains stable. STM measurements for coverages from 0.05 ML to 0.6 ML show that
there is an excess of smallest islands (each of them fills up just one
half-unit cell - HUC) in all stages of growth. Formation of 2D wetting layer
proceeds by continuous nucleation of the smallest islands in the proximity of
larger 2D islands (extended over several HUCs) and following coalescence with
them. Such a growth scenario is verified by kinetic Monte Carlo simulation
which uses a coarse-grained model based on a limited capacity of HUC and a
mechanism which increases nucleation probability in a neighbourhood of already
saturated HUCs (correlated nucleation). The model provides a good fit for
experimental dependences of the relative number of Ag-occupied HUCs and the
preference in occupation of faulted HUCs on temperature and amount of deposited
Ag. Parameters obtained for the hopping of Ag adatoms between HUCs agree with
those reported earlier for initial stages of growth. The model provides two new
parameters - maximum number of Ag atoms inside HUC, and on HUC boundary.Comment: LaTeX2e, BibTeX, 9 pages, 7 images, accepted to Phys. Rev.
A Simple Model for Anisotropic Step Growth
We consider a simple model for the growth of isolated steps on a vicinal
crystal surface. It incorporates diffusion and drift of adatoms on the terrace,
and strong step and kink edge barriers. Using a combination of analytic methods
and Monte Carlo simulations, we study the morphology of growing steps in
detail. In particular, under typical Molecular Beam Epitaxy conditions the step
morphology is linearly unstable in the model and develops fingers separated by
deep cracks. The vertical roughness of the step grows linearly in time, while
horizontally the fingers coarsen proportional to . We develop scaling
arguments to study the saturation of the ledge morphology for a finite width
and length of the terrace.Comment: 20 pages, 12 figures; [email protected]
The impact of regional and neighbourhood deprivation on physical health in Germany: a multilevel study
Voigtländer S, Berger U, Razum O. The impact of regional and neighbourhood deprivation on physical health in Germany: a multilevel study. BMC Public Health. 2010;10(1): 403.Background There is increasing evidence that individual health is at least partly determined by neighbourhood and regional factors. Mechanisms, however, remain poorly understood, and evidence from Germany is scant. This study explores whether regional as well as neighbourhood deprivation are associated with physical health and to what extent this association can be explained by specific neighbourhood exposures. Methods Using 2004 data from the German Socio-Economic Panel Study (SOEP) merged with regional and neighbourhood characteristics, we fitted multilevel linear regression models with subjective physical health, as measured by the SF-12, as the dependent variable. The models include regional and neighbourhood proxies of deprivation (i.e. regional unemployment quota, average purchasing power of the street section) as well as specific neighbourhood exposures (i.e. perceived air pollution). Individual characteristics including socioeconomic status and health behaviour have been controlled for. Results This study finds a significant association between area deprivation and physical health which is independent of compositional factors and consistent across different spatial scales. Furthermore the association between neighbourhood deprivation and physical health can be partly explained by specific features of the neighbourhood environment. Among these perceived air pollution shows the strongest association with physical health (-2.4 points for very strong and -1.5 points for strong disturbance by air pollution, standard error (SE) = 0.8 and 0.4, respectively). Beta coefficients for perceived air pollution, perceived noise and the perceived distance to recreational resources do not diminish when including individual health behaviour in the models. Conclusions This study highlights the difference regional and in particular neighbourhood deprivation make to the physical health of individuals in Germany. The results support the argument that specific neighbourhood exposures serve as an intermediary step between deprivation and health. As people with a low socioeconomic status were more likely to be exposed to unfavourable neighbourhood characteristics these conditions plausibly contribute towards generating health inequalities
Why honey is effective as a medicine. 1. Its use in modern medicine
Honey has been used as a medicine for thousands of years and its curative properties are well documented. However, modern medicine turned its back on honey and it is only now, with the advent of multi-resistant bacteria, that the antibiotic properties of honey are being rediscovered
Patterned nanostructure in AgCo/Pt/MgO(001) thin film
The formation of patterned nanostructure in AgCo/Pt/MgO(001) thin film is
simulated by a technique of combining molecular dynamics and phase-field
theory. The dislocation (strain) network existing in Pt/MgO is used as a
template whose pattern is transferred to AgCo phase in spinodal decomposition,
resulting in regular arrays of Co islands that are attracted by the
dislocations. The influence of various factors, such as component concentration
and film thickness, is studied. It is found that the spinodal decomposition of
AgCo in this system is mainly characterized by a competition between a
surface-directed layer structure and the strain-induced patterned structure,
where the patterned Ag-Co structure only dominates in a small range near the
interface (less than 10 atomic layers). However, if the interlayer diffusion
can be minimized by controlling film growth conditions, it is shown that the
patterned structure can be formed throughout the entire film.Comment: 8 pages, 12 figure
Economic-demographic interactions in long-run growth
Cliometrics confirms that Malthus’ model of the pre-industrial economy, in which increases in productivity raise population but higher population drives down wages, is a good description for much of demographic/economic history. A contributor to the Malthusian equilibrium was the Western European Marriage Pattern, the late age of female first marriage, which promised to retard the fall of living standards by restricting fertility. The demographic transition and the transition from Malthusian economies to modern economic growth attracted many Cliometric models surveyed here. A popular model component is that lower levels of mortality over many centuries increased the returns to, or preference for, human capital investment so that technical progress eventually accelerated. This initially boosted birth rates and population growth accelerated. Fertility decline was earliest and most striking in late eighteenth century France. By the 1830s the fall in French marital fertility is consistent with a response to the rising opportunity cost of children. The rest of Europe did not begin to follow until end of the nineteenth century. Interactions between the economy and migration have been modelled with Cliometric structures closely related to those of natural increase and the economy. Wages were driven up by emigration from Europe and reduced in the economies receiving immigrants
Genetic Cross-Interaction between APOE and PRNP in Sporadic Alzheimer's and Creutzfeldt-Jakob Diseases
Alzheimer's disease (AD) and Creutzfeldt-Jakob disease (CJD) represent two distinct clinical entities belonging to a wider group, generically named as conformational disorders that share common pathophysiologic mechanisms. It is well-established that the APOE ε4 allele and homozygosity at polymorphic codon 129 in the PRNP gene are the major genetic risk factors for AD and human prion diseases, respectively. However, the roles of PRNP in AD, and APOE in CJD are controversial. In this work, we investigated for the first time, APOE and PRNP genotypes simultaneously in 474 AD and 175 sporadic CJD (sCJD) patients compared to a common control population of 335 subjects. Differences in genotype distribution between patients and control subjects were studied by logistic regression analysis using age and gender as covariates. The effect size of risk association and synergy factors were calculated using the logistic odds ratio estimates. Our data confirmed that the presence of APOE ε4 allele is associated with a higher risk of developing AD, while homozygosity at PRNP gene constitutes a risk for sCJD. Opposite, we found no association for PRNP with AD, nor for APOE with sCJD. Interestingly, when AD and sCJD patients were stratified according to their respective main risk genes (APOE for AD, and PRNP for sCJD), we found statistically significant associations for the other gene in those strata at higher previous risk. Synergy factor analysis showed a synergistic age-dependent interaction between APOE and PRNP in both AD (SF = 3.59, p = 0.027), and sCJD (SF = 7.26, p = 0.005). We propose that this statistical epistasis can partially explain divergent data from different association studies. Moreover, these results suggest that the genetic interaction between APOE and PRNP may have a biological correlate that is indicative of shared neurodegenerative pathways involved in AD and sCJD
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