GINI DP 15: Can higher employment levels bring down poverty in the EU?

At the European level and in most EU member states, higher employment levels are seen as key to better poverty outcomes. But what can we expect the actual impact to be? Up until now shift-share analysis has been used to estimate the impact of rising employment on relative income poverty. This method has serious limitations. We propose a more sophisticated simulation model that builds on regression based estimates of employment probabilities and wages. We use this model to estimate the impact on relative income poverty of moving towards the Europe 2020 target of 75 percent of the working aged population in work. Two sensitivity checks are included: giving priority in job allocation to jobless households and imputing low instead of estimated wages. This article shows that employment growth does not necessarily result in lower relative poverty shares, a result that is largely consistent with observed outcomes over the past decade.

Singular components of spectral measures for ergodic Jacobi matrices

For ergodic 1d Jacobi operators we prove that the random singular components of any spectral measure are almost surely mutually disjoint as long as one restricts to the set of positive Lyapunov exponent. In the context of extended Harper's equation this yields the first rigorous proof of the Thouless' formula for the Lyapunov exponent in the dual regions.Comment: to appear in the Journal of Mathematical Physics, vol 52 (2011

Argenteum (Arg) mutant of Pisum: Genetic control and breeding behavior

Pea plants bearing the dominant gene argenteum (Arg) have gray-green, silvery foliage that contrasts sharply with the green of normal (arg) plants. The mutant phenotype results from extensive air spaces beneath the leaf epidermis. Arg segregates in a Mendelian manner and is linked with PI and other markers on chromosome 6. The phenotype, however, is not completely stable. Instability is marked by variegation—irregular patches of green tissue—and by distorted segregation ratios. Distorted ratios result from a higher than expected number of green offspring, the excess being attributable to plants that mimic those produced by Mendelian segregation but originating in a non-Mendelian manner. The marker, PI, aids in distinguishing such green plants, designated "arg”, from normal arg/arg segregants. Green "arg” plants also may descend directly from Arg/Arg plants. Arg/Arg plants that are valegated in the reproductive region produce more "arg” offspring than those that are varlegated In the vegetative region only, or those that are not variegated (visually) at all. Once the Arg phenotype is converted to "arg” the latter is in herited as monogenic recessive. Phenotypic instability could not be satisfactorily explained by any of the mechanisms investigated, including nuclear/cytoplasm interaction and modifier gene action. An hypothesis invoking high mutability would require simultaneous or sequential mutation at both Arg alleles of Arg/Arg plants. Moreover, since "arg” plants can be induced to deveiop a near-mutant phenotype upon exposure to high growth temperature, this implies that "arg” is not a back mutation to arg. Thus, the distinction between tissue specific gene action and gene change is still unclea

Quantum Fluctuations Driven Orientational Disordering: A Finite-Size Scaling Study

The orientational ordering transition is investigated in the quantum generalization of the anisotropic-planar-rotor model in the low temperature regime. The phase diagram of the model is first analyzed within the mean-field approximation. This predicts at $T=0$ a phase transition from the ordered to the disordered state when the strength of quantum fluctuations, characterized by the rotational constant $\Theta$, exceeds a critical value $\Theta_{\rm c}^{MF}$. As a function of temperature, mean-field theory predicts a range of values of $\Theta$ where the system develops long-range order upon cooling, but enters again into a disordered state at sufficiently low temperatures (reentrance). The model is further studied by means of path integral Monte Carlo simulations in combination with finite-size scaling techniques, concentrating on the region of parameter space where reentrance is predicted to occur. The phase diagram determined from the simulations does not seem to exhibit reentrant behavior; at intermediate temperatures a pronounced increase of short-range order is observed rather than a genuine long-range order.Comment: 27 pages, 8 figures, RevTe

Structure and Dynamics of amorphous Silica Surfaces

We use molecular dynamics computer simulations to study the equilibrium properties of the surface of amorphous silica. Two types of geometries are investigated: i) clusters with different diameters (13.5\AA, 19\AA, and 26.5\AA) and ii) a thin film with thickness 29\AA. We find that the shape of the clusters is independent of temperature and that it becomes more spherical with increasing size. The surface energy is in qualitative agreement with the experimental value for the surface tension. The density distribution function shows a small peak just below the surface, the origin of which is traced back to a local chemical ordering at the surface. Close to the surface the partial radial distribution functions as well as the distributions of the bond-bond angles show features which are not observed in the interior of the systems. By calculating the distribution of the length of the Si-O rings we can show that these additional features are related to the presence of two-membered rings at the surface. The surface density of these structures is around 0.6/nm^2 in good agreement with experimental estimates. From the behavior of the mean-squared displacement at low temperatures we conclude that at the surface the cage of the particles is larger than the one in the bulk. Close to the surface the diffusion constant is somewhat larger than the one in the bulk and with decreasing temperature the relative difference grows. The total vibrational density of states at the surface is similar to the one in the bulk. However, if only the one for the silicon atoms is considered, significant differences are found.Comment: 30 pages of Latex, 16 figure

The "Spontaneous” Formation of Rudimentary Carpels on Leaf Tissue

A number of photoperiodic pea plants (Pisum sativum L.), which remained vegetative under a short photoperiod, formed rudimentary carpels on leaf tissue. Laminar tissue became folded upward and fused to form the adaxial suture. Styles and stigmas of the rudimentary carpels closely resembled the same structures of normal carpels. The finding is believed to support the classical interpretation: that the carpel is a modified lea

Hydrogen Absorption Properties of Metal-Ethylene Complexes

Recently, we have predicted [Phys. Rev. Lett. 97, 226102 (2006)] that a single ethylene molecule can form stable complexes with light transition metals (TM) such as Ti and the resulting TMn-ethylene complex can absorb up to ~12 and 14 wt % hydrogen for n=1 and 2, respectively. Here we extend this study to include a large number of other metals and different isomeric structures. We obtained interesting results for light metals such as Li. The ethylene molecule is able to complex with two Li atoms with a binding energy of 0.7 eV/Li which then binds up to two H2 molecules per Li with a binding energy of 0.24 eV/H2 and absorption capacity of 16 wt %, a record high value reported so far. The stability of the proposed metal-ethylene complexes was tested by extensive calculations such as normal-mode analysis, finite temperature first-principles molecular dynamics (MD) simulations, and reaction path calculations. The phonon and MD simulations indicate that the proposed structures are stable up to 500 K. The reaction path calculations indicate about 1 eV activation barrier for the TM2-ethylene complex to transform into a possible lower energy configuration where the ethylene molecule is dissociated. Importantly, no matter which isometric configuration the TM2-ethylene complex possesses, the TM atoms are able to bind multiple hydrogen molecules with suitable binding energy for room temperature storage. These results suggest that co-deposition of ethylene with a suitable precursor of TM or Li into nanopores of light-weight host materials may be a very promising route to discovering new materials with high-capacity hydrogen absorption properties