Persistence of the School Entry Age Effect in a System of Flexible Tracking

In Germany, the streaming of students into an academic or nonacademic track at age 10 can be revised at later stages of secondary education. To investigate the importance of such revisions, we use administrative data on the student population in the German state of Hessen to measure the persistence of school entry age’s impact on choice of secondary school track. Based on exogenous variation in the school entry age by birth month, we obtain regression discontinuity estimates for different cohorts and grades up to the end of secondary education. We show that the effect of original school entry age on a student’s later attending grammar school disappears exactly at the grade level in which educational institutions facilitate track modification.Education, identification, regression discontinuity design, instrumental variables, relative maturity

Positively deflected anomaly mediation in the light of the Higgs boson discovery

Anomaly-mediated supersymmetry breaking (AMSB) is a well-known mechanism for flavor-blind transmission of supersymmetry breaking from the hidden sector to the visible sector. However, the pure AMSB scenario suffers from a serious drawback, namely, the tachyonic slepton problem, and needs to be extended. The so-called (positively) deflected AMSB is a simple extension to solve the problem and also provides us with the usual neutralino lightest superpartner as a good candidate for dark matter in the Universe. Motivated by the recent discovery of the Higgs boson at the Large Hadron Collider (LHC) experiments, we perform the parameter scan in the deflected AMSB scenario by taking into account a variety of phenomenological constraints such as the dark matter relic density and the observed Higgs boson mass around 125-126 GeV. We identify the allowed parameter region and list benchmark mass spectra. We find that in most of the allowed parameter regions, the dark matter neutralino is Higgsino-like and its elastic scattering cross section with nuclei is within the future reach of the direct dark matter search experiments, while (colored) sparticles are quite heavy and their discovery at the LHC is challenging.Comment: 16 pages, 5 figures, Version to be published in PR

Optimal Design of Earned Income Tax Credits: Evidence from a British Natural Experiment

With many countries considering the adoption of a system of earned income tax credits, it is useful to analyze how different types of credits affect labor supply and earnings. This paper focuses on a 1999 reform to the UK tax credit system, which increased the value of the credit and reduced the phase-out rate. Using panel data, with individual fixed effects, I compare eligibles and ineligibles within five groups: all individuals; those whose demographic characteristics predict that they will have low earnings; single women; women in couples; and men in couples. Over a 15-month period, boosting the credit appears to have raised the labor participation rates, hours, and earnings of those who were eligible to receive it.working families’ tax credit, earned income tax credit, wage subsidies, labor supply, earnings, self-reported health status

Damage Evolution in Quasi-Brittle Materials: Experimental Analysis by AE and Numerical Simulation

This work investigates the extension of a total-collapse prediction method to include local failures in quasi-brittle materials as they undergo damage processes. The analysis is experimentally conducted with acoustic emission data from a basalt specimen under a prescribed displacement loading test. The proposed failure index is compared with the well-established b-value to evaluate its usefulness; the simulation results are also used to further investigations. In particular, the simulations show that the parameter calculation can be carried out by indirectly estimating the elastic energy released within the system throughout the damage process, which cannot be measured directly. It is concluded that the proposed method is valid, consistently outperforming the b-value as a failure precursor throughout the experimental studies

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 346)

This bibliography lists 134 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during Jan. 1991. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance

Relativistic model of hidden bottom tetraquarks

The relativistic model of the ground state and excited heavy tetraquarks with hidden bottom is formulated within the diquark-antidiquark picture. The diquark structure is taken into account by calculating the diquark-gluon vertex in terms of the diquark wave functions. Predictions for the masses of bottom counterparts to the charm tetraquark candidates are given.Comment: 6 page

A Performance Analysis of Movement Patterns

This study investigates the differences in movement patterns followed by users navigating within a virtual environment. The analysis has been carried out between two groups of users, identified on the basis of their performance on a search task. Results indicate significant differences between efficient and inefficient navigators’ trajectories. They are related to rotational, translational and localised-landmarks behaviour. These findings are discussed in the light of theoretical outcomes provided by environmental psychology

Positron and positronium affinities in the work-formalism Hartree-Fock approximation

Positron binding to anions is investigated within the work formalism proposed by Harbola and Sahni for the halide anions and the systems Li^- through O^- excluding Be^- and N^-. The toal ground-state energies of the anion-positron bound systems are empirically found to be an upper bound to the Hartree-Fock energies. The computed expectation values as well as positron and positronium affinities are in good agreement with their restricted Hartree-Fock counterparts. Binding of a positron to neutral species is also investigated using an iterative method.Comment: 12 pages, to appear in Physical Review