All pronouns are not acquired equally in Dutch: Elicitation of object and quantitative pronouns

This research reports the results of eliciting pronouns in two syntactic environments: Object pronouns and quantitative er (Q-er). Thus another type of language is added to the literature on subject and object clitic acquisition in the Romance languages (Jakubowicz et al., 1998; Hamann et al., 1996). Quantitative er is a unique pronoun in the Germanic languages; it has the same distribution as partitive clitics in Romance. Q-er is an N'-anaphor and occurs obligatorily with headless noun phrases with a numeral or weak quantifier. Q-er is licensed only when the context offers an antecedent; it binds an empty position in the NP. Data from typically-developing children aged 5;0-6;0 show that object and Q-er pronouns are not acquired equally; it is proposed that this is due to their different syntax. The use of Q-er involves more sophisticated syntactic knowledge: Q-er occurs at the left edge of the VP and binds an empty position in the NP, whereas object pronouns are simply stand-ins for full NPs and occur in the same position. These Dutch data reveal that pronouns are not used as exclusively as object clitics are in the Romance languages (Varlakosta, in prep.)

'Nee, ze heeft er twee': Acquisition of the Dutch quantitative 'er'

We present the first study on the acquisition of the Dutch quantitative pronoun er in sentences such as de vrouw draagt er drie ‘the woman is carrying three.’ There is a large literature on Dutch children’s interpretation of pronouns and a few recent production studies, all specifically looking at 3rd person singular pronouns and the so-called Delay of Principle B effect (Coopmans & Philip, 1996; Koster, 1993; Spenader, Smits and Hendriks, 2009). However, no one has studied children’s use of quantitative er. Dutch is the only Germanic language with such a pronoun

Determining the Surface-To-Bulk Progression in the Normal-State Electronic Structure of Sr2RuO4 by Angle-Resolved Photoemission and Density Functional Theory

In search of the potential realization of novel normal-state phases on the surface of Sr2RuO4 - those stemming from either topological bulk properties or the interplay between spin-orbit coupling (SO) and the broken symmetry of the surface - we revisit the electronic structure of the top-most layers by ARPES with improved data quality as well as ab-initio LDA slab calculations. We find that the current model of a single surface layer (\surd2x\surd2)R45{\deg} reconstruction does not explain all detected features. The observed depth-dependent signal degradation, together with the close quantitative agreement with LDA+SO slab calculations based on the LEED-determined surface crystal structure, reveal that (at a minimum) the sub-surface layer also undergoes a similar although weaker reconstruction. This points to a surface-to-bulk progression of the electronic states driven by structural instabilities, with no evidence for Dirac and Rashba-type states or surface magnetism.Comment: 4 pages, 4 figures, 1 table. Further information and PDF available at: http://www.phas.ubc.ca/~quantmat/ARPES/PUBLICATIONS/articles.htm

Rashba spin-splitting control at the surface of the topological insulator Bi2Se3

The electronic structure of Bi2Se3 is studied by angle-resolved photoemission and density functional theory. We show that the instability of the surface electronic properties, observed even in ultra-high-vacuum conditions, can be overcome via in-situ potassium deposition. In addition to accurately setting the carrier concentration, new Rashba-like spin-polarized states are induced, with a tunable, reversible, and highly stable spin splitting. Ab-initio slab calculations reveal that these Rashba state are derived from the 5QL quantum-well states. While the K-induced potential gradient enhances the spin splitting, this might be already present for pristine surfaces due to the symmetry breaking of the vacuum-solid interface.Comment: A high-resolution version can be found at http://www.physics.ubc.ca/~quantmat/ARPES/PUBLICATIONS/Articles/BiSe_K.pd

Na2IrO3 as a spin-orbit-assisted antiferromagnetic insulator with a 340 meV gap

We study Na2IrO3 by ARPES, optics, and band structure calculations in the local-density approximation (LDA). The weak dispersion of the Ir 5d-t2g manifold highlights the importance of structural distortions and spin-orbit coupling (SO) in driving the system closer to a Mott transition. We detect an insulating gap {\Delta}_gap = 340 meV which, at variance with a Slater-type description, is already open at 300 K and does not show significant temperature dependence even across T_N ~ 15 K. An LDA analysis with the inclusion of SO and Coulomb repulsion U reveals that, while the prodromes of an underlying insulating state are already found in LDA+SO, the correct gap magnitude can only be reproduced by LDA+SO+U, with U = 3 eV. This establishes Na2IrO3 as a novel type of Mott-like correlated insulator in which Coulomb and relativistic effects have to be treated on an equal footing.Comment: Accepted in Physical Review Letters. Auxiliary and related material can be found at: http://www.phas.ubc.ca/~quantmat/ARPES/PUBLICATIONS/articles.htm

Quality over quantity:A transactional model of social withdrawal and friendship development in late adolescence

The aim of this study was to test a longitudinal, transactional model that describes how social withdrawal and friendship development are interrelated in late adolescence, and to investigate if post-secondary transitions are catalysts of change for highly withdrawn adolescents' friendships. Unilateral friendship data of 1,019 adolescents (61.3% female, 91% Dutch-origin) from the Tracking Adolescents' Individual Lives Survey (TRAILS) cohort were collected five times from ages 17 to 18 years. Social withdrawal was assessed at 16 and 19 years. The transactional model was tested within a Structural Equation Modeling framework, with intercepts and slopes of friendship quantity, quality, and stability as mediators and residential transitions, education transitions, and sex as moderators. The results confirmed the presence of a transactional relation between withdrawal and friendship quality. Whereas higher age 16 withdrawal predicted having fewer, lower-quality, and less-stable friendships, only having lower-quality friendships, in turn, predicted higher age 19 withdrawal, especially in girls. Residential transitions were catalysts of change for highly withdrawn youth's number of friends: higher withdrawal predicted a moderate increase in number of friends for adolescents who relocated, and no change for those who made an educational transition or did not transition. Taken together, these results indicate that the quality of friendships-over and above number of friends and the stability of those friendships-is particularly important for entrenching or diminishing withdrawal in late adolescence, and that relocating provides an opportunity for withdrawn late adolescents to expand their friendship networks