City University London

About: City University London is a education organization based out in London, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 5735 authors who have published 17285 publications receiving 453290 citations.

Oscillations of the exchange in magnetic multilayers as an analog of de Haas-van Alphen effect.

Abstract: A theory of oscillations in the exchange coupling between two transition-metal ferromagnets separated by a nonmagnetic transition-metal spacer is developed for a one-band model. A close analogy between oscillations in the exchange and de Haas--van Alphen oscillations is established and exploited to show that the period, asymptotic decay, and temperature dependence of the oscillations are determined by properties of the Fermi surface in the spacer layer. The theory describes many features of the oscillations in the exchange coupling observed recently in Co/Ru, Co/Cr, and Fe/Cr superlattices.

Screening for speech and language delay: a systematic review of the literature

Abstract: Study selection Study designs of evaluations included in the review For intervention: the studies had to detail the number of participants in each group and the nature, duration, span, and delivery of treatment, provide a comparison of preand postintervention speech and language measures, and fulfill one of three design criteria: experimental study with randomised non-treatment controls; quasi-experimental studies (with non-random/pseudo-random or non-equivalent non-treatment control groups); or a single-subject experimental design with graphical displays or session-by-session data for individuals.

Financial Dependence and International Trade

Abstract: Does financial development translate into a comparative advantage in industries that use more external finance? The author uses industry-level data on firms' dependence on external finance for 36 industries and 56 countries to examine this question. It is shown that countries with better-developed financial systems have higher export shares and trade balances in industries that use more external finance. These results are robust to the use of alternative measures of external dependence and financial development and are not due to reverse causality or simultaneity bias.

Dimer models from mirror symmetry and quivering amoebae

Abstract: Dimer models are 2-dimensional combinatorial systems that have been shown to encode the gauge groups, matter content and tree-level superpotential of the world-volume quiver gauge theories obtained by placing D3-branes at the tip of a singular toric Calabi-Yau cone. In particular the dimer graph is dual to the quiver graph. However, the string theoretic explanation of this was unclear. In this paper we use mirror symmetry to shed light on this: the dimer models live on a T^2 subspace of the T^3 fiber that is involved in mirror symmetry and is wrapped by D6-branes. These D6-branes are mirror to the D3-branes at the singular point, and geometrically encode the same quiver theory on their world-volume.