The development of complex verb constructions in British Sign Language

This study focuses on the mapping of events onto verb-argument structures in British Sign Language (BSL). The development of complex sentences in BSL is described in a group of 30 children, aged 3;2–12;0, using data from comprehension measures and elicited sentence production. The findings support two interpretations: firstly, in the mapping of concepts onto language, children acquiring BSL overgeneralize the use of argument structure related to perspective shifting;secondly, these overgeneralizations are predicted by the typological characteristics of the language and modality. Children under age 6;0, in attempting to produce sentences encoded through a perspective shift, begin by breaking down double-verb constructions (AB verbs) into components, producing only the part of the verb phrase which describes the perspective of the patient. There is also a prolonged period of development of non-manual features, with the full structure not seen in its adult form until after 9;0. The errors in the use of AB verbs and the subsequent protracted development of correct usage are explained in terms of the conceptual–linguistic interface

An Investigation of AdS2_2 Backreaction and Holography

We investigate a dilaton gravity model in AdS$_2$ proposed by Almheiri and Polchinski and develop a 1d effective description in terms of a dynamical boundary time with a Schwarzian derivative action. We show that the effective model is equivalent to a 1d version of Liouville theory, and investigate its dynamics and symmetries via a standard canonical framework. We include the coupling to arbitrary conformal matter and analyze the effective action in the presence of possible sources. We compute commutators of local operators at large time separation, and match the result with the time shift due to a gravitational shockwave interaction. We study a black hole evaporation process and comment on the role of entropy in this model.Comment: 32 pages, 6 figures, v3: typos corrected and references added, matches published versio

The influence of the diffusion barrier on the AC loss of Nb3Sn superconductors

Nb3Sn superconductors as they are applied in the ITER fusion programme, are equipped with diffusion barriers made of V, Ta, and V-Nb, all having superconducting properties. If an external ac magnetic field is applied, superconducting shielding currents are induced in the barrier which enclose a bundle of Nb3Sn filaments. As a consequence they are shielded and no ac loss will occur in the filaments. When the penetration field of the barrier material is exceeded, additionally the loss of the barrier and for higher fields also the loss of the Nb3Sn multifilamentary zone is generated. As long as the barrier is superconducting it will cause a substantial increase of ac loss. As a consequence the ac loss of the conductor in terms hysteresis loss per cycle and coupling time constants are strongly influenced. This aspect has to be considered carefully when properties of Nb3Sn conductors are determined at low magnetic fields

Smarter Programming of the Female Condom: Increasing Its Impact on HIV Prevention in the Developing World

The purpose of this study was to investigate the relative value of the female condom for HIV prevention within heterosexual relationships in the developing world. In the last ten years, the world has witnessed both historic financial commitments to HIV/AIDS and new prevention options, including biomedical prevention research, male circumcision, and a dramatic scale-up of voluntary counseling and testing. At the same time, where HIV remains at epidemic levels in many countries, there has been a growing commitment to treatment access alongside prevention programs. However, portions of populations, particularly youth and women, remain highly vulnerable to HIV infection. Accordingly, the global health community can benefit from a better understanding of how existing prevention options should be effectively and efficiently delivered to reduce HIV in the developing world. This report provides guidance for the global health community for considering how the female condom fits within the set of prevention interventions currently available

Superconducting spin precession magnets for a new neutron spectrometer

The required field shape of optimal Larmor precession magnets to obtain the bestpossible homogeneity is B0cos2(¿z/L). In practice this field shape is approximated by 30 superimposed concentric solenoids. The coils are made with an extreme dimensional precision with a typical error of 10 ¿m. A special winding technique in combination with a relatively thin superconducting wire of 230 ¿m diameter provided a significant overall accuracy. In this paper the design and construction aspects of the superconducting Larmor precession magnets will be discussed. Results of the magnetic field optimisation as well as preliminary test results of the magnets are presented. However, the ultimate performance will be investigated when the magnets are put into operation in the new neutron Larmor precession spectrometer at the Institut Laue Langevin

Predicted band structures of III-V semiconductors in wurtzite phase

While non-nitride III-V semiconductors typically have a zincblende structure, they may also form wurtzite crystals under pressure or when grown as nanowhiskers. This makes electronic structure calculation difficult since the band structures of wurtzite III-V semiconductors are poorly characterized. We have calculated the electronic band structure for nine III-V semiconductors in the wurtzite phase using transferable empirical pseudopotentials including spin-orbit coupling. We find that all the materials have direct gaps. Our results differ significantly from earlier {\it ab initio} calculations, and where experimental results are available (InP, InAs and GaAs) our calculated band gaps are in good agreement. We tabulate energies, effective masses, and linear and cubic Dresselhaus zero-field spin-splitting coefficients for the zone-center states. The large zero-field spin-splitting coefficients we find may lead to new functionalities for designing devices that manipulate spin degrees of freedom

Sensible and latent heating of the atmosphere as inferred from DST-6 data

The average distribution of convective latent heating, boundary layer sensible heat flux, and vertical velocity are determined for the winter 1976 DST period from GLAS model diagnostics. Key features are the regions of intense latent heating over Brazil, Central Africa, and Indonesia; and the regions of strong sensible heating due to air mass modification over the North Atlantic and North Pacific Oceans