The phonology of name signs: a comparison between the Sign Languages of Uganda, Mali, Adamorobe and The Netherlands

Language Use in Past and Presen

Two-Dimensional Self-Assembly in Diblock Copolymers

Submitted to Phys. Rev. Lett.Diblock copolymers confined to a two-dimensional surface may produce uniform features of macromolecular dimensions (10 â 100 nm). We present a mathematical model for nanoscale pattern formation in such polymers which captures the dynamic evolution of a solution of poly(styrene)- b-poly(ethylene oxide), PS-b-PEO, in solvent at an air-water interface. The model has no fitting parameters and incorporates the effects of surface tension gradients, entanglement or vitrification, and diffusion. The resultant morphologies are quantitatively compared with experimental data.NS

Flavor coupled with chiral oscillations in the presence of an external magnetic field

By reporting to the Dirac wave-packet prescription where it is formally assumed the {\em fermionic} nature of the particles, we shall demonstrate that chiral oscillations implicitly aggregated to the interference between positive and negative frequency components of mass-eigenstate wave-packets introduce some small modifications to the standard neutrino flavor conversion formula. Assuming the correspondent spinorial solutions of a ``modified'' Dirac equation, we are specifically interested in quantifying flavor coupled with chiral oscillations for a {\em fermionic} Dirac-{\em type} particle (neutrino) non-minimally coupling with an external magnetic field {\boldmath$B$}. The viability of the intermediate wave-packet treatment becomes clear when we assume {\boldmath$B$} orthogonal/parallel to the direction of the propagating particle.Comment: 21 page

Upper Limits on Electric and Weak Dipole Moments of W-Boson

The total cross-sections of the reaction e+e- --> W+W-, as measured at LEP-II at centre-of-mass energies between 183 and 207 GeV are used to derive the upper limits on the parameters of CP-violating (P-odd and C-even) triple gauge-boson couplings WW\gamma and WWZ. The 95% CL limits |\widetilde{\kappa}_Z|<0.13 and |\widetilde{\lambda}_Z|<0.31 are obtained assuming local SU(2)_L x U(1)_Y gauge invariance. Our results are comparable with the previous ones obtained through the analysis of the W decay products. We also discuss the upper limits on the electric dipole moment (EDM) of the W-boson, which follow from the precision measurements of the electron and neutron EDM.Comment: 9 pages, 4 figure

The pragmatics of articles in Dutch children with specific language impairment

Previous studies have found that the morpho-syntactic aspects of grammatical morphemes, including articles, pose problems for Dutch-speaking children with Specific Language Impairment (SLI). In the present study it is demonstrated that article errors in Dutch children with SLI appear to be modulated by the pragmatic context to some extent. This study examines the pragmatic aspects of articles in 19 6- to 8-year-old children with SLI, comparing the results with those of 26 monolingual typically developing age-matched (TD-AM) and 17 language-matched (TD-LM) children. An elicitation task was used to test the specific discourse-new context (definite articles) and non-specific context (indefinite articles). In both contexts, the SLI group omitted articles more often than the TD-AM group, thus behaving similarly to the younger TD-LM group. The SLI group substituted articles more often than children in both control groups. Many children in the SLI group displayed variable behaviour and relatively many children with SLI used definite articles in non-specific contexts. We conclude that processing limitations in SLI may lead to less stable lexical knowledge of articles and hinder the successful integration of lexical, syntactic and pragmatic information that is required for target-like use of articles

Virus shapes and buckling transitions in spherical shells

We show that the icosahedral packings of protein capsomeres proposed by Caspar and Klug for spherical viruses become unstable to faceting for sufficiently large virus size, in analogy with the buckling instability of disclinations in two-dimensional crystals. Our model, based on the nonlinear physics of thin elastic shells, produces excellent one parameter fits in real space to the full three-dimensional shape of large spherical viruses. The faceted shape depends only on the dimensionless Foppl-von Karman number \gamma=YR^2/\kappa, where Y is the two-dimensional Young's modulus of the protein shell, \kappa is its bending rigidity and R is the mean virus radius. The shape can be parameterized more quantitatively in terms of a spherical harmonic expansion. We also investigate elastic shell theory for extremely large \gamma, 10^3 < \gamma < 10^8, and find results applicable to icosahedral shapes of large vesicles studied with freeze fracture and electron microscopy.Comment: 11 pages, 12 figure