Multiple level enhancement of children's picture books with augmented reality

This paper reports a case study on using Augmented Reality (AR) in children’s books. in which we explored the use of various types of interactions at different levels. An AR enhanced 2-page spread is developed to explore interactivity in printed books. We describe the design process and the insights gained into the requirements for AR enhancement of children’s books

Quasi-Particles in Two-Dimensional Hubbard Model: Splitting of Spectral Weight

It is shown that the energy $(\varepsilon)$ and momentum $(k)$ dependences of the electron self-energy function $\Sigma (k, \varepsilon + i0) \equiv \Sigma^{R}(k, \varepsilon)$ are, ${\rm Im} \Sigma^{R} (k, \varepsilon) = -a\varepsilon^{2}|\varepsilon - \xi_{k}|^{- \gamma (k)}$ where $a$ is some constant, $\xi_{k} = \varepsilon(k)-\mu, \varepsilon(k)$ being the band energy, and the critical exponent $\gamma(k)$, which depends on the curvature of the Fermi surface at $k$, satisfies, $0 \leq \gamma(k) \leq 1$. This leads to a new type of electron liquid, which is the Fermi liquid in the limit of $\varepsilon, \xi_{k} \rightarrow 0$ but for $\xi_{k} \neq 0$ has a split one-particle spectra as in the Tomonaga-Luttinger liquid.Comment: 8 pages (LaTeX) 4 figures available upon request will be sent by air mail. KomabaCM-preprint-O

GRB 050408: An Atypical Gamma-Ray Burst as a Probe of an Atypical Galactic Environment

The bright GRB 050408 was localized by HETE-II near local midnight, enabling an impressive ground-based followup effort as well as space-based followup from Swift. The Swift data from the X-Ray Telescope (XRT) and our own optical photometry and spectrum of the afterglow provide the cornerstone for our analysis. Under the traditional assumption that the visible waveband was above the peak synchrotron frequency and below the cooling frequency, the optical photometry from 0.03 to 5.03 days show an afterglow decay corresponding to an electron energy index of p_lc = 2.05 +/- 0.04, without a jet break as suggested by others. A break is seen in the X-ray data at early times (at ~12600 sec after the GRB). The spectral slope of the optical spectrum is consistent with p_lc assuming a host-galaxy extinction of A_V = 1.18 mag. The optical-NIR broadband spectrum is also consistent with p = 2.05, but prefers A_V = 0.57 mag. The X-ray afterglow shows a break at 1.26 x 10^4 sec, which may be the result of a refreshed shock. This burst stands out in that the optical and X-ray data suggest a large H I column density of N_HI ~ 10^22 cm^-2; it is very likely a damped Lyman alpha system and so the faintness of the host galaxy (M_V > -18 mag) is noteworthy. Moreover, we detect extraordinarily strong Ti II absorption lines with a column density through the GRB host that exceeds the largest values observed for the Milky Way by an order of magnitude. Furthermore, the Ti II equivalent width is in the top 1% of Mg II absorption-selected QSOs. This suggests that the large-scale environment of GRB 050408 has significantly lower Ti depletion than the Milky Way and a large velocity width (delta v > 200 km/s).Comment: ApJ submitte

Why highly expressed proteins evolve slowly

Much recent work has explored molecular and population-genetic constraints on the rate of protein sequence evolution. The best predictor of evolutionary rate is expression level, for reasons which have remained unexplained. Here, we hypothesize that selection to reduce the burden of protein misfolding will favor protein sequences with increased robustness to translational missense errors. Pressure for translational robustness increases with expression level and constrains sequence evolution. Using several sequenced yeast genomes, global expression and protein abundance data, and sets of paralogs traceable to an ancient whole-genome duplication in yeast, we rule out several confounding effects and show that expression level explains roughly half the variation in Saccharomyces cerevisiae protein evolutionary rates. We examine causes for expression's dominant role and find that genome-wide tests favor the translational robustness explanation over existing hypotheses that invoke constraints on function or translational efficiency. Our results suggest that proteins evolve at rates largely unrelated to their functions, and can explain why highly expressed proteins evolve slowly across the tree of life.Comment: 40 pages, 3 figures, with supporting informatio

Lateral phase separation in mixtures of lipids and cholesterol

In an effort to understand "rafts" in biological membranes, we propose phenomenological models for saturated and unsaturated lipid mixtures, and lipid-cholesterol mixtures. We consider simple couplings between the local composition and internal membrane structure, and their influence on transitions between liquid and gel membrane phases. Assuming that the gel transition temperature of the saturated lipid is shifted by the presence of the unsaturated lipid, and that cholesterol acts as an external field on the chain melting transition, a variety of phase diagrams are obtained. The phase diagrams for binary mixtures of saturated/unsaturated lipids and lipid/cholesterol are in semi-quantitative agreement with the experiments. Our results also apply to regions in the ternary phase diagram of lipid/lipid/cholesterol systems

Concurrent constraint programming with process mobility

We propose an extension of concurrent constraint programming with primitives for process migration within a hierarchical network, and we study its semantics. To this purpose, we first investigate a "pure " paradigm for process migration, namely a paradigm where the only actions are those dealing with transmissions of processes. Our goal is to give a structural definition of the semantics of migration; namely, we want to describe the behaviour of the system, during the transmission of a process, in terms of the behaviour of the components. We achieve this goal by using a labeled transition system where the effects of sending a process, and requesting a process, are modeled by symmetric rules (similar to handshaking-rules for synchronous communication) between the two partner nodes in the network. Next, we extend our paradigm with the primitives of concurrent constraint programming, and we show how to enrich the semantics to cope with the notions of environment and constraint store. Finally, we show how the operational semantics can be used to define an interpreter for the basic calculus.

The Radio Afterglow From GRB 980519: A Test of the Jet and Circumstellar Models

We present multi-frequency radio observations from the afterglow of GRB 980519 beginning 7.2 hours after the gamma-ray burst and ending 63 days later. The fast decline in the optical and X-ray light curves for this burst has been interpreted either as afterglow emission originating from a collimated outflow -- a jet -- or the result of a blast wave propagating into a medium whose density is shaped by the wind of an evolved massive star. These two models predict divergent behavior for the radio afterglow, and therefore, radio observations are capable, in principle, of discriminating between the two. We show that a wind model describes the subsequent evolution of the radio afterglow rather well. However, we see strong modulation of the light curve, which we interpret as diffractive scintillation. These variations prevent us from decisively rejecting the jet model.Comment: ApJ, submitte

On the Stability and Single-Particle Properties of Bosonized Fermi Liquids

We study the stability and single-particle properties of Fermi liquids in spatial dimensions greater than one via bosonization. For smooth non-singular Fermi liquid interactions we obtain Shankar's renormalization- group flows and reproduce well known results for quasi-particle lifetimes. We demonstrate by explicit calculation that spin-charge separation does not occur when the Fermi liquid interactions are regular. We also explore the relationship between quantized bosonic excitations and zero sound modes and present a concise derivation of both the spin and the charge collective mode equations. Finally we discuss some aspects of singular Fermi liquid interactions.Comment: 13 pages plus three postscript figures appended; RevTex 3.0; BUP-JBM-