Killer-cell immunoglobulin-like receptor diversity in an admixed South American population

Natural Killer (NK) cells are innate immune cells that mediate antiviral and antitumor responses. NK cell activation and induction of effector functions are tightly regulated by the integration of activating and inhibitory receptors such as killer immunoglobulin-like receptors (KIR)

Refined Factorizations of Solvable Potentials

A generalization of the factorization technique is shown to be a powerful algebraic tool to discover further properties of a class of integrable systems in Quantum Mechanics. The method is applied in the study of radial oscillator, Morse and Coulomb potentials to obtain a wide set of raising and lowering operators, and to show clearly the connection that link these systems.Comment: 11 pages, LaTeX file, no figure

Preparing the COROT space mission: new variable stars in the galactic Anticenter direction

The activities related to the preparation of the asteroseismic, photometric space mission COROT are described. Photoelectric observations, wide--field CCD photometry, uvbyB calibrations and further time--series have been obtained at different observatories and telescopes. They have been planned to complete the COROT programme in the direction of the galactic Anticenter. In addition to suitable asteroseismic targets covering the different evolutionary stages between ZAMS and TAMS, we discovered several other variable stars, both pulsating and geometrical. We compared results on the incidence of variability in the galactic Center and Anticenter directions. Physical parameters have been obtained and evolutionary tracks fitting them have been calculated. The peculiarities of some individual stars alre pointed out. Paper based on observations collected at the San Pedro Martir, Sierra Nevada, Teide, La Silla, Haute-Provence and Roque de Los Muchachos (Telescopio Nazionale Galileo and Mercator telescopes) observatories.Comment: 13 pages, 9 figures. Accepted for The Astronomical Journal (2005 May volume

Fano-Rashba effect in quantum dots

We consider the electronic transport through a Rashba quantum dot coupled to ferromagnetic leads. We show that the interference of localized electron states with resonant electron states leads to the appearance of the Fano-Rashba effect. This effect occurs due to the interference of bound levels of spin-polarized electrons with the continuum of electronic states with an opposite spin polarization. We investigate this Fano-Rashba effect as a function of the applied magnetic field and Rashba spin-orbit coupling.Comment: 8 pages, 6 figures. To appear in Nanotechnolog

Two Skyrmion Dynamics with Omega Mesons

We present our first results of numerical simulations of two skyrmion dynamics using an $\omega$-meson stabilized effective Lagrangian. We consider skyrmion-skyrmion scattering with a fixed initial velocity of $\beta=0.5$, for various impact parameters and groomings. The physical picture that emerges is surprisingly rich, while consistent with previous results and general conservation laws. We find meson radiation, skyrmion scattering out of the scattering plane, orbiting and capture to bound states.Comment: 19 pages, 22 figure

Scanning the Parameter Space of Holographic Superconductors

We study various physical quantities associated with holographic s-wave superconductors as functions of the scaling dimensions of the dual condensates. A bulk scalar field with negative mass squared $m^2$, satisfying the Breitenlohner-Freedman stability bound and the unitarity bound, and allowed to vary in $0.5$ unit intervals, were considered. We observe that all the physical quantities investigated are sensitive to the scaling dimensions of the dual condensates. For all the $m^2$, the characteristic lengths diverge at the critical temperature in agreement with the Ginzburg-Landau theory. The Ginzburg-Landau parameter, obtained from these length scales indicates that the holographic superconductors can be type I or type II depending on the charge and the scaling dimensions of the dual condensates. For a fixed charge, there exists a critical scaling dimension, above which a holographic superconductor is type I, below which it becomes a type II.Comment: 24 pages 47 figure

Borromean Binding of Three or Four Bosons

We estimate the ratio $R=g_{3}/g_{2}$ of the critical coupling constants $g_{2}$ and $g_{3}$ which are required to achieve binding of 2 or 3 bosons, respectively, with a short-range interaction, and examine how this ratio depends on the shape of the potential. Simple monotonous potentials give $R\simeq 0.8$. A wide repulsive core pushes this ratio close to R=1. On the other hand, for an attractive well protected by an external repulsive barrier, the ratio approaches the rigorous lower bound $R=2/3$. We also present results for N=4 bosons, sketch the extension to $N>4$, and discuss various consequences.Comment: 12 pages, RevTeX, 5 Figures in tex include