Grace and Power: Base Communities and Nonviolence in Brazil

Reviewed Book: Barbé, Dominique. Grace and Power: Base Communities and Nonviolence in Brazil. Maryknoll, NY: Orbis Books, 1987

The Auroral Oval And The High-Latitude Ionosphere

Thesis (Ph.D.) University of Alaska Fairbanks, 197

Physical Instances of Noncommuting Coordinates

Noncommuting spatial coordinates and fields can be realized in actual physical situations. Plane wave solutions to noncommuting photodynamics exhibit violaton of Lorentz invariance (special relativity).Comment: 13 pp., using sprocl and amsmath macros; Email correspondence to [email protected]; talk given at Feza Gursey Institute, Istanbul, Turkey -- June 2001; "Symmetry Methods in Physics", Yerevan, Armenia -- July 2001; "CPT and Lorentz Symmetry II", Bloomington, IN -- August 2001; "Particles and Strings", Trento, Italy -- September 2001; "VIII Adriatic Meeting", Dubrovnik, Croatia -- September 200

High-temperature liquid-mercury cathodes for ion thrusters Quarterly progress report, 1 Dec. 1966 - 28 Feb. 1967

High temperature liquid mercury cathodes for ion thrusters - thermal design analysi

Effects of boundary roughness on a Q-factor of whispering-gallery-mode lasing microdisk cavities

We perform numerical studies of the effect of sidewall imperfections on the resonant state broadening of the optical microdisk cavities for lasing applications. We demonstrate that even small edge roughness causes a drastic degradation of high-Q whispering gallery (WG) mode resonances reducing their Q-values by many orders of magnitude. At the same time, low-Q WG resonances are rather insensitive to the surface roughness. The results of numerical simulation obtained using the scattering matrix technique, are analyzed and explained in terms of wave reflection at a curved dielectric interface combined with the examination of Poincare surface of sections in the classical ray picture.Comment: 4 pages, 3 figure

Optimal 2,3-Trees

The 2,3-trees that are optimal in the sense of having minimal expected number of nodes visited per access are characterized in terms of their “profiles”. The characterization leads directly to a linear-time algorithm for constructing a K-key optimal 2,3-tree for a sorted list of K keys. A number of results are derived that demonstrate how different in structure these optimal 2,3-trees are from their “average” cousins

Effective conductivity of composites of graded spherical particles

We have employed the first-principles approach to compute the effective response of composites of graded spherical particles of arbitrary conductivity profiles. We solve the boundary-value problem for the polarizability of the graded particles and obtain the dipole moment as well as the multipole moments. We provide a rigorous proof of an {\em ad hoc} approximate method based on the differential effective multipole moment approximation (DEMMA) in which the differential effective dipole approximation (DEDA) is a special case. The method will be applied to an exactly solvable graded profile. We show that DEDA and DEMMA are indeed exact for graded spherical particles.Comment: submitted for publication

IPMK and ??-catenin mediate PLC-??1-dependent signaling in myogenic differentiation

In previous studies, we have reported that phospholipase C (PLC)-??1 plays a crucial role in myogenic differentiation and we determined the importance of its catalytic activity for the initiation of this process. Here we define the effectors that take part to its signaling pathway. We show that the Inositol Polyphosphate Multikinase (IPMK) is able to promote myogenic differentiation since its overexpression determines the up-regulation of several myogenic markers. Moreover, we demonstrate that IPMK activates the same cyclin D3 promoter region targeted by PLC-??1 and that IPMKinduced promoter activation relies upon c-jun binding to the promoter, as we have shown previously for PLC-??1. Furthermore, our data shows that IPMK overexpression causes an increase in ??-catenin translocation and accumulation to the nuclei of differentiating myoblasts resulting in higher MyoD activation. Finally, we describe that PLC-??1 overexpression determines too an increase in ??-catenin translocation and that PLC-??1, IPMK and ??-catenin are mediators of the same signaling pathway since their overexpression results in cyclin D3 and myosin heavy chain (MYH) induction.ope

Testing Non-commutative QED, Constructing Non-commutative MHD

The effect of non-commutativity on electromagnetic waves violates Lorentz invariance: in the presence of a background magnetic induction field b, the velocity for propagation transverse to b differs from c, while propagation along b is unchanged. In principle, this allows a test by the Michelson-Morley interference method. We also study non-commutativity in another context, by constructing the theory describing a charged fluid in a strong magnetic field, which forces the fluid particles into their lowest Landau level and renders the fluid dynamics non-commutative, with a Moyal product determined by the background magnetic field.Comment: 14 pages, LaTeX; minor corrections, references adde

Forced and self-excited oscillations of an optomechanical cavity

We experimentally study forced and self oscillations of an optomechanical cavity which is formed between a fiber Bragg grating that serves as a static mirror and between a freely suspended metallic mechanical resonator that serves as a moving mirror. In the domain of small amplitude mechanical oscillations, we find that the optomechanical coupling is manifested as changes in the effective resonance frequency, damping rate and cubic nonlinearity of the mechanical resonator. Moreover, self oscillations of the micromechanical mirror are observed above a certain optical power threshold. A comparison between the experimental results and a theoretical model that we have recently presented yields a good agreement. The comparison also indicates that the dominant optomechanical coupling mechanism is the heating of the metallic mirror due to optical absorption.Comment: 11 pages, 6 figure