The persistence of a visual dominance effect in a telemanipulator task: A comparison between visual and electrotactile feedback

The possibility to use an electrotactile stimulation in teleoperation and to observe the interpretation of such information as a feedback to the operator was investigated. It is proposed that visual feedback is more informative than an electrotactile one; and that complex electrotactile feedback slows down both the motor decision and motor response processes, is processed as an all or nothing signal, and bypasses the receptive structure and accesses directly in a working memory where information is sequentially processed and where memory is limited in treatment capacity. The electrotactile stimulation is used as an alerting signal. It is suggested that the visual dominance effect is the result of the advantage of both a transfer function and a sensory memory register where information is pretreated and memorized for a short time. It is found that dividing attention has an effect on the acquisition of the information but not on the subsequent decision processes

Comment on ``Inflation and flat directions in modular invariant superstring effective theories''

The inflation model of Gaillard, Lyth and Murayama is revisited, with a systematic scan of the parameter space for dilaton stabilization during inflation.Comment: 7 pages, 2 figure

One-Loop Pauli-Villars Regularization of Supergravity I: Canonical Gauge Kinetic Energy

It is shown that the one-loop coefficients of on-shell operators of standard supergravity with canonical gauge kinetic energy can be regulated by the introduction of Pauli-Villars chiral and abelian gauge multiplets, subject to a condition on the matter representations of the gauge group. Aspects of the anomaly structure of these theories under global nonlinear symmetries and an anomalous gauge symmetry are discussed.Comment: 46 pages, full postscript also available from http://phyweb.lbl.gov/theorygroup/papers/preprints.html/41981.ps . Misprints and errors in equations present in the original version have been correcte

Three-way electrical gating characteristics of metallic Y-junction carbon nanotubes

Y-junction based carbon nanotube (CNT) transistors exhibit interesting switching behaviors, and have the structural advantage that the electrical gate for current modulation can be formed by any of the three constituent branches. In this letter, we report on the gating characteristics of metallic Y-CNT morphologies. By measuring the output conductance and transconductance we conclude that the efficiency and gain depend on the branch diameter and is electric field controlled. Based on these principles, we propose a design for a Y-junction based CNT switching device, with tunable electrical properties

Upsilon cross section in p+p collisions at STAR

The main focus of the heavy flavor program at RHIC is to investigate the properties of the dense matter produced in heavy-ion collisions by studying its effect on open heavy flavor and quarkonia production. This in turn requires a detailed understanding of their production in elementary p+p collisions so that the dense matter effects can be later unfolded. In this paper, we present the first mid-rapidity cross section measurement of bottomonium at $\sqrt{s}=200$ GeV with the STAR experiment. We compare our results with perturbative QCD calculations. A brief status on the study of charmonium in STAR is given.Comment: 4 pages, 4 figures. To appear in the proceedings of Quark Matter 2006 as a special issue of Journal of Physics G: Nuclear and Particle Physic

Lepton-Flavour Violation in Ordinary and Supersymmetric Grand Unified Theories

By an explicit calculation we show that in ordinary SU(5) logarithmic divergence in the amplitude of $\mu \to e\gamma$ cancels among diagrams and remaining finite part is suppressed by at least $1/M_{GUT}^2$. In SUSY SU(5), when the effect of flavour changing wave function renormalization is taken into account such logarithmic correction disappears, provided a condition is met among SUSY breaking masses. In SUGRA-inspired SUSY GUT the remaining logarithmic effect is argued not to be taken as a prediction of the theory.Comment: 8 pages, LaTeX209 file, using axodraw.st

One-loop Regularization of Supergravity II: The Dilaton and the Superfield Formulation

The on-shell regularization of the one-loop divergences of supergravity theories is generalized to include a dilaton of the type occurring in effective field theories derived from superstring theory, and the superfield structure of the one-loop corrections is given. Field theory anomalies and quantum contributions to soft supersymmetry breaking are discussed. The latter are sensitive to the precise choice of couplings that generate Pauli-Villars masses, which in turn reflect the details of the underlying theory above the scale of the effective cut-off. With a view to the implementation the Green-Schwarz and other mechanisms for canceling field theory anomalies under a U(1) gauge transformation and under the T-duality group of modular transformations, we show that the K\"ahler potential renormalization for the untwisted sector of orbifold compactification can be made invariant under these groups.Comment: 46 pages, full postscript also available from http://phyweb.lbl.gov/theorygroup/papers/43259.p

Gaugino Condensation with S-Duality and Field-Theoretical Threshold Corrections

We study gaugino condensation in the presence of an intermediate mass scale in the hidden sector. S-duality is imposed as an approximate symmetry of the effective supergravity theory. Furthermore, we include in the K\"ahler potential the renormalization of the gauge coupling and the one-loop threshold corrections at the intermediate scale. It is shown that confinement is indeed achieved. Furthermore, a new running behaviour of the dilaton arises which we attribute to S-duality. We also discuss the effects of the intermediate scale, and possible phenomenological implications of this model.Comment: 19 pages, LaTeX, 3 postscript figures include

Full Component Lagrangian in the Linear Multiplet Formulation of String-inspired Effective Supergravity

We compute the component field 4-dimensional N=1 supergravity Lagrangian that is obtained from a superfield Lagrangian in the U(1)_K formalism with a linear dilaton multiplet. All fermionic terms are presented. In a variety of important ways, our results generalize those that have been reported previously, and are flexible enough to accomodate many situations of phenomenological interest in string-inspired effective supergravity, especially models based on orbifold compactifications of the weakly-coupled heterotic string. We provide for an effective theory of hidden gaugino and matter condensation. We include supersymmetric Green-Schwarz counterterms associated with the cancellation of U(1) and modular duality anomalies; the modular duality counterterm is of a rather general form. Our assumed form for the dilaton Kahler potential is quite general and can accomodate Kahler stabilization methods. We note possible applications of our results. We also discuss the usefulness of the linear dilaton formulation as a complement to the chiral dilaton approach.Comment: 2+34 page

Evidence for membrane affinity of the C-terminal domain of bovine milk PP3 component

AbstractComponent PP3 is a phosphoglycoprotein isolated from bovine milk with unknown biological function, which displays in its C-terminal region a basic amphipathic α-helix, a feature often involved in membrane association. According to that, the behaviour of PP3 and of a synthetic peptide from the C-terminal domain (residues 113–135) was investigated in lipid environment. Conductance measurements indicated that the peptide was able to associate and form channels in planar lipid bilayers composed of neutral or charged phospholipids. Electrostatic interactions seemed to promote voltage-dependant channel formation but this was not absolutely required since the pore-forming ability of the 113–135 C-terminal peptide was also detected with the zwitterionic lipid bilayer. Additionally, a spectroscopic study using circular dichroism argues that the peptide adopts an α-helical conformation in interaction with neutral or charged micelles. Thus, the conducting aggregates in bilayers might be composed of a bundle of peptides in helical conformation. Besides, similar conductance measurements performed with the whole PP3 protein did not induce any channel fluctuations. However, with the latter, an early breakdown of the bilayers occurred, a finding that can be tentatively explained by a massive incorporation of PP3. In the light of the present results, it could be inferred that PP3 membrane attachment may be achieved by oligomerization of the C-terminal amphipathic helical region