5,433 research outputs found
Spherical harmonic decomposition applied to spatial-temporal analysis of human high-density EEG
We demonstrate an application of spherical harmonic decomposition to analysis
of the human electroencephalogram (EEG). We implement two methods and discuss
issues specific to analysis of hemispherical, irregularly sampled data.
Performance of the methods and spatial sampling requirements are quantified
using simulated data. The analysis is applied to experimental EEG data,
confirming earlier reports of an approximate frequency-wavenumber relationship
in some bands.Comment: 12 pages, 8 figures, submitted to Phys. Rev. E, uses APS RevTeX
style
On the Stability of Non-Extremal Conifold Backgrounds with Sources
We present finite temperature solutions describing N_c D5 branes wrapped on
the S^2 of the resolved conifold in the presence of N_f flavor brane sources
and their backreaction, i.e. N_f/N_c ~ 1. In these solutions the dilaton does
not blow up at infinity but stabilizes to a finite value. Thus, we can use them
to generate new ones with D5 and D3 charge. The resulting backgrounds are
non-extremal versions of the "flavored" resolved deformed conifold. It is
tempting to interpret these solutions as gravity duals of finite temperature
field theories exhibiting non-trivial phenomena as Seiberg dualities, Higgsing
and confinement. However, a first necessary step in this direction is to
investigate their stability. We study the specific heat of these new flavored
backgrounds and find that they are thermodynamically unstable. Our results on
the stability also apply to some of the non-extremal backgrounds with
Klebanov-Strassler asymptotics found in the literature.Comment: 34+16 pages, 26 figures. Published versio
Deforming baryons into confining strings
We find explicit probe D3-brane solutions in the infrared of the
Maldacena-Nunez background. The solutions describe deformed baryon vertices: q
external quarks are separated in spacetime from the remaining N-q. As the
separation is taken to infinity we recover known solutions describing infinite
confining strings in gauge theory. We present results for the
mass of finite confining strings as a function of length. We also find probe
D2-brane solutions in a confining type IIA geometry, the reduction of a G_2
holonomy M theory background. The relation between these deformed baryons and
confining strings is not as straightforward.Comment: 1+13 pages. LaTeX. 3 Figures. Factor of 2N fixed to N for the IIA
background. Minor changes to tex
Predictive Power of Strong Coupling in Theories with Large Distance Modified Gravity
We consider theories that modify gravity at cosmological distances, and show
that any such theory must exhibit a strong coupling phenomenon, or else it is
either inconsistent or is already ruled out by the solar system observations.
We show that all the ghost-free theories that modify dynamics of spin-2
graviton on asymptotically flat backgrounds, automatically have this property.
Due to the strong coupling effect, modification of the gravitational force is
source-dependent, and for lighter sources sets in at shorter distances. This
universal feature makes modified gravity theories predictive and potentially
testable not only by cosmological observations, but also by precision
gravitational measurements at scales much shorter than the current cosmological
horizon. We give a simple parametrization of consistent large distance modified
gravity theories and their predicted deviations from the Einsteinian metric
near the gravitating sources.Comment: 12 pages, Latex, to be published in New Journal of Physic
Two Cases of Autoimmune Syndrome Induced by Adjuvants (ASIA): A Multifaceted Condition Calling for a Multidisciplinary Approach
Silicone implants have been used for cosmetic enhancement and reconstructive purposes for over 60 years. Despite assiduous efforts to ensure safety, there is continuous evidence that they are not as biologically inert as previously postulated. We present two cases of autoimmune syndrome induced by adjuvants (ASIA) in Hispanic women. The first patient developed biopsy-proven immune-mediated necrotizing myopathy that was successfully treated with the combination of silicone explantation along with immunosuppressive therapy. Findings after implant removal demonstrated rupture and leakage of silicone from gluteal implants. The second patient developed autoimmune hemolytic anemia in the setting of a ruptured silicone breast implant. Similarly, the patient was treated with corticosteroids followed by breast implant removal with complete resolution of symptoms. The successful treatment of these patients was achieved by collaboration between rheumatology and plastic surgery, which emphasizes the need for a multidisciplinary approach in the diagnosis and management of patients with ASIA
One dimensional Coulomb-like problem in deformed space with minimal length
Spectrum and eigenfunctions in the momentum representation for 1D Coulomb
potential with deformed Heisenberg algebra leading to minimal length are found
exactly. It is shown that correction due to the deformation is proportional to
square root of the deformation parameter. We obtain the same spectrum using
Bohr-Sommerfeld quantization condition.Comment: 11 pages, typos corrected, references adde
Extended Recurrence Plot Analysis and its Application to ERP Data
We present new measures of complexity and their application to event related
potential data. The new measures base on structures of recurrence plots and
makes the identification of chaos-chaos transitions possible. The application
of these measures to data from single-trials of the Oddball experiment can
identify laminar states therein. This offers a new way of analyzing
event-related activity on a single-trial basis.Comment: 21 pages, 8 figures; article for the workshop ''Analyzing and
Modelling Event-Related Brain Potentials: Cognitive and Neural Approaches``
at November 29 - December 01, 2001 in Potsdam, German
Separation of Spontaneous Chiral Symmetry Breaking and Confinement via AdS/CFT Correspondence
We analyze, in the framework of AdS/CFT correspondence, the gauge theory
phase structure that are supposed to be dual to the recently found
non-supersymmetric dilatonic deformations to AdS_5 X S^5 in type IIB string
theory. Analyzing the probe D7-brane dynamics in the backgrounds of our
interest, which corresponds to the fundamental N=2 hypermultiplet, we show that
the chiral bi-fermion condensation responsible for spontaneous chiral symmetry
breaking is not logically related to the phenomenon of confinement.Comment: LaTex, 21 pages, 3 figures. v2: references adde
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