Reality and causality in quantum gravity modified electrodynamics

We present a general description of the propagation properties of quantum gravity modified electrodynamics characterized by constitutive relations up to second order in the correction parameter. The effective description corresponds to an electrodynamics in a dispersive and absorptive non-local medium, where the Green functions and the refraction indices can be explicitly calculated. The reality of the electromagnetic field together with the requirement of causal propagation in a given referrence frame leads to restrictions in the form of such refraction indices. In particular, absorption must be present in all cases and, contrary to the usual assumption, it is the dominant aspect in those effective models which exhibit linear effects in the correction parameter not related to birefringence. In such a situation absorption is linear while propagation is quadratical in the correction parameter.Comment: 15 pages, LaTex, minor changes to clarify some points, version accepted for publicatio

Comparison of Perceived Exertion While Exercising at the Same Intensity on Land and Aquatic Treadmills

The purpose of this study was to determine if at the same intensity, two separate modalities of exercise could be perceived to have different difficulties. The modalities chosen for this study were underwater treadmill versus land treadmill. It was hypothesized that at the same sub maximal protocol, the underwater treadmill would be perceived as easier than the land treadmill. Both an objective measure, heart rate, and a subjective measure, a 10-point Borg rate of perceived exertion (RPE) scale (Borg, 1982), were used. Ten healthy University of Akron students from the ages 19-23 were used for this study. The students did two separate trials, one land and one underwater, one week apart. Some were selected to do the underwater treadmill first while others did the land treadmill first. The students participated in a 7 stage, 14-minute protocol while wearing a heart rate monitor and sharing their perceived exertion on a 10-point scale after every stage. The results found that the heart rates at all stages were not significantly different between the land treadmill and underwater treadmill. This indicates that the intensity of the protocol was relatively the same. The RPE measurements of the participants were also found to not be significantly different between the land and underwater treadmill. This suggests that both protocols were perceived to have similar intensities. It was concluded that the protocols both objectively and subjectively had similar intensities

Genome-Wide Analysis of Binding Sites and Direct Target Genes of the Orphan Nuclear Receptor NR2F1/COUP-TFI

Identification of bona fide direct nuclear receptor gene targets has been challenging but essential for understanding regulation of organismal physiological processes.We describe a methodology to identify transcription factor binding sites and target genes in vivo by intersecting microarray data, computational binding site queries, and evolutionary conservation. We provide detailed experimental validation of each step and, as a proof of principle, utilize the methodology to identify novel direct targets of the orphan nuclear receptor NR2F1 (COUP-TFI). The first step involved validation of microarray gene expression profiles obtained from wild-type and COUP-TFI(-/-) inner ear tissues. Secondly, we developed a bioinformatic tool to search for COUP-TFI DNA binding sites in genomes, using a classification-type Hidden Markov Model trained with 49 published COUP-TF response elements. We next obtained a ranked list of candidate in vivo direct COUP-TFI targets by integrating the microarray and bioinformatics analyses according to the degree of binding site evolutionary conservation and microarray statistical significance. Lastly, as proof-of-concept, 5 specific genes were validated for direct regulation. For example, the fatty acid binding protein 7 (Fabp7) gene is a direct COUP-TFI target in vivo because: i) we identified 2 conserved COUP-TFI binding sites in the Fabp7 promoter; ii) Fapb7 transcript and protein levels are significantly reduced in COUP-TFI(-/-) tissues and in MEFs; iii) chromatin immunoprecipitation demonstrates that COUP-TFI is recruited to the Fabp7 promoter in vitro and in vivo and iv) it is associated with active chromatin having increased H3K9 acetylation and enrichment for CBP and SRC-1 binding in the newborn brain.We have developed and validated a methodology to identify in vivo direct nuclear receptor target genes. This bioinformatics tool can be modified to scan for response elements of transcription factors, cis-regulatory modules, or any flexible DNA pattern

A new method for the spectroscopic identification of stellar non-radial pulsation modes. II. Mode identification of the Delta Scuti star FG Virginis

We present a mode identification based on new high-resolution time-series spectra of the non-radially pulsating Delta Scuti star FG~Vir (HD 106384, V = 6.57, A5V). From 2002 February to June a global Delta Scuti Network (DSN) campaign, utilizing high-resolution spectroscopy and simultaneous photometry has been conducted for FG~Vir in order to provide a theoretical pulsation model. In this campaign we have acquired 969 Echelle spectra covering 147 hours at six observatories. The mode identification was carried out by analyzing line profile variations by means of the Fourier parameter fit method, where the observational Fourier parameters across the line are fitted with theoretical values. This method is especially well suited for determining the azimuthal order m of non-radial pulsation modes and thus complementary with the method of Daszynska-Daszkiewicz (2002) which does best at identifying the degree l. 15 frequencies between 9.2 and 33.5 c/d were detected spectroscopically. We determined the azimuthal order m of 12 modes and constrained their harmonic degree l. Only modes of low degree (l <= 4) were detected, most of them having axisymmetric character mainly due to the relatively low projected rotational velocity of FG Vir. The detected non-axisymmetric modes have azimuthal orders between -2 and 1. We derived an inclination of 19 degrees, which implies an equatorial rotational rate of 66 km/s.Comment: 14 pages, 26 figure

Energy Dissipation Burst on the Traffic Congestion

We introduce an energy dissipation model for traffic flow based on the optimal velocity model (OV model). In this model, vehicles are defined as moving under the rule of the OV model, and energy dissipation rate is defined as the product of the velocity of a vehicle and resistant force which works to it.Comment: 15 pages, 19 Postscript figures. Reason for replacing: This is the submitted for

Phenomenological description of quantum gravity inspired modified classical electrodynamics

We discuss a large class of phenomenological models incorporating quantum gravity motivated corrections to electrodynamics. The framework is that of electrodynamics in a birefringent and dispersive medium with non-local constitutive relations, which are considered up to second order in the inverse of the energy characterizing the quantum gravity scale. The energy-momentum tensor, Green functions and frequency dependent refraction indices are obtained, leading to departures from standard physics. The effective character of the theory is also emphasized by introducing a frequency cutoff. The analysis of its effects upon the standard notion of causality is performed, showing that in the radiation regime the expected corrections get further suppressed by highly oscillating terms, thus forbiding causality violations to show up in the corresponding observational effects.Comment: 14 pages, to be published in Obregon Festschrift 2006, Gen. Rel. and Gra

Mimicking Mills’ syndrome: progressive spastic hemiparesis on upper motor neuron dominant amyotrophic lateral sclerosis

Mills’ syndrome is an idiopathic, slowly progressive, spastic hemiparetic variant of primary lateral sclerosis (PLS). Despite this classic definition, this syndrome has recently been suggested to be present on all the variants of motor neuron disease (MND) spectrum (ALS, PLS or UMNdALS). Authors presented a 63 years old male with history of gradually progressive right-side hemiparesis associated with dysarthria and dysphagia. Neurologic examination revealed intact cognition, weak bilateral orofacial muscles, marked right-side spasticity with hyperreflexia and mild sensory deficit, progressing to right-upper extremity atrophy upon follow-up. Relevant blood and CSF examinations were within normal limits. MRI of brain and cervical spine were unremarkable. electromyography (EMG), nerve conduction velocity (NCV), facial motor and blinks studies initially revealed no evidence of lower motor neuron involvement. Based on the revised El escorial criteria, patient was diagnosed as upper motor neuron dominant amyotrophic lateral sclerosis (UMNdALS) mimicking the classic PLS-Mills’ hemiparetic variant

Parallel Ant Colony Optimization on the University Course-Faculty Timetabling Problem in MSU-IIT Distributed Application in Erlang/OTP

The University Course-Faculty Timetabling Problem (UCFTP) occurs in the Mindanao State University-Iligan Institute of Technology (MSU-IIT) as the delegation of classrooms for available subjects including time schedule and appropriate faculty personnel, taking into consideration constraints such as classroom capacities, location, and faculty preferences, etc. It is a more difficult variant of the classical University Course Timetabling Problem, which is an assignment problem and known to be NP-hard. This paper presents parallel Ant Colony Optimization Max-Min Ant System (ACO-MMAS) algorithm as an approach in solving the UCFTP instance in the institute. ACO employs virtual ants moving across a search space and using an indirect form of constructive feedback by depositing pheromones on the paths they traverse in order to influence other ants in their searches. We have developed an application to automate the timetabling process using Erlang/OTP, a functional language specializing in concurrent and distributed systems. UCFTP was successfully represented into a mathematical problem instance and solved using the ACO-MMAS algorithm applied on a distributed network setup under Parallel Independent Run and Unidirectional Ring topologies. Extensive testing was performed to properly analyze the search behavior under different parameter settings

Strong Continuum-continuum Couplings In The Direct Ionization Of Ar And He Atoms By 6-MeV/u U38+ And Th38+ Projectiles

Doubly differential cross sections have been measured as a function of the electron energy and observation angle for electron emission following collisions of 6-MeV/u U38+ and Th38+ on He and Ar. The electron-emission data show an enhancement at forward angles and a decrease at backward angles with respect to scaled-cross-section results based on the Born approximation. Comparison with classical-trajectory Monte Carlo calculations suggests that the deviation from the Born approximation can be explained by continuum-continuum couplings. By comparing with previously published data, we found that the forward enhancement as well as the backward decrease follow a q/vp (q,vp are the projectile charge and velocity) scaling. © 1989 The American Physical Society