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Sample records for multiple sine wave

  1. Producing undistorted acoustic sine waves.

    PubMed

    Boutin, Henri; Smith, John; Wolfe, Joe

    2014-04-01

    A simple digital method is described that can produce an undistorted acoustic sine wave using an amplifier and loudspeaker having considerable intrinsic distortion, a common situation at low frequencies and high power. The method involves, first, using a pure sine wave as the input and measuring the distortion products. An iterative procedure then progressively adds harmonics with appropriate amplitude and phase to cancel any distortion products. The method is illustrated by producing a pure 52 Hz sine wave at 107 dB sound pressure level with harmonic distortion reduced over the audible range to >65 dB below the fundamental.

  2. Contrast sensitivity in relapsing-remitting multiple sclerosis assessed by sine-wave gratings and angular frequency stimuli.

    PubMed

    Vieira-Gutemberg, Jákina G; Mendes-Santos, Liana C; Cavalcanti-Galdino, Melyssa K; Santos, Natanael A; DE Bustamante Simas, Maria Lúcia

    2014-11-01

    Previous studies have shown that multiple sclerosis (MS) affects the visual system, mainly by reducing contrast sensitivity (CS), a function that can be assessed by measuring contrast sensitivity function (CSF). To this end, we measured both the CSF for sine-wave gratings and angular frequency stimuli with 20 participants aged between 21 and 44 years, of both genders, with normal or corrected to normal visual acuity. Of these 20 participants, there were 10 volunteers with clinically defined MS of the relapsing-remitting clinical form, with no history of optic neuritis (ON), as well as 10 healthy volunteers who served as the control group (CG). We used a forced-choice detection paradigm. The results showed reduced CS to both classes of stimuli. Differences were found for sine-wave gratings at spatial frequencies of 0.5, 1.25, and 2.5 cycles per degree (cpd) (P < 0.002) and for angular frequency stimuli of 4, 24, and 48 cycles/360° (P < 0.05). On the one hand, comparing the maxima of the respective CSFs, the CS to angular frequency stimuli (24 cycles/360°) was 1.61-fold higher than that of the CS to vertical sine-wave gratings (4.0 cpd) in the CG; for the MS group, these values were 1.55-fold higher. On the other hand, CS in the MS group attained only 75% for 24 cycles/360° and 78% for 4.0 cpd of the 100% CS estimates found for the CG at the peak frequencies. These findings suggest that MS affects the visual system, mostly at its maximum contrast sensitivities. Also, since angular frequencies and sine-wave gratings operate at distinct levels of contrast in the visual system, MS seems to affect CS at both high and low levels of contrast.

  3. The sine wave protocol: decrease movement time without increasing errors.

    PubMed

    Boyle, Jason B; Kennedy, Deanna M; Wang, Chaoyi; Shea, Charles H

    2014-01-01

    Practice tracking a sine wave template has been shown (J. B. Boyle, D. Kennedy, & C. H. Shea, 2012) to greatly enhance performance on a difficult Fitts task of the same amplitude. The purpose of the experiment was to replicate this finding and determine whether enhancements related to the sine wave practice are specific to the amplitude experienced during the sine wave practice. Following sine wave or Fitts task practice with amplitudes of 16° or 24°, participants were tested under the conditions they had practiced under (Test 1) and then all groups were tested under Fitts task conditions (Test 2; ID = 6, amplitude = 16°). Participants who practiced with the sine wave templates were able to move faster on Test 2 where a 16° amplitude Fitts task was used than participants that had practiced either the 16° or 24° amplitude Fitts tasks. The movements produced by the sine groups on Test 2 were not only faster than the movements of the Fitts groups on Test 2, but dwell time was lower with percent time to peak velocity and harmonicity higher for the Sine groups than for the Fitts groups. The decreased movement times for the sine groups on Test 2 were accomplished with hits or endpoint variability similar to that of the Fitts group.

  4. SINEs.

    PubMed

    Kramerov, Dmitri A; Vassetzky, Nikita S

    2011-01-01

    Short interspersed elements (SINEs) are mobile genetic elements that invade the genomes of many eukaryotes. Since their discovery about 30 years ago, many gaps in our understanding of the biology and function of SINEs have been filled. This review summarizes the past and recent advances in the studies of SINEs. The structure and origin of SINEs as well as the processes involved in their amplification, transcription, RNA processing, reverse transcription, and integration of a SINE copy into the genome are considered. Then we focus on the significance of SINEs for the host genomes. While these genomic parasites can be deleterious to the cell, the long-term being in the genome has made SINEs a valuable source of genetic variation providing regulatory elements for gene expression, alternative splice sites, polyadenylation signals, and even functional RNA genes. Copyright © 2011 John Wiley & Sons, Ltd.

  5. The Perception of "Sine-Wave Speech" by Adults with Developmental Dyslexia.

    ERIC Educational Resources Information Center

    Rosner, Burton S.; Talcott, Joel B.; Witton, Caroline; Hogg, James D.; Richardson, Alexandra J.; Hansen, Peter C.; Stein, John F.

    2003-01-01

    "Sine-wave speech" sentences contain only four frequency-modulated sine waves, lacking many acoustic cues present in natural speech. Adults with (n=19) and without (n=14) dyslexia were asked to reproduce orally sine-wave utterances in successive trials. Results suggest comprehension of sine-wave sentences is impaired in some adults with…

  6. The Perception of "Sine-Wave Speech" by Adults with Developmental Dyslexia.

    ERIC Educational Resources Information Center

    Rosner, Burton S.; Talcott, Joel B.; Witton, Caroline; Hogg, James D.; Richardson, Alexandra J.; Hansen, Peter C.; Stein, John F.

    2003-01-01

    "Sine-wave speech" sentences contain only four frequency-modulated sine waves, lacking many acoustic cues present in natural speech. Adults with (n=19) and without (n=14) dyslexia were asked to reproduce orally sine-wave utterances in successive trials. Results suggest comprehension of sine-wave sentences is impaired in some adults with…

  7. Sine-wave speech recognition in a tonal language.

    PubMed

    Feng, Yan-Mei; Xu, Li; Zhou, Ning; Yang, Guang; Yin, Shan-Kai

    2012-02-01

    It is hypothesized that in sine-wave replicas of natural speech, lexical tone recognition would be severely impaired due to the loss of F0 information, but the linguistic information at the sentence level could be retrieved even with limited tone information. Forty-one native Mandarin-Chinese-speaking listeners participated in the experiments. Results showed that sine-wave tone-recognition performance was on average only 32.7% correct. However, sine-wave sentence-recognition performance was very accurate, approximately 92% correct on average. Therefore the functional load of lexical tones on sentence recognition is limited, and the high-level recognition of sine-wave sentences is likely attributed to the perceptual organization that is influenced by top-down processes. © 2012 Acoustical Society of America

  8. Linear sine wave profiling to machine instability targets

    DOE PAGES

    Schmidt, Derek William; Martinez, John Israel

    2016-08-01

    Specialized machining processes and programming have been developed to deliver thin tin and copper Richtmyer-Meshkov instability targets that have different amplitude perturbations across the face of one 4-in.-diameter target. Typical targets have anywhere from two to five different regions of sine waves that have different amplitudes varying from 4 to 200 μm across the face of the target. The puck is composed of multiple rings that are zero press fit together and diamond turned to create a flat platform with a tolerance of 2 μm for the shock experiment. A custom software program was written in Labview to write themore » point-to-point program for the diamond-turning profiler through the X-Y-Z movements to cut the pure planar straight sine wave geometry. As a result, the software is optimized to push the profile of the whole part into the face while eliminating any unneeded passes that do not cut any material.« less

  9. Linear sine wave profiling to machine instability targets

    SciTech Connect

    Schmidt, Derek William; Martinez, John Israel

    2016-08-01

    Specialized machining processes and programming have been developed to deliver thin tin and copper Richtmyer-Meshkov instability targets that have different amplitude perturbations across the face of one 4-in.-diameter target. Typical targets have anywhere from two to five different regions of sine waves that have different amplitudes varying from 4 to 200 μm across the face of the target. The puck is composed of multiple rings that are zero press fit together and diamond turned to create a flat platform with a tolerance of 2 μm for the shock experiment. A custom software program was written in Labview to write the point-to-point program for the diamond-turning profiler through the X-Y-Z movements to cut the pure planar straight sine wave geometry. As a result, the software is optimized to push the profile of the whole part into the face while eliminating any unneeded passes that do not cut any material.

  10. Linear sine wave profiling to machine instability targets

    SciTech Connect

    Schmidt, Derek William; Martinez, John Israel

    2016-08-01

    Specialized machining processes and programming have been developed to deliver thin tin and copper Richtmyer-Meshkov instability targets that have different amplitude perturbations across the face of one 4-in.-diameter target. Typical targets have anywhere from two to five different regions of sine waves that have different amplitudes varying from 4 to 200 μm across the face of the target. The puck is composed of multiple rings that are zero press fit together and diamond turned to create a flat platform with a tolerance of 2 μm for the shock experiment. A custom software program was written in Labview to write the point-to-point program for the diamond-turning profiler through the X-Y-Z movements to cut the pure planar straight sine wave geometry. As a result, the software is optimized to push the profile of the whole part into the face while eliminating any unneeded passes that do not cut any material.

  11. Cardiac damage produced by transchest damped sine wave shocks.

    PubMed

    Tacker, W A; Davis, J S; Lie, J T; Titus, J L; Geddes, L A

    1978-01-01

    High-energy transchest damped wave sine defibrillation shocks have been shown to produce cardiac damage when applied in rapid sequence. However, there are no reports as to whether single, threshold-intensity shocks produce damage. In this study, nonfibrillating dogs were subjected either to a single, threshold-intensity (1 A/kg) shock, or to a series of 6 shocks with high intensity (3 to 4.8 A/kg). Electrodes of 8 cm diameter were used to apply the shock through the chest wall. Dogs receiving shocks of adequate (but not excessive) strength to defibrillate showed no cardiac damage, although they exhibited transient ventricular arrhythmias after the shock was applied. All dogs receiving the higher intensity, multiple shocks showed gross and microscopic evidence of cardiac damage. Ventricular lesions were observed in both right and left ventricular free walls and were sometimes transmural in extent. ECG analysis of the records from the dogs receiving multiple, high-intensity shocks showed second and third degree A-V block, ventricular ectopic beats, ventricular tachycardia, S-T segment changes, and T-wave inversion. Although multiple, high-energy, high-current defibrillation shocks produce permanent cardiac damage in dogs, threshold shocks do not produce morphologic changes.

  12. Are brief pulse and sine wave ECT equally efficient?

    PubMed

    Fox, H A; Rosen, A; Campbell, R J

    1989-11-01

    The literature reflects that brief pulse electroconvulsive therapy (ECT) uses less energy to elicit seizures and produces less cognitive disturbance than does sine wave ECT. However, the relative effectiveness and efficiency of the two waveforms have not been firmly established. In an effort to clarify these issues, the authors retrospectively compared a diagnostically heterogeneous group of 197 patients who received sine wave ECT with a similar group of 144 patients who received brief pulse ECT. The average number of ECT treatments administered to each group was essentially the same. Among a more homogeneous group of patients with affective disorders treated with either bilateral or mixed electrode placements, the number of treatments required with each waveform did not differ significantly.

  13. Advanced Sine Wave Modulation of Continuous Wave Laser System for Atmospheric CO2 Differential Absorption Measurements

    NASA Technical Reports Server (NTRS)

    Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.

    2014-01-01

    NASA Langley Research Center in collaboration with ITT Exelis have been experimenting with Continuous Wave (CW) laser absorption spectrometer (LAS) as a means of performing atmospheric CO2 column measurements from space to support the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission.Because range resolving Intensity Modulated (IM) CW lidar techniques presented here rely on matched filter correlations, autocorrelation properties without side lobes or other artifacts are highly desirable since the autocorrelation function is critical for the measurements of lidar return powers, laser path lengths, and CO2 column amounts. In this paper modulation techniques are investigated that improve autocorrelation properties. The modulation techniques investigated in this paper include sine waves modulated by maximum length (ML) sequences in various hardware configurations. A CW lidar system using sine waves modulated by ML pseudo random noise codes is described, which uses a time shifting approach to separate channels and make multiple, simultaneous online/offline differential absorption measurements. Unlike the pure ML sequence, this technique is useful in hardware that is band pass filtered as the IM sine wave carrier shifts the main power band. Both amplitude and Phase Shift Keying (PSK) modulated IM carriers are investigated that exibit perfect autocorrelation properties down to one cycle per code bit. In addition, a method is presented to bandwidth limit the ML sequence based on a Gaussian filter implemented in terms of Jacobi theta functions that does not seriously degrade the resolution or introduce side lobes as a means of reducing aliasing and IM carrier bandwidth.

  14. Kinematic analysis of tandem gait on a sine wave walkway.

    PubMed

    Kawakami, Shingo; Fujisawa, Hiroyuki; Tomizawa, Yoshiyuki; Murakami, Kenichi

    2016-09-01

    [Purpose] The purpose of this study was to ascertain the kinematic characteristics on a horizontal plane, including knee joint rotation, when walking with a tandem gait on a sine wave walkway. [Subjects and Methods] Eighteen healthy adults were enrolled as subjects in this study. They walked with a tandem gait on a sine wave walkway. A three-dimensional motion analysis system was used to record data and calculate the trunk, hip joint, and knee joint rotation angles. [Results] The rotation angle ranges for the trunk, hip joint, and knee joint were 23.3°, 53.3°, and 47.3°, respectively. The trunk generally rotated towards the direction of movement, and when turning left using the left leg as the pivot, the hip joint was internally rotated and the knee joint was externally rotated. In contrast, when making a directional change to the right using the left leg as the pivot, the hip joint was externally rotated and the knee joint was internally rotated. [Conclusion] Through tandem gait analysis on a sine wave walkway, knee joint rotation was found to be important in changes of direction.

  15. AUDITORY-PHONETIC PROJECTION AND LEXICAL STRUCTURE IN THE RECOGNITION OF SINE-WAVE WORDS.

    PubMed

    Remez, Robert E; Dubowski, Kathryn R; Broder, Robin S; Davids, Morgana L; Grossman, Yael S; Moskalenko, Marina; Pardo, Jennifer S; Hasbun, Sara Maria

    2009-04-01

    Speech remains intelligible despite the elimination of canonical acoustic correlates of phonemes from the spectrum. A portion of this perceptual flexibility can be attributed to modulation sensitivity in the auditory-to-phonetic projection, though signal-independent properties of lexical neighborhoods also affect intelligibility in utterances composed of words. Three tests were conducted to estimate the effects of exposure to natural and sine-wave samples of speech in this kind of perceptual versatility. First, sine-wave versions of the easy/hard word sets were created, modeled on the speech samples of a single talker. The performance difference in recognition of easy and hard words was used to index the perceptual reliance on signal-independent properties of lexical contrasts. Second, several kinds of exposure produced familiarity with an aspect of sine-wave speech: 1) sine-wave sentences modeled on the same talker; 2) sine-wave sentences modeled on a different talker, to create familiarity with a sine-wave carrier; and 3) natural sentences spoken by the same talker, to create familiarity with the idiolect expressed in the sine-wave words. Recognition performance with both easy and hard sine-wave words improved after exposure only to sine-wave sentences modeled on the same talker. Third, a control test showed that signal-independent uncertainty is a plausible cause of differences in recognition of easy and hard sine-wave words. The conditions of beneficial exposure reveal the specificity of attention underlying versatility in speech perception.

  16. Auditory-phonetic projection and lexical structure in the recognition of sine-wave words.

    PubMed

    Remez, Robert E; Dubowski, Kathryn R; Broder, Robin S; Davids, Morgana L; Grossman, Yael S; Moskalenko, Marina; Pardo, Jennifer S; Hasbun, Sara Maria

    2011-06-01

    Speech remains intelligible despite the elimination of canonical acoustic correlates of phonemes from the spectrum. A portion of this perceptual flexibility can be attributed to modulation sensitivity in the auditory-to-phonetic projection, although signal-independent properties of lexical neighborhoods also affect intelligibility in utterances composed of words. Three tests were conducted to estimate the effects of exposure to natural and sine-wave samples of speech in this kind of perceptual versatility. First, sine-wave versions of the easy and hard word sets were created, modeled on the speech samples of a single talker. The performance difference in recognition of easy and hard words was used to index the perceptual reliance on signal-independent properties of lexical contrasts. Second, several kinds of exposure produced familiarity with an aspect of sine-wave speech: (a) sine-wave sentences modeled on the same talker; (b) sine-wave sentences modeled on a different talker, to create familiarity with a sine-wave carrier; and (c) natural sentences spoken by the same talker, to create familiarity with the idiolect expressed in the sine-wave words. Recognition performance with both easy and hard sine-wave words improved after exposure only to sine-wave sentences modeled on the same talker. Third, a control test showed that signal-independent uncertainty is a plausible cause of differences in recognition of easy and hard sine-wave words. The conditions of beneficial exposure reveal the specificity of attention underlying versatility in speech perception.

  17. Recognition of sine wave modeled consonants by normal hearing and hearing-impaired individuals

    NASA Astrophysics Data System (ADS)

    Balachandran, Rupa

    Sine wave modeling is a parametric tool for representing the speech signal with a limited number of sine waves. It involves replacing the peaks of the speech spectrum with sine waves and discarding the rest of the lower amplitude components during synthesis. It has the potential to be used as a speech enhancement technique for hearing-impaired adults. The present study answers the following basic questions: (1) Are sine wave synthesized speech tokens more intelligible than natural speech tokens? (2) What is the effect of varying the number of sine waves on consonant recognition in quiet? (3) What is the effect of varying the number of sine waves on consonant recognition in noise? (4) How does sine wave modeling affect the transmission of speech feature in quiet and in noise? (5) Are there differences in recognition performance between normal hearing and hearing-impaired listeners? VCV syllables representing 20 consonants (/p/, /t/, /k/, /b/, /d/, /g/, /f/, /theta/, /s/, /∫/, /v/, /z/, /t∫/, /dy/, /j/, /w/, /r/, /l/, /m/, /n/) in three vowel contexts (/a/, /i/, /u/) were modeled with 4, 8, 12, and 16 sine waves. A consonant recognition task was performed in quiet, and in background noise (+10 dB and 0 dB SNR). Twenty hearing-impaired listeners and six normal hearing listeners were tested under headphones at their most comfortable listening level. The main findings were: (1) Recognition of unprocessed speech was better that of sine wave modeled speech. (2) Asymptotic performance was reached with 8 sine waves in quiet for both normal hearing and hearing-impaired listeners. (3) Consonant recognition performance in noise improved with increasing number of sine waves. (4) As the number of sine waves was decreased, place information was lost first, followed by manner, and finally voicing. (5) Hearing-impaired listeners made more errors then normal hearing listeners, but there were no differences in the error patterns made by both groups.

  18. Variable phase sine wave generator for active phased arrays

    NASA Astrophysics Data System (ADS)

    Waters, W. M.

    1992-09-01

    A waveform generator is provided for generating a high frequency waveform. A pulse generator provides a pulse train at a low frequency. A pulse converter converts the pulse train into an alternatingly positive and negative groups of pulses. A bandpass filter passes the alternatingly positive and negative groups of pulses in a frequency band centered at the high frequency to output the generated waveform at the high frequency. When the groups of pulses are a pair of pulses, a sine wave is output from the bandpass filter. A pulse delay circuit can be used to variably delay the pulse train and thereby cause a phase change in the generated waveform.

  19. Statistical properties of two sine waves in Gaussian noise.

    NASA Technical Reports Server (NTRS)

    Esposito, R.; Wilson, L. R.

    1973-01-01

    A detailed study is presented of some statistical properties of a stochastic process that consists of the sum of two sine waves of unknown relative phase and a normal process. Since none of the statistics investigated seem to yield a closed-form expression, all the derivations are cast in a form that is particularly suitable for machine computation. Specifically, results are presented for the probability density function (pdf) of the envelope and the instantaneous value, the moments of these distributions, and the relative cumulative density function (cdf).

  20. Interactions among periodic waves and solitary waves of the (N+1)-dimensional sine-Gordon field

    SciTech Connect

    Lou, S.Y.; Hu Hengchun; Tang Xiaoyan

    2005-03-01

    Exact solutions of the (n+1)-dimensional sine-Gordon field equation are studied with help of those of the cubic nonlinear Klein-Gordon fields. The mapping relations among the sine-Gordon field equation and the cubic nonlinear Klein-Gordon fields are pure algebraic. By solving the cubic nonlinear Klein-Gordon equations, many new types of exact explicit solutions such as the periodic-periodic interaction waves, periodic-kink interaction waves, periodic perturbed 'snake' shape solitary waves, etc., are displayed both analytically and graphically.

  1. AUDITORY-PHONETIC PROJECTION AND LEXICAL STRUCTURE IN THE RECOGNITION OF SINE-WAVE WORDS

    PubMed Central

    Remez, Robert E.; Dubowski, Kathryn R.; Broder, Robin S.; Davids, Morgana L.; Grossman, Yael S.; Moskalenko, Marina; Pardo, Jennifer S.; Hasbun, Sara Maria

    2010-01-01

    Speech remains intelligible despite the elimination of canonical acoustic correlates of phonemes from the spectrum. A portion of this perceptual flexibility can be attributed to modulation sensitivity in the auditory-to-phonetic projection, though signal-independent properties of lexical neighborhoods also affect intelligibility in utterances composed of words. Three tests were conducted to estimate the effects of exposure to natural and sine-wave samples of speech in this kind of perceptual versatility. First, sine-wave versions of the easy/hard word sets were created, modeled on the speech samples of a single talker. The performance difference in recognition of easy and hard words was used to index the perceptual reliance on signal-independent properties of lexical contrasts. Second, several kinds of exposure produced familiarity with an aspect of sine-wave speech: 1) sine-wave sentences modeled on the same talker; 2) sine-wave sentences modeled on a different talker, to create familiarity with a sine-wave carrier; and 3) natural sentences spoken by the same talker, to create familiarity with the idiolect expressed in the sine-wave words. Recognition performance with both easy and hard sine-wave words improved after exposure only to sine-wave sentences modeled on the same talker. Third, a control test showed that signal-independent uncertainty is a plausible cause of differences in recognition of easy and hard sine-wave words. The conditions of beneficial exposure reveal the specificity of attention underlying versatility in speech perception. PMID:20865138

  2. Rapid fabrication and characterization of sine wave targets

    SciTech Connect

    Day, R.D.; Armijo, E.; Gobby, P.; Hatch, D.; Rivera, G.; Salzer, L.; Townsend, J.

    1997-09-01

    The effect of surface perturbations on Inertial Confinement Fusion target performance is currently being researched at Los Alamos National Laboratory (LANL). These perturbations can cause hydrodynamic instabilities which in turn reduce the targets` yield. To systematically measure the growth of these instabilities requires targets to be produced which have perturbations of a known amplitude and spatial frequency. The authors have recently assembled hardware onto one of their diamond turning lathes which enables them to machine and measure these sine waves in about 15 minutes. This is a significant reduction in time from the two and one half hours required by the previous method. This paper discusses the hardware, how it works, and how well the system is working for them to produce these targets.

  3. Brain-wave representation of words by superposition of a few sine waves

    PubMed Central

    Suppes, Patrick; Han, Bing

    2000-01-01

    Data from three previous experiments were analyzed to test the hypothesis that brain waves of spoken or written words can be represented by the superposition of a few sine waves. First, we averaged the data over trials and a set of subjects, and, in one case, over experimental conditions as well. Next we applied a Fourier transform to the averaged data and selected those frequencies with high energy, in no case more than nine in number. The superpositions of these selected sine waves were taken as prototypes. The averaged unfiltered data were the test samples. The prototypes were used to classify the test samples according to a least-squares criterion of fit. The results were seven of seven correct classifications for the first experiment using only three frequencies, six of eight for the second experiment using nine frequencies, and eight of eight for the third experiment using five frequencies. PMID:10890906

  4. Brain-wave representation of words by superposition of a few sine waves.

    PubMed

    Suppes, P; Han, B

    2000-07-18

    Data from three previous experiments were analyzed to test the hypothesis that brain waves of spoken or written words can be represented by the superposition of a few sine waves. First, we averaged the data over trials and a set of subjects, and, in one case, over experimental conditions as well. Next we applied a Fourier transform to the averaged data and selected those frequencies with high energy, in no case more than nine in number. The superpositions of these selected sine waves were taken as prototypes. The averaged unfiltered data were the test samples. The prototypes were used to classify the test samples according to a least-squares criterion of fit. The results were seven of seven correct classifications for the first experiment using only three frequencies, six of eight for the second experiment using nine frequencies, and eight of eight for the third experiment using five frequencies.

  5. Plane wave holonomies in quantum gravity. II. A sine wave solution

    NASA Astrophysics Data System (ADS)

    Neville, Donald E.

    2015-08-01

    This paper constructs an approximate sinusoidal wave packet solution to the equations of canonical gravity. The theory uses holonomy-flux variables with support on a lattice (LHF =lattice-holonomy flux ). There is an SU(2) holonomy on each edge of the LHF simplex, and the goal is to study the behavior of these holonomies under the influence of a passing gravitational wave. The equations are solved in a small sine approximation: holonomies are expanded in powers of sines and terms beyond sin2 are dropped; also, fields vary slowly from vertex to vertex. The wave is unidirectional and linearly polarized. The Hilbert space is spanned by a set of coherent states tailored to the symmetry of the plane wave case. Fixing the spatial diffeomorphisms is equivalent to fixing the spatial interval between vertices of the loop quantum gravity lattice. This spacing can be chosen such that the eigenvalues of the triad operators are large, as required in the small sine limit, even though the holonomies are not large. Appendices compute the energy of the wave, estimate the lifetime of the coherent state packet, discuss circular polarization and coarse-graining, and determine the behavior of the spinors used in the U(N) SHO realization of LQG.

  6. Explicit solutions to the intrinsic generalization for the wave and sine-Gordon equations

    NASA Astrophysics Data System (ADS)

    Gu, Chaohao; Hu, Hesheng

    1993-09-01

    The Darboux matrix method is used to study intrinsic generalized wave equation and intrinsic generalized sine-Gordon equation which have been studied by Beals and Tenenblat. Explicit formulas for exact solutions are obtained.

  7. A sine-wave-shaped skin incision for inserting deep-brain stimulators.

    PubMed

    Solmaz, Bilgehan; Tatarli, Necati; Ceylan, Davut; Bayri, Yaşar; Ziyal, M Ibrahim; Şeker, Aşkin

    2014-08-01

    The sine-wave-shaped skin incision is a technique that minimizes skin-related complications near burr hole caps after electrode placement for deep-brain stimulation (DBS). Between 2011 and 2013, 54 DBS electrodes were implanted in 27 consecutive patients with Parkinson's disease (PD), essential tremor, or dystonia. The sine-wave incision was used in 26 patients and conventional bilateral linear scalp incisions were used in one patient. None of the patients whose operations involved sine-wave-shaped incisions developed hardware-linked complications such as skin infection or skin erosion. The one patient who underwent conventional bilateral linear scalp incisions developed a skin infection. By preserving the vascular anatomy of the scalp and reducing skin tension at the wound site, the sine-wave-shaped incision promotes wound healing.

  8. Wide-band doubler and sine wave quadrature generator

    NASA Technical Reports Server (NTRS)

    Crow, R. B.

    1969-01-01

    Phase-locked loop with photoresistive control, which provides both sine and cosine outputs for subcarrier demodulation, serves as a telemetry demodulator signal conditioner with a second harmonic signal for synchronization with the locally generated code.

  9. Sine-wave and noise-vocoded sine-wave speech in a tone language: Acoustic details matter.

    PubMed

    Rosen, Stuart; Hui, Sze Ngar Catherine

    2015-12-01

    Sine-wave speech (SWS) is a highly simplified version of speech consisting only of frequency- and amplitude-modulated sinusoids representing the formants. That listeners can successfully understand SWS has led to claims that speech perception must be based on abstract properties of the stimuli far removed from their specific acoustic form. Here it is shown, in bilingual Cantonese/English listeners, that performance with Cantonese SWS is improved by noise vocoding, with no effect on English SWS utterances. This manipulation preserves the abstract informational structure in the signals but changes its surface form. The differential effects of noise vocoding likely arise from the fact that Cantonese is a tonal language and hence more reliant on fundamental frequency (F0) contours for its intelligibility. SWS does not preserve tonal information from the original speech but does have false tonal information signalled by the lowest frequency sinusoid. Noise vocoding SWS appears to minimise the tonal percept, which thus interferes less in the perception of Cantonese. It has no effect in English, which is minimally reliant on F0 variations for intelligibility. Therefore it is not only the informational structure of a sound that is important but also how its acoustic detail interacts with the phonological structure of a given language.

  10. Spatiotemporal chaos in sine-Gordon systems subjected to wave fields: onset and suppression.

    PubMed

    Chacón, R; Bellorín, A; Guerrero, L E; González, J A

    2008-04-01

    The onset of spatiotemporal chaos in a damped sine-Gordon system subjected to a plane wave field as well as its suppression by an additional small-amplitude plane wave field are proposed theoretically and confirmed numerically. The relevance of these findings in the context of nonlinear magnetization waves is discussed.

  11. Circumpapillary course of retinal pigment epithelium can be fit to sine wave and amplitude of sine wave is significantly correlated with ovality ratio of optic disc.

    PubMed

    Yamashita, Takehiro; Sakamoto, Taiji; Yoshihara, Naoya; Terasaki, Hiroto; Kii, Yuya; Tanaka, Minoru; Nakao, Kumiko

    2015-01-01

    The purpose of this study was to develop a method of quantifying the degree of optic disc tilt in normal eyes. This was a prospective, observational cross sectional study of 126 right eyes of 126 healthy volunteers. The optic disc tilt was determined from the circular peripapillary optical coherence tomographic (OCT) scan images. The course of the retinal pigment epithelium (RPE) layer in the peripapillary cross sectional scan images was fit to a sine wave curve, and the amplitude of the sine curve was used to reflect the degree of the optic disc tilt in the optical axis. The repeatability of the amplitude determinations was calculated. The correlation between the amplitude and the ovality ratio of the optic disc was determined. The correlation between the amplitude and the body height was also calculated. The mean amplitude was 36.6 ± 17.5 pixels, which was significantly and inversely correlated with the ovality ratio of the optic disc (R = -0.59, P < 0.001). The intra-rater and inter-rater correlation coefficients of the amplitude were significant high (P < 0.001, both). The amplitude was significantly and inversely correlated with the body height (R = -0.38, P < 0.001), but not with the axial length. In conclusion, a sine wave function can be used to describe the course of the RPE in the circumpapillary OCT images. The results indicate that the amplitude of the sine wave can be used to represent the degree of optic disc tilt. Thus, the sine wave analyses can be used as a quantifiable and repeatable method to determine the optic disc tilt.

  12. Analog circuit for the measurement of phase difference between two noisy sine-wave signals

    NASA Technical Reports Server (NTRS)

    Shakkottai, P.; Kwack, E. Y.; Back, L. H.

    1989-01-01

    A simple circuit was designed to measure the phase difference between two noisy sine waves. It locks over a wide range of frequencies and produces an output proportional to the phase difference of rapidly varying signals. A square wave locked in frequency and phase to the first signal is produced by a phase-locked loop and is amplified by an operational amplifier.

  13. Analog circuit for the measurement of phase difference between two noisy sine-wave signals

    NASA Technical Reports Server (NTRS)

    Shakkottai, P.; Kwack, E. Y.; Back, L. H.

    1989-01-01

    A simple circuit was designed to measure the phase difference between two noisy sine waves. It locks over a wide range of frequencies and produces an output proportional to the phase difference of rapidly varying signals. A square wave locked in frequency and phase to the first signal is produced by a phase-locked loop and is amplified by an operational amplifier.

  14. Toddlers' comprehension of degraded signals: Noise-vocoded versus sine-wave analogs

    PubMed Central

    Newman, Rochelle S.; Chatterjee, Monita; Morini, Giovanna; Remez, Robert E.

    2015-01-01

    Recent findings suggest that development changes the ability to comprehend degraded speech. Preschool children showed greater difficulties perceiving noise-vocoded speech (a signal that integrates amplitude over broad frequency bands) than sine-wave speech (which maintains the spectral peaks without the spectrum envelope). In contrast, 27-month-old children in the present study could recognize speech with either type of degradation and performed slightly better with eight-channel vocoded speech than with sine-wave speech. This suggests that children's identification performance depends critically on the degree of degradation and that their success in recognizing unfamiliar speech encodings is encouraging overall. PMID:26428832

  15. Relative contributions of formants to the intelligibility of sine-wave sentences in Mandarin Chinese.

    PubMed

    Han, Yiyuan; Chen, Fei

    2017-06-01

    Early sine-wave speech (SWS) studies showed that the first three formants contain sufficient intelligibility information. The present work assessed the relative perceptual contributions of the first three formants. Mandarin sentences were edited to generate two SWS conditions: removal of one of the first three formant trajectories, and preservation of only one formant trajectory. In addition, SWS synthesis was implemented in the absence of sine-wave amplitude modulation. The results consistently showed that the trajectory of the second formant contributed the most to intelligibility, and the effect of amplitude modulation was smaller than that of the formant number.

  16. Toddlers' comprehension of degraded signals: Noise-vocoded versus sine-wave analogs.

    PubMed

    Newman, Rochelle S; Chatterjee, Monita; Morini, Giovanna; Remez, Robert E

    2015-09-01

    Recent findings suggest that development changes the ability to comprehend degraded speech. Preschool children showed greater difficulties perceiving noise-vocoded speech (a signal that integrates amplitude over broad frequency bands) than sine-wave speech (which maintains the spectral peaks without the spectrum envelope). In contrast, 27-month-old children in the present study could recognize speech with either type of degradation and performed slightly better with eight-channel vocoded speech than with sine-wave speech. This suggests that children's identification performance depends critically on the degree of degradation and that their success in recognizing unfamiliar speech encodings is encouraging overall.

  17. Sine-wave gating InGaAs/InP single photon detector with ultralow afterpulse

    NASA Astrophysics Data System (ADS)

    He, De-Yong; Wang, Shuang; Chen, Wei; Yin, Zhen-Qiang; Qian, Yong-Jun; Zhou, Zheng; Guo, Guang-Can; Han, Zheng-Fu

    2017-03-01

    Sine-wave gating method is widely used in high-speed single photon detection (SPD) but shows extra afterpulse probability compared with the self-differencing technique. Here, we demonstrate that most extra afterpulses of the sine-wave gating SPD come from successive avalanche signals and distortion of electrical filters and also propose an effective method by removing the wider filtered avalanche signals to reduce the afterpulse probability. At 1 GHz gating frequency, the ultralow afterpulse probability is characterized as 1.0% and 0.54% for a photon detection efficiency of 20.7% and 10.9%, respectively.

  18. Acute effect of alcohol intake on sine-wave Cartesian and polar contrast sensitivity functions.

    PubMed

    Cavalcanti-Galdino, M K; Silva, J A da; Mendes, L C; Santos, N A da; Simas, M L B

    2014-04-01

    The aim of this study was to assess contrast sensitivity for angular frequency stimuli as well as for sine-wave gratings in adults under the effect of acute ingestion of alcohol. We measured the contrast sensitivity function (CSF) for gratings of 0.25, 1.25, 2.5, 4, 10, and 20 cycles per degree of visual angle (cpd) as well as for angular frequency stimuli of 1, 2, 4, 24, 48, and 96 cycles/360°. Twenty adults free of ocular diseases, with normal or corrected-to-normal visual acuity, and no history of alcoholism were enrolled in two experimental groups: 1) no alcohol intake (control group) and 2) alcohol ingestion (experimental group). The average concentration of alcohol in the experimental group was set to about 0.08%. We used a paradigm involving a forced-choice method. Maximum sensitivity to contrast for sine-wave gratings in the two groups occurred at 4 cpd sine-wave gratings and at 24 and 48 cycles/360° for angular frequency stimuli. Significant changes in contrast sensitivity were observed after alcohol intake compared with the control condition at spatial frequency of 4 cpd and 1, 24, and 48 cycles/360° for angular frequency stimuli. Alcohol intake seems to affect the processing of sine-wave gratings at maximum sensitivity and at the low and high frequency ends for angular frequency stimuli, both under photopic luminance conditions.

  19. A watt-class 1-THz backward-wave oscillator based on sine waveguide

    SciTech Connect

    Xu Xiong; Wei Yanyu; Shen Fei; Yin Hairong; Xu Jin; Gong Yubin; Wang Wenxiang

    2012-01-15

    A novel backward wave oscillator was proposed by utilizing a concise sine waveguide slow-wave structure combined with sheet electron beam to operate at terahertz frequency band. First, the design method was described, and the dispersion curve and interaction impedance of the sine waveguide were calculated, then the device oscillation frequency and operating voltage were determined. Next, the circuit transmission losses were learned over the tunable frequency range. Finally, the particle-in-cell simulation method was applied to predict its signal generation performance. The investigation results show that, the backward wave oscillator can produce over 1.9 -W peak power output at the central operating frequency of 1-THz under 27-kV operating voltage and 5-mA beam current. And the interaction efficiency at 1-THz is more than 1.4% with a circuit length of 7.2-mm. It, therefore, will be considered as a promising watt-class terahertz radiation source.

  20. Sine wave gating silicon single-photon detectors for multiphoton entanglement experiments

    NASA Astrophysics Data System (ADS)

    Zhou, Nan; Jiang, Wen-Hao; Chen, Luo-Kan; Fang, Yu-Qiang; Li, Zheng-Da; Liang, Hao; Chen, Yu-Ao; Zhang, Jun; Pan, Jian-Wei

    2017-08-01

    Silicon single-photon detectors (SPDs) are the key devices for detecting single photons in the visible wavelength range. Here we present high detection efficiency silicon SPDs dedicated to the generation of multiphoton entanglement based on the technique of high-frequency sine wave gating. The silicon single-photon avalanche diode components are acquired by disassembling 6 commercial single-photon counting modules (SPCMs). Using the new quenching electronics, the average detection efficiency of SPDs is increased from 68.6% to 73.1% at a wavelength of 785 nm. These sine wave gating SPDs are then applied in a four-photon entanglement experiment, and the four-fold coincidence count rate is increased by 30% without degrading its visibility compared with the original SPCMs.

  1. Sine wave gating silicon single-photon detectors for multiphoton entanglement experiments.

    PubMed

    Zhou, Nan; Jiang, Wen-Hao; Chen, Luo-Kan; Fang, Yu-Qiang; Li, Zheng-Da; Liang, Hao; Chen, Yu-Ao; Zhang, Jun; Pan, Jian-Wei

    2017-08-01

    Silicon single-photon detectors (SPDs) are the key devices for detecting single photons in the visible wavelength range. Here we present high detection efficiency silicon SPDs dedicated to the generation of multiphoton entanglement based on the technique of high-frequency sine wave gating. The silicon single-photon avalanche diode components are acquired by disassembling 6 commercial single-photon counting modules (SPCMs). Using the new quenching electronics, the average detection efficiency of SPDs is increased from 68.6% to 73.1% at a wavelength of 785 nm. These sine wave gating SPDs are then applied in a four-photon entanglement experiment, and the four-fold coincidence count rate is increased by 30% without degrading its visibility compared with the original SPCMs.

  2. On the solution of the generalized wave and generalized sine-Gordon equations

    NASA Technical Reports Server (NTRS)

    Ablowitz, M. J.; Beals, R.; Tenenblat, K.

    1986-01-01

    The generalized wave equation and generalized sine-Gordon equations are known to be natural multidimensional differential geometric generalizations of the classical two-dimensional versions. In this paper, a system of linear differential equations is associated with these equations, and it is shown how the direct and inverse problems can be solved for appropriately decaying data on suitable lines. An initial-boundary value problem is solved for these equations.

  3. On the solution of the generalized wave and generalized sine-Gordon equations

    NASA Technical Reports Server (NTRS)

    Ablowitz, M. J.; Beals, R.; Tenenblat, K.

    1986-01-01

    The generalized wave equation and generalized sine-Gordon equations are known to be natural multidimensional differential geometric generalizations of the classical two-dimensional versions. In this paper, a system of linear differential equations is associated with these equations, and it is shown how the direct and inverse problems can be solved for appropriately decaying data on suitable lines. An initial-boundary value problem is solved for these equations.

  4. Phonetic matching of auditory and visual speech develops during childhood: evidence from sine-wave speech.

    PubMed

    Baart, Martijn; Bortfeld, Heather; Vroomen, Jean

    2015-01-01

    The correspondence between auditory speech and lip-read information can be detected based on a combination of temporal and phonetic cross-modal cues. Here, we determined the point in developmental time at which children start to effectively use phonetic information to match a speech sound with one of two articulating faces. We presented 4- to 11-year-olds (N=77) with three-syllabic sine-wave speech replicas of two pseudo-words that were perceived as non-speech and asked them to match the sounds with the corresponding lip-read video. At first, children had no phonetic knowledge about the sounds, and matching was thus based on the temporal cues that are fully retained in sine-wave speech. Next, we trained all children to perceive the phonetic identity of the sine-wave speech and repeated the audiovisual (AV) matching task. Only at around 6.5 years of age did the benefit of having phonetic knowledge about the stimuli become apparent, thereby indicating that AV matching based on phonetic cues presumably develops more slowly than AV matching based on temporal cues. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Full-wave analysis of the high frequency characteristics of the sine waveguide slow-wave structure

    NASA Astrophysics Data System (ADS)

    Lei, Xia; Wei, Yanyu; Wang, Yuanyuan; Zhou, Qing; Wu, Gangxiong; Ding, Chong; Li, Qian; Zhang, Luqi; Jiang, Xuebing; Gong, Yubin; Wang, Wenxiang

    2017-08-01

    A theoretical model for calculation of the high frequency characteristics of the sine waveguide slow-wave structure (SWS) is proposed. The formulas of dispersion and interaction impedances of the hybrid modes are obtained by combining the Helmholtz equation with the appropriate boundary conditions. Using the full wave analysis method, it is proved that the periodic structures with a half-period shift followed leads to a pairwise closing of passbands characteristic of adjacent mode. The sine waveguide SWS for 0.22THz traveling wave tube (TWT) is chosen as an illustrative example to verify the validity of the theoretical model, and the calculation results of the dispersion curve and interaction impedance curve are consistent with the HFSS simulation results. In addition, the influences of dimensions of sine waveguide on the high frequency characteristics of +1st spatial harmonic wave are investigated by numerical calculation. The study indicates that the appropriate SWS parameters are helpful for improving the bandwidth and increasing output power of TWT.

  6. Transthoracic cardioversion of atrial fibrillation: comparison of rectilinear biphasic versus damped sine wave monophasic shocks.

    PubMed

    Mittal, S; Ayati, S; Stein, K M; Schwartzman, D; Cavlovich, D; Tchou, P J; Markowitz, S M; Slotwiner, D J; Scheiner, M A; Lerman, B B

    2000-03-21

    Clinical studies have shown that biphasic shocks are more effective than monophasic shocks for ventricular defibrillation. The purpose of this study was to compare the efficacy of a rectilinear biphasic waveform with a standard damped sine wave monophasic waveform for the transthoracic cardioversion of atrial fibrillation. In this prospective, randomized, multicenter trial, patients undergoing transthoracic cardioversion of atrial fibrillation were randomized to receive either damped sine wave monophasic or rectilinear biphasic shocks. Patients randomized to the monophasic protocol (n=77) received sequential shocks of 100, 200, 300, and 360 J. Patients randomized to the biphasic protocol (n=88) received sequential shocks of 70, 120, 150, and 170 J. First-shock efficacy with the 70-J biphasic waveform (60 of 88 patients, 68%) was significantly greater than that with the 100-J monophasic waveform (16 of 77 patients, 21%, P<0.0001), and it was achieved with 50% less delivered current (11+/-1 versus 22+/-4 A, P<0.0001). Similarly, the cumulative efficacy with the biphasic waveform (83 of 88 patients, 94%) was significantly greater than that with the monophasic waveform (61 of 77 patients, 79%; P=0.005). The following 3 variables were independently associated with successful cardioversion: use of a biphasic waveform (relative risk, 4.2; 95% confidence intervals, 1.3 to 13.9; P=0.02), transthoracic impedance (relative risk, 0.64 per 10-Omega increase in impedance; 95% confidence intervals, 0.46 to 0.90; P=0.005), and duration of atrial fibrillation (relative risk, 0.97 per 30 days of atrial fibrillation; 95% confidence intervals, 0.96 to 0.99; P=0.02). For transthoracic cardioversion of atrial fibrillation, rectilinear biphasic shocks have greater efficacy (and require less energy) than damped sine wave monophasic shocks.

  7. Comparison of IPDA lidar receiver sensitivity for coherent detection and for direct detection using sine-wave and pulsed modulation.

    PubMed

    Sun, Xiaoli; Abshire, James B

    2012-09-10

    We use theoretical models to compare the receiver signal to noise ratio (SNR) vs. average rate of detected signal photons for an integrated path differential absorption (IPDA) lidar using coherent detection with continuous wave (CW) lasers and direct detection with sine-wave and pulse modulations. The results show the coherent IPDA lidar has high receiver gain and narrow bandwidth to overcome the effects of detector circuit noise and background light, but the actual receiver performance can be limited by the coherent mixing efficiency, speckle and other factors. For direct detection, using sine-wave modulation allows the use of a low peak power laser transmitter and synchronous detection. The pulse modulation technique requires higher laser peak powers but is more efficient than sine-wave modulation in terms of average detected signal photon rate required to achieve a given receiver SNR. We also conducted experiments for the direct detection cases and the results agreed well with theory.

  8. A Simple Robust PID Controller Design Method Based on Sine Wave Identification of the Uncertain Plant

    NASA Astrophysics Data System (ADS)

    Bucz, Štefan; Marič, Ladislav; Harsányi, Ladislav; Veselý, Vojtech

    2010-05-01

    The paper deals with the development and application of a new simple empirical approach to the design of robust PID controllers for technological processes in industrial practice. The main advantage of the proposed approach is the possibility to specify the required performance before the design algorithm implementation. Identification of characteristic data of the black-box type plant with varying parameters is carried out using the sine wave excitation signal, thus allowing to design the controller without necessarily knowing the mathematical model of the plant. The proposed approach has been verified on a real-world physical process.

  9. Criteria for representing circular arc and sine wave spar webs by non-curved elements

    NASA Technical Reports Server (NTRS)

    Jenkins, J. M.

    1979-01-01

    The basic problem of how to simply represent a curved web of a spar in a finite element structural model was addressed. The ratio of flat web to curved web axial deformations and longitudinal rotations were calculated using NASTRAN models. Multiplying factors were developed from these calculations for various web thicknesses. These multiplying factors can be applied directly to the area and moment of inertia inputs of the finite element model. This allows the thermal stress relieving configurations of sine wave and circular arc webs to be simply accounted for in finite element structural models.

  10. Deterministic approach for multiple-source tsunami hazard assessment for Sines, Portugal

    NASA Astrophysics Data System (ADS)

    Wronna, M.; Omira, R.; Baptista, M. A.

    2015-11-01

    In this paper, we present a deterministic approach to tsunami hazard assessment for the city and harbour of Sines, Portugal, one of the test sites of project ASTARTE (Assessment, STrategy And Risk Reduction for Tsunamis in Europe). Sines has one of the most important deep-water ports, which has oil-bearing, petrochemical, liquid-bulk, coal, and container terminals. The port and its industrial infrastructures face the ocean southwest towards the main seismogenic sources. This work considers two different seismic zones: the Southwest Iberian Margin and the Gloria Fault. Within these two regions, we selected a total of six scenarios to assess the tsunami impact at the test site. The tsunami simulations are computed using NSWING, a Non-linear Shallow Water model wIth Nested Grids. In this study, the static effect of tides is analysed for three different tidal stages: MLLW (mean lower low water), MSL (mean sea level), and MHHW (mean higher high water). For each scenario, the tsunami hazard is described by maximum values of wave height, flow depth, drawback, maximum inundation area and run-up. Synthetic waveforms are computed at virtual tide gauges at specific locations outside and inside the harbour. The final results describe the impact at the Sines test site considering the single scenarios at mean sea level, the aggregate scenario, and the influence of the tide on the aggregate scenario. The results confirm the composite source of Horseshoe and Marques de Pombal faults as the worst-case scenario, with wave heights of over 10 m, which reach the coast approximately 22 min after the rupture. It dominates the aggregate scenario by about 60 % of the impact area at the test site, considering maximum wave height and maximum flow depth. The HSMPF scenario inundates a total area of 3.5 km2.

  11. Speech perception of sine-wave signals by children with cochlear implants.

    PubMed

    Nittrouer, Susan; Kuess, Jamie; Lowenstein, Joanna H

    2015-05-01

    Children need to discover linguistically meaningful structures in the acoustic speech signal. Being attentive to recurring, time-varying formant patterns helps in that process. However, that kind of acoustic structure may not be available to children with cochlear implants (CIs), thus hindering development. The major goal of this study was to examine whether children with CIs are as sensitive to time-varying formant structure as children with normal hearing (NH) by asking them to recognize sine-wave speech. The same materials were presented as speech in noise, as well, to evaluate whether any group differences might simply reflect general perceptual deficits on the part of children with CIs. Vocabulary knowledge, phonemic awareness, and "top-down" language effects were all also assessed. Finally, treatment factors were examined as possible predictors of outcomes. Results showed that children with CIs were as accurate as children with NH at recognizing sine-wave speech, but poorer at recognizing speech in noise. Phonemic awareness was related to that recognition. Top-down effects were similar across groups. Having had a period of bimodal stimulation near the time of receiving a first CI facilitated these effects. Results suggest that children with CIs have access to the important time-varying structure of vocal-tract formants.

  12. Speech perception of sine-wave signals by children with cochlear implants

    PubMed Central

    Nittrouer, Susan; Kuess, Jamie; Lowenstein, Joanna H.

    2015-01-01

    Children need to discover linguistically meaningful structures in the acoustic speech signal. Being attentive to recurring, time-varying formant patterns helps in that process. However, that kind of acoustic structure may not be available to children with cochlear implants (CIs), thus hindering development. The major goal of this study was to examine whether children with CIs are as sensitive to time-varying formant structure as children with normal hearing (NH) by asking them to recognize sine-wave speech. The same materials were presented as speech in noise, as well, to evaluate whether any group differences might simply reflect general perceptual deficits on the part of children with CIs. Vocabulary knowledge, phonemic awareness, and “top-down” language effects were all also assessed. Finally, treatment factors were examined as possible predictors of outcomes. Results showed that children with CIs were as accurate as children with NH at recognizing sine-wave speech, but poorer at recognizing speech in noise. Phonemic awareness was related to that recognition. Top-down effects were similar across groups. Having had a period of bimodal stimulation near the time of receiving a first CI facilitated these effects. Results suggest that children with CIs have access to the important time-varying structure of vocal-tract formants. PMID:25994709

  13. Radial frequency stimuli and sine-wave gratings seem to be processed by distinct contrast brain mechanisms.

    PubMed

    Simas, M L B; Nogueira, R M T B L; Santos, N A

    2005-03-01

    An assumption commonly made in the study of visual perception is that the lower the contrast threshold for a given stimulus, the more sensitive and selective will be the mechanism that processes it. On the basis of this consideration, we investigated contrast thresholds for two classes of stimuli: sine-wave gratings and radial frequency stimuli (i.e., j0 targets or stimuli modulated by spherical Bessel functions). Employing a suprathreshold summation method, we measured the selectivity of spatial and radial frequency filters using either sine-wave gratings or j0 target contrast profiles at either 1 or 4 cycles per degree of visual angle (cpd), as the test frequencies. Thus, in a forced-choice trial, observers chose between a background spatial (or radial) frequency alone and the given background stimulus plus the test frequency (1 or 4 cpd sine-wave grating or radial frequency). Contrary to our expectations, the results showed elevated thresholds (i.e., inhibition) for sine-wave gratings and decreased thresholds (i.e., summation) for radial frequencies when background and test frequencies were identical. This was true for both 1- and 4-cpd test frequencies. This finding suggests that sine-wave gratings and radial frequency stimuli are processed by different quasi-linear systems, one working at low luminance and contrast level (sine-wave gratings) and the other at high luminance and contrast levels (radial frequency stimuli). We think that this interpretation is consistent with distinct foveal only and foveal-parafoveal mechanisms involving striate and/or other higher visual areas (i.e., V2 and V4).

  14. Nonlinear waves in networks: Model reduction for the sine-Gordon equation

    NASA Astrophysics Data System (ADS)

    Caputo, Jean-Guy; Dutykh, Denys

    2014-08-01

    To study how nonlinear waves propagate across Y- and T-type junctions, we consider the two-dimensional (2D) sine-Gordon equation as a model and examine the crossing of kinks and breathers. Comparing energies for different geometries reveals that, for small widths, the angle of the fork plays no role. Motivated by this, we introduce a one-dimensional effective model whose solutions agree well with the 2D simulations for kink and breather solutions. These exhibit two different behaviors: a kink crosses if it has sufficient energy; conversely a breather crosses when v >1-ω, where v and ω are, respectively, its velocity and frequency. This methodology can be generalized to more complex nonlinear wave models.

  15. Nonlinear waves in networks: model reduction for the sine-Gordon equation.

    PubMed

    Caputo, Jean-Guy; Dutykh, Denys

    2014-08-01

    To study how nonlinear waves propagate across Y- and T-type junctions, we consider the two-dimensional (2D) sine-Gordon equation as a model and examine the crossing of kinks and breathers. Comparing energies for different geometries reveals that, for small widths, the angle of the fork plays no role. Motivated by this, we introduce a one-dimensional effective model whose solutions agree well with the 2D simulations for kink and breather solutions. These exhibit two different behaviors: a kink crosses if it has sufficient energy; conversely a breather crosses when v>1-ω, where v and ω are, respectively, its velocity and frequency. This methodology can be generalized to more complex nonlinear wave models.

  16. Transcranial magnetic stimulation with a half-sine wave pulse elicits direction-specific effects in human motor cortex.

    PubMed

    Jung, Nikolai H; Delvendahl, Igor; Pechmann, Astrid; Gleich, Bernhard; Gattinger, Norbert; Siebner, Hartwig R; Mall, Volker

    2012-11-05

    Transcranial magnetic stimulation (TMS) commonly uses so-called monophasic pulses where the initial rapidly changing current flow is followed by a critically dampened return current. It has been shown that a monophasic TMS pulse preferentially excites different cortical circuits in the human motor hand area (M1-HAND), if the induced tissue current has a posterior-to-anterior (PA) or anterior-to-posterior (AP) direction. Here we tested whether similar direction-specific effects could be elicited in M1-HAND using TMS pulses with a half-sine wave configuration. In 10 young participants, we applied half-sine pulses to the right M1-HAND which elicited PA or AP currents with respect to the orientation of the central sulcus.Measurements of the motor evoked potential (MEP) revealed that PA half-sine stimulation resulted in lower resting motor threshold (RMT) than AP stimulation. When stimulus intensity (SI) was gradually increased as percentage of maximal stimulator output, the stimulus-response curve (SRC) of MEP amplitude showed a leftward shift for PA as opposed to AP half-sine stimulation. Further, MEP latencies were approximately 1 ms shorter for PA relative to AP half-sine stimulation across the entire SI range tested. When adjusting SI to the respective RMT of PA and AP stimulation, the direction-specific differences in MEP latencies persisted, while the gain function of MEP amplitudes was comparable for PA and AP stimulation. Using half-sine pulse configuration, single-pulse TMS elicits consistent direction-specific effects in M1-HAND that are similar to TMS with monophasic pulses. The longer MEP latency for AP half-sine stimulation suggests that PA and AP half-sine stimulation preferentially activates different sets of cortical neurons that are involved in the generation of different corticospinal descending volleys.

  17. Mapping displacement and deformation of the heart with local sine-wave modeling.

    PubMed

    Arts, T; Prinzen, Frits W; Delhaas, T; Milles, J R; Rossi, Alessandro C; Clarysse, Patrick

    2010-05-01

    The new SinMod method extracts motion from magnetic resonance imaging (MRI)-tagged (MRIT) image sequences. Image intensity in the environment of each pixel is modeled as a moving sine wavefront. Displacement is estimated at subpixel accuracy. Performance is compared with the harmonic-phase analysis (HARP) method, which is currently the most common method used to detect motion in MRIT images. SinMod can handle line tags, as well as speckle patterns. In artificial images (tag distance six pixels), SinMod detects displacements accurately (error < 0.02 pixels). Effects of noise are suppressed effectively. Sharp transitions in motion at the boundary of an object are smeared out over a width of 0.6 tag distance. For MRIT images of the heart, SinMod appears less sensitive to artifacts, especially later in the cardiac cycle when image quality deteriorates. For each pixel, the quality of the sine-wave model in describing local image intensity is quantified objectively. If local quality is low, artifacts are avoided by averaging motion over a larger environment. Summarizing, SinMod is just as fast as HARP, but it performs better with respect to accuracy of displacement detection, noise reduction, and avoidance of artifacts.

  18. Multiple source genes of HAmo SINE actively expanded and ongoing retroposition in cyprinid genomes relying on its partner LINE.

    PubMed

    Tong, Chaobo; Gan, Xiaoni; He, Shunping

    2010-04-29

    We recently characterized HAmo SINE and its partner LINE in silver carp and bighead carp based on hybridization capture of repetitive elements from digested genomic DNA in solution using a bead-probe 1. To reveal the distribution and evolutionary history of SINEs and LINEs in cyprinid genomes, we performed a multi-species search for HAmo SINE and its partner LINE using the bead-probe capture and internal-primer-SINE polymerase chain reaction (PCR) techniques. Sixty-seven full-size and 125 internal-SINE sequences (as well as 34 full-size and 9 internal sequences previously reported in bighead carp and silver carp) from 17 species of the family Cyprinidae were aligned as well as 14 new isolated HAmoL2 sequences. Four subfamilies (type I, II, III and IV), which were divided based on diagnostic nucleotides in the tRNA-unrelated region, expanded preferentially within a certain lineage or within the whole family of Cyprinidae as multiple active source genes. The copy numbers of HAmo SINEs were estimated to vary from 104 to 106 in cyprinid genomes by quantitative RT-PCR. Over one hundred type IV members were identified and characterized in the primitive cyprinid Danio rerio genome but only tens of sequences were found to be similar with type I, II and III since the type IV was the oldest subfamily and its members dispersed in almost all investigated cyprinid fishes. For determining the taxonomic distribution of HAmo SINE, inter-primer SINE PCR was conducted in other non-cyprinid fishes, the results shows that HAmo SINE- related sequences may disperse in other families of order Cypriniforms but absent in other orders of bony fishes: Siluriformes, Polypteriformes, Lepidosteiformes, Acipenseriformes and Osteoglossiforms. Depending on HAmo LINE2, multiple source genes (subfamilies) of HAmo SINE actively expanded and underwent retroposition in a certain lineage or within the whole family of Cyprinidae. From this perspective, HAmo SINE should provide useful phylogenetic makers

  19. Study of a high power sine waveguide traveling wave tube amplifier centered at 8 GHz

    NASA Astrophysics Data System (ADS)

    Hoff, Brad W.; Simon, David S.; French, David M.; Lau, Y. Y.; Wong, Patrick

    2016-10-01

    Performance of a 20-stage X-band sine waveguide amplifier, driven by a 40 A, 100 kV, cylindrical electron beam, is studied using numerical simulation and interpreted using Pierce's classical traveling wave tube theory. For an input signal power level of 1.8 kW, particle-in-cell simulations predict gain and bandwidth values exceeding 14 dB and 13%, respectively. For an input signal power level of 7.2 kW, particle-in-cell simulations predict gain and bandwidth values exceeding 12 dB and 15%, respectively, with output power levels exceeding 110 kW at peak gain. Also given are: an assessment of the space charge factor (Pierce's QC parameter) for the complex circuit using simulation data, and an evaluation of the harmonic contents in the beam current.

  20. Obtaining changes in calibration-coil to seismometer output constants using sine waves

    USGS Publications Warehouse

    Ringler, Adam T.; Hutt, Charles R.; Gee, Lind S.; Sandoval, Leo D.; Wilson, David C.

    2013-01-01

    The midband sensitivity of a broadband seismometer is one of the most commonly used parameters from station metadata. Thus, it is critical for station operators to robustly estimate this quantity with a high degree of accuracy. We develop an in situ method for estimating changes in sensitivity using sine‐wave calibrations, assuming the calibration coil and its drive are stable over time and temperature. This approach has been used in the past for passive instruments (e.g., geophones) but has not been applied, to our knowledge, to derive sensitivities of modern force‐feedback broadband seismometers. We are able to detect changes in sensitivity to well within 1%, and our method is capable of detecting these sensitivity changes using any frequency of sine calibration within the passband of the instrument.

  1. Nonlinear disintegration of sine wave in the framework of the Gardner equation

    NASA Astrophysics Data System (ADS)

    Kurkin, Andrey; Talipova, Tatiana; Kurkina, Oxana; Rouvinskaya, Ekaterina; Pelinovsky, Efim

    2016-04-01

    Nonlinear disintegration of sine wave is studied in the framework of the Gardner equation (extended version of the Korteweg - de Vries equation with both quadratic and cubic nonlinear terms). Undular bores appear here as an intermediate stage of wave evolution. Our numerical computations demonstrate the features of undular bore developing for different signs of the cubic nonlinear term. If cubic nonlinear term is negative, and initial wave amplitude is large enough, two undular bores are generated from the two breaking points formed on both crest slopes (within dispersionless Gardner equation). Undular bore consists of one table-top soliton and a group of small soliton-like waves passing through the table-top soliton. If the cubic nonlinear term is positive and again the wave amplitude is large enough, the breaking points appear on crest and trough generating groups of positive and negative solitary-like pulses. It is shown that nonlinear interaction of waves happens according to one of scenarios of two-soliton interaction of "exchange" or "overtake" types with a phase shift. If small-amplitude pulses interact with large-amplitude soliton-like pulses, their speed in average is negative in the case when "free" velocity is positive. Nonlinear interaction leads to the generation of higher harmonics and spectrum width increases with amplitude increase independently of the sign of cubic nonlinear term. The breaking asymptotic k4/3 predicted within the dispersionless Gardner equation emerges during the process of undular bore development. The formation of soliton-like perturbations leads to appearance of several spectral peaks which are downshifting with time.

  2. Determination of the number of cells in a stepped sine wave inverter for equal charge transfer

    NASA Astrophysics Data System (ADS)

    Appelbaum, J.; Gabbay, D.

    1985-07-01

    The synthesis of an inverter sine wave output voltage by a staircase wave shape of low level voltage sources (cells) is accomplished by combining the cells in series at specific time intervals. Different cells of the inverter are then connected to the load for different time durations which results in unequal discharging of the cells. In order for the cells to transfer equal charge during the system operation, each voltage step should consist of a different number of cells in a parallel combination (module), the number of which depends on the time along the wave shape. The number of cells in each module is determined from the circuit current analysis and the appropriate switching time intervals, and is performed for a resistive and an inductive load. This number depends on the number of inverter voltage steps, the cell internal resistance, and the type of the load. The proper number of cells in the modules ensures identical state of charge of the cells, and equal cell recharging, and simplifies cell inspection, maintenance, and replacement.

  3. Scenario Based Approach for Multiple Source Tsunami Hazard Assessment for Sines, Portugal

    NASA Astrophysics Data System (ADS)

    Wronna, Martin; Omira, Rachid; Baptista, Maria Ana

    2015-04-01

    In this paper, we present a scenario-based approach for tsunami hazard assessment for the city and harbour of Sines, Portugal one the test-sites of project ASTARTE. Sines holds one of the most important deep-water ports which contains oil-bearing, petrochemical, liquid bulk, coal and container terminals. The port and its industrial infrastructures are facing the ocean to the southwest facing the main seismogenic sources. This work considers two different seismic zones: the Southwest Iberian Margin and the Gloria Fault. Within these two regions, a total of five scenarios were selected to assess tsunami impact at the test site. These scenarios correspond to the worst-case credible scenario approach based upon the largest events of the historical and paleo tsunami catalogues. The tsunami simulations from the source area towards the coast is carried out using NSWING a Non-linear Shallow Water Model With Nested Grids. The code solves the non-linear shallow water equations using the discretization and explicit leap-frog finite difference scheme, in a Cartesian or Spherical frame. The initial sea surface displacement is assumed to be equal to the sea bottom deformation that is computed by Okada equations. Both uniform and non-uniform slip conditions are used. The presented results correspond to the models using non-uniform slip conditions. In this study, the static effect of tides is analysed for three different tidal stages MLLW (mean lower low water) MSL (mean sea level) and MHHW (mean higher high water). For each scenario, inundation is described by maximum values of wave height, flow depth, drawdown, run-up and inundation distance. Synthetic waveforms are computed at virtual tide gages at specific locations outside and inside the harbour. The final results consist of Aggregate Scenario Maps presented for the different inundation parameters. This work is funded by ASTARTE - Assessment, Strategy And Risk Reduction for Tsunamis in Europe - FP7-ENV2013 6.4-3, Grant 603839

  4. A prospective randomized comparison of defibrillation efficacy of truncated pulses and damped sine wave pulses in humans.

    PubMed

    Bardy, G H; Zaghi, H; Gartman, D; Poole, J E; Kudenchuk, P K; Dolack, G L; Johnson, G; Troutman, C

    1994-09-01

    Damped sine wave pulses have been used for nearly 50 years in transthoracic defibrillation systems. The purpose of this study was to determine whether damped sine wave pulses have a role in implantable defibrillators. In 21 survivors of cardiac arrest, we prospectively compared defibrillation efficacy of a standard truncated capacitor (RC) monophasic pulse with a damped sine wave inductor-capacitor (LRC) pulse using a right ventricular-left ventricular epicardial patch-patch electrode system. The RC pulse was a standard 65% tilt monophasic waveform generated from a 120 mu F capacitor. The LRC pulse was designed to simulate the waveform currently used in transthoracic defibrillators and was generated by passing the charge stored on a 40 mu F capacitor through a 37-mH inductor. Capacitor voltage, peak delivered voltage, peak delivered current, discharge pathway resistance, delivered energy, and stored energy were compared for the two waveforms at the defibrillation threshold. There was no difference in defibrillation efficacy for the two waveforms. Peak delivered voltage was similar at the defibrillation threshold: 313 +/- 101 V for the RC pulse and 342 +/- 119 V for the LRC pulse (P = 0.16). Similarly, no differences were found in defibrillation threshold peak delivered current: 8.6 +/- 2.5 (RC) versus 9.3 +/- 2.7 (LRC) amperes (A) (P = 0.20); discharge pathway resistance: 37 +/- 11 (RC) versus 38 +/- 13 (LRC) omega (P = 0.71); delivered energy: 7.0 +/- 4.5 (RC) versus 7.0 +/- 4.0 (LRC) joules (J) (P = 0.88); and stored energy: 8.7 +/- 5.7 (RC) versus 9.8 +/- 5.4 (LRC) J (P = 0.35). Although both waveforms performed the same, it was necessary to use substantially higher stored voltages with the damped sine wave delivery system than with the truncated waveform delivery system: 356 +/- 110 V for the RC pulse and 675 +/- 192 V for the LRC pulse (P < 0.0001). This study demonstrates that RC monophasic pulses provide equally effective epicardial defibrillation as LRC

  5. Audio-visual integration of speech with time-varying sine wave speech replicas

    NASA Astrophysics Data System (ADS)

    Tuomainen, Jyrki; Andersen, Tobias; Tiippana, Kaisa; Sams, Mikko

    2002-11-01

    We tested whether listener's knowledge about the nature of the auditory stimuli had an effect on audio-visual (AV) integration of speech. First, subjects were taught to categorize two sine-wave (sw) replicas of the real speech tokens /omso/ and /onso/ into two arbitrary nonspeech categories without knowledge of the speech-like nature of the sounds. A test with congruent and incongruent AV-stimulus condition (together with auditory-only presentations of the sw stimuli) demonstrated no AV integration, but instead close to perfect categorization of stimuli in the two arbitrary categories according to the auditory presentation channel. Then, the same subjects (of which most were still under the impression that the sw-stimuli were nonspeech sounds) were taught to categorize the sw stimuli as /omso/ and /onso/, and again tested with the same AV stimuli as used in the nonspeech sw condition. This time, subjects showed highly reliable AV integration similar to integration obtained with real speech stimuli in a separate test. We suggest that AV integration only occurs when subject are in a so-called ''speech mode.''

  6. Evaluation of the operating internal resistance, inductance, and capacitance of intact damped sine wave defibrillators.

    PubMed

    Babbs, C F; Whistler, S J

    1978-01-01

    A method is developed for determing actual values of circuit elements in a damped sine wave (Lown waveform) defibrillator solely from measurements of the output, using two or more power resistors and a storage oscilloscope. If a defibrillator containing capacitance C, inductance L, and internal resistance RI, is discharged into increasing 5- to 100-ohm resistive loads R, it is shown for underdamped output waveforms that â = RI/2L + R/2L and ĉ = CRI + CR, where â = pi[t2tan(pit1/t2)], ĉ = 2â/[â2 + (pi/t2)2], t1 = time from onset to peak, and t2 = time from onset to first zero crossing of the output waveform on the oscilloscope trace. Linear plots of â vs R are constructed for seven defibrillators, and values of RI and L computed as intercept/slope and 1/(2 slope) respectively. C is given by the slope of a linear plot of ĉ vs R. Delivered energy is accurately predicted as stored energy X R/(RI + R).

  7. Study of flow induced by sine wave and saw tooth plasma actuators

    NASA Astrophysics Data System (ADS)

    Liu, Zhifeng; Wang, Lianze; Fu, Song

    2011-11-01

    The effect of plasma actuator that uses saw-tooth or sine-wave shape electrodes on boundary layer flows is experimentally investigated. The measurement results are compared with a corresponding standard configuration (conventional design using two rectangular strip electrodes)—the actuator that produces a nearly two-dimensional horizontal wall jet upon actuation. PIV measurements are used to characterize the actuators in a quiescent chamber. Operating in a steady manner, the new actuators result in the formation of streamwise and spanwise vortices. That is to say, the new actuators render the plasma actuators inducing three-dimensional variations in the shear layer, offering significant flexibility in flow control. The affected flowfield with the new actuators is significantly larger than that with the conventional linear actuators. While the conventional linear actuators affect primarily the boundary layer flow on a scale of about 1 cm above the wall, the new actuators affect the near wall region at a significantly larger scale. This new design broadens the applicability and enhances the flow control effects and it is potentially a more efficient flow control device.

  8. Early malnutrition diffusely affects children contrast sensitivity to sine-wave gratings of different spatial frequencies.

    PubMed

    Dos Santos, Natanael Antonio; Alencar, Caroline Costa Gomes

    2010-08-01

    Cognitive, behavioral and neurophysiological deficits, associated with malnutrition, are described in the literature. The aim of this study was to evaluate the visual contrast sensitivity in children with early malnutrition, classified according to the anthropometric parameters of Waterlow. Visual contrast sensitivity of 16 boys from 7-10 years old was measured using the staircase psychophysical method, using vertical sine-wave gratings of 0.25, 1.0, 2.0 and 8.0 cycles per degree (cpd) of visual angle. Malnourished children were approximately 3.3, 10.9 and 6.6 times less sensitive to the frequencies of 0.25, 1.0 and 2.0 cpd, respectively, although they were approximately 1.1 times more sensitive to the frequency of 8.0 cpd. It is likely that early malnutrition adversely affected the magnocellular pathway on the one hand, since early malnourished children needed more contrast to detect low and low-to-medium frequencies; on the other hand, early malnutrition did not affect the parvocellular pathway, since there was an increase of sensitivity to the highest frequency.

  9. Sines and Cosines. Part 1 of 3

    NASA Technical Reports Server (NTRS)

    Apostol, Tom M. (Editor)

    1992-01-01

    Applying the concept of similarities, the mathematical principles of circular motion and sine and cosine waves are presented utilizing both film footage and computer animation in this 'Project Mathematics' series video. Concepts presented include: the symmetry of sine waves; the cosine (complementary sine) and cosine waves; the use of sines and cosines on coordinate systems; the relationship they have to each other; the definitions and uses of periodic waves, square waves, sawtooth waves; the Gibbs phenomena; the use of sines and cosines as ratios; and the terminology related to sines and cosines (frequency, overtone, octave, intensity, and amplitude).

  10. Light redirecting system using sine-wave based panels for dense urban areas

    NASA Astrophysics Data System (ADS)

    Mohamed, Mohamed W. N.; Mashaly, Islam A.; Mohamed, Osama N.; El-Henawy, Sally I.; Galal, Ola; Taha, Iman; Nassar, Khaled; Safwat, Amr M. E.

    2014-09-01

    Cities and towns around the world are becoming more condensed due to the shrinking amount of buildable areas, which significantly reduces the amount of light that occupants have access to. This lack of natural lighting results in health, safety and quality of life degradation. This paper presents a new technique of transmitting sunlight downward into narrow alleys and streets, by using a daylighting guiding acrylic panel that is capable of changing the direction and distribution of the incident light. The core of the proposed daylight guidance system is made up of light transmission panels with high quality. The corrugations have sine wave shaped cross-section so that the panel functions as an optical diffuser perpendicular to the direction of sunlight propagation. The day lighting system consists of the corrugated panels and a lattice frame, which supports the panel. The proposed system is to be mounted on the building roof facing the sun so as to redirect the incident sunlight downward into the narrow alleys or streets. Since building sizes and orientations are different the frame is arranged such that substantially deep light penetration and high luminance level can be achieved. Simulation results show that the proposed panel improves the illuminance values by more than 200% and 400% in autumn and winter, respectively, provides fan-out angle that exceeds 80° for certain solar altitudes and the transmitted power percentage varies from 40% to 90% as the solar altitude varies from 10° to 80°. Experimental results are in a good agreement with the simulations.

  11. Zooming in: From spatially extended traveling waves to localized structures: The case of the Sine-Gordon equation in (1+3) dimensions.

    PubMed

    Zarmi, Yair

    2017-01-01

    The Sine-Gordon equation in (1+3) dimensions has N-traveling front ("kink", "domain wall")- solutions for all N ≥ 1. A nonlinear functional of the solution, which vanishes on a single-front, maps multi-front solutions onto sets of infinitely long, but laterally bounded, rods, which move in space. Each rod is localized in the vicinity of the intersection of two Sine-Gordon fronts. The rod systems are solutions of the linear wave equation, driven by a term that is constructed out of Sine-Gordon fronts. An additional linear operation maps multi-rod systems onto sets of blobs. Each blob is localized in the vicinity of rod intersection, and moves in space. The blob systems are solutions of the linear wave equation, driven by a term that is also constructed out of Sine-Gordon fronts. The temporal evolution of multi-blob solutions mimics elastic collisions of systems of spatially extended particles.

  12. Verification of low frequency ac-dc transfer differences of thermal converters using sampling with sine-wave fit

    NASA Astrophysics Data System (ADS)

    Funck, Torsten; Spiegel, Thomas

    2015-09-01

    Thermal converters show significant ac-dc transfer differences at low frequencies due to nonlinearities of the heat transport mechanism and of the thermal-to-electric conversion. It is assumed that the ac-dc transfer differences at low frequencies are proportional to the input power. We have proved this assumption by an independent method with sampling techniques. A novel approach based on sine-wave fitting is used to calculate the RMS value of the sampled signal from the samples. It makes use of the low noise in a metrological environment. Expanded uncertainties in the order of 1.2 μV/V have been achieved.

  13. Bidirectional coupling of two erbium-doped fibre ring lasers subject to sine-wave pump modulation

    NASA Astrophysics Data System (ADS)

    Martín, J. C.

    2011-03-01

    Two erbium-doped fibre ring lasers are subject to different sine-wave pump modulation conditions, so that each of them may present periodic or chaotic response. For each working condition, the response of both lasers is analyzed for different coupling factors of their cavities. Many possible situations are found: as the coupling factor is swept from 0 to the maximum coupling allowed by the setup, for some modulation conditions no change of regime (periodic or chaotic) is observed, while in other cases the regime changes several times. Besides, it is found that the correlation between both laser emissions may not increase monotonously with the coupling factor: for certain intermediate coupling values, a correlation minimum is found. Nevertheless, a similar feature of all cases is the coupling ratio necessary to achieve a synchronized behaviour: it does not depend strongly on the modulation conditions chosen. The experimental results are compared with numerical simulations. An acceptable agreement is obtained.

  14. Truncated Painleve expansion: Tanh-traveling wave solutions and reduction of sine-Poisson equation to a quadrature for stationary and nonstationary three-dimensional collisionless cold plasma

    SciTech Connect

    Ibrahim, R. S.; El-Kalaawy, O. H.

    2006-10-15

    The relativistic nonlinear self-consistent equations for a collisionless cold plasma with stationary ions [R. S. Ibrahim, IMA J. Appl. Math. 68, 523 (2003)] are extended to 3 and 3+1 dimensions. The resulting system of equations is reduced to the sine-Poisson equation. The truncated Painleve expansion and reduction of the partial differential equation to a quadrature problem (RQ method) are described and applied to obtain the traveling wave solutions of the sine-Poisson equation for stationary and nonstationary equations in 3 and 3+1 dimensions describing the charge-density equilibrium configuration model.

  15. Persistent hiccups and vomiting with multiple cranial nerve palsy in a case of zoster sine herpete.

    PubMed

    Yoshida, Takeshi; Fujisaki, Natsumi; Nakachi, Ryo; Sueyoshi, Takeshi; Suwazono, Shugo; Suehara, Masahito

    2014-01-01

    A 76-year-old man came to our hospital complaining of hiccups and vomiting lasting for five days. A neurological examination showed dysfunction of cranial nerves V, VII, VIII, IX and X on the left side. Cerebrospinal fluid polymerase chain reaction for varicella zoster virus-DNA was positive. The patient responded well to treatment with intravenous acyclovir and steroids. To the best of our knowledge, this is the first case report of zoster sine herpete presenting with persistent hiccups and vomiting. It is important to keep in mind that herpes zoster can present with symptoms that closely resemble those of intractable hiccups and nausea of neuromyelitis optica. Early detection of the virus is critical for making appropriate treatment decisions.

  16. Investigation of 0.38 THz backward-wave oscillator based on slotted sine waveguide and pencil electron beam

    SciTech Connect

    Zhang, Luqi; Wei, Yanyu; Wang, Bing; Shen, Wenan; Xu, Jin; Gong, Yubin; Park, Gun-Sik

    2016-03-15

    A novel backward wave oscillator (BWO) is presented by utilizing a slotted sine waveguide with a pencil electron beam to produce the high power terahertz wave. The high frequency characteristics including dispersion properties, interaction impedances, and transmission characteristics of the slotted sine waveguide are analyzed in detail. The high frequency system including the output coupler, slow wave structure (SWS), and reflector are designed properly. A 3-D particle-in-cell mode is applied to predict the device performance of the BWO based on the novel SWS. The investigation results demonstrate that this device can generate over 8.05 W output power in the frequency range of 363.4–383.8 GHz by using a 30 mA pencil electron beam and adjusting the beam voltage from 20 kV to 32 kV.

  17. Recirculation in multiple wave conversions

    SciTech Connect

    Kaufman, A. N.; Brizard, A.J.; Kaufman, A.N.; Tracy, E.R.

    2008-07-30

    A one-dimensional multiple wave-conversion model is constructed that allows energy recirculation in ray phase space. Using a modular eikonal approach, the connection coefficients for this model are calculated by ray phase-space methods. Analytical results (confirmed numerically) show that all connection coefficients exhibit interference effects that depend on an interference phase, calculated from the coupling constants and the area enclosed by the intersecting rays. This conceptual model, which focuses on the topology of intersecting rays in phase space, is used to investigate how mode conversion between primary and secondary waves is modified by the presence of a tertiary wave.

  18. Zooming in: From spatially extended traveling waves to localized structures: The case of the Sine-Gordon equation in (1+3) dimensions

    PubMed Central

    2017-01-01

    The Sine-Gordon equation in (1+3) dimensions has N-traveling front (“kink”, “domain wall”)- solutions for all N ≥ 1. A nonlinear functional of the solution, which vanishes on a single-front, maps multi-front solutions onto sets of infinitely long, but laterally bounded, rods, which move in space. Each rod is localized in the vicinity of the intersection of two Sine-Gordon fronts. The rod systems are solutions of the linear wave equation, driven by a term that is constructed out of Sine-Gordon fronts. An additional linear operation maps multi-rod systems onto sets of blobs. Each blob is localized in the vicinity of rod intersection, and moves in space. The blob systems are solutions of the linear wave equation, driven by a term that is also constructed out of Sine-Gordon fronts. The temporal evolution of multi-blob solutions mimics elastic collisions of systems of spatially extended particles. PMID:28422999

  19. Towards mitigating the effect of sine-Gaussian noise transients on searches for gravitational waves from compact binary coalescences

    NASA Astrophysics Data System (ADS)

    Bose, Sukanta; Dhurandhar, Sanjeev; Gupta, Anuradha; Lundgren, Andrew

    2016-12-01

    Gravitational wave signals were recently detected directly by LIGO from the coalescences of two stellar mass black hole pairs. These detections have strengthened our long held belief that compact binary coalescences (CBCs) are the most promising gravitational wave detection prospects accessible to ground-based interferometric detectors. For detecting CBC signals, it is of vital importance to characterize and identify non-Gaussian and nonstationary noise in these detectors. In this work, we model two important classes of transient artifacts that contribute to this noise and adversely affect the detector sensitivity to CBC signals. One of them is the sine-Gaussian "glitch," characterized by a central frequency f0 and a quality factor Q and the other is the chirping sine-Gaussian glitch, which is characterized by f0, Q as well as a chirp parameter. We study the response that a bank of compact binary inspiral templates has to these two families of glitches when they are used to match filter data containing any of these glitches. Two important characteristics of this response are the distributions of the signal-to-noise ratio and the time lag (i.e., how long after the occurrence of a glitch the signal-to-noise ratio of a trigger arises from its matched filtering by a template peaks) of individual templates. We show how these distributions differ from those when the detector data has a real CBC signal instead of a glitch. We argue that these distinctions can be utilized to develop useful signal-artifact discriminators that add negligibly to the computational cost of a CBC search. Specifically, we show how the central frequency of a glitch can be used to set adaptive time windows around it so that any template trigger occurring in that window can be quarantined for further vetting of its supposed astrophysical nature. Second, we recommend focusing efforts on reducing the incidence of glitches with low central-frequency values because they create CBC triggers with the

  20. New Algorithms for the Detection and Elimination of Sine Waves and Other Narrow-Band Signals in the Presence of Broadband Signals and Noise

    DTIC Science & Technology

    1992-10-01

    SUBJECT TERMS (ConinL’e on revE’Se if necessary and tdcntit) b) block number) FIE.D GROI P SuB-GIOut, narrow-band interference removal adaptive...notches, the notches will jump at random between sine waves. This pattern is indicated in the table by the word "Jump". 4. Values of pain and pa., in the

  1. Laser ranging at 1550 nm with 1-GHz sine-wave gated InGaAs/InP APD single-photon detector.

    PubMed

    Ren, Min; Gu, Xiaorong; Liang, Yan; Kong, Weibin; Wu, E; Wu, Guang; Zeng, Heping

    2011-07-04

    We demonstrated a laser ranging system with single photon detection at 1550 nm. The single-photon detector was a 1-GHz sine-wave gated InGaAs/InP avalanche photodiode. In daylight, 8-cm depth resolution was achieved directly by using a time-of-flight approach based on time-correlated single photon counting measurement. This system presented a potential for low energy level and eye-safe laser ranging system in long-range measurement.

  2. Nonlinear disintegration of sine wave in the framework of the Gardner equation

    NASA Astrophysics Data System (ADS)

    Kurkina, Oxana; Rouvinskaya, Ekaterina; Talipova, Tatiana; Kurkin, Andrey; Pelinovsky, Efim

    2016-10-01

    Internal tidal wave entering shallow waters transforms into an undular bore and this process can be described in the framework of the Gardner equation (extended version of the Korteweg-de Vries equation with both quadratic and cubic nonlinear terms). Our numerical computations demonstrate the features of undular bore developing for different signs of the cubic nonlinear term. If cubic nonlinear term is negative, and initial wave amplitude is large enough, two undular bores are generated from the two breaking points formed on both crest slopes (within dispersionless Gardner equation). Undular bore consists of one table-top soliton and a group of small soliton-like waves passing through the table-top soliton. If the cubic nonlinear term is positive and again the wave amplitude is large enough, the breaking points appear on crest and trough generating groups of positive and negative soliton-like pulses. This is the main difference with respect to the classic Korteweg-de Vries equation, where the breaking point is single. It is shown also that nonlinear interaction of waves happens similarly to one of scenarios of two-soliton interaction of "exchange" or "overtake" types with a phase shift. If small-amplitude pulses interact with large-amplitude soliton-like pulses, their speed in average is negative in the case when "free" velocity is positive. Nonlinear interaction leads to the generation of higher harmonics and spectrum width increases with amplitude increase independently of the sign of cubic nonlinear term. The breaking asymptotic k 4 / 3 predicted within the dispersionless Gardner equation emerges during the process of undular bore development. The formation of soliton-like perturbations leads to appearance of several spectral peaks which are downshifting with time.

  3. Response functions for sine- and square-wave modulations of disparity.

    NASA Technical Reports Server (NTRS)

    Richards, W.

    1972-01-01

    Depth sensations cannot be elicited by modulations of disparity that are more rapid than about 6 Hz, regardless of the modulation amplitude. Vergence tracking also fails at similar modulation rates, suggesting that this portion of the oculomotor system is limited by the behavior of disparity detectors. For sinusoidal modulations of disparity between 1/2 to 2 deg of disparity, most depth-response functions exhibit a low-frequency decrease that is not observed with square-wave modulations of disparity.

  4. Modulated Sine Waves for Differential Absorption Measurements Using a CW Laser System

    NASA Technical Reports Server (NTRS)

    Campbell, Joel F. (Inventor); Lin, Bing (Inventor); Nehrir, Amin R. (Inventor)

    2015-01-01

    A continuous wave Light Detection and Ranging (CW LiDAR) system utilizes two or more laser frequencies and time or range shifted pseudorandom noise (PN) codes to discriminate between the laser frequencies. The performance of these codes can be improved by subtracting out the bias before processing. The CW LiDAR system may be mounted to an artificial satellite orbiting the earth, and the relative strength of the return signal for each frequency can be utilized to determine the concentration of selected gases or other substances in the atmosphere.

  5. On the possibility of the observation of the resonance interaction between kinks of the sine-Gordon equation and localized waves in real physical systems

    NASA Astrophysics Data System (ADS)

    Ekomasov, E. G.; Gumerov, A. M.; Kudryavtsev, R. V.

    2015-06-01

    The resonance dynamics of kinks of the sine-Gordon equation in a system with a single point impurity with allowance for the generation of localized waves in the presence of an external force and dissipation has been studied. Equations of motion for the coordinate of the kink center and the amplitude of the impurity mode have been found. The analysis of solutions of these equations and results of the numerical simulation of the modified sine-Gordon equation have showed that damping and the external force act against the appearance of the resonance reflection of the kink from the attractive impurity. However, the resonance energy exchange between solitons causing it still takes place.

  6. Multiple scroll wave chimera states

    NASA Astrophysics Data System (ADS)

    Maistrenko, Volodymyr; Sudakov, Oleksandr; Osiv, Oleksiy; Maistrenko, Yuri

    2017-06-01

    We report the appearance of three-dimensional (3D) multiheaded chimera states that display cascades of self-organized spatiotemporal patterns of coexisting coherence and incoherence. We demonstrate that the number of incoherent chimera domains can grow additively under appropriate variations of the system parameters generating thereby head-adding cascades of the scroll wave chimeras. The phenomenon is derived for the Kuramoto model of N 3 identical phase oscillators placed in the unit 3D cube with periodic boundary conditions, parameters being the coupling radius r and phase lag α. To obtain the multiheaded chimeras, we perform the so-called `cloning procedure' as follows: choose a sample single-headed 3D chimera state, make appropriate scale transformation, and put some number of copies of them into the unit cube. After that, start numerical simulations with slightly perturbed initial conditions and continue them for a sufficiently long time to confirm or reject the state existence and stability. In this way it is found, that multiple scroll wave chimeras including those with incoherent rolls, Hopf links and trefoil knots admit this sort of multiheaded regeneration. On the other hand, multiple 3D chimeras without spiral rotations, like coherent and incoherent balls, tubes, crosses, and layers appear to be unstable and are destroyed rather fast even for arbitrarily small initial perturbations.

  7. Receiver Signal to Noise Ratios for IPDA Lidars Using Sine-wave and Pulsed Laser Modulation and Direct Detections

    NASA Technical Reports Server (NTRS)

    Sun, Xiaoli; Abshire, James B.

    2011-01-01

    seeder lasers, one on-line and one offline that are intensity modulated by two different frequency sine-waves signals before being amplified by a common laser amplifier. The receiver uses narrowband amplitude demodulation, or lock-in, Signal processing at the given laser modulation frequencies [3,4]. The laser transmitter operates in a quasi CW mode with the peak power equal to twice the average power. The on-line and off-line lasers can be transmitted at the same time without interference. Another direct detection technique uses a low duty cycle pulsed laser modulation [5,6] with the laser wavelengths alternating between on-line and off-line on successive pulses. The receiver uses time resolved detection and can also provide simultaneous target range measurement. With a lower laser duty cycle it requires a much higher peak laser power for the same average power.

  8. Propagation and excitation of multiple surface waves

    NASA Astrophysics Data System (ADS)

    Faryad, Muhammad

    Surface waves are the solutions of the frequency-domain Maxwell equations at the planar interface of two dissimilar materials. The time-averaged Poynting vector of a surface wave (i) has a significant component parallel to the interface and (ii) decays at sufficiently large distances normal to the interface. If one of the partnering materials is a metal and the other a dielectric, the surface waves are called surface plasmon-polariton (SPP) waves. If both partnering materials are dielectric, with at least one being periodically nonhomogeneous normal to the interface, the surface waves are called Tamm waves; and if that dielectric material is also anisotropic, the surface waves are called Dyakonov--Tamm waves. SPP waves also decays along the direction of propagation, whereas Tamm and Dyakonov--Tamm waves propagate with negligible losses. The propagation and excitation of multiple SPP waves guided by the interface of a metal with a periodically nonhomogeneous sculptured nematic thin film (SNTF), and the interface of a metal with a rugate filter were theoretically investigated. The SNTF is an anisotropic material with a permittivity dyadic that is periodically nonhomogeneous in the thickness direction. A rugate filter is also a periodically nonhomogeneous dielectric material; however, it is an isotropic material. Multiple SPP waves of the same frequency but with different polarization states, phase speeds, attenuation rates, and spatial field profiles were found to be guided by a metal/SNTF interface, a metal/rugate-filter interface, and a metal slab in the SNTF. Multiple Dyakonov--Tamm waves of the same frequency but different polarization states, phase speeds, and spatial field profiles were found to be guided by a structural defect in an SNTF, and by a dielectric slab in an SNTF. The characteristics of multiple SPP and Dyakonov--Tamm waves were established by the investigations on canonical boundary-value problems. The Turbadar-Kretschmann-Raether (TKR) and the

  9. Sine-Gordon Equation in (1+2) and (1+3) dimensions: Existence and Classification of Traveling-Wave Solutions

    PubMed Central

    Zarmi, Yair

    2015-01-01

    The (1+1)-dimensional Sine-Gordon equation passes integrability tests commonly applied to nonlinear evolution equations. Its kink solutions (one-dimensional fronts) are obtained by a Hirota algorithm. In higher space-dimensions, the equation does not pass these tests. Although it has been derived over the years for quite a few physical systems that have nothing to do with Special Relativity, the Sine-Gordon equation emerges as a non-linear relativistic wave equation. This opens the way for exploiting the tools of the Theory of Special Relativity. Using no more than the relativistic kinematics of tachyonic momentum vectors, from which the solutions are constructed through the Hirota algorithm, the existence and classification of N-moving-front solutions of the (1+2)- and (1+3)-dimensional equations for all N ≥ 1 are presented. In (1+2) dimensions, each multi-front solution propagates rigidly at one velocity. The solutions are divided into two subsets: Solutions whose velocities are lower than a limiting speed, c = 1, or are greater than or equal to c. To connect with concepts of the Theory of Special Relativity, c will be called “the speed of light.” In (1+3)-dimensions, multi-front solutions are characterized by spatial structure and by velocity composition. The spatial structure is either planar (rotated (1+2)-dimensional solutions), or genuinely three-dimensional – branes. Planar solutions, propagate rigidly at one velocity, which is lower than, equal to, or higher than c. Branes must contain clusters of fronts whose speed exceeds c = 1. Some branes are “hybrids”: different clusters of fronts propagate at different velocities. Some velocities may be lower than c but some must be equal to, or exceed, c. Finally, the speed of light cannot be approached from within the subset of slower-than-light solutions in both (1+2) and (1+3) dimensions. PMID:26020922

  10. Sine-Gordon Equation in (1+2) and (1+3) dimensions: Existence and Classification of Traveling-Wave Solutions.

    PubMed

    Zarmi, Yair

    2015-01-01

    The (1+1)-dimensional Sine-Gordon equation passes integrability tests commonly applied to nonlinear evolution equations. Its kink solutions (one-dimensional fronts) are obtained by a Hirota algorithm. In higher space-dimensions, the equation does not pass these tests. Although it has been derived over the years for quite a few physical systems that have nothing to do with Special Relativity, the Sine-Gordon equation emerges as a non-linear relativistic wave equation. This opens the way for exploiting the tools of the Theory of Special Relativity. Using no more than the relativistic kinematics of tachyonic momentum vectors, from which the solutions are constructed through the Hirota algorithm, the existence and classification of N-moving-front solutions of the (1+2)- and (1+3)-dimensional equations for all N ≥ 1 are presented. In (1+2) dimensions, each multi-front solution propagates rigidly at one velocity. The solutions are divided into two subsets: Solutions whose velocities are lower than a limiting speed, c = 1, or are greater than or equal to c. To connect with concepts of the Theory of Special Relativity, c will be called "the speed of light." In (1+3)-dimensions, multi-front solutions are characterized by spatial structure and by velocity composition. The spatial structure is either planar (rotated (1+2)-dimensional solutions), or genuinely three-dimensional--branes. Planar solutions, propagate rigidly at one velocity, which is lower than, equal to, or higher than c. Branes must contain clusters of fronts whose speed exceeds c = 1. Some branes are "hybrids": different clusters of fronts propagate at different velocities. Some velocities may be lower than c but some must be equal to, or exceed, c. Finally, the speed of light cannot be approached from within the subset of slower-than-light solutions in both (1+2) and (1+3) dimensions.

  11. Pain relief by transcutaneous electric nerve stimulation with bidirectional modulated sine waves in patients with chronic back pain: a randomized, double-blind, sham-controlled study.

    PubMed

    Shimoji, Koki; Takahashi, Norio; Nishio, Yasuyuki; Koyanagi, Mika; Aida, Sumihisa

    2007-01-01

    Objectives.  Newly developed bidirectional modulated sine waves (BMW) might provide some derived benefit to patients with low back pain. Pain relief by transcutaneous electric nerve stimulation (TENS) with BMWs was tested. Materials and Methods.  Analgesic effects of BMWs and conventional bidirectional pulsed waves on chronic back pain in 28 patients were compared, and effects of repeated TENS using BMWs on chronic back pain were investigated in 21 patients by means of a randomized double-blind, sham-controlled, parallel-group method. Pain intensity was assessed using numerical rating scale (NRS). Results.  There was significant immediate reduction in NRS in patients receiving BMWs, and 60 min after treatment compared to sham TENS. Weekly repeated treatments using massage and TENS with BMWs for 5 weeks resulted in a decrease of NRS, but there were no significant differences between the TENS plus massage and sham TENS plus massage groups. Conclusions.  This study shows that TENS with BMWs significantly inhibits chronic back pain, and treatment effects are attained within a day. The results also suggest that there were no statistically significant long-term effects of TENS with BMW in the repeated treatment.

  12. Multiple M-Wave Interaction with Fluxes

    SciTech Connect

    Bandos, Igor A.

    2010-08-13

    We present the equations of motion for multiple M0-brane (multiple M-wave) systems in general 11 dimensional supergravity background. These are obtained in the frame of superembedding approach, but have a rigid structure: they can be restored from SO(1,1)xSO(9) symmetry characteristic for M0. BPS (Bogomol'nyi-Prasad-Sommerfield) conditions for the 1/2 supersymmetric solution of these equations have the fuzzy 2-sphere solution modeling M2-brane.

  13. Time domain wave separation using multiple microphones.

    PubMed

    Kemp, Jonathan A; van Walstijn, Maarten; Campbell, D Murray; Chick, John P; Smith, Richard A

    2010-07-01

    Methods of measuring the acoustic behavior of tubular systems can be broadly characterized as steady state measurements, where the measured signals are analyzed in terms of infinite duration sinusoids, and reflectometry measurements which exploit causality to separate the forward and backward going waves in a duct. This paper sets out a multiple microphone reflectometry technique which performs wave separation by using time domain convolution to track the forward and backward going waves in a cylindrical source tube. The current work uses two calibration runs (one for forward going waves and one for backward going waves) to measure the time domain transfer functions for each pair of microphones. These time domain transfer functions encode the time delay, frequency dependent losses and microphone gain ratios for travel between microphones. This approach is applied to the measurement of wave separation, bore profile and input impedance. The work differs from existing frequency domain methods in that it combines the information of multiple microphones within a time domain algorithm, and differs from existing time domain methods in its inclusion of the effect of losses and gain ratios in intermicrophone transfer functions.

  14. A NEED FOR DYNAMIC HEMATOLOGY AND SERUM BIOCHEMISTRY REFERENCE TOOLS: NOVEL USE OF SINE WAVE FUNCTIONS TO PRODUCE SEASONALLY VARYING REFERENCE CURVES IN PLATYPUSES (ORNITHORHYNCHUS ANATINUS).

    PubMed

    Macgregor, James W; Holyoake, Carly S; Connolly, Joanne H; Robertson, Ian D; Fleming, Patricia A; Warren, Kristin S

    2017-04-01

    Seasonal changes in hematology and serum biochemistry results, described by separate reference intervals for different seasons, have been reported in many animals. We developed a novel method to investigate seasonal variation in values and a reference tool (the reference curve) based on sine wave functions that, for suitable variables, represents data more appropriately than a fixed reference interval. We applied these techniques to values observed in blood samples from 126 adult wild platypuses ( Ornithorhynchus anatinus ; 58 females and 68 males). Samples were collected under isoflurane anesthesia from animals captured in the Inglis Catchment in northwest Tasmania. In general, packed cell volume (PCV), red cell count (RCC), and hemoglobin (Hb) values appeared to be lower than those in two studies that previously reported platypus hematology reference intervals. This likely resulted from reduced stress-related splenic contraction or isoflurane-associated splenic sequestration of red blood cells in our study. Reference curves were described for five variables (PCV, RCC, Hb, albumin, and magnesium). We found evidence that this seasonal variation may result from metabolic changes associated with seasonal variations in environmental temperature. These observations suggest that it is important for researchers reporting platypus hematology and serum biochemistry to look for seasonal changes in their data to ensure it is appropriately interpreted.

  15. DNA cleavage and Trp53 differentially affect SINE transcription.

    PubMed

    Hagan, Christy R; Rudin, Charles M

    2007-03-01

    Among the cellular responses observed following treatment with DNA-damaging agents is the activation of Short Interspersed Elements (SINEs; retrotransposable genetic elements that comprise over 10% of the human genome). By placing a human SINE (the Alu element) into murine cells, we have previously shown that DNA-damaging agents such as etoposide can induce both upregulation of SINE transcript levels and SINE retrotransposition. A similarly cytotoxic (but not genotoxic) exposure to vincristine was not associated with SINE activation. Here we demonstrate that multiple other genotoxic exposures are associated with upregulation of SINE transcript levels. By comparing the effects of similarly cytotoxic doses of the topoisomerase II inhibitors etoposide and merbarone, we confirm that DNA strand breakage is specifically associated with SINE induction. By evaluating transcription rate and RNA stability, we demonstrate that SINE induction by genotoxic exposure is associated with transcriptional induction and not with transcript stabilization. Finally we demonstrate that SINE induction by genotoxic stress is mediated by a Trp53-independent pathway, and in fact that Trp53 plays an inhibitory role in attenuating the transcriptional induction of SINE elements following exposure to a genotoxic agent. Together these data support a model in which initial DNA damage can trigger genomic instability due to SINE activation, a response which may be amplified in cancer cells lacking functional TP53. Copyright (c) 2006 Wiley-Liss, Inc.

  16. Shape and wobbling wave excitations in Josephson junctions: Exact solutions of the (2+1) -dimensional sine-Gordon model

    NASA Astrophysics Data System (ADS)

    Gulevich, D. R.; Kusmartsev, F. V.; Savel'Ev, Sergey; Yampol'Skii, V. A.; Nori, Franco

    2009-09-01

    We predict a class of excitations propagating along a Josephson vortex in two-dimensional Josephson junctions. These excitations are associated with the distortion of a Josephson vortex line of an arbitrary profile. We derive a universal analytical expression for the energy of arbitrary-shape excitations, investigate their influence on the dynamics of a vortex line, and discuss conditions where such excitations can be created. Finally, we show that such excitations play the role of a clock for a relativistically-moving Josephson vortex and suggest an experiment to measure a time-dilation effect analogous to that in special relativity. The position of the shape excitation on a Josephson vortex acts like a “minute hand” showing the time in the rest frame associated with the vortex. Remarkably, at some conditions, the shape wave can carry negative energy: a vortex with the shape excitation can have less energy than the same vortex without it.

  17. Shape and wobbling wave excitations in Josephson junctions: Exact solutions of the (2+1)-dimensional sine-Gordon model

    SciTech Connect

    Gulevich, D. R.; Savel'ev, Sergey; Kusmartsev, F. V.; Yampol'skii, V. A.; Nori, Franco

    2009-09-01

    We predict a class of excitations propagating along a Josephson vortex in two-dimensional Josephson junctions. These excitations are associated with the distortion of a Josephson vortex line of an arbitrary profile. We derive a universal analytical expression for the energy of arbitrary-shape excitations, investigate their influence on the dynamics of a vortex line, and discuss conditions where such excitations can be created. Finally, we show that such excitations play the role of a clock for a relativistically-moving Josephson vortex and suggest an experiment to measure a time-dilation effect analogous to that in special relativity. The position of the shape excitation on a Josephson vortex acts like a 'minute hand' showing the time in the rest frame associated with the vortex. Remarkably, at some conditions, the shape wave can carry negative energy: a vortex with the shape excitation can have less energy than the same vortex without it.

  18. Multiple-frequency tomography with shear waves and Love waves

    NASA Astrophysics Data System (ADS)

    Tian, Yue

    In this thesis I study the velocity and attenuation structure of the North American mantle using multiple-frequency shear-wave and Love-wave measurements, together with finite-frequency sensitivity kernels. The software for dynamic ray tracing and fast computation of body-wave finite-frequency sensitivity kernels is described and extensively validated and tested for accuracy. The program works for arbitrarily defined phases and one-dimensional background models. In kinematic and dynamic ray tracing, an integration step size of about 20 km is needed to produce travel-time errors under 0.1 s for the most common seismic phases. In kernel computation, a minimum integration step size of 10--30 km is sufficient to obtain numerical errors of the kernel's spatial quadrature below observational uncertainties. Larger errors may occur for long-period minimax phases such as SS . The paraxial approximation fails and errors become intolerable at epicentral distances larger than 140°. A global data set is built to contain multiple-frequency SH-wave travel-time and amplitude anomalies and SS-wave differential delays, estimated by band-pass filtering and cross-correlation. Most of the data are recorded at USArray stations. Frequency dependence is observed for all three types of data, and is strongest for amplitudes. The shallow structure is constrained by the addition of Love-wave phase delays. Velocity and attenuation heterogeneities are simultaneously estimated by allowing for focusing. The velocity model shows evidence of heavy fragmentation of the Farallon slab, including two separate subduction systems under western and eastern North America respectively, trench-perpendicular slab tears, and blob-like slab fragments in the lower mantle. The velocity model reveals a lower-mantle plume originating at about 1500 km depth beneath the Yellowstone area and tilting about 40° from vertical. Complex interaction between the plume and slab fragments is observed. High correlation

  19. Genetic code for sine

    NASA Astrophysics Data System (ADS)

    Abdullah, Alyasa Gan; Wah, Yap Bee

    2015-02-01

    The computation of the approximate values of the trigonometric sines was discovered by Bhaskara I (c. 600-c.680), a seventh century Indian mathematician and is known as the Bjaskara's I's sine approximation formula. The formula is given in his treatise titled Mahabhaskariya. In the 14th century, Madhava of Sangamagrama, a Kerala mathematician astronomer constructed the table of trigonometric sines of various angles. Madhava's table gives the measure of angles in arcminutes, arcseconds and sixtieths of an arcsecond. The search for more accurate formulas led to the discovery of the power series expansion by Madhava of Sangamagrama (c.1350-c. 1425), the founder of the Kerala school of astronomy and mathematics. In 1715, the Taylor series was introduced by Brook Taylor an English mathematician. If the Taylor series is centered at zero, it is called a Maclaurin series, named after the Scottish mathematician Colin Maclaurin. Some of the important Maclaurin series expansions include trigonometric functions. This paper introduces the genetic code of the sine of an angle without using power series expansion. The genetic code using square root approach reveals the pattern in the signs (plus, minus) and sequence of numbers in the sine of an angle. The square root approach complements the Pythagoras method, provides a better understanding of calculating an angle and will be useful for teaching the concepts of angles in trigonometry.

  20. Generalized sine condition.

    PubMed

    Elazhary, Tamer T; Zhou, Ping; Zhao, Chunyu; Burge, James H

    2015-06-01

    The classic Abbe sine condition relates pupil distortion to aberrations with linear field dependence such as coma. This paper provides a fully generalized form of the sine condition that does not use any symmetry. It accurately predicts the change in aberration in the presence of field independent and pupil aberrations. The definitions of the image, object, and coordinate system are completely arbitrary. The relationship is verified using ray trace simulations of a number of systems that have varying degrees of complexity. The potential applications are discussed.

  1. Wave propagation in a multiple interfaces nanowaveguide

    NASA Astrophysics Data System (ADS)

    Luis-Ramos, A.; Rojas-García, I.; Gómez-Pavón, L. C.; Félix-Beltrán, O.; Martí-Panameño, E.; Parada-Alfonso, R.

    2011-09-01

    The multiple functions and potential applications of nanotechnology have become a necessary and powerful tool in scientific work everyday. Nanotechnology is interdisciplinary science involving physics, chemistry, biology, materials science and wide range of engineering disciplines. His versatility has led to an increasing use in wide range of fields. For example, electronic engineering has shown an interest growing in the design of nanodevices due to continued miniaturization of them. The investigations have focused on the manufacture of electronic circuits and their applications complex systems, in addition to this, nanotechnology already plays an important role in development of new materials with tailored features and chemical properties, so their study is important today. Nanosensors have been under investigation for some institutions in recent years. A nanosensor is a device built on an atomic scale based on measurements nanometers, whose purpose is mainly to obtain data on the atomic scale transfer so they can be easily analyzed. In this work We study wave propagation in a low-dimensional planar nano-waveguide, to establish the principle of operation of an optical structure to propose the design of a nanosensor.

  2. Asymptotic safety in the sine-Gordon model

    NASA Astrophysics Data System (ADS)

    Kovács, J.; Nagy, S.; Sailer, K.

    2015-02-01

    In the framework of the functional renormalization group method, it is shown that the phase structure of the two-dimensional sine-Gordon model possesses a nontrivial UV fixed point which makes the model asymptotically safe. The fixed point exhibits strong singularity similar to the scaling found in the vicinity of the infrared fixed point. The singularity signals the upper energy-scale limit to the validity of the model. We argue that the sine-Gordon model with a momentum-dependent wave-function renormalization is in a dual connection with the massive sine-Gordon model.

  3. Bistability in the sine-Gordon equation: The ideal switch

    SciTech Connect

    Khomeriki, R.; Leon, J.

    2005-05-01

    The sine-Gordon equation, used as the representative nonlinear wave equation, presents a bistable behavior resulting from nonlinearity and generating hysteresis properties. We show that the process can be understood in a comprehensive analytical formulation and that it is a generic property of nonlinear systems possessing a natural band gap. The approach allows one to discover that the sine-Gordon equation can work as an ideal switch by reaching a transmissive regime with vanishing driving amplitude.

  4. Squared sine logistic map

    NASA Astrophysics Data System (ADS)

    de Carvalho, R. Egydio; Leonel, Edson D.

    2016-12-01

    A periodic time perturbation is introduced in the logistic map as an attempt to investigate new scenarios of bifurcations and new mechanisms toward the chaos. With a squared sine perturbation we observe that a point attractor reaches the chaotic attractor without following a cascade of bifurcations. One fixed point of the system presents a new scenario of bifurcations through an infinite sequence of alternating changes of stability. At the bifurcations, the perturbation does not modify the scaling features observed in the convergence toward the stationary state.

  5. Identification of a family of SINEs and LINEs in the Pipistrellus kuhli genome: a new structural and functional symbiotic relationship.

    PubMed

    Fantaccione, Stefania; Woodrow, Pasqualina; Pontecorvo, Giovanni

    2008-02-01

    We initially describe a novel tRNA-derived SINE family, abundantly and randomly distributed in the genome of the bat Pipistrellus kuhli. We present evidence that the LINE retrotransposition machinery is recruited for the creation of a new chimerical retrotranscript constituted by the partial LINE reverse transcriptase ORF2, which is interrupted by the SINE15 retrotransposon. Structural homology between SINE15 and Homo sapiens helix 6 7SL RNA allows us to propose multiple genome partners for SINE retrotransposition, such as SRP proteins and LINE enzymatic machinery. Moreover, on the basis of the LINE and SINE/LINE chimerical transcripts, we propose a mutual relationship between SINE and LINE retrotransposons.

  6. Information transport by sine-Gordon solitons in microtubules

    NASA Astrophysics Data System (ADS)

    Abdalla, Elcio; Maroufi, Bouchra; Melgar, Bertha Cuadros; Sedra, Moulay Brahim

    2001-12-01

    We study the problem of information propagation in brain microtubules. After considering the propagation of electromagnetic waves in a fluid of permanent electric dipoles, the problem reduces to the sine-Gordon wave equation in one space and one time dimensions. The problem of propagation of information is thus set.

  7. Extracorporeal Acoustic Wave Therapy and Multiple Symmetric Lipomatosis

    PubMed Central

    Vindigni, Vincenzo; Bassetto, Franco

    2015-01-01

    Summary: Acoustic waves are mechanical waves recently used to activate tissue metabolism by exploiting the cell permeabilization caused by their passage. We report a case of a retroauricular lipoma in a 44-year-old woman affected by multiple symmetric lipomatosis and treated with extracorporeal acoustic wave therapy. The adipose thickness of the lipoma was reduced from 35.8 to 21 mm, with increased softness at palpatory examination. PMID:26180731

  8. Genomic gems: SINE RNAs regulate mRNA production

    PubMed Central

    Ponicsan, Steven L.; Kugel, Jennifer F.; Goodrich, James A.

    2010-01-01

    Summary Mammalian short interspersed elements (SINEs) are abundant retrotransposons that have long been considered junk DNA; however, RNAs transcribed from mouse B2 and human Alu SINEs have recently been found to control mRNA production at multiple levels. Upon cell stress B2 and Alu RNAs bind RNA polymerase II (Pol II) and repress transcription of some protein-encoding genes. Bidirectional transcription of a B2 SINE establishes a boundary that places the growth hormone locus in a permissive chromatin state during mouse development. Alu RNAs embedded in Pol II transcripts can promote evolution and proteome diversity through exonization via alternative splicing. Given the diverse means by which SINE encoded RNAs impact production of mRNAs, this genomic junk is proving to contain hidden gems. PMID:20176473

  9. Genomic gems: SINE RNAs regulate mRNA production.

    PubMed

    Ponicsan, Steven L; Kugel, Jennifer F; Goodrich, James A

    2010-04-01

    Mammalian short interspersed elements (SINEs) are abundant retrotransposons that have long been considered junk DNA; however, RNAs transcribed from mouse B2 and human Alu SINEs have recently been found to control mRNA production at multiple levels. Upon cell stress B2 and Alu RNAs bind RNA polymerase II (Pol II) and repress transcription of some protein-encoding genes. Bi-directional transcription of a B2 SINE establishes a boundary that places the growth hormone locus in a permissive chromatin state during mouse development. Alu RNAs embedded in Pol II transcripts can promote evolution and proteome diversity through exonization via alternative splicing. Given the diverse means by which SINE encoded RNAs impact production of mRNAs, this genomic junk is proving to contain hidden gems.

  10. MetaSINEs: Broad Distribution of a Novel SINE Superfamily in Animals.

    PubMed

    Nishihara, Hidenori; Plazzi, Federico; Passamonti, Marco; Okada, Norihiro

    2016-02-12

    SINEs (short interspersed elements) are transposable elements that typically originate independently in each taxonomic clade (order/family). However, some SINE families share a highly similar central sequence and are thus categorized as a SINE superfamily. Although only four SINE superfamilies (CORE-SINEs, V-SINEs, DeuSINEs, and Ceph-SINEs) have been reported so far, it is expected that new SINE superfamilies would be discovered by deep exploration of new SINEs in metazoan genomes. Here we describe 15 SINEs, among which 13 are novel, that have a similar 66-bp central region and therefore constitute a new SINE superfamily, MetaSINEs. MetaSINEs are distributed from fish to cnidarians, suggesting their common evolutionary origin at least 640 Ma. Because the 3' tails of MetaSINEs are variable, these SINEs most likely survived by changing their partner long interspersed elements for retrotransposition during evolution. Furthermore, we examined the presence of members of other SINE superfamilies in bivalve genomes and characterized eight new SINEs belonging to the CORE-SINEs, V-SINEs, and DeuSINEs, in addition to the MetaSINEs. The broad distribution of bivalve SINEs suggests that at least three SINEs originated in the common ancestor of Bivalvia. Our comparative analysis of the central domains of the SINEs revealed that, in each superfamily, only a restricted region is shared among all of its members. Because the functions of the central domains of the SINE superfamilies remain unknown, such structural information of SINE superfamilies will be useful for future experimental and comparative analyses to reveal why they have been retained in metazoan genomes during evolution. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  11. MetaSINEs: Broad Distribution of a Novel SINE Superfamily in Animals

    PubMed Central

    Nishihara, Hidenori; Plazzi, Federico; Passamonti, Marco; Okada, Norihiro

    2016-01-01

    SINEs (short interspersed elements) are transposable elements that typically originate independently in each taxonomic clade (order/family). However, some SINE families share a highly similar central sequence and are thus categorized as a SINE superfamily. Although only four SINE superfamilies (CORE-SINEs, V-SINEs, DeuSINEs, and Ceph-SINEs) have been reported so far, it is expected that new SINE superfamilies would be discovered by deep exploration of new SINEs in metazoan genomes. Here we describe 15 SINEs, among which 13 are novel, that have a similar 66-bp central region and therefore constitute a new SINE superfamily, MetaSINEs. MetaSINEs are distributed from fish to cnidarians, suggesting their common evolutionary origin at least 640 Ma. Because the 3′ tails of MetaSINEs are variable, these SINEs most likely survived by changing their partner long interspersed elements for retrotransposition during evolution. Furthermore, we examined the presence of members of other SINE superfamilies in bivalve genomes and characterized eight new SINEs belonging to the CORE-SINEs, V-SINEs, and DeuSINEs, in addition to the MetaSINEs. The broad distribution of bivalve SINEs suggests that at least three SINEs originated in the common ancestor of Bivalvia. Our comparative analysis of the central domains of the SINEs revealed that, in each superfamily, only a restricted region is shared among all of its members. Because the functions of the central domains of the SINE superfamilies remain unknown, such structural information of SINE superfamilies will be useful for future experimental and comparative analyses to reveal why they have been retained in metazoan genomes during evolution. PMID:26872770

  12. Leaky-wave multiple dichroic beamformers

    NASA Astrophysics Data System (ADS)

    James, J. R.; Kinany, S. J. A.; Peel, P. D.; Andrasic, G.

    1989-08-01

    It is demonstrated that multiple frequency selective surfaces (FSSs) placed parallel to a low-directivity aperture exhibit useful beamforming properties at the expense of a narrowing of the radiation pattern bandwidth and a thicker structure. The beam-forming techniques are very compatible with printed technology employing layers of metal foil and low-permittivity dielectric materials. The application of the technique to a microstrip patch antenna is used as an example.

  13. Multiple scattering induced negative refraction of matter waves.

    PubMed

    Pinsker, Florian

    2016-02-09

    Starting from fundamental multiple scattering theory it is shown that negative refraction indices are feasible for matter waves passing a well-defined ensemble of scatterers. A simple approach to this topic is presented and explicit examples for systems of scatterers in 1D and 3D are stated that imply negative refraction for a generic incoming quantum wave packet. Essential features of the effective scattering field, densities and frequency spectrum of scatterers are considered. Additionally it is shown that negative refraction indices allow perfect transmission of the wave passing the ensemble of scatterers. Finally the concept of the superlens is discussed, since it is based on negative refraction and can be extended to matter waves utilizing the observations presented in this paper which thus paves the way to 'untouchable' quantum systems in analogy to cloaking devices for electromagnetic waves.

  14. Multiple scattering induced negative refraction of matter waves

    PubMed Central

    Pinsker, Florian

    2016-01-01

    Starting from fundamental multiple scattering theory it is shown that negative refraction indices are feasible for matter waves passing a well-defined ensemble of scatterers. A simple approach to this topic is presented and explicit examples for systems of scatterers in 1D and 3D are stated that imply negative refraction for a generic incoming quantum wave packet. Essential features of the effective scattering field, densities and frequency spectrum of scatterers are considered. Additionally it is shown that negative refraction indices allow perfect transmission of the wave passing the ensemble of scatterers. Finally the concept of the superlens is discussed, since it is based on negative refraction and can be extended to matter waves utilizing the observations presented in this paper which thus paves the way to ‘untouchable’ quantum systems in analogy to cloaking devices for electromagnetic waves. PMID:26857266

  15. A secure double-image sharing scheme based on Shamir's three-pass protocol and 2D Sine Logistic modulation map in discrete multiple-parameter fractional angular transform domain

    NASA Astrophysics Data System (ADS)

    Sui, Liansheng; Duan, Kuaikuai; Liang, Junli

    2016-05-01

    A secure double-image sharing scheme is proposed by using the Shamir's three-pass protocol in the discrete multiple-parameter fractional angular transform domain. First, an enlarged image is formed by assembling two plain images successively in the horizontal direction and scrambled in the chaotic permutation process, in which the sequences of chaotic pairs are generated by the two-dimensional Sine Logistic modulation map. Second, the scrambled image is divided into two components which are used to constitute a complex image. One component is normalized and regarded as the phase part of the complex image as well as other is considered as the amplitude part. Finally, the complex image is shared between the sender and the receiver by using the Shamir's three-pass protocol, in which the discrete multiple-parameter fractional angular transform is used as the encryption function due to its commutative property. The proposed double-image sharing scheme has an obvious advantage that the key management is convenient without distributing the random phase mask keys in advance. Moreover, the security of the image sharing scheme is enhanced with the help of extra parameters of the discrete multiple-parameter fractional angular transform. To the best of our knowledge, this is the first report on integrating the Shamir's three-pass protocol with double-image sharing scheme in the information security field. Simulation results and security analysis verify the feasibility and effectiveness of the proposed scheme.

  16. Functional Renormalization Group Approach to the Sine-Gordon Model

    SciTech Connect

    Nagy, S.; Sailer, K.; Nandori, I.; Polonyi, J.

    2009-06-19

    The renormalization group flow is presented for the two-dimensional sine-Gordon model within the framework of the functional renormalization group method by including the wave-function renormalization constant. The Kosterlitz-Thouless-Berezinski type phase structure is recovered as the interpolating scaling law between two competing IR attractive area of the global renormalization group flow.

  17. ECG manifestations of multiple electrolyte imbalance: peaked T wave to P wave ("tee-pee sign").

    PubMed

    Johri, Amer M; Baranchuk, Adrian; Simpson, Christopher S; Abdollah, Hoshiar; Redfearn, Damian P

    2009-04-01

    The surface electrocardiogram (ECG) is a useful instrument in the detection of metabolic disturbances. The accurate characterization of these disturbances, however, may be considerably more difficult when more than one metabolic abnormality is present in the same individual. While "classic" ECG presentations of common electrolyte disturbances are well described, multiple electrolyte disturbances occurring simultaneously may generate ECG abnormalities that are not as readily recognizable. We report a case of hyperkalemia, with concurrent hypocalcemia and hypomagnesemia resulting in (1) peaking of the T wave, (2) a prominent U wave, and (3) prolongation of the descending limb of the T wave such that it overlapped with the next P wave. In this particular ECG from a patient with combined electrolyte imbalance, we have dubbed the unusual appearance of the segment between the peak of the T wave to the next P wave as the "tee-pee" sign.

  18. Multiple-frequency surface acoustic wave devices as sensors

    NASA Astrophysics Data System (ADS)

    Ricco, Antonio J.; Martin, Stephen J.

    We have designed, fabricated, and tested a multiple-frequency acoustic wave (MUFAW) device on ST-cut quartz with nominal surface acoustic wave (SAW) center frequencies of 16, 40, 100, and 250 MHz. The four frequencies are obtained by patterning four sets of input and output interdigital transducers of differing periodicities on a single substrate. Such a device allows the frequency dependence of AW sensor perturbations to be examined, aiding in the elucidation of the operative interaction mechanism(s). Initial measurements of the SAW response to the vacuum deposition of a thin nickel film show the expected frequency dependence of mass sensitivity in addition to the expected frequency independence of the magnitude of the acoustoelectric effect. By measuring changes in both wave velocity and attenuation at multiple frequencies, extrinsic perturbations such as temperature and pressure changes are readily differentiated from one another and from changes in surface mass.

  19. The Evolution of SINEs and LINEs in the genus Chironomus (Diptera).

    PubMed

    Papusheva, Ekaterina; Gruhl, Mary C; Berezikov, Eugene; Groudieva, Tatiana; Scherbik, Svetlana V; Martin, Jon; Blinov, Alexander; Bergtrom, Gerald

    2004-03-01

    Genomic DNA amplification from 51 species of the family Chironomidae shows that most contain relatives of NLRCth1 LINE and CTRT1 SINE retrotransposons first found in Chironomus thummi. More than 300 cloned PCR products were sequenced. The amplified region of the reverse transcriptase gene in the LINEs is intact and highly conserved, suggesting active elements. The SINEs are less conserved, consistent with minimal/no selection after transposition. A mitochondrial gene phylogeny resolves the Chironomus genus into six lineages (Guryev et al. 2001). LINE and SINE phylogenies resolve five of these lineages, indicating their monophyletic origin and vertical inheritance. However, both the LINE and the SINE tree topologies differ from the species phylogeny, resolving the elements into "clusters I-IV" and "cluster V" families. The data suggest a descent of all LINE and SINE subfamilies from two major families. Based on the species phylogeny, a few LINEs and a larger number of SINEs are cladisitically misplaced. Most misbranch with LINEs or SINEs from species with the same families of elements. From sequence comparisons, cladistically misplaced LINEs and several misplaced SINEs arose by convergent base substitutions. More diverged SINEs result from early transposition and some are derived from multiple source SINEs in the same species. SINEs from two species (C. dorsalis, C. pallidivittatus), expected to belong to the clusters I-IV family, branch instead with cluster V family SINEs; apparently both families predate separation of cluster V from clusters I-IV species. Correlation of the distribution of active SINEs and LINEs, as well as similar 3' sequence motifs in CTRT1 and NLRCth1, suggests coevolving retrotransposon pairs in which CTRT1 transposition depends on enzymes active during NLRCth1 LINE mobility.

  20. Multiple attenuation to reflection seismic data using Radon filter and Wave Equation Multiple Rejection (WEMR) method

    SciTech Connect

    Erlangga, Mokhammad Puput

    2015-04-16

    Separation between signal and noise, incoherent or coherent, is important in seismic data processing. Although we have processed the seismic data, the coherent noise is still mixing with the primary signal. Multiple reflections are a kind of coherent noise. In this research, we processed seismic data to attenuate multiple reflections in the both synthetic and real seismic data of Mentawai. There are several methods to attenuate multiple reflection, one of them is Radon filter method that discriminates between primary reflection and multiple reflection in the τ-p domain based on move out difference between primary reflection and multiple reflection. However, in case where the move out difference is too small, the Radon filter method is not enough to attenuate the multiple reflections. The Radon filter also produces the artifacts on the gathers data. Except the Radon filter method, we also use the Wave Equation Multiple Elimination (WEMR) method to attenuate the long period multiple reflection. The WEMR method can attenuate the long period multiple reflection based on wave equation inversion. Refer to the inversion of wave equation and the magnitude of the seismic wave amplitude that observed on the free surface, we get the water bottom reflectivity which is used to eliminate the multiple reflections. The WEMR method does not depend on the move out difference to attenuate the long period multiple reflection. Therefore, the WEMR method can be applied to the seismic data which has small move out difference as the Mentawai seismic data. The small move out difference on the Mentawai seismic data is caused by the restrictiveness of far offset, which is only 705 meter. We compared the real free multiple stacking data after processing with Radon filter and WEMR process. The conclusion is the WEMR method can more attenuate the long period multiple reflection than the Radon filter method on the real (Mentawai) seismic data.

  1. Multiple Signal Classification for Gravitational Wave Burst Search

    NASA Astrophysics Data System (ADS)

    Cao, Junwei; He, Zhengqi

    2013-01-01

    This work is mainly focused on the application of the multiple signal classification (MUSIC) algorithm for gravitational wave burst search. This algorithm extracts important gravitational wave characteristics from signals coming from detectors with arbitrary position, orientation and noise covariance. In this paper, the MUSIC algorithm is described in detail along with the necessary adjustments required for gravitational wave burst search. The algorithm's performance is measured using simulated signals and noise. MUSIC is compared with the Q-transform for signal triggering and with Bayesian analysis for direction of arrival (DOA) estimation, using the Ω-pipeline. Experimental results show that MUSIC has a lower resolution but is faster. MUSIC is a promising tool for real-time gravitational wave search for multi-messenger astronomy.

  2. Multiple Scattering of Waves in Discrete Random Media.

    DTIC Science & Technology

    1987-12-31

    2.2 Material Properties for Piezoelectric Composites (SH Wave Incidence) Case I Case 2 P, (kg/m ) 6600 7000 3 1100 1000 c44 (N/nm) 8.5 x 109 8 .S x...patterns of R-1 and R.4 are presented as Figures 7 and 8 respectively. The matrix material was chosen to be PVC and the dielectric constant of PVC...PENNSYLVANIA STATE UNIVERSITY * RESEARCH CENTER FOR THE ENGINEERING OF ELECTRONIC & ACOUSTIC MATERIALS 00 Multiple Scattering of Waves 0 in Discrete

  3. Universal precision sine bar attachment

    NASA Technical Reports Server (NTRS)

    Mann, Franklin D. (Inventor)

    1989-01-01

    This invention relates to an attachment for a sine bar which can be used to perform measurements during lathe operations or other types of machining operations. The attachment can be used for setting precision angles on vises, dividing heads, rotary tables and angle plates. It can also be used in the inspection of machined parts, when close tolerances are required, and in the layout of precision hardware. The novelty of the invention is believed to reside in a specific versatile sine bar attachment for measuring a variety of angles on a number of different types of equipment.

  4. Optimization on the focusing of multiple shock waves

    NASA Astrophysics Data System (ADS)

    Qiu, Shi; Eliasson, Veronica

    2016-11-01

    Focusing of multiple shock waves can lead to extreme thermodynamic conditions, which are desired for applications like shock wave lithotripsy and inertial confinement fusion. To study shock focusing effects, multiple energy sources have been placed in a circular pattern around an intended target, while the distance between each source and the target is fixed. All the sources are set to release the same amount of energy at the same time in order to create multiple identical shock waves. The object is to optimize the thermodynamic conditions at the target by rearranging the initial placement of each source. However, dealing with this optimization problem can be challenging due to the high computational cost introduced by solving the Euler equations. To avoid this issue, both numerical and analytical methods have been applied to handle shock focusing more efficiently. A numerical method, an approximate theory named Geometrical Shock Dynamics (GSD), has been utilized to describe the motion of shock. Using an analytical method, a transition curve between regular and irregular reflection has been employed to predict shock interactions. Results show that computational cost can be reduced dramatically by combining GSD and a transition curve. In addition, optimization results based on varying initial setups is discussed.

  5. A Generalized Multiple Discrete Interaction Approximation for resonant four-wave interactions in wind wave models

    NASA Astrophysics Data System (ADS)

    Tolman, Hendrik L.

    2013-10-01

    For several decades, the Discrete Interaction Approximation (DIA) for nonlinear resonant four-wave interactions has been the engine of third-generation wind-wave models. The present study presents a Generalized Multiple DIA (GMD) which expands upon the DIA by (i) expanding the definition of the representative quadruplet, (ii) formulating the DIA for arbitrary water depths, (iii) providing complimentary deep and shallow water scaling terms and (iv) allowing for multiple representative quadruplets. The GMD is rigorously derived to be an extension of the DIA, and is backward compatible with it. The free parameters of the GMD are optimized holistically, by optimizing full model behavior in the WAVEWATCH III® wave model as reported in a companion paper. Here, a cascade of GMD configurations with increasing complexity, accuracy and cost is presented. First, the performance of these configurations is discussed using idealized test cases used to optimize the GMD. It is shown that in deep water, GMD configurations can be found which remove most of the errors of the DIA. The GMD is also capable of representing four-wave interactions in extremely shallow water, although some remaining spurious behavior makes applications of this part of the GMD less suitable for operational wave models. Finally, several GMD configurations are applied to an idealized hurricane case, showing that results from idealized test cases indeed are representative for real-world applications, and confirming that such GMD configurations are economically feasible in operational wind wave models. Finally, the DIA results in surprisingly large model errors in hurricane conditions.

  6. Application of the sine-Poisson equation in solar magnetostatics

    NASA Technical Reports Server (NTRS)

    Webb, G. M.; Zank, G. P.

    1990-01-01

    Solutions of the sine-Poisson equations are used to construct a class of isothermal magnetostatic atmospheres, with one ignorable coordinate corresponding to a uniform gravitational field in a plane geometry. The distributed current in the model (j) is directed along the x-axis, where x is the horizontal ignorable coordinate; (j) varies as the sine of the magnetostatic potential and falls off exponentially with distance vertical to the base with an e-folding distance equal to the gravitational scale height. Solutions for the magnetostatic potential A corresponding to the one-soliton, two-soliton, and breather solutions of the sine-Gordon equation are studied. Depending on the values of the free parameters in the soliton solutions, horizontally periodic magnetostatic structures are obtained possessing either a single X-type neutral point, multiple neural X-points, or solutions without X-points.

  7. Application of the sine-Poisson equation in solar magnetostatics

    NASA Technical Reports Server (NTRS)

    Webb, G. M.; Zank, G. P.

    1990-01-01

    Solutions of the sine-Poisson equations are used to construct a class of isothermal magnetostatic atmospheres, with one ignorable coordinate corresponding to a uniform gravitational field in a plane geometry. The distributed current in the model (j) is directed along the x-axis, where x is the horizontal ignorable coordinate; (j) varies as the sine of the magnetostatic potential and falls off exponentially with distance vertical to the base with an e-folding distance equal to the gravitational scale height. Solutions for the magnetostatic potential A corresponding to the one-soliton, two-soliton, and breather solutions of the sine-Gordon equation are studied. Depending on the values of the free parameters in the soliton solutions, horizontally periodic magnetostatic structures are obtained possessing either a single X-type neutral point, multiple neural X-points, or solutions without X-points.

  8. Inertial solitary waves with multiple eddy bifurcations in stratified flow

    NASA Astrophysics Data System (ADS)

    Miroshnikov, Victor A.

    2000-11-01

    It has been long recognized that internal nonlinear waves are important dynamical feature in both the oceans and the lower atmosphere. The theoretical work reported herein studies fully nonlinear internal solitary waves with vortical cores formed by the flow separation that is effected by uniform or exponential stratification, uniform rotation, inertia, constant shear, and asymmetry of the upstream flow. The kinematic problem is formulated by the Long's equation for high Froude numbers when gravity is negligible compared with inertia. The exact nonlinear solution is derived in the form of the infinite series in modified spherical Bessel functions complemented by the recurrence relation. The dynamic problem is solved by the Bernoulli integral generalized for stratified rotating fluid. Necessary and sufficient conditions are obtained for the formation of one-, two-, and three-eddy bifurcations of open-ended wavy streamlines resulting in wave-vortex structures with multiple eddies and vortex shells. Complete set of one-, two-, and three-eddy bifurcations is considered that includes embedded, expanded, degenerated, and combined bifurcations. Symbolic calculations of the series solution up to 150,000 terms are implemented by the code for symbolic programming. Properties and nonlinear stability of the wave-eddy structures are studied. The results are compared with the field observations with reasonable agreement.

  9. Analysis of millimetre-wave polarization diverse multiple-input multiple-output capacity

    PubMed Central

    Lawrence, Nicholas P.; Ng, Brian W.-H.; Hansen, Hedley J.

    2015-01-01

    Millimetre-waves offer the possibility of wide bandwidth and consequently high data rate for wireless communications. For both uni- and dual-polarized systems, signals sent over a link may suffer severe degradation due to antenna misalignment. Orientation robustness may be enhanced by the use of mutual orthogonality in three dimensions. Multiple-input multiple-output polarization diversity offers a way of improving signal reception without the limitations associated with spatial diversity. Scattering effects often assist propagation through multipath. However, high path loss at millimetre-wave frequencies may limit any reception enhancement through scattering. We show that the inclusion of a third orthogonal dipole provides orientation robustness in this setting, as well as in a rich scattering environment, by means of a Rician fading channel model covering all orientations for a millimetre-wave, tri-orthogonal, half-wave dipole transmitter and receiver employing polarization diversity. Our simulation extends the analysis into three dimensions, fully exploiting individual sub-channel paths. In both the presence and absence of multipath effects, capacity is observed to be higher than that of a dual-polarized system over the majority of a field of view. PMID:27019723

  10. Analysis of millimetre-wave polarization diverse multiple-input multiple-output capacity.

    PubMed

    Lawrence, Nicholas P; Ng, Brian W-H; Hansen, Hedley J; Abbott, Derek

    2015-12-01

    Millimetre-waves offer the possibility of wide bandwidth and consequently high data rate for wireless communications. For both uni- and dual-polarized systems, signals sent over a link may suffer severe degradation due to antenna misalignment. Orientation robustness may be enhanced by the use of mutual orthogonality in three dimensions. Multiple-input multiple-output polarization diversity offers a way of improving signal reception without the limitations associated with spatial diversity. Scattering effects often assist propagation through multipath. However, high path loss at millimetre-wave frequencies may limit any reception enhancement through scattering. We show that the inclusion of a third orthogonal dipole provides orientation robustness in this setting, as well as in a rich scattering environment, by means of a Rician fading channel model covering all orientations for a millimetre-wave, tri-orthogonal, half-wave dipole transmitter and receiver employing polarization diversity. Our simulation extends the analysis into three dimensions, fully exploiting individual sub-channel paths. In both the presence and absence of multipath effects, capacity is observed to be higher than that of a dual-polarized system over the majority of a field of view.

  11. Multiple slow waves in metaporous layers for broadband sound absorption

    NASA Astrophysics Data System (ADS)

    Yang, Jieun; Lee, Joong Seok; Kim, Yoon Young

    2017-01-01

    Sound absorption for a broad frequency range requires sound dissipation. The mechanics of acoustic metamaterials for non-dissipative applications has been extensively studied, but sound absorption using dissipative porous metamaterials has been less explored because of the complexity resulting from the coupling of its dissipative mechanism and metamaterial behavior. We investigated broadband sound absorption by engineering dissipative metaporous layers, which absorb sound by the mechanism of multiple slow waves, and combined local and global resonance phenomena. A set of rigid partitions of varying lengths was elaborately inserted in a hard-backed porous layer of a finite thickness. An effective medium theory was used to explain the physics involved; high performance at a low-frequency range was found to be mainly due to the formation of global resonances caused by multiple slow waves over the thickness of the metaporous layer, while enhancement at a high-frequency range was attributed to the combined effects of the global resonances and the local resonances directly related to the sizes of the inserted partitions.

  12. Multiple scales of shock waves in dissipative laminate materials.

    PubMed

    Franco Navarro, Pedro; Benson, David J; Nesterenko, Vitali F

    2016-09-01

    The shock waves generated by a plate impact are numerically investigated in Al-W laminates with different mesostructures. The main characteristic time scales (and the corresponding spatial scales) related to the formation of the stationary shock are identified: the duration (width) of the leading front, the time (distance) from the impact required to establish a stationary profile, and the shock front width, identified as a time span (distance) from the initial state to the final quasiequilibrium state. It is demonstrated that the width of the leading front and the maximum strain rates are determined by the dispersive and the nonlinear parameters of the laminate and not by the dissipation, as is the case for uniform solids. The characteristic spatial scale of the leading front is related to the spatial scale observed on solitarylike waves, which are satisfactorily described by the Korteweg-de Vries (KdV) approximation, as well as the speed of the wave and the ratio of maximum to final strain. The dissipation affects the width of the transition distance (shock front width) where multiple loading-unloading cycles bring the laminate into the final quasiequilibrium state. This spatial scale is of the same order of magnitude as the distance to form stationary shock wave. The period of fast decaying oscillations is well described by the KdV approach and scales linearly with the cell size. The rate of the decay of the oscillations in the numerical calculations does not scale with the square of the cell size as expected from the dissipative KdV approach that assumes a constant viscosity. This is due to the different mechanisms of dissipation in high-amplitude compression pulses.

  13. MyrSINEs: a novel SINE family in the anteater genomes.

    PubMed

    Nishihara, Hidenori; Kuno, Shuichi; Nikaido, Masato; Okada, Norihiro

    2007-10-01

    Recent rapid generation of genomic sequence data has allowed many researchers to perform comparative analyses in various mammalian species. However, characterization of transposable elements, such as short interspersed repetitive elements (SINEs), has not been reported for several mammalian groups. Because SINEs occupy a large portion of the mammalian genome, they are believed to have contributed to the constitution and diversification of the host genomes during evolution. In the present study, we characterized a novel SINE family in the anteater genomes and designated it the MyrSINE family. Typical SINEs consist of a tRNA-related, a tRNA-unrelated and an AT-rich (or poly-A) region. MyrSINEs have only tRNA-related and poly-A regions; they are included in a group called t-SINE. The tRNA-related regions of the MyrSINEs were found to be derived from tRNA(Gly). We demonstrate that the MyrSINE family can be classified into three subfamilies. Two of the MyrSINE subfamilies are distributed in the genomes of both giant anteater and tamandua, while the other is present only in the giant anteater. We discuss the evolutionary history of MyrSINEs and their relationship to the evolution of anteaters. We also speculate that the simple structure of t-SINEs may be a potential evolutionary source for the generation of the typical SINE structure.

  14. PCR-based approach to SINE isolation: simple and complex SINEs.

    PubMed

    Borodulina, Olga R; Kramerov, Dmitri A

    2005-04-11

    Highly repeated copies of short interspersed elements (SINEs) occur in eukaryotic genomes. The distribution of each SINE family is usually restricted to some genera, families, or orders. SINEs have an RNA polymerase III internal promoter, which is composed of boxes A and B. Here we propose a method for isolation of novel SINE families based on genomic DNA PCR with oligonucleotide identical to box A as a primer. Cloning of the size-heterogeneous PCR-products and sequencing of their terminal regions allow determination of SINE structure. Using this approach, two novel SINE families, Rhin-1 and Das-1, from the genomes of great horseshoe bat (Rhinolophus ferrumequinum) and nine-banded armadillo (Dasypus novemcinctus), respectively, were isolated and studied. The distribution of Rhin-1 is restricted to two of six bat families tested. Copies of this SINE are characterized by frequent internal insertions and significant length (200-270 bp). Das-1 being only 90 bp in length is one of the shortest SINEs known. Most of Das-1 nucleotide sequences demonstrate significant similarity to alanine tRNA which appears to be an evolutionary progenitor of this SINE. Together with three other known SINEs (ID, Vic-1, and CYN), Das-1 constitutes a group of simple SINEs. Interestingly, three SINE families of this group are alanine tRNA-derived. Most probably, this tRNA gave rise to short and simple but successful SINEs several times during mammalian evolution.

  15. Characterization of a novel SINE superfamily from invertebrates: "Ceph-SINEs" from the genomes of squids and cuttlefish.

    PubMed

    Akasaki, Tetsuya; Nikaido, Masato; Nishihara, Hidenori; Tsuchiya, Kotaro; Segawa, Susumu; Okada, Norihiro

    2010-04-01

    Five tRNA-derived short interspersed repetitive elements (SINEs), named SepiaSINE, Sepioth-SINE1, Sepioth-SINE2A, Sepioth-SINE2B and OegopSINE, were isolated from the genomes of three decabrachian species [Sepia officinalis (order Sepiida), Sepiotheuthis lessoniana (suborder Myopsida), and Mastigoteuthis cordiformes (suborder Oegopsida)], by random sequencing and genome screening. In addition, two tRNA-derived SINEs, named IdioSINE1 and IdioSINE2, were further detected from EST (expressed sequence tag) data of Idiosepius paradoxus (order Idiosepiida), using a GenBank FASTA search with a conserved sequence of the SepiaSINE as the query. All the isolated SINEs had a common and unique highly conserved 149-bp sequence in their central structures (Sepioth-SINE2B and IdioSINEs, however, had a continuous 73-bp deletion in the conserved region.), and are therefore grouped as the fourth SINE superfamily "Ceph-SINEs", following the CORE-SINE, V-SINE, and DeuSINE superfamilies. Our analysis suggested that the central conserved region called the "Ceph-domain" might have originated before the diversification of cephalopods (505 myr ago). A sequence alignment of Sepioth-SINE1, Sepioth-SINE2A, and Sepioth-SINE2B demonstrated that Sepioth-SINE2A has a chimeric structure shared with two other SINEs. The above relationship suggests possible template switching in the central conserved domain during reverse transcription for the birth of Sepioth-SINE2A, providing the possibility that the presence of the conserved domain contributed to yield a variety of SINEs during evolution. Furthermore, the distributions of the isolated SINEs showed that order Sepiida, suborders Oegopsida and Myopsida, and order Idiosepiida have their own independent SINE(s), and suggest that order Sepiida can be largely separated into two groups, with clarification of the phylogenetic relatedness between subfamily Sepioteuthinae and the other loliginid squids.

  16. Transcriptome-wide effects of inverted SINEs on gene expression and their impact on RNA polymerase II activity.

    PubMed

    Tajaddod, Mansoureh; Tanzer, Andrea; Licht, Konstantin; Wolfinger, Michael T; Badelt, Stefan; Huber, Florian; Pusch, Oliver; Schopoff, Sandy; Janisiw, Michael; Hofacker, Ivo; Jantsch, Michael F

    2016-10-25

    Short interspersed elements (SINEs) represent the most abundant group of non-long-terminal repeat transposable elements in mammalian genomes. In primates, Alu elements are the most prominent and homogenous representatives of SINEs. Due to their frequent insertion within or close to coding regions, SINEs have been suggested to play a crucial role during genome evolution. Moreover, Alu elements within mRNAs have also been reported to control gene expression at different levels. Here, we undertake a genome-wide analysis of insertion patterns of human Alus within transcribed portions of the genome. Multiple, nearby insertions of SINEs within one transcript are more abundant in tandem orientation than in inverted orientation. Indeed, analysis of transcriptome-wide expression levels of 15 ENCODE cell lines suggests a cis-repressive effect of inverted Alu elements on gene expression. Using reporter assays, we show that the negative effect of inverted SINEs on gene expression is independent of known sensors of double-stranded RNAs. Instead, transcriptional elongation seems impaired, leading to reduced mRNA levels. Our study suggests that there is a bias against multiple SINE insertions that can promote intramolecular base pairing within a transcript. Moreover, at a genome-wide level, mRNAs harboring inverted SINEs are less expressed than mRNAs harboring single or tandemly arranged SINEs. Finally, we demonstrate a novel mechanism by which inverted SINEs can impact on gene expression by interfering with RNA polymerase II.

  17. Polymorphic light eruption sine eruption.

    PubMed

    Dover, J S; Hawk, J L

    1988-01-01

    We describe seven patients, four female and three male, who developed intense pruritus on sun-exposed skin without visible change. The clinical features resembled those of polymorphic light eruption (PLE) without rash. Four patients also occasionally developed typical PLE upon sun exposure, but sun-induced pruritus alone occurred most frequently. No patient was taking any drug therapy. One patient developed similar pruritus following solar simulated irradiation, and one following PUVA therapy. All other laboratory investigations were negative. Treatment with low dose UVB phototherapy or PUVA therapy was effective. The condition, which we have called polymorphic light eruption sine eruptione (PLESE), appears to be a variant of PLE not previously reported.

  18. Generalized Sine-Gordon equation and dislocation dynamics of superlattice

    NASA Astrophysics Data System (ADS)

    Wu, Muying; Chen, Guihua; Luo, Shiyu

    2013-07-01

    By introducing a damping term, the Seeger equation describing the dislocations motion is reduced to the generalized Sine-Gordon equation, which is further reduced to the pendulum equation for the traveling wave solutions. The characteristics of the phase plane of the unperturbated system is analyzed and the chaotic behavior of the system is discussed with Melnikov method. It is shown that the energy of dislocation wave can efficiently transfer and release to the superlattice for appropriately chosen parameters, such that the stability of the superlattice can be improved.

  19. Multiresonance modes in sine-Gordon brane models

    NASA Astrophysics Data System (ADS)

    Cruz, W. T.; Maluf, R. V.; Dantas, D. M.; Almeida, C. A. S.

    2016-12-01

    In this work, we study the localization of the vector gauge field in two five-dimensional braneworlds generated by scalar fields coupled to gravity. The sine-Gordon like potentials are employed to produce different thick brane setups. A zero mode localized is obtained, and we show the existence of reverberations with the wave solutions indicating a quasi-localized massive mode. More interesting results are achieved when we propose a double sine-Gordon potential to the scalar field. The resulting thick brane shows a more detailed topology with the presence of an internal structure composed by two kinks. The massive spectrum of the gauge field is revalued on this scenario revealing the existence of various resonant modes. Furthermore, we compute the corrections to Coulomb law coming from these massive KK vector modes in these thick scenarios, which is concluded that the dilaton parameter regulates these corrections.

  20. EISCAT observations during MAC/SINE and MAC/Epsilon

    NASA Technical Reports Server (NTRS)

    Roettger, J.; Hoppe, U.-P.; Hall, C.

    1989-01-01

    The EISCAT incoherent scatter radar facility in Tromsoe, Norway was operated during the MAC/SINE campaign for 78 hours in the period 10 June to 17 July 1987, and during the MAC/Epsilon campaign for 90 hours in the period 15 October to 5 November 1987. The VHF (224 MHz) radar operations during MAC/SINE yielded most interesting observations of strong coherent echoes from the mesopause region. Characteristic data of these polar mesospheric summer echoes are presented. The UHF (933 MHz) radar operations during MAC/Epsilon were done with 18 deg off zenith beam and allows the deduction of meridonal and horizontal wind components as well as radial velocity spectra in addition to the usual electron density profiles in the D and lower E regions. Some results from the VHF and UHF radars indicating the presence of gravity waves are examined.

  1. The Sine _beta β operator

    NASA Astrophysics Data System (ADS)

    Valkó, Benedek; Virág, Bálint

    2017-07-01

    We show that Sine$_\\beta$, the bulk limit of the Gaussian $\\beta$-ensembles is the spectrum of a self-adjoint random differential operator \\[ f\\to 2 {R_t^{-1}} \\left[ \\begin{array}{cc} 0 &-\\tfrac{d}{dt} \\tfrac{d}{dt} &0 \\end{array} \\right] f, \\qquad f:[0,1)\\to \\mathbb R^2, \\] where $R_t$ is the positive definite matrix representation of hyperbolic Brownian motion with variance $4/\\beta$ in logarithmic time. The result connects the Montgomery-Dyson conjecture about the Sine$_2$ process and the non-trivial zeros of the Riemann zeta function, the Hilbert-P\\'olya conjecture and de Brange's attempt to prove the Riemann hypothesis. We identify the Brownian carousel as the Sturm-Liouville phase function of this operator. We provide similar operator representations for several other finite dimensional random ensembles and their limits: finite unitary or orthogonal ensembles, Hua-Pickrell ensembles and their limits, hard-edge $\\beta$-ensembles, as well as the Schr\\"odinger point process. In this more general setting, hyperbolic Brownian motion is replaced by a random walk or Brownian motion on the affine group. Our approach provides a unified framework to study $\\beta$-ensembles that has so far been missing in the literature. In particular, we connect It\\^o's classification of affine Brownian motions with the classification of limits of random matrix ensembles.

  2. Basis properties of the p, q-sine functions.

    PubMed

    Boulton, Lyonell; Lord, Gabriel J

    2015-02-08

    We improve the currently known thresholds for basisness of the family of periodically dilated p,q-sine functions. Our findings rely on a Beurling decomposition of the corresponding change of coordinates in terms of shift operators of infinite multiplicity. We also determine refined bounds on the Riesz constant associated with this family. These results seal mathematical gaps in the existing literature on the subject.

  3. An ancient retrovirus-like element contains hot spots for SINE insertion.

    PubMed Central

    Cantrell, M A; Filanoski, B J; Ingermann, A R; Olsson, K; DiLuglio, N; Lister, Z; Wichman, H A

    2001-01-01

    Vertebrate retrotransposons have been used extensively for phylogenetic analyses and studies of molecular evolution. Information can be obtained from specific inserts either by comparing sequence differences that have accumulated over time in orthologous copies of that insert or by determining the presence or absence of that specific element at a particular site. The presence of specific copies has been deemed to be an essentially homoplasy-free phylogenetic character because the probability of multiple independent insertions into any one site has been believed to be nil. Mys elements are a type of LTR-containing retrotransposon present in Sigmodontine rodents. In this study we have shown that one particular insert, mys-9, is an extremely old insert present in multiple species of the genus Peromyscus. We have found that different copies of this insert show a surprising range of sizes, due primarily to a continuing series of SINE (short interspersed element) insertions into this locus. We have identified two hot spots for SINE insertion within mys-9 and at each hot spot have found that two independent SINE insertions have occurred at identical sites. These results have major repercussions for phylogenetic analyses based on SINE insertions, indicating the need for caution when one concludes that the existence of a SINE at a specific locus in multiple individuals is indicative of common ancestry. Although independent insertions at the same locus may be rare, SINE insertions are not homoplasy-free phylogenetic markers. PMID:11404340

  4. Channel and collateral effect of millimeter-wave multiplicate spectrum

    NASA Astrophysics Data System (ADS)

    Dong, Shuyi; Tang, Li; Di, Wenyuan; Zhang, Dongguo; Li, Ning; Zhao, Yongjiu

    1998-11-01

    Combining with acupuncture and moxibustion theory of China, this paper discussed acupuncture and moxibustion effect of millimeter wave multiplied with infrared ray and bass spectrum, and provided a feasible path for applications of millimeter wave in biomedical engineering.

  5. On the Generation of Multiple Atmospheric Pressure Waves Observed During Violent Volcanic Eruptions.

    NASA Astrophysics Data System (ADS)

    Medici, E. F.; Waite, G. P.

    2015-12-01

    One or more atmospheric pressure waves followed by a supersonic jet may be generated during the over pressurized vapor-solid-liquid mixture ejection of a violent volcanic eruption. The source of these multiple atmospheric pressure waves could have different origins. Among the physical mechanisms that could explain these behaviors are pulsating eruptions, the dynamics of shock waves, coupled pressure wave-supersonic jet interaction, or a combination of all these factors. In order to elucidate the causes of these complex fluid flow dynamics, a series of analog volcanic eruption experiments using an atmospheric shock tube were performed. During the testing, single and multiple pressure waves and the subsequent supersonic jet were generated. The controlled laboratory conditions enable studies of the most relevant variables potentially responsible for the formation of the multiple pressure waves. The tests were performed using dry, compressed nitrogen at standard room temperature that was free of particles. Yet, under this idealization of a real volcanic eruption, multiple pressure waves were observed on the high-speed video imaging and recorded on the pressure transducer. The amount of energy being released on each test was varied to achieve different discharge dynamics and the formation of single and multiple pressure waves. The preliminary experimental observations indicate a coupled pressure wave-jet interaction as source of multiple pressure waves.

  6. Investigation into the superposition of multiple mode shape composed traveling waves

    NASA Astrophysics Data System (ADS)

    Musgrave, Patrick F.; Malladi, V. V. N. Sriram; Tarazaga, Pablo A.

    2017-04-01

    Structural traveling waves have potential applications in numerous areas such as propulsion and skin friction drag reduction. Recent research has shown that via the two-mode excitation method, traveling waves can be generated in both one- and two-dimensional structures via the use of low-profile piezoelectric actuators. Traveling waves on a one-dimensional beam propagate in a single direction, while those on a two-dimensional structure, such as a plate, do not necessarily propagate uniformly across the surface. The propagation patterns can include unidirectional traveling waves with spatial phase shifts, wave fronts moving in opposing directions, or even rotationally moving waves. These propagation patterns depend on the participating modes and vary based on the excitation frequency, thus if multiple frequency traveling waves are generated on a plate, multiple propagation patterns are superimposed. In this study, traveling waves were generated in a plate at two different frequencies. Those frequencies were then simultaneously excited on the plate to generate a propagation pattern containing traveling waves at both frequencies. The superimposed propagation pattern was then analyzed by comparing it with a numerical combination of the individual frequency patterns. The experimentally superimposed traveling waves were found to be a linear combination of the individual frequency waves. In addition, by combining multiple frequency waves, the percentage of the plate containing traveling waves increased.

  7. SINEs as driving forces in genome evolution.

    PubMed

    Schmitz, J

    2012-01-01

    SINEs are short interspersed elements derived from cellular RNAs that repetitively retropose via RNA intermediates and integrate more or less randomly back into the genome. SINEs propagate almost entirely vertically within their host cells and, once established in the germline, are passed on from generation to generation. As non-autonomous elements, their reverse transcription (from RNA to cDNA) and genomic integration depends on the activity of the enzymatic machinery of autonomous retrotransposons, such as long interspersed elements (LINEs). SINEs are widely distributed in eukaryotes, but are especially effectively propagated in mammalian species. For example, more than a million Alu-SINE copies populate the human genome (approximately 13% of genomic space), and few master copies of them are still active. In the organisms where they occur, SINEs are a challenge to genomic integrity, but in the long term also can serve as beneficial building blocks for evolution, contributing to phenotypic heterogeneity and modifying gene regulatory networks. They substantially expand the genomic space and introduce structural variation to the genome. SINEs have the potential to mutate genes, to alter gene expression, and to generate new parts of genes. A balanced distribution and controlled activity of such properties is crucial to maintaining the organism's dynamic and thriving evolution. Copyright © 2012 S. Karger AG, Basel.

  8. Overview of multi-input frequency domain modal testing methods with an emphasis on sine testing

    NASA Technical Reports Server (NTRS)

    Rost, Robert W.; Brown, David L.

    1988-01-01

    An overview of the current state of the art multiple-input, multiple-output modal testing technology is discussed. A very brief review of the current time domain methods is given. A detailed review of frequency and spatial domain methods is presented with an emphasis on sine testing.

  9. Multiple Scattering of Electromagnetic Waves in Discrete Random Media.

    DTIC Science & Technology

    1984-12-31

    purposes, we have also investigated the electromagnetic wave propagation through randomly distributed and oriented scatterers by introducing the concept...computer to determine whether or not particle overlap has occurred. The implementation of the "physics" of the system and orientations of non-spherical...34Coherent electromagnetic wave propagation through randomly distributed and oriented pair-correlated dielectric scatterers," Radio Sci., 19, 1445-1449

  10. Tailored complex 3D vortex lattice structures by perturbed multiples of three-plane waves.

    PubMed

    Xavier, Jolly; Vyas, Sunil; Senthilkumaran, Paramasivam; Joseph, Joby

    2012-04-20

    As three-plane waves are the minimum number required for the formation of vortex-embedded lattice structures by plane wave interference, we present our experimental investigation on the formation of complex 3D photonic vortex lattice structures by a designed superposition of multiples of phase-engineered three-plane waves. The unfolding of the generated complex photonic lattice structures with higher order helical phase is realized by perturbing the superposition of a relatively phase-encoded, axially equidistant multiple of three noncoplanar plane waves. Through a programmable spatial light modulator assisted single step fabrication approach, the unfolded 3D vortex lattice structures are experimentally realized, well matched to our computer simulations. The formation of higher order intertwined helices embedded in these 3D spiraling vortex lattice structures by the superposition of the multiples of phase-engineered three-plane waves interference is also studied.

  11. Optical sensing of analytes in aqueous solutions with a multiple surface-plasmon-polariton-wave platform

    PubMed Central

    Swiontek, Stephen E.; Pulsifer, Drew P.; Lakhtakia, Akhlesh

    2013-01-01

    The commonly used optical sensor based on surface plasmon-polariton wave phenomenon can sense just one chemical, because only one SPP wave can be guided by the interface of a metal and a dielectric material contained in the sensor. Multiple analytes could be detected and/or the sensing reliability for a single analyte could be enhanced, if multiple SPP-wave modes could be excited on a single metal/dielectric interface. For that to happen, the partnering dielectric material must be periodically non-homogeneous. Using a chiral sculptured thin film (CSTF) as that material in a SPP-wave platform, we show that the angular locations of multiple SPP-wave modes shift when the void regions of the CSTF are infiltrated with a fluid. The sensitivities realized in the proof-of-concept experiments are comparable to state-of-research values. PMID:23474988

  12. Sine-Gordon quantum mechanics on the complex plane and N=2 gauge theory

    SciTech Connect

    He Wei

    2010-05-15

    We study the relation between the N=2 gauge theory in the {Omega} background and the quantized integral system recently proposed by Nekrasov and Shatashvili. We focus on the simplest case, the pure Yang-Mills theory with the SU(2) gauge group and the corresponding sine-Gordon integral model on the complex plane. We analyze the periodic wave function and the corresponding energy spectrum of the sine-Gordon quantum mechanics, and find this model contains information of the low energy effective theory of the gauge theory.

  13. SINEBase: a database and tool for SINE analysis.

    PubMed

    Vassetzky, Nikita S; Kramerov, Dmitri A

    2013-01-01

    SINEBase (http://sines.eimb.ru) integrates the revisited body of knowledge about short interspersed elements (SINEs). A set of formal definitions concerning SINEs was introduced. All available sequence data were screened through these definitions and the genetic elements misidentified as SINEs were discarded. As a result, 175 SINE families have been recognized in animals, flowering plants and green algae. These families were classified by the modular structure of their nucleotide sequences and the frequencies of different patterns were evaluated. These data formed the basis for the database of SINEs. The SINEBase website can be used in two ways: first, to explore the database of SINE families, and second, to analyse candidate SINE sequences using specifically developed tools. This article presents an overview of the database and the process of SINE identification and analysis.

  14. SINEBase: a database and tool for SINE analysis

    PubMed Central

    Vassetzky, Nikita S.; Kramerov, Dmitri A.

    2013-01-01

    SINEBase (http://sines.eimb.ru) integrates the revisited body of knowledge about short interspersed elements (SINEs). A set of formal definitions concerning SINEs was introduced. All available sequence data were screened through these definitions and the genetic elements misidentified as SINEs were discarded. As a result, 175 SINE families have been recognized in animals, flowering plants and green algae. These families were classified by the modular structure of their nucleotide sequences and the frequencies of different patterns were evaluated. These data formed the basis for the database of SINEs. The SINEBase website can be used in two ways: first, to explore the database of SINE families, and second, to analyse candidate SINE sequences using specifically developed tools. This article presents an overview of the database and the process of SINE identification and analysis. PMID:23203982

  15. Functional noncoding sequences derived from SINEs in the mammalian genome

    PubMed Central

    Nishihara, Hidenori; Smit, Arian F.A.; Okada, Norihiro

    2006-01-01

    Recent comparative analyses of mammalian sequences have revealed that a large number of nonprotein-coding genomic regions are under strong selective constraint. Here, we report that some of these loci have been derived from a newly defined family of ancient SINEs (short interspersed repetitive elements). This is a surprising result, as SINEs and other transposable elements are commonly thought to be genomic parasites. We named the ancient SINE family AmnSINE1, for Amniota SINE1, because we found it to be present in mammals as well as in birds, and some copies predate the mammalian-bird split 310 million years ago (Mya). AmnSINE1 has a chimeric structure of a 5S rRNA and a tRNA-derived SINE, and is related to five tRNA-derived SINE families that we characterized here in the coelacanth, dogfish shark, hagfish, and amphioxus genomes. All of the newly described SINE families have a common central domain that is also shared by zebrafish SINE3, and we collectively name them the DeuSINE (Deuterostomia SINE) superfamily. Notably, of the ∼1000 still identifiable copies of AmnSINE1 in the human genome, 105 correspond to loci phylogenetically highly conserved among mammalian orthologs. The conservation is strongest over the central domain. Thus, AmnSINE1 appears to be the best example of a transposable element of which a significant fraction of the copies have acquired genomic functionality. PMID:16717141

  16. Functional noncoding sequences derived from SINEs in the mammalian genome.

    PubMed

    Nishihara, Hidenori; Smit, Arian F A; Okada, Norihiro

    2006-07-01

    Recent comparative analyses of mammalian sequences have revealed that a large number of nonprotein-coding genomic regions are under strong selective constraint. Here, we report that some of these loci have been derived from a newly defined family of ancient SINEs (short interspersed repetitive elements). This is a surprising result, as SINEs and other transposable elements are commonly thought to be genomic parasites. We named the ancient SINE family AmnSINE1, for Amniota SINE1, because we found it to be present in mammals as well as in birds, and some copies predate the mammalian-bird split 310 million years ago (Mya). AmnSINE1 has a chimeric structure of a 5S rRNA and a tRNA-derived SINE, and is related to five tRNA-derived SINE families that we characterized here in the coelacanth, dogfish shark, hagfish, and amphioxus genomes. All of the newly described SINE families have a common central domain that is also shared by zebrafish SINE3, and we collectively name them the DeuSINE (Deuterostomia SINE) superfamily. Notably, of the approximately 1000 still identifiable copies of AmnSINE1 in the human genome, 105 correspond to loci phylogenetically highly conserved among mammalian orthologs. The conservation is strongest over the central domain. Thus, AmnSINE1 appears to be the best example of a transposable element of which a significant fraction of the copies have acquired genomic functionality.

  17. Multiple Re-Reflections and Focusing of Waves by a Metamaterial Layer

    NASA Astrophysics Data System (ADS)

    Miron'chev, A. S.; Yakubov, V. P.

    2016-12-01

    The effect of electromagnetic wave focusing by a plane metamaterial layer with arbitrary parameters is theoretically simulated. Results of focusing of radiation of two point-sized radiation sources obtained without and with taking into account multiple re-reflections of waves are presented.

  18. Electromagnetic Ion Cyclotron Wave Triggering by Solar Wind Dynamic Pressure Enhancements at Multiple Locations

    NASA Astrophysics Data System (ADS)

    Cho, J.; Lee, D. Y.; Kim, H.

    2016-12-01

    Electromagnetic Ion cyclotron (EMIC) waves are one of the key plasma waves which play a critical role in the magnetosphere by interacting with charged particles. One of the generation mechanisms of EMIC waves is magnetospheric compression due to impact of enhanced solar wind dynamic pressure Pdyn. With the multi-satellite (the Van Allen Probes and two GOES satellites) observations in the inner magnetosphere and ground-based magnetometers, we examine two EMIC wave events that are triggered by Pdyn enhancements under prolonged northward IMF quiet time preconditions. For both events, the impact of enhanced Pdyn causes EMIC waves at multiple points. However, we find a strong spatial dependence of EMIC wave triggering and the accompanied wave properties. For Event 1, a satellite near noon observes no dramatic EMIC waves. In contrast, three other satellites are situated at a nearly same dawn side zone but at slightly different L shells and see notable EMIC waves but in different frequencies relative to local ion gyrofrequencies. These waves are found inside or outer edge of the plasmasphere. For Event 2, the satellites are situated at three different MLT zones, late afternoon-dusk, early evening-pre-midnight, and post-midnight, when they see the triggered EMIC waves. They are again found at different frequencies relative to local ion gyrofrequencies, and all outside the plasmasphere. Furthermore, the triggered EMIC waves for both events are observed from high-latitude ground stations in Antarctica. The results in this work imply that triggering of EMIC waves by enhanced Pdyn can occur at multiple points but with different wave properties, which must be due to different local plasma and magnetic conditions.

  19. Gravity localization in sine-Gordon braneworlds

    SciTech Connect

    Cruz, W.T.; Maluf, R.V.; Sousa, L.J.S.; Almeida, C.A.S.

    2016-01-15

    In this work we study two types of five-dimensional braneworld models given by sine-Gordon potentials. In both scenarios, the thick brane is generated by a real scalar field coupled to gravity. We focus our investigation on the localization of graviton field and the behaviour of the massive spectrum. In particular, we analyse the localization of massive modes by means of a relative probability method in a Quantum Mechanics context. Initially, considering a scalar field sine-Gordon potential, we find a localized state to the graviton at zero mode. However, when we consider a double sine-Gordon potential, the brane structure is changed allowing the existence of massive resonant states. The new results show how the existence of an internal structure can aid in the emergence of massive resonant modes on the brane.

  20. Linking multiple relaxation, power-law attenuation, and fractional wave equations.

    PubMed

    Näsholm, Sven Peter; Holm, Sverre

    2011-11-01

    The acoustic wave attenuation is described by an experimentally established frequency power law in a variety of complex media, e.g., biological tissue, polymers, rocks, and rubber. Recent papers present a variety of acoustical fractional derivative wave equations that have the ability to model power-law attenuation. On the other hand, a multiple relaxation model is widely recognized as a physically based description of the acoustic loss mechanisms as developed by Nachman et al. [J. Acoust. Soc. Am. 88, 1584-1595 (1990)]. Through assumption of a continuum of relaxation mechanisms, each with an effective compressibility described by a distribution related to the Mittag-Leffler function, this paper shows that the wave equation corresponding to the multiple relaxation approach is identical to a given fractional derivative wave equation. This work therefore provides a physically based motivation for use of fractional wave equations in acoustic modeling.

  1. Newly discovered young CORE-SINEs in marsupial genomes.

    PubMed

    Munemasa, Maruo; Nikaido, Masato; Nishihara, Hidenori; Donnellan, Stephen; Austin, Christopher C; Okada, Norihiro

    2008-01-15

    Although recent mammalian genome projects have uncovered a large part of genomic component of various groups, several repetitive sequences still remain to be characterized and classified for particular groups. The short interspersed repetitive elements (SINEs) distributed among marsupial genomes are one example. We have identified and characterized two new SINEs from marsupial genomes that belong to the CORE-SINE family, characterized by a highly conserved "CORE" domain. PCR and genomic dot blot analyses revealed that the distribution of each SINE shows distinct patterns among the marsupial genomes, implying different timing of their retroposition during the evolution of marsupials. The members of Mar3 (Marsupialia 3) SINE are distributed throughout the genomes of all marsupials, whereas the Mac1 (Macropodoidea 1) SINE is distributed specifically in the genomes of kangaroos. Sequence alignment of the Mar3 SINEs revealed that they can be further divided into four subgroups, each of which has diagnostic nucleotides. The insertion patterns of each SINE at particular genomic loci, together with the distribution patterns of each SINE, suggest that the Mar3 SINEs have intensively amplified after the radiation of diprotodontians, whereas the Mac1 SINE has amplified only slightly after the divergence of hypsiprimnodons from other macropods. By compiling the information of CORE-SINEs characterized to date, we propose a comprehensive picture of how SINE evolution occurred in the genomes of marsupials.

  2. Carnivore-specific SINEs (Can-SINEs): distribution, evolution, and genomic impact.

    PubMed

    Walters-Conte, Kathryn B; Johnson, Diana L E; Allard, Marc W; Pecon-Slattery, Jill

    2011-01-01

    Short interspersed nuclear elements (SINEs) are a type of class 1 transposable element (retrotransposon) with features that allow investigators to resolve evolutionary relationships between populations and species while providing insight into genome composition and function. Characterization of a Carnivora-specific SINE family, Can-SINEs, has, has aided comparative genomic studies by providing rare genomic changes, and neutral sequence variants often needed to resolve difficult evolutionary questions. In addition, Can-SINEs constitute a significant source of functional diversity with Carnivora. Publication of the whole-genome sequence of domestic dog, domestic cat, and giant panda serves as a valuable resource in comparative genomic inferences gleaned from Can-SINEs. In anticipation of forthcoming studies bolstered by new genomic data, this review describes the discovery and characterization of Can-SINE motifs as well as describes composition, distribution, and effect on genome function. As the contribution of noncoding sequences to genomic diversity becomes more apparent, SINEs and other transposable elements will play an increasingly large role in mammalian comparative genomics.

  3. Carnivore-Specific SINEs (Can-SINEs): Distribution, Evolution, and Genomic Impact

    PubMed Central

    Johnson, Diana L.E.; Allard, Marc W.; Pecon-Slattery, Jill

    2011-01-01

    Short interspersed nuclear elements (SINEs) are a type of class 1 transposable element (retrotransposon) with features that allow investigators to resolve evolutionary relationships between populations and species while providing insight into genome composition and function. Characterization of a Carnivora-specific SINE family, Can-SINEs, has, has aided comparative genomic studies by providing rare genomic changes, and neutral sequence variants often needed to resolve difficult evolutionary questions. In addition, Can-SINEs constitute a significant source of functional diversity with Carnivora. Publication of the whole-genome sequence of domestic dog, domestic cat, and giant panda serves as a valuable resource in comparative genomic inferences gleaned from Can-SINEs. In anticipation of forthcoming studies bolstered by new genomic data, this review describes the discovery and characterization of Can-SINE motifs as well as describes composition, distribution, and effect on genome function. As the contribution of noncoding sequences to genomic diversity becomes more apparent, SINEs and other transposable elements will play an increasingly large role in mammalian comparative genomics. PMID:21846743

  4. Imaging Moving Objects from Multiply Scattered Waves and Multiple Sensors

    DTIC Science & Technology

    2013-04-18

    Online at stacks.iop.org/IP/29/054012 Abstract In this paper, we develop a linearized imaging theory that combines the spatial, temporal and spectral...public release; distribution unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT In this paper, we develop a linearized imaging theory that combines the...spatial, temporal and spectral components of multiply scattered waves as they scatter from moving objects. In particular, we consider the case of

  5. Non-Abelian sine-Gordon solitons

    NASA Astrophysics Data System (ADS)

    Nitta, Muneto

    2015-06-01

    We point out that non-Abelian sine-Gordon solitons stably exist in the U (N) chiral Lagrangian. They also exist in a U (N) gauge theory with two N by N complex scalar fields coupled to each other. One non-Abelian sine-Gordon soliton can terminate on one non-Abelian global vortex. They are relevant in chiral Lagrangian of QCD or in color-flavor locked phase of high density QCD, where the anomaly is suppressed at asymptotically high temperature or density, respectively.

  6. Sine-Bar Attachment For Machine Tools

    NASA Technical Reports Server (NTRS)

    Mann, Franklin D.

    1988-01-01

    Sine-bar attachment for collets, spindles, and chucks helps machinists set up quickly for precise angular cuts that require greater precision than provided by graduations of machine tools. Machinist uses attachment to index head, carriage of milling machine or lathe relative to table or turning axis of tool. Attachment accurate to 1 minute or arc depending on length of sine bar and precision of gauge blocks in setup. Attachment installs quickly and easily on almost any type of lathe or mill. Requires no special clamps or fixtures, and eliminates many trial-and-error measurements. More stable than improvised setups and not jarred out of position readily.

  7. Sines and Cosines. Part 3 of 3

    NASA Technical Reports Server (NTRS)

    Apostol, Tom M. (Editor)

    1994-01-01

    In this 'Project Mathematics' series video, the addition formulas of sines and cosines are explained and their real life applications are demonstrated. Both film footage and computer animation is used. Several mathematical concepts are discussed and include: Ptolemy's theorem concerned with quadrilaterals; the difference between a central angle and an inscribed angle; sines and chord lengths; special angles; subtraction formulas; and a application to simple harmonic motion. A brief history of the city Alexandria, its mathematicians, and their contribution to the field of mathematics is shown.

  8. Sine-Bar Attachment For Machine Tools

    NASA Technical Reports Server (NTRS)

    Mann, Franklin D.

    1988-01-01

    Sine-bar attachment for collets, spindles, and chucks helps machinists set up quickly for precise angular cuts that require greater precision than provided by graduations of machine tools. Machinist uses attachment to index head, carriage of milling machine or lathe relative to table or turning axis of tool. Attachment accurate to 1 minute or arc depending on length of sine bar and precision of gauge blocks in setup. Attachment installs quickly and easily on almost any type of lathe or mill. Requires no special clamps or fixtures, and eliminates many trial-and-error measurements. More stable than improvised setups and not jarred out of position readily.

  9. Electro-mechanical sine/cosine generator

    NASA Technical Reports Server (NTRS)

    Flagge, B. (Inventor)

    1972-01-01

    An electromechanical device for generating both sine and cosine functions is described. A motor rotates a cylinder about an axis parallel to and a slight distance from the central axis of the cylinder. Two noncontacting displacement sensing devices are placed ninety degrees apart, equal distances from the axis of rotation of the cylinder and short distances above the surface of cylinder. Each of these sensing devices produces an electrical signal proportional to the distance that it is away from the cylinder. Consequently, as the cylinder is rotated the outputs from the two sensing devices are the sine and cosine functions.

  10. A Persistent Feature of Multiple Scattering of Waves in the Time-Domain: A Tutorial

    NASA Technical Reports Server (NTRS)

    Lock, James A.; Mishchenko, Michael I.

    2015-01-01

    The equations for frequency-domain multiple scattering are derived for a scalar or electromagnetic plane wave incident on a collection of particles at known positions, and in the time-domain for a plane wave pulse incident on the same collection of particles. The calculation is carried out for five different combinations of wave types and particle types of increasing geometrical complexity. The results are used to illustrate and discuss a number of physical and mathematical characteristics of multiple scattering in the frequency- and time-domains. We argue that frequency-domain multiple scattering is a purely mathematical construct since there is no temporal sequencing information in the frequency-domain equations and since the multi-particle path information can be dispelled by writing the equations in another mathematical form. However, multiple scattering becomes a definite physical phenomenon in the time-domain when the collection of particles is illuminated by an appropriately short localized pulse.

  11. A Persistent Feature of Multiple Scattering of Waves in the Time-Domain: A Tutorial

    NASA Technical Reports Server (NTRS)

    Lock, James A.; Mishchenko, Michael I.

    2015-01-01

    The equations for frequency-domain multiple scattering are derived for a scalar or electromagnetic plane wave incident on a collection of particles at known positions, and in the time-domain for a plane wave pulse incident on the same collection of particles. The calculation is carried out for five different combinations of wave types and particle types of increasing geometrical complexity. The results are used to illustrate and discuss a number of physical and mathematical characteristics of multiple scattering in the frequency- and time-domains. We argue that frequency-domain multiple scattering is a purely mathematical construct since there is no temporal sequencing information in the frequency-domain equations and since the multi-particle path information can be dispelled by writing the equations in another mathematical form. However, multiple scattering becomes a definite physical phenomenon in the time-domain when the collection of particles is illuminated by an appropriately short localized pulse.

  12. Modified sine bar device measures small angles with high accuracy

    NASA Technical Reports Server (NTRS)

    Thekaekara, M.

    1968-01-01

    Modified sine bar device measures small angles with enough accuracy to calibrate precision optical autocollimators. The sine bar is a massive bar of steel supported by two cylindrical rods at one end and one at the other.

  13. Multiple charge density wave transitions in Gd2Te5

    SciTech Connect

    Shin, K.Y.; Ru, N.; Condron, C.L.; Wu, Y.Q.; Kramer, M.J.; Toney, M.F.; Fisher, I.R.; /Stanford U., Geballe Lab. /Stanford U., Appl. Phys. Dept.

    2010-02-15

    Diffraction measurements performed via transmission electron microscopy and high resolution X-ray scattering reveal two distinct charge density wave transitions in Gd{sub 2}Te{sub 5} at T{sub c1} = 410(3) and T{sub c2} = 532(3) K, associated with the on-axis incommensurate lattice modulation and off-axis commensurate lattice modulation respectively. Analysis of the temperature dependence of the order parameters indicates a non-vanishing coupling between these two distinct CDW states.

  14. Multiple and spin off initiation of atmospheric convectively coupled Kelvin waves

    NASA Astrophysics Data System (ADS)

    Baranowski, Dariusz B.; Flatau, Maria K.; Flatau, Piotr J.; Schmidt, Jerome M.

    2017-02-01

    A novel atmospheric convectively coupled Kelvin wave trajectories database, derived from Tropical Rainfall Measuring Mission precipitation data, is used to investigate initiation of sequential Kelvin wave events. Based on the analysis of beginnings of trajectories from years 1998-2012 it is shown that sequential event initiations can be divided into two distinct categories: multiple initiations and spin off initiations, both of which involve interactions with ocean surface and upper ocean temperature variability. The results of composite analysis of the 83 multiple Kelvin wave initiations show that the local thermodynamic forcing related to the diurnal sea surface temperature variability is responsible for sequential Kelvin wave development. The composite analysis of 91 spin off Kelvin wave initiations shows that the dynamic forcing is a dominant effect and the local thermodynamic forcing is secondary. Detail case studies of both multiple and spin off initiations confirm statistical analysis. A multiple initiation occurs in the presence of the high upper ocean diurnal cycle and a spin off initiation results from both dynamic and local thermodynamic processes. The dynamic forcing is related to increased wind speed and latent heat flux likely associated with an off equatorial circulation. In addition a theoretical study of the sequential Kelvin waves is performed using a shallow water model. Finally, conceptual models of these two types of initiations are proposed.

  15. Commuting Flows and Infinite-Dimensional Tori: Sine-Gordon

    NASA Astrophysics Data System (ADS)

    Schwarz, Martin

    2017-02-01

    The present work concerns the periodic sine-Gordon equation. We explain why the complete set of conserved functionals for sine-Gordon is an infinite-dimensional torus; the periodic sine-Gordon solution is almost periodic in time on an infinite-dimensional torus.

  16. Sine-Fitting Software for IEEE Standard 1057

    SciTech Connect

    Blair, Jerome

    1999-05-01

    Software application that performs the calculations related to the sine-fit tests of IEEE Standard 1057/94. Example outputs and explainations of these outputs to determine the important characteristics of the device under test. This application performs the calculations related to sine-fit tests and uses 4-parameter sine fit from IEEE Standard 1057-1994.

  17. Benjamin Banneker and the Law of Sines

    ERIC Educational Resources Information Center

    Mahoney, John F.

    2005-01-01

    Benjamin Banneker, a self-taught mathematician, surveyor and astronomer published annual almanacs containing his astronomical observations and predictions. Banneker who also used logarithms to apply the Law of Sines believed that the method used to solve a mathematical problem depends on the tools available.

  18. Benjamin Banneker and the Law of Sines

    ERIC Educational Resources Information Center

    Mahoney, John F.

    2005-01-01

    Benjamin Banneker, a self-taught mathematician, surveyor and astronomer published annual almanacs containing his astronomical observations and predictions. Banneker who also used logarithms to apply the Law of Sines believed that the method used to solve a mathematical problem depends on the tools available.

  19. Ground vibration test results of a JetStar airplane using impulsive sine excitation

    NASA Technical Reports Server (NTRS)

    Kehoe, Michael W.; Voracek, David F.

    1989-01-01

    Structural excitation is important for both ground vibration and flight flutter testing. The structural responses caused by this excitation are analyzed to determine frequency, damping, and mode shape information. Many excitation waveforms have been used throughout the years. The use of impulsive sine (sin omega t)/omega t as an excitation waveform for ground vibration testing and the advantages of using this waveform for flight flutter testing are discussed. The ground vibration test results of a modified JetStar airplane using impulsive sine as an excitation waveform are compared with the test results of the same airplane using multiple-input random excitation. The results indicated that the structure was sufficiently excited using the impulsive sine waveform. Comparisons of input force spectrums, mode shape plots, and frequency and damping values for the two methods of excitation are presented.

  20. Ground vibration test results of a JetStar airplane using impulsive sine excitation

    NASA Technical Reports Server (NTRS)

    Kehoe, Michael W.; Voracek, David F.

    1989-01-01

    Structural excitation is important for both ground vibration and flight flutter testing. The structural responses caused by this excitation are analyzed to determine frequency, damping, and mode shape information. Many excitation waveforms have been used throughout the years. The use of impulsive sine (sin omega t)/omega t as an excitation waveform for ground vibration testing and the advantages of using this waveform for flight flutter testing are discussed. The ground vibration test results of a modified JetStar airplane using impulsive sine as an excitation waveform are compared with the test results of the same airplane using multiple-input random excitation. The results indicated that the structure was sufficiently excited using the impulsive sine waveform. Comparisons of input force spectrums, mode shape plots, and frequency and damping values for the two methods of excitation are presented.

  1. Influence of multiple ion species on low-frequency electromagnetic wave instabilities. [in solar wind

    NASA Technical Reports Server (NTRS)

    Brinca, Armando L.; Tsurutani, Bruce T.

    1989-01-01

    The effect of multiple (singly ionized) coexisting newborn ion species on the stability of low-frequency electromagnetic waves was investigated using a plasma model in which solar wind magnetoplasma is made up of isotropic Maxwellian electron and proton populations with a common number density of 4.95/cu cm and temperatures equal to 17.2 eV and 6.9 eV, respectively. It is shown that the effect of multiple ions on wave growth, for given background magnetoplasma conditions and relative densities, depends not only on their mass but also on the physical nature of the wave modes. If the ion masses are disparate, each one of the coexisting ion beams tends to stimulate instabilities without undue influence from the other species. If the masses of newborn ions are similar, they can strongly catalyze wave growth of fluidlike nonresonant modes, but bring about weak growth enhancements in cyclotron resonant instabilities.

  2. SINE_scan: an efficient tool to discover short interspersed nuclear elements (SINEs) in large-scale genomic datasets.

    PubMed

    Mao, Hongliang; Wang, Hao

    2017-03-01

    Short Interspersed Nuclear Elements (SINEs) are transposable elements (TEs) that amplify through a copy-and-paste mode via RNA intermediates. The computational identification of new SINEs are challenging because of their weak structural signals and rapid diversification in sequences. Here we report SINE_Scan, a highly efficient program to predict SINE elements in genomic DNA sequences. SINE_Scan integrates hallmark of SINE transposition, copy number and structural signals to identify a SINE element. SINE_Scan outperforms the previously published de novo SINE discovery program. It shows high sensitivity and specificity in 19 plant and animal genome assemblies, of which sizes vary from 120 Mb to 3.5 Gb. It identifies numerous new families and substantially increases the estimation of the abundance of SINEs in these genomes. The code of SINE_Scan is freely available at http://github.com/maohlzj/SINE_Scan , implemented in PERL and supported on Linux. wangh8@fudan.edu.cn. Supplementary data are available at Bioinformatics online.

  3. Four-wave mixing in Bose-Einstein condensate systems with multiple spin states

    SciTech Connect

    Burke, J.P. Jr.; Julienne, P. S.; Williams, C.J.; Band, Y.B.; Trippenbach, M.

    2004-09-01

    We calculate the four-wave mixing (FWM) in a Bose-Einstein condensate system having multiple spin wave packets that are initially overlapping in physical space, but have nonvanishing relative momentum that causes them to recede from one another. Three receding condensate atom wave packets can result in production of a fourth wave packet by the process of FWM due to atom-atom interactions. We consider cases where the four final wave packets are composed of one, two, three, and four different internal spin components. FWM with one or two-spin state wave packets is much stronger than three- or four-spin state FWM, wherein two of the coherent moving Bose-Einstein condensate wave packets form a spin-polarization grating that rotates the spin projection of the third wave into that of the fourth diffracted wave (as opposed to the one- or two-spin state case where a regular density grating is responsible for the diffraction). Calculations of FWM for {sup 87}Rb and {sup 23}Na condensate systems are presented.

  4. Flat pancake distant dipolar fields for enhancement of intermolecular multiple-quantum coherence signals.

    PubMed

    Cai, Congbo; Lin, Yulan; Cai, Shuhui; Sun, Huijun; Zhong, Jianhui; Chen, Zhong

    2012-03-07

    Intermolecular multiple-quantum coherences (iMQCs) originated from distant dipolar field (DDF) possess some appealing unique properties for magnetic resonance imaging (MRI). DDF is usually induced with continuous wave (i.e., sine- or square-wave) magnetization modulation in the whole sample. In this article, a spatially localized and enhanced DDF was optimally tailored in a thin slice with an adiabatic inversion pulse. Evidence was provided to show that careful tailoring of the spatially localized DDF can generate highly efficient iMQC signals, with more than two-fold enhancement compared to the conventional sine-wave magnetization modulation method, and 1.5 times of that with the square-wave modulation under the similar condition. Theoretical predictions, simulation results, and experimental verifications agree well with each other. Practical implementation of this approach for efficient iMQC MRI was explored. © 2012 American Institute of Physics

  5. Basilar-membrane interference patterns from multiple internal reflection of cochlear traveling waves.

    PubMed

    Shera, Christopher A; Cooper, Nigel P

    2013-04-01

    At low stimulus levels, basilar-membrane (BM) mechanical transfer functions in sensitive cochleae manifest a quasiperiodic rippling pattern in both amplitude and phase. Analysis of the responses of active cochlear models suggests that the rippling is a mechanical interference pattern created by multiple internal reflection within the cochlea. In models, the interference arises when reverse-traveling waves responsible for stimulus-frequency otoacoustic emissions (SFOAEs) reflect off the stapes on their way to the ear canal, launching a secondary forward-traveling wave that combines with the primary wave produced by the stimulus. Frequency-dependent phase differences between the two waves then create the rippling pattern measurable on the BM. Measurements of BM ripples and SFOAEs in individual chinchilla ears demonstrate that the ripples are strongly correlated with the acoustic interference pattern measured in ear-canal pressure, consistent with a common origin involving the generation of SFOAEs. In BM responses to clicks, the ripples appear as temporal fine structure in the response envelope (multiple lobes, waxing and waning). Analysis of the ripple spacing and response phase gradients provides a test for the role of fast- and slow-wave modes of reverse energy propagation within the cochlea. The data indicate that SFOAE delays are consistent with reverse slow-wave propagation but much too long to be explained by fast waves.

  6. Basilar-membrane interference patterns from multiple internal reflection of cochlear traveling waves

    PubMed Central

    Shera, Christopher A.; Cooper, Nigel P.

    2013-01-01

    At low stimulus levels, basilar-membrane (BM) mechanical transfer functions in sensitive cochleae manifest a quasiperiodic rippling pattern in both amplitude and phase. Analysis of the responses of active cochlear models suggests that the rippling is a mechanical interference pattern created by multiple internal reflection within the cochlea. In models, the interference arises when reverse-traveling waves responsible for stimulus-frequency otoacoustic emissions (SFOAEs) reflect off the stapes on their way to the ear canal, launching a secondary forward-traveling wave that combines with the primary wave produced by the stimulus. Frequency-dependent phase differences between the two waves then create the rippling pattern measurable on the BM. Measurements of BM ripples and SFOAEs in individual chinchilla ears demonstrate that the ripples are strongly correlated with the acoustic interference pattern measured in ear-canal pressure, consistent with a common origin involving the generation of SFOAEs. In BM responses to clicks, the ripples appear as temporal fine structure in the response envelope (multiple lobes, waxing and waning). Analysis of the ripple spacing and response phase gradients provides a test for the role of fast- and slow-wave modes of reverse energy propagation within the cochlea. The data indicate that SFOAE delays are consistent with reverse slow-wave propagation but much too long to be explained by fast waves. PMID:23556591

  7. Generalized F-statistic: Multiple detectors and multiple gravitational wave pulsars

    NASA Astrophysics Data System (ADS)

    Cutler, Curt; Schutz, Bernard F.

    2005-09-01

    The F-statistic, derived by Jaranowski, Krolak and Schutz (1998), is the optimal (frequentist) statistic for the detection of nearly periodic gravitational waves from known neutron stars, in the presence of stationary, Gaussian detector noise. The F-statistic was originally derived for the case of a single detector, whose noise spectral density was assumed constant in time, and for a single known neutron star. Here we show how the F-statistic can be straightforwardly generalized to the cases of (1) a network of detectors with time-varying noise curves, and (2) a collection of known sources (e.g., all known millisecond pulsars within some fixed distance). Fortunately, all the important ingredients that go into our generalized F-statistics are already calculated in the single-source/single-detector searches that are currently implemented, e.g., in the Laser Interferometer Gravitational-Wave Observatory software library, so implementation of optimal multidetector, multisource searches should require negligible additional cost in computational power or software development. This paper also includes an analysis of the likely efficacy of a collection-type search, and derives criteria for deciding which candidate sources should be included in a collection, if one is trying to maximize the detectability of the whole. In particular we show that for sources distributed uniformly in a thin disk, the strongest source in the collection should have signal-to-noise-squared ˜5 times larger than weakest source, for an optimized collection. We show that gravitational waves from collection of the few brightest (in gravitational waves) neutron stars could perhaps be detected before the single brightest source, but that this is far from guaranteed. Once gravitational waves from the few brightest neutron stars have been discovered, grouping more distant (individually undetectable) pulsars into collections, and then searching for those collections, should be an effective way of

  8. Rocket measurements of electron density irregularities during MAC/SINE

    NASA Technical Reports Server (NTRS)

    Ulwick, J. C.

    1989-01-01

    Four Super Arcas rockets were launched at the Andoya Rocket Range, Norway, as part of the MAC/SINE campaign to measure electron density irregularities with high spatial resolution in the cold summer polar mesosphere. They were launched as part of two salvos: the turbulent/gravity wave salvo (3 rockets) and the EISCAT/SOUSY radar salvo (one rocket). In both salvos meteorological rockets, measuring temperature and winds, were also launched and the SOUSY radar, located near the launch site, measured mesospheric turbulence. Electron density irregularities and strong gradients were measured by the rocket probes in the region of most intense backscatter observed by the radar. The electron density profiles (8 to 4 on ascent and 4 on descent) show very different characteristics in the peak scattering region and show marked spatial and temporal variability. These data are intercompared and discussed.

  9. Short interspersed elements (SINEs) of the Geomyoidea superfamily rodents.

    PubMed

    Gogolevsky, Konstantin P; Kramerov, Dmitri A

    2006-05-24

    A new short interspersed element (SINE) was isolated from the genome of desert kangaroo rat (Dipodomys deserti) using single-primer PCR. This SINE consists of two monomers: the left monomer (IDL) resembles rodent ID element and other tRNAAla(CGC)-derived SINEs, whereas the right one (Geo) shows no similarity with known SINE sequences. PCR and hybridization analyses demonstrated that IDL-Geo SINE is restricted to the rodent superfamily Geomyoidea (families Geomyidea and Heteromyidea). Isolation and analysis of IDL-Geo from California pocket mouse (Chaetodipus californicus) and Botta's pocket gopher (Thomomys bottae) revealed some species-specific features of this SINE family. The structure and evolution of known dimeric SINEs are discussed.

  10. Multiple scattering of surface waves by cavities in a half-space

    SciTech Connect

    Phan, Haidang; Cho, Younho; Ju, Taeho; Achenbach, Jan D.

    2014-02-18

    Scattering of surface waves from multiple two-dimensional cavities at the surface of a homogenous, isotropic, linearly elastic half-space is analyzed in this work. For the case of multiple cavities, the scattered field is shown to be equivalent to the total radiation from the distributions of tractions, calculated from the incident wave, over the surfaces of the cavities. The multiple-scattering model is obtained from known single-scattering calculation for a cavity by the use of the self-consistent method. The second order approximation to the multiple-scattering problem by a random distribution of cavities is then considered and solved analytically. The vertical displacement at some distance from the cavities is calculated and verified by the solution of the same problem obtained by the boundary element method (BEM). The analytical and BEM results are graphically displayed and show good agreement when the depths of the cavities are small compared to the wavelength.

  11. Probing atmospheric water vapor profiles via multiple scattering of electromagnetic waves

    NASA Technical Reports Server (NTRS)

    Tang, C. C. H.

    1971-01-01

    A theoretical analysis on the multiple scattering of electromagnetic waves propagating in a finite inhomogeneous medium is presented and applied to the study of wave propagation in a clear atmosphere (fine weather conditions). It is shown that the analysis offers a method of synthesizing the water vapor density profile in a clear atmosphere by measuring the resultant reflections from the density profile at several different frequencies. It is also shown that the resultant reflection emerges as the consequence of multiple scattering of partial reflections from various parts of the inhomogeneous medium. The solutions of the multiple scattering approach are shown to be more accurate than those of the WKB approach, which neglects the multiple scattering effects.

  12. Large-amplitude nonlinear normal modes of the discrete sine lattices

    NASA Astrophysics Data System (ADS)

    Smirnov, Valeri V.; Manevitch, Leonid I.

    2017-02-01

    We present an analytical description of the large-amplitude stationary oscillations of the finite discrete system of harmonically coupled pendulums without any restrictions on their amplitudes (excluding a vicinity of π ). Although this model has numerous applications in different fields of physics, it was studied earlier in the infinite limit only. The discrete chain with a finite length can be considered as a well analytical analog of the coarse-grain models of flexible polymers in the molecular dynamics simulations. The developed approach allows to find the dispersion relations for arbitrary amplitudes of the nonlinear normal modes. We emphasize that the long-wavelength approximation, which is described by well-known sine-Gordon equation, leads to an inadequate zone structure for the amplitudes of about π /2 even if the chain is long enough. An extremely complex zone structure at the large amplitudes corresponds to multiple resonances between nonlinear normal modes even with strongly different wave numbers. Due to the complexity of the dispersion relations the modes with shorter wavelengths may have smaller frequencies. The stability of the nonlinear normal modes under condition of the resonant interaction are discussed. It is shown that this interaction of the modes in the vicinity of the long wavelength edge of the spectrum leads to the localization of the oscillations. The thresholds of instability and localization are determined explicitly. The numerical simulation of the dynamics of a finite-length chain is in a good agreement with obtained analytical predictions.

  13. Bifurcations, crisis, unstable dimension variability and the spreading transition in the coupled sine circle map system

    NASA Astrophysics Data System (ADS)

    Das, A.; Jabeen, Z.; Gupte, N.

    2014-12-01

    The dynamical behavior of spatially extended dynamical systems can have interesting consequences for their statistics. We demonstrate this in a specific context, a system of coupled sine circle maps, and discuss the interconnection between the statistical and dynamical behaviors of the system. The system has an interesting phase diagram in parameter space wherein a spreading transition is seen across an infection line, with spatio-temporal and spatial intermittency of distinct universality classes (directed percolation and non-directed percolation) seen in the spreading/non-spreading regimes. The dynamical origins of the spreading transition, lie in a crisis arising from a tangent bifurcation in the system. In addition to changing the statistics, and therefore the universality class of the system, the crisis also has dynamical consequences. Unstable dimension variability is seen in the neighbourhood of this crisis, and multiple routes to crisis are seen due to the presence of multi-attractor solutions. We examine the system using a variety of characterizers such as finite time Lyapunov exponents and their distributions. We discuss the signatures of the phenomena seen in the quantifiers, and also whether similar techniques can be extended to other situations. Finally, we demonstrate the success of the quantifiers in another regime, spatio-temporal intermittency with travelling wave laminar solutions, and a solitonic regime.

  14. Rogue waves and W-shaped solitons in the multiple self-induced transparency system

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Liu, Chong; Wang, Lei

    2017-09-01

    We study localized nonlinear waves on a plane wave background in the multiple self-induced transparency (SIT) system, which describes an important enhancement of the amplification and control of optical waves compared to the single SIT system. A hierarchy of exact multiparametric rational solutions in a compact determinant representation is presented. We demonstrate that this family of solutions contain known rogue wave solutions and unusual W-shaped soliton solutions. State transitions between the fundamental rogue waves and W-shaped solitons as well as higher-order nonlinear superposition modes are revealed in the zero-frequency perturbation region by the suitable choice for the background wavenumber of the electric field component. Particularly, it is found that the multiple SIT system can admit both stationary and nonstationary W-shaped solitons in contrast to the stationary results in the single SIT system. Moreover, the W-shaped soliton complex which is formed by a certain number of fundamental W-shaped solitons with zero phase parameters and its decomposition mechanism in the case of the nonzero phase parameters are shown. Meanwhile, some important characteristics of the nonlinear waves including trajectories and spectrum are discussed through the numerical and analytical methods.

  15. The noncommutative sine-Gordon breather

    SciTech Connect

    Fischer, Andre; Lechtenfeld, Olaf

    2009-09-15

    As shown by Lechtenfeld et al. [Nucl. Phys. B 705, 447 (2005)], there exists a noncommutative deformation of the sine-Gordon model which remains (classically) integrable but features a second scalar field. We employ the dressing method (adapted to the Moyal-deformed situation) for constructing the deformed kink-antikink and breather configurations. Explicit results and plots are presented for the leading noncommutativity correction to the breather. Its temporal periodicity is unchanged.

  16. A Cryogenic Half-Wave Plate Module to Measure Polarization at Multiple FIR Passbands

    NASA Technical Reports Server (NTRS)

    Rennick, Timothy S.; Vaillancourt, John E.; Hildebrand, Roger H.; Heimsath, Stephen J.

    2002-01-01

    One of the key components in a far-infrared polarimeter that is being designed at the University of Chicago is a locally-powered half-wave plate module. This compact, lightweight, and reliable module will operate at cryogenic temperatures, rotating a half-wave plate about its axis within the optical path. By doing so, polarization measurements can be made. Further, by utilizing multiple half-wave plate modules within the polarimeter, multiple wavelengths or passbands can be studied. In this paper, we describe the design and performance of a relatively inexpensive prototype module that was assembled and tested successfully, outline the difficulties that had to be overcome, and recommend improvements to future modules. This effort now lays some of the groundwork for a next-generation polarimeter for far-infrared astronomy.

  17. Exact renormalization group and Sine Gordon theory

    NASA Astrophysics Data System (ADS)

    Oak, Prafulla; Sathiapalan, B.

    2017-07-01

    The exact renormalization group is used to study the RG flow of quantities in field theories. The basic idea is to write an evolution operator for the flow and evaluate it in perturbation theory. This is easier than directly solving the differential equation. This is illustrated by reproducing known results in four dimensional ϕ 4 field theory and the two dimensional Sine-Gordon theory. It is shown that the calculation of beta function is somewhat simplified. The technique is also used to calculate the c-function in two dimensional Sine-Gordon theory. This agrees with other prescriptions for calculating c-functions in the literature. If one extrapolates the connection between central charge of a CFT and entanglement entropy in two dimensions, to the c-function of the perturbed CFT, then one gets a value for the entanglement entropy in Sine-Gordon theory that is in exact agreement with earlier calculations (including one using holography) in arXiv:1610.04233.

  18. Critical boundary sine-Gordon revisited

    SciTech Connect

    Hasselfield, M.; Lee, Taejin; Semenoff, G.W. . E-mail: gordonws@phas.ubc.ca; Stamp, P.C.E.

    2006-12-15

    We revisit the exact solution of the two space-time dimensional quantum field theory of a free massless boson with a periodic boundary interaction and self-dual period. We analyze the model by using a mapping to free fermions with a boundary mass term originally suggested in Ref. [J. Polchinski, L. Thorlacius, Phys. Rev. D 50 (1994) 622]. We find that the entire SL (2, C) family of boundary states of a single boson are boundary sine-Gordon states and we derive a simple explicit expression for the boundary state in fermion variables and as a function of sine-Gordon coupling constants. We use this expression to compute the partition function. We observe that the solution of the model has a strong-weak coupling generalization of T-duality. We then examine a class of recently discovered conformal boundary states for compact bosons with radii which are rational numbers times the self-dual radius. These have simple expression in fermion variables. We postulate sine-Gordon-like field theories with discrete gauge symmetries for which they are the appropriate boundary states.

  19. Shear wavelength estimation based on inverse filtering and multiple-point shear wave generation

    NASA Astrophysics Data System (ADS)

    Kitazaki, Tomoaki; Kondo, Kengo; Yamakawa, Makoto; Shiina, Tsuyoshi

    2016-07-01

    Elastography provides important diagnostic information because tissue elasticity is related to pathological conditions. For example, in a mammary gland, higher grade malignancies yield harder tumors. Estimating shear wave speed enables the quantification of tissue elasticity imaging using time-of-flight. However, time-of-flight measurement is based on an assumption about the propagation direction of a shear wave which is highly affected by reflection and refraction, and thus might cause an artifact. An alternative elasticity estimation approach based on shear wavelength was proposed and applied to passive configurations. To determine the elasticity of tissue more quickly and more accurately, we proposed a new method for shear wave elasticity imaging that combines the shear wavelength approach and inverse filtering with multiple shear wave sources induced by acoustic radiation force (ARF). The feasibility of the proposed method was verified using an elasticity phantom with a hard inclusion.

  20. Damage Evaluation Based on a Wave Energy Flow Map Using Multiple PZT Sensors

    PubMed Central

    Liu, Yaolu; Hu, Ning; Xu, Hong; Yuan, Weifeng; Yan, Cheng; Li, Yuan; Goda, Riu; Alamusi; Qiu, Jinhao; Ning, Huiming; Wu, Liangke

    2014-01-01

    A new wave energy flow (WEF) map concept was proposed in this work. Based on it, an improved technique incorporating the laser scanning method and Betti's reciprocal theorem was developed to evaluate the shape and size of damage as well as to realize visualization of wave propagation. In this technique, a simple signal processing algorithm was proposed to construct the WEF map when waves propagate through an inspection region, and multiple lead zirconate titanate (PZT) sensors were employed to improve inspection reliability. Various damages in aluminum and carbon fiber reinforced plastic laminated plates were experimentally and numerically evaluated to validate this technique. The results show that it can effectively evaluate the shape and size of damage from wave field variations around the damage in the WEF map. PMID:24463430

  1. An experimental investigation of multiple shock wave/turbulent boundary layer interactions in a circular duct

    NASA Technical Reports Server (NTRS)

    Om, D.; Childs, M. E.

    1983-01-01

    Detailed pitot, static and wall pressure measurements have been obtained for multiple shock wave/turbulent boundary layer interactions in a circular duct at a free-stream Mach number of 1.49 and at a unit Reynolds number of 4.90 x 10 to the 6th per meter. The details of the flow field show the formation of a series of normal shock waves with successively decreasing strength and with decreasing distance between the successive shock waves. The overall pressure recovery is much lower than the single normal shock pressure recovery at the same free-stream Mach number. A one-dimensional flow model based on the boundary layer displacement buildup is postulated to explain the formation of a series of normal shock waves.

  2. Proposal for all-optical generation of multiple-frequency millimeter-wave signals for RoF system with multiple base stations using FWM in SOA.

    PubMed

    Zhang, Chongfu; Wang, Leyang; Qiu, Kun

    2011-07-18

    An approach for the multiple-frequency millimeter-wave (mm-wave) signals generation is proposed and demonstrated, specifically, which can be applied to a radio-over-fiber (RoF) system with multiple base stations (BSs). In this scheme, optical double sideband (ODSB) modulation is achieved using a Mach-Zehnder modulator (MZM) to generate the two-sideband signals. New frequencies of the optical signals are obtained by using four-wave mixing (FWM) in a semiconductor optical amplifier (SOA). At the BSs, two different frequencies are achieved using a comb optical filter (COF), and which then input a photodiode (PD) to generate the mm-wave signals with the frequencies of 20, 40 or 60 GHz for different BSs, by mixing of these frequencies components. Experimental results verify that the proposed multiple-frequency mm-wave signals generation scheme for a RoF system with multiple base stations can work properly.

  3. Multiple reversals of pulse waves in an excitable medium resulting from switching the polarity of dc electric fields

    NASA Astrophysics Data System (ADS)

    Pornprompanya, Methasit; Müller, Stefan C.; Ševčíková, Hana

    2003-07-01

    A planar wave propagating in the Belousov-Zhabotinsky reaction medium with pyrogallol as substrate is shown to undergo multiple reversals upon switching the polarity of an imposed dc electric field. During the multiple reversals an asymmetry arises in: (i) the propagation velocities of reversed waves, (ii) the ferroin concentrations in front of reversed waves shortly before switching the electric field polarity, and (iii) the location at which a new wave emerges in the wake of the original one. Multiple reversals occur in a limited range of control parameter values and depend on the pyrogallol concentration.

  4. Bridging Three Orders of Magnitude: Multiple Scattered Waves Sense Fractal Microscopic Structures via Dispersion.

    PubMed

    Lambert, Simon A; Näsholm, Sven Peter; Nordsletten, David; Michler, Christian; Juge, Lauriane; Serfaty, Jean-Michel; Bilston, Lynne; Guzina, Bojan; Holm, Sverre; Sinkus, Ralph

    2015-08-28

    Wave scattering provides profound insight into the structure of matter. Typically, the ability to sense microstructure is determined by the ratio of scatterer size to probing wavelength. Here, we address the question of whether macroscopic waves can report back the presence and distribution of microscopic scatterers despite several orders of magnitude difference in scale between wavelength and scatterer size. In our analysis, monosized hard scatterers 5  μm in radius are immersed in lossless gelatin phantoms to investigate the effect of multiple reflections on the propagation of shear waves with millimeter wavelength. Steady-state monochromatic waves are imaged in situ via magnetic resonance imaging, enabling quantification of the phase velocity at a voxel size big enough to contain thousands of individual scatterers, but small enough to resolve the wavelength. We show in theory, experiments, and simulations that the resulting coherent superposition of multiple reflections gives rise to power-law dispersion at the macroscopic scale if the scatterer distribution exhibits apparent fractality over an effective length scale that is comparable to the probing wavelength. Since apparent fractality is naturally present in any random medium, microstructure can thereby leave its fingerprint on the macroscopically quantifiable power-law exponent. Our results are generic to wave phenomena and carry great potential for sensing microstructure that exhibits intrinsic fractality, such as, for instance, vasculature.

  5. Bridging Three Orders of Magnitude: Multiple Scattered Waves Sense Fractal Microscopic Structures via Dispersion

    NASA Astrophysics Data System (ADS)

    Lambert, Simon A.; Näsholm, Sven Peter; Nordsletten, David; Michler, Christian; Juge, Lauriane; Serfaty, Jean-Michel; Bilston, Lynne; Guzina, Bojan; Holm, Sverre; Sinkus, Ralph

    2015-08-01

    Wave scattering provides profound insight into the structure of matter. Typically, the ability to sense microstructure is determined by the ratio of scatterer size to probing wavelength. Here, we address the question of whether macroscopic waves can report back the presence and distribution of microscopic scatterers despite several orders of magnitude difference in scale between wavelength and scatterer size. In our analysis, monosized hard scatterers 5 μ m in radius are immersed in lossless gelatin phantoms to investigate the effect of multiple reflections on the propagation of shear waves with millimeter wavelength. Steady-state monochromatic waves are imaged in situ via magnetic resonance imaging, enabling quantification of the phase velocity at a voxel size big enough to contain thousands of individual scatterers, but small enough to resolve the wavelength. We show in theory, experiments, and simulations that the resulting coherent superposition of multiple reflections gives rise to power-law dispersion at the macroscopic scale if the scatterer distribution exhibits apparent fractality over an effective length scale that is comparable to the probing wavelength. Since apparent fractality is naturally present in any random medium, microstructure can thereby leave its fingerprint on the macroscopically quantifiable power-law exponent. Our results are generic to wave phenomena and carry great potential for sensing microstructure that exhibits intrinsic fractality, such as, for instance, vasculature.

  6. Analysis of multiple wavelengths of Lamb waves generated by meander-line coil EMATs.

    PubMed

    Zhai, Guofu; Jiang, Tao; Kang, Lei

    2014-02-01

    The electromagnetic acoustic transducers (EMATs) with a meander-line coil possess the capability of generating Lamb waves carrying multiple wavelengths, and the characteristics of multiple wavelengths is analyzed by developing a spatial transversal filter model for the EMAT. It is shown that the characteristics is due to the wavelength spectrum of the EMATs, which is a wavelength-domain representation of information about the wavelength components, and the magnitude of each components is modulated by an envelope which depends on the geometric pattern of the meander-line coil. The characteristics of multiple wavelengths might cause the multi-modes phenomenon, therefore a method for removing the effect of multiple wavelengths is proposed. It is shown that the effect can be removed by designing an EMAT which can produce a special envelop to suppress the harmonic wavelengths. Experiments are set up to study the characteristics of multiple wavelengths and verify the validity of the proposed method.

  7. FIRST SDO AIA OBSERVATIONS OF A GLOBAL CORONAL EUV 'WAVE': MULTIPLE COMPONENTS AND 'RIPPLES'

    SciTech Connect

    Liu Wei; Nitta, Nariaki V.; Schrijver, Carolus J.; Title, Alan M.; Tarbell, Theodore D.

    2010-11-01

    We present the first Solar Dynamics Observatory Atmospheric Imaging Assembly (AIA) observations of a global coronal EUV disturbance (so-called 'EIT wave') revealed in unprecedented detail. The disturbance observed on 2010 April 8 exhibits two components: one diffuse pulse superimposed, on which are multiple sharp fronts that have slow and fast components. The disturbance originates in front of erupting coronal loops and some sharp fronts undergo accelerations, both effects implying that the disturbance is driven by a coronal mass ejection. The diffuse pulse, propagating at a uniform velocity of 204-238 km s{sup -1} with very little angular dependence within its extent in the south, maintains its coherence and stable profile for {approx}30 minutes. Its arrival at increasing distances coincides with the onsets of loop expansions and the slow sharp front. The fast sharp front overtakes the slow front, producing multiple 'ripples' and steepening the local pulse, and both fronts propagate independently afterward. This behavior resembles the nature of real waves. Unexpectedly, the amplitude and FWHM of the diffuse pulse decrease linearly with distance. A hybrid model, combining both wave and non-wave components, can explain many, but not all, of the observations. Discoveries of the two-component fronts and multiple ripples were made possible for the first time thanks to AIA's high cadences ({<=}20 s) and high signal-to-noise ratio.

  8. Delayed Triggering of Early Aftershocks by Multiple Waves Circling the Earth

    NASA Astrophysics Data System (ADS)

    Sullivan, B.; Peng, Z.

    2011-12-01

    It is well known that direct surface waves of large earthquakes are capable of triggering shallow earthquakes and deep tremor at long-range distances. Recent studies have shown that multiple surface waves circling the earth could also remotely trigger microearthquakes [Peng et al., 2011]. However, it is still not clear whether multiple surface waves returning back to the mainshock epicenters could also trigger/modulate aftershock activities. Here we conduct a study to search for evidence of such triggering by systematically examining aftershock activities of 20 magnitude-8-or-higher earthquakes since 1990 that are capable of producing surface waves circling the globe repeatedly. We compute the magnitude of completeness for each sequence, and stack all the sequences together to compute the seismicity and moment rates by sliding data windows. The sequences are also shuffled randomly and these rates are compared to the actual data as well as synthetic aftershock sequences to estimate the statistical significance of the results. We also compare them with varying stacks of magnitude 7-8 earthquakes to better understand the possible biases that could be introduced by our rate calculation method. Our preliminary results suggest that there is some moderate increase of early aftershock activity after a few hours when the surface waves return to the epicentral region. However, we could not completely rule out the possibility that such an increase is purely due to random fluctuations of aftershocks or caused by missing aftershocks in the first few hours after the mainshock. We plan to examine continuous waveform data of selected sequences to obtain a better understanding of the multiple surface waves and aftershock activity.

  9. Conserved domains and SINE diversity during animal evolution.

    PubMed

    Luchetti, Andrea; Mantovani, Barbara

    2013-10-01

    Eukaryotic genomes harbour a number of mobile genetic elements (MGEs); moving from one genomic location to another, they are known to impact on the host genome. Short interspersed elements (SINEs) are well-represented, non-autonomous retroelements and they are likely the most diversified MGEs. In some instances, sequence domains conserved across unrelated SINEs have been identified; remarkably, one of these, called Nin, has been conserved since the Radiata-Bilateria splitting. Here we report on two new domains: Inv, derived from Nin, identified in insects and in deuterostomes, and Pln, restricted to polyneopteran insects. The identification of Inv and Pln sequences allowed us to retrieve new SINEs, two in insects and one in a hemichordate. The diverse structural combination of the different domains in different SINE families, during metazoan evolution, offers a clearer view of SINE diversity and their frequent de novo emergence through module exchange, possibly underlying the high evolutionary success of SINEs. © 2013 Elsevier Inc. All rights reserved.

  10. The Behavior of Multiple Acoustic Waves in the Lakes Bottom Sediments.

    NASA Astrophysics Data System (ADS)

    Krylov, P.; Nourgaliev, D. K.; Yasonov, P.

    2016-12-01

    Seismic studies are used for various tasks, such as the study of the bottom sediments properties, finding sunken objects, reconstruction the reservoir history, etc. Multiple acoustic waves are an enormous obstacle in obtaining full seismic record. Multiples from the bottom of a body of water (the surface of the base of water and the rock or sediment beneath it) and the air-water surface are common in lake seismic data. Multiple reflections on the seismic cross-sections are usually located on the double distance from the air/water surface. However, sometime multiple reflections from liquid deposits cannot be generated or they reflected from the deeper horizons. It is observed the phenomenon of changes in reflectance of the water/weakly consolidated sediments acoustic boundary under the influence of the acoustic wave. This phenomenon lies in the fact that after the first acoustic impact and reflection of acoustic wave for some time the reflectance of this boundary remains close to 0. This event on a cross-section can explain by the short-term changes in the properties of bottom sediments under the influence of shock? acoustic wave, with a further reduction of these properties to the next wave generation (generation period of 2 seconds). Perhaps in these deposits occurs thixotropic process. The paper presents the seismic acoustic cross-sections of Lake Balkhash (Kazakhstan), Turgoyak (Russia). The work was carried out according to the Russia Government's Program of Competitive Growth of Kazan Federal University, supported by the grant provided to the Kazan State University for performing the state program in the field of scientific research, and partially supported by the Russian Foundation for Basic research (grants ð 14-05-00785, 16-35-00452).

  11. Localized structures and spatiotemporal chaos: comparison between the driven damped sine-Gordon and the Lugiato-Lefever model

    NASA Astrophysics Data System (ADS)

    Ferré, Michel A.; Clerc, Marcel G.; Coulibally, Saliya; Rojas, René G.; Tlidi, Mustapha

    2017-06-01

    Driven damped coupled oscillators exhibit complex spatiotemporal dynamics. An archetype model is the driven damped sine-Gordon equation, which can describe several physical systems such as coupled pendula, extended Josephson junction, optical systems and driven magnetic wires. Close to resonance an enveloped model in the form Lugiato-Lefever equation can be derived from the driven damped sine-Gordon equation. We compare the dynamics obtained from both models. Unexpectedly, qualitatively similar dynamical behaviors are obtained for both models including homogeneous steady states, localized structures, and pattern waves. For large forcing, both systems share similar spatiotemporal chaos.

  12. Bov-B-mobilized SINEs in vertebrate genomes.

    PubMed

    Gogolevsky, Konstantin P; Vassetzky, Nikita S; Kramerov, Dmitri A

    2008-01-15

    Two new short retroposon families (SINEs) have been found in the genome of springhare Pedetes capensis (Rodentia). One of them, Ped-1, originated from 5S rRNA, while the other one, Ped-2, originated from tRNA-derived SINE ID. In contrast to most currently active mammalian SINEs mobilized by L1 long retrotransposon (LINE), Ped-1 and Ped-2 are mobilized by Bov-B, a LINE family of the widely distributed RTE clade. The 3' part of these SINEs originates from two sequences in the 5' and 3' regions of Bov-B. Such bipartite structure of the LINE-derived part has been revealed in all Bov-B-mobilized SINEs known to date (AfroSINE, Bov-tA, Mar-1, and Ped-1/2), which distinguishes them from other SINEs with only a 3' LINE-derived part. Structural analysis and the distribution of Bov-B LINEs and partner SINEs supports the horizontal transfer of Bov-B, while the SINEs emerged independently in lineages with this LINE.

  13. Numerical simulation of seismic wave field in graded geological media containing multiple cavities

    NASA Astrophysics Data System (ADS)

    Fontara, Ioanna-Kleoniki; Dineva, Petia S.; Manolis, George D.; Wuttke, Frank

    2016-08-01

    In this study, we develop an efficient boundary integral equation method for estimation of seismic motion in a graded medium with multiple cavities under antiplane strain conditions. This inhomogeneous and heterogeneous medium is subjected to either time-harmonic incident shear seismic waves or to body waves radiating from a point seismic source. Three different types of soil material gradient are considered: (i) density and shear modulus vary proportionally as quadratic functions of depth, but the wave velocity remains constant; (ii) the soil material is viscoelastic, with a shear modulus and density that vary with respect to the spatial coordinates in an arbitrary fashion, so that the wave velocity is both frequency and position-dependent and (iii) the soil material has position-dependent shear modulus and constant density, yielding a linear profile for the wave velocity. Three different, frequency-dependent boundary integral equation schemes are respectively developed for the aforementioned three types of graded soil materials based on: (i) Green's function for the quadratically graded elastic half-plane; (ii) a fundamental solution for the viscoelastic full-plane with position-dependent wave speed profiles and (iii) a fundamental solution for an elastic full-plane with a linearly varying wave speed profile. Next, a number of cases involving geological media with position-dependent material properties and any number of cavities of various shapes and geometry are solved in the frequency domain. The numerical results reveal the dependency of the wave fields and zones of stress concentration on the following key factors: (i) type and properties of the soil material gradient; (ii) type and characteristics of the applied seismic load; (iii) shape, position and number of cavities and (iv) interaction phenomena between the cavities and the free surface.

  14. Critical immune and vaccination thresholds for determining multiple influenza epidemic waves

    PubMed Central

    Matrajt, Laura; Longini, Ira M.

    2013-01-01

    Previous influenza pandemics (1918, 1957, and 1968) have all had multiple waves. The 2009 pandemic influenza A(H1N1) (pandemic H1N1) started in April 2009 and was followed, in the United States (US) and temperate Northern Hemisphere, by a second wave during the fall of 2009. The ratio of susceptible and immune individuals in a population at the end of a wave determines the potential and magnitude of a subsequent wave. As influenza vaccines are not completely protective, there was a combined immunity in the population at the beginning of 2010 (due to vaccination and due to previous natural infection), and it was uncertain if this mixture of herd immunity was enough to prevent a third wave of pandemic influenza during the winter of 2010. Motivated by this problem, we developed a mathematical deterministic two-group epidemic model with vaccination and calibrated it for the 2009 pandemic H1N1. Then, applying methods from mathematical epidemiology we developed a scheme that allowed us to determine critical thresholds for vaccine-induced and natural immunity that would prevent the spread of influenza. Finally, we estimated the level of combined immunity in the US during winter 2010. Our results suggest that a third wave was unlikely if the basic reproduction number R0 were below 1.6, plausible if the original R0 was 1.6, and likely if the original R0 was 1.8 or higher. Given that the estimates for the basic reproduction number for pandemic influenza place it in the range between 1.4 and 1.6 [1, 2, 3, 4, 5, 6, 7], our approach accurately predicted the absence of a third wave of influenza in the US during the winter of 2010. We also used this scheme to accurately predict the second wave of pandemic influenza in London and the West Midlands, UK during the fall of 2009. PMID:22325011

  15. Interaction between sine-Gordon breathers

    SciTech Connect

    Kevrekidis, P. G.; Saxena, A.; Bishop, A. R.

    2001-08-01

    Using the exact breather lattice solution of the sine-Gordon equation, we obtain the asymptotic interaction between two breathers. We identify the exponential dependence of the interaction on the breather separation as well as its power-law dependence on the breather frequency. Numerical simulation of the breather lattice demonstrates its instability. However, stabilization of such structures is found to be feasible through ac driving and damping. Finally, other limits of the original periodic solution are traced, obtaining the leading-order terms in the interaction between ''pseudosphere'' solutions and kink-antikink pairs.

  16. Sines and Cosines. Part 2 of 3

    NASA Technical Reports Server (NTRS)

    Apostol, Tom M. (Editor)

    1993-01-01

    The Law of Sines and the Law of Cosines are introduced and demonstrated in this 'Project Mathematics' series video using both film footage and computer animation. This video deals primarily with the mathematical field of Trigonometry and explains how these laws were developed and their applications. One significant use is geographical and geological surveying. This includes both the triangulation method and the spirit leveling method. With these methods, it is shown how the height of the tallest mountain in the world, Mt. Everest, was determined.

  17. Broadband Lamb wave trapping in cellular metamaterial plates with multiple local resonances.

    PubMed

    Zhao, De-Gang; Li, Yong; Zhu, Xue-Feng

    2015-03-20

    We have investigated the Lamb wave propagation in cellular metamaterial plates constructed by bending-dominated and stretch-dominated unit-cells with the stiffness differed by orders of magnitude at an ultralow density. The simulation results show that ultralight metamaterial plates with textured stubs deposited on the surface can support strong local resonances for both symmetric and anti-symmetric modes at low frequencies, where Lamb waves at the resonance frequencies are highly localized in the vibrating stubs. The resonance frequency is very sensitive to the geometry of textured stubs. By reasonable design of the geometry of resonant elements, we establish a simple loaded-bar model with the array of oscillators having a gradient relative density (or weight) that can support multiple local resonances, which permits the feasibility of a broadband Lamb wave trapping. Our study could be potentially significant in designing ingenious weight-efficient acoustic devices for practical applications, such as shock absorption, cushioning, and vibrations traffic, etc.

  18. Multiple-wave diffraction in high energy resolution back-reflecting x-ray optics.

    PubMed

    Stetsko, Yuri P; Keister, J W; Coburn, D S; Kodituwakku, C N; Cunsolo, A; Cai, Y Q

    2011-10-07

    We have studied the effects of multiple-wave diffraction in a novel optical scheme recently published by Shvyd'ko et al. utilizing Bragg diffraction of x rays in backscattering geometry from asymmetrically cut crystals for achieving energy resolutions beyond the intrinsic width of the Bragg reflection. By numerical simulations based on dynamic x-ray diffraction and by experimentation involving two-dimensional angular scans of the back-reflecting crystal, multiple-wave diffraction was found to contribute up to several tens percent loss of efficiency but can be avoided without degrading the energy resolution of the original scheme by careful choice of azimuthal orientation of the diffracting crystal surface and by tilting of the crystal perpendicular to the dispersion plane.

  19. Simulation of elastic wave diffraction by multiple strip-like cracks in a layered periodic composite

    NASA Astrophysics Data System (ADS)

    Golub, M. V.

    2016-12-01

    The problem of numerical simulation of the steady-state harmonic vibrations of a layered phononic crystal (elastic periodic composite) with a set of strip-like cracks parallel to the layer boundaries is solved, and the accompanying wave phenomena are considered. The transfer matrix method (propagator matrix method) is used to describe the incident wave field. It allows one not only to construct the wave fields but also to calculate the pass bands and band gaps and to find the localization factor. The wave field scattered by multiple defects is represented by means of an integral approach as a superposition of the fields scattered by all cracks. An integral representation in the form of a convolution of the Fourier symbols of Green's matrices for the corresponding layered structures and a Fourier transform of the crack opening displacement vector is constructed for each of the scattered fields. The crack opening displacements are determined by the boundary integral equation method using the Bubnov-Galerkin scheme, where Chebyshev polynomials of the second kind, which take into account the behavior of the solution near the crack edges, are chosen as the projection and basis systems. The system of linear algebraic equations with a diagonal predominance of components arising when the system of integral equations is discretized has a block structure. The characteristics describing qualitatively and quantitatively the wave processes that take place under the diffraction of plane elastic waves by multiple cracks in a phononic crystal are analyzed. The resonant properties of a system of defects and the influence of the relative positions and sizes of defects in a layered phononic crystal on the resonant properties are studied. To obtain clearer results and to explain them, the energy flux vector is calculated and the energy surfaces and streamlines corresponding to them are constructed.

  20. Multiple harmonic ULF waves in the plasma sheet boundary layer observed by Cluster

    NASA Astrophysics Data System (ADS)

    Engebretson, M. J.; Kahlstorf, C. R. G.; Posch, J. L.; Keiling, A.; Walsh, A. P.; Denton, R. E.; Broughton, M. C.; Owen, C. J.; FornaçOn, K.-H.; RèMe, H.

    2010-12-01

    The passage of the Cluster satellites in a polar orbit through Earth's magnetotail has provided numerous observations of harmonically related Pc 1-2 ULF wave events, with the fundamental near the local proton cyclotron frequency Ωcp. Broughton et al. (2008) reported observations by Cluster of three such events in the plasma sheet boundary layer, and used the wave telescope technique to determine that their wave vectors k were nearly perpendicular to B. This paper reports the results of a search for such waves throughout the 2003 Cluster tail passage. During the 4 month period of July-October 2003, 35 multiple-harmonic wave events were observed, all in the plasma sheet boundary layer (PSBL). From the first observed event (22 July) to the last (28 October), 13 of Cluster's 42 tail passes had at least one event. The wave events were rather evenly distributed from XGSE = -7 RE out to the Cluster apogee distance of -18 RE, with one event observed at -4 RE. ZGSE for these events ranged from -10 to -3 RE and +3 to +7 RE (i.e., there were no events for ∣Z∣ < 3 RE). The wave events, with durations from ˜1 to 50 min, were consistently associated with signatures of the PSBL: elevated fluxes of counterstreaming ions with energies ranging from ˜3 to 30 keV, and elevated fluxes of electrons with energies ranging from 0.25 to ˜5 keV. Analysis of plasma parameters suggests that although waves occurred only when the ion beta exceeded 0.1 (somewhat larger than typical for the PSBL), ion particle pressure may be of more physical importance in controlling wave occurrence. Electron distributions were more isotropic in pitch angles than the ion distributions, but some evidence of counterstreaming electrons was detected in 83% of the events. The ions also showed clear signatures of shell-like or ring-like distributions; i.e., with reduced fluxes below the energy of maximum flux. The suprathermal ion fluxes were asymmetric in all events studied, with more ions streaming earthward

  1. Ultrashort light bullets described by the two-dimensional sine-Gordon equation

    SciTech Connect

    Leblond, Herve; Mihalache, Dumitru

    2010-06-15

    By using a reductive perturbation technique applied to a two-level model, this study puts forward a generic two-dimensional sine-Gordon evolution equation governing the propagation of femtosecond spatiotemporal optical solitons in Kerr media beyond the slowly varying envelope approximation. Direct numerical simulations show that, in contrast to the long-wave approximation, no collapse occurs, and that robust (2+1)-dimensional ultrashort light bullets may form from adequately chosen few-cycle input spatiotemporal wave forms. In contrast to the case of quadratic nonlinearity, the light bullets oscillate in both space and time and are therefore not steady-state lumps.

  2. Extension of the double-wave-vector diffusion-weighting experiment to multiple concatenations.

    PubMed

    Finsterbusch, Jürgen

    2009-06-01

    Experiments involving two diffusion-weightings in a single acquisition, so-called double- or two-wave-vector experiments, have recently been applied to measure the microscopic anisotropy in macroscopically isotropic samples or to estimate pore or compartment sizes. These informations are derived from the signal modulation observed when varying the wave vectors' orientations. However, the modulation amplitude can be small and, for short mixing times between the two diffusion-weightings, decays with increased gradient pulse lengths which hampers its detectability on whole-body MR systems. Here, an approach is investigated that involves multiple concatenations of the two diffusion-weightings in a single experiment. The theoretical framework for double-wave-vector experiments of fully restricted diffusion is adapted and the corresponding tensor approach recently presented for short mixing times extended and compared to numerical simulations. It is shown that for short mixing times (i) the extended tensor approach well describes the signal behavior observed for multiple concatenations and (ii) the relative amplitude of the signal modulation increases with the number of concatenations. Thus, the presented extension of the double-wave-vector experiment may help to improve the detectability of the signal modulations observed for short mixing times, in particular on whole-body MR systems with their limited gradient amplitudes.

  3. Multiple-mode Lamb wave scattering simulations using 3D elastodynamic finite integration technique.

    PubMed

    Leckey, Cara A C; Rogge, Matthew D; Miller, Corey A; Hinders, Mark K

    2012-02-01

    We have implemented three-dimensional (3D) elastodynamic finite integration technique (EFIT) simulations to model Lamb wave scattering for two flaw-types in an aircraft-grade aluminum plate, a rounded rectangle flat-bottom hole and a disbond of the same shape. The plate thickness and flaws explored in this work include frequency-thickness regions where several Lamb wave modes exist and sometimes overlap in phase and/or group velocity. For the case of the flat-bottom hole the depth was incrementally increased to explore progressive changes in multiple-mode Lamb wave scattering due to the damage. The flat-bottom hole simulation results have been compared to experimental data and are shown to provide key insight for this well-defined experimental case by explaining unexpected results in experimental waveforms. For the rounded rectangle disbond flaw, which would be difficult to implement experimentally, we found that Lamb wave behavior differed significantly from the flat-bottom hole flaw. Most of the literature in this field is restricted to low frequency-thickness regions due to difficulties in interpreting data when multiple modes exist. We found that benchmarked 3D EFIT simulations can yield an understanding of scattering behavior for these higher frequency-thickness regions and in cases that would be difficult to set up experimentally. Additionally, our results show that 2D simulations would not have been sufficient for modeling the complicated scattering that occurred. Published by Elsevier B.V.

  4. Wave multiple scattering by a finite number of unclosed circular cylinders

    NASA Technical Reports Server (NTRS)

    Veliyev, E. I.; Veremey, V. V.

    1984-01-01

    The boundary value problem of plane H-polarized electromagnetic wave multiple scattering by a finite number of unclosed circular cylinders is solved. The solution is obtained by two different methods: the method of successive scattering and the method of partial matrix inversion for simultaneous dual equations. The advantages of the successive scattering method are shown. Computer calculations of the suface currents and the total cross section are presented for the structure of two screens.

  5. Multiple-scattering corrections in diluted magnetic semiconductors: A plane-wave expansion

    NASA Astrophysics Data System (ADS)

    Scalbert, D.; Ghazali, A.; Benoit à la Guillaume, C.

    1993-12-01

    Energy levels of band edges in diluted magnetic semiconductors are calculated in the effective-mass approximation, retaining off-diagonal terms in the exchange interaction and using a plane-wave expansion. This model accounts qualitatively for the observed asymmetry in the splitting of the A exciton in a magnetic field in Cd1-xMnxS for which multiple-scattering corrections are expected to be important.

  6. Atomic multiple-wave interferometer phase-shifted by the scalar Aharonov-Bohm effect

    SciTech Connect

    Aoki, Takatoshi; Yasuhara, Makoto; Morinaga, Atsuo

    2003-05-01

    A time-domain atomic multiple-wave interferometer using laser-cooled and trapped sodium atoms has been developed under pulsed magnetic fields. Each atomic phase was shifted due to the scalar Aharonov-Bohm effect by applying spatially homogeneous pulsed magnetic fields between numerous Raman excitation laser pulses. Interference fringes with a finesse of 11 were demonstrated for 11 successive Raman pulses and ten magnetic-field pulses.

  7. A three-dimensional numerical study on instability of sinusoidal flame induced by multiple shock waves

    NASA Astrophysics Data System (ADS)

    Chen, Xiao; Dong, Gang; Jiang, Hua

    2017-03-01

    The instabilities of a three-dimensional sinusoidally premixed flame induced by an incident shock wave with Mach = 1.7 and its reshock waves were studied by using the Navier-Stokes (NS) equations with a single-step chemical reaction and a high resolution, 9th-order weighted essentially non-oscillatory scheme. The computational results were validated by the grid independence test and the experimental results in the literature. The computational results show that after the passage of incident shock wave the flame interface develops in symmetric structure accompanied by large-scale transverse vortex structures. After the interactions by successive reshock waves, the flame interface is gradually destabilized and broken up, and the large-scale vortex structures are gradually transformed into small-scale vortex structures. The small-scale vortices tend to be isotropic later. The results also reveal that the evolution of the flame interface is affected by both mixing process and chemical reaction. In order to identify the relationship between the mixing and the chemical reaction, a dimensionless parameter, η , that is defined as the ratio of mixing time scale to chemical reaction time scale, is introduced. It is found that at each interaction stage the effect of chemical reaction is enhanced with time. The enhanced effect of chemical reaction at the interaction stage by incident shock wave is greater than that at the interaction stages by reshock waves. The result suggests that the parameter η can reasonably character the features of flame interface development induced by the multiple shock waves.

  8. A three-dimensional numerical study on instability of sinusoidal flame induced by multiple shock waves

    NASA Astrophysics Data System (ADS)

    Chen, Xiao; Dong, Gang; Jiang, Hua

    2017-04-01

    The instabilities of a three-dimensional sinusoidally premixed flame induced by an incident shock wave with Mach = 1.7 and its reshock waves were studied by using the Navier-Stokes (NS) equations with a single-step chemical reaction and a high resolution, 9th-order weighted essentially non-oscillatory scheme. The computational results were validated by the grid independence test and the experimental results in the literature. The computational results show that after the passage of incident shock wave the flame interface develops in symmetric structure accompanied by large-scale transverse vortex structures. After the interactions by successive reshock waves, the flame interface is gradually destabilized and broken up, and the large-scale vortex structures are gradually transformed into small-scale vortex structures. The small-scale vortices tend to be isotropic later. The results also reveal that the evolution of the flame interface is affected by both mixing process and chemical reaction. In order to identify the relationship between the mixing and the chemical reaction, a dimensionless parameter, η , that is defined as the ratio of mixing time scale to chemical reaction time scale, is introduced. It is found that at each interaction stage the effect of chemical reaction is enhanced with time. The enhanced effect of chemical reaction at the interaction stage by incident shock wave is greater than that at the interaction stages by reshock waves. The result suggests that the parameter η can reasonably character the features of flame interface development induced by the multiple shock waves.

  9. Wave interactions with multiple semi-immersed Jarlan-type perforated breakwaters

    NASA Astrophysics Data System (ADS)

    Elbisy, Moussa S.

    2017-06-01

    This study examines wave interactions with multiple semi-immersed Jarlan-type perforated breakwaters. A numerical model based on linear wave theory and an eigenfunction expansion method has been developed to study the hydrodynamic characteristics of breakwaters. The numerical results show a good agreement with previous analytical results and experimental data for limiting cases of double partially immersed impermeable walls and double and triple Jarlan-type breakwaters. The wave transmission coefficient C T; reflection coefficient C R, and energy dissipation coefficient C E coefficients and the horizontal wave force exerted on the front and rear walls are examined. The results show that C R reaches the maximum value when B/L = 0.46 n while it is smallest when B/L=0.46 n+0.24 ( n=0, 1, 2,...). An economical triple semi-immersed Jarlan-type perforated breakwater can be designed with B/L = 0.25 and C R and C T ranging from 0.25 to 0.32 by choosing a relative draft d/h of 0.35 and a permeability parameter of the perforated front walls being 0.5 for an incident wave number kh nearly equal to 2.0. The triple semi-immersed Jarlan-type perforated breakwaters with significantly reduced C R, will enhance the structure's wave absorption ability, and lead to smaller wave forces compared with the double one. The proposed model may be used to predict the response of a structure in the preliminary design stage for practical engineering.

  10. The number of full-sine cycles per pulse influences the efficacy of multicycle transcranial magnetic stimulation.

    PubMed

    Pechmann, Astrid; Delvendahl, Igor; Bergmann, Til O; Ritter, Christoph; Hartwigsen, Gesa; Gleich, Bernhard; Gattinger, Norbert; Mall, Volker; Siebner, Hartwig R

    2012-04-01

    Previous studies have shown that the efficacy of transcranial magnetic stimulation (TMS) to excite corticospinal neurons depends on pulse waveform. In this study, we examined whether the effectiveness of polyphasic TMS can be increased by using a pulse profile that consists of multiple sine cycles. In eight subjects, single-pulse TMS was applied to the left primary motor hand area through a round coil attached to a stimulator device that generated polyphasic pulses consisting of one to six full-sine cycles with a cycle length of 86 μs. In different blocks, we varied the number of sine cycles per pulse and recorded the motor-evoked potential (MEP) from the right first dorsal interosseus muscle. For each stimulus type, we determined resting motor threshold (RMT), stimulus-response curve (SRC), and mean MEP amplitude evoked at maximal stimulator output to assess the efficacy of stimulation. Multicycle pulses were more effective than a single full-sine cycle in exciting corticospinal neurons. TMS with multicycle pulses resulted in lower RMT, larger MEP amplitudes at maximal stimulator output and a steeper slope of the SRC relative to a TMS pulse consisting of a single-sine cycle. The increase in efficacy was already evident when two full-sine cycles were used and did not increase further by adding more cycles to the TMS pulse. Increasing the number of full-sine cycles per pulse can improve the efficacy of TMS to excite corticospinal neurons, but there is no simple linear relationship between the number of cycles and TMS efficacy. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Selective repression of SINE transcription by RNA polymerase III.

    PubMed

    Varshney, Dhaval; Vavrova-Anderson, Jana; Oler, Andrew J; Cairns, Bradley R; White, Robert J

    2015-01-01

    A million copies of the Alu short interspersed nuclear element (SINE) are scattered throughout the human genome, providing ∼11% of our total DNA. SINEs spread by retrotransposition, using a transcript generated by RNA polymerase (pol) III from an internal promoter. Levels of these pol III-dependent Alu transcripts are far lower than might be expected from the abundance of the template. This was believed to reflect transcriptional suppression through DNA methylation, denying pol III access to most SINEs through chromatin-mediated effects. Contrary to expectations, our recent study found no evidence that methylation of SINE DNA reduces its occupancy or expression by pol III. However, histone H3 associated with SINEs is prominently methylated on lysine 9, a mark that correlates with transcriptional silencing. The SUV39 methyltransferases that deposit this mark can be found at many SINEs. Furthermore, a selective inhibitor of SUV39 stimulates pol III recruitment to these loci, as well as SINE expression. These data suggest that methylation of histone H3 rather than DNA may mediate repression of SINE transcription by pol III, at least under the conditions we studied.

  12. Measuring Differential Delays With Sine-Squared Pulses

    NASA Technical Reports Server (NTRS)

    Hurst, Robert N.

    1994-01-01

    Technique for measuring differential delays among red, green, and blue components of video signal transmitted on different parallel channels exploits sine-squared pulses that are parts of standard test signals transmitted during vertical blanking interval of frame period. Technique does not entail expense of test-signal generator. Also applicable to nonvideo signals including sine-squared pulses.

  13. Does homologous reinfection drive multiple-wave influenza outbreaks? Accounting for immunodynamics in epidemiological models.

    PubMed

    Camacho, A; Cazelles, B

    2013-12-01

    Epidemiological models of influenza transmission usually assume that recovered individuals instantly develop a fully protective immunity against the infecting strain. However, recent studies have highlighted host heterogeneity in the development of this immune response, characterized by delay and even absence of protection, that could lead to homologous reinfection (HR). Here, we investigate how these immunological mechanisms at the individual level shape the epidemiological dynamics at the population level. In particular, because HR was observed during the successive waves of past pandemics, we assess its role in driving multiple-wave influenza outbreaks. We develop a novel mechanistic model accounting for host heterogeneity in the immune response. Immunological parameters are inferred by fitting our dynamical model to a two-wave influenza epidemic that occurred on the remote island of Tristan da Cunha (TdC) in 1971, and during which HR occurred in 92 of 284 islanders. We then explore the dynamics predicted by our model for various population settings. We find that our model can explain HR over both short (e.g. week) and long (e.g. month) time-scales, as reported during past pandemics. In particular, our results reveal that the HR wave on TdC was a natural consequence of the exceptional contact configuration and high susceptibility of this small and isolated community. By contrast, in larger, less mixed and partially protected populations, HR alone cannot generate multiple-wave outbreaks. However, in the latter case, we find that a significant proportion of infected hosts would remain unprotected at the end of the pandemic season and should therefore benefit from vaccination. Crucially, we show that failing to account for these unprotected individuals can lead to large underestimation of the magnitude of the first post-pandemic season. These results are relevant in the context of the 2009 A/H1N1 influenza post-pandemic era.

  14. Does homologous reinfection drive multiple-wave influenza outbreaks? Accounting for immunodynamics in epidemiological models☆

    PubMed Central

    Camacho, A.; Cazelles, B.

    2013-01-01

    Epidemiological models of influenza transmission usually assume that recovered individuals instantly develop a fully protective immunity against the infecting strain. However, recent studies have highlighted host heterogeneity in the development of this immune response, characterized by delay and even absence of protection, that could lead to homologous reinfection (HR). Here, we investigate how these immunological mechanisms at the individual level shape the epidemiological dynamics at the population level. In particular, because HR was observed during the successive waves of past pandemics, we assess its role in driving multiple-wave influenza outbreaks. We develop a novel mechanistic model accounting for host heterogeneity in the immune response. Immunological parameters are inferred by fitting our dynamical model to a two-wave influenza epidemic that occurred on the remote island of Tristan da Cunha (TdC) in 1971, and during which HR occurred in 92 of 284 islanders. We then explore the dynamics predicted by our model for various population settings. We find that our model can explain HR over both short (e.g. week) and long (e.g. month) time-scales, as reported during past pandemics. In particular, our results reveal that the HR wave on TdC was a natural consequence of the exceptional contact configuration and high susceptibility of this small and isolated community. By contrast, in larger, less mixed and partially protected populations, HR alone cannot generate multiple-wave outbreaks. However, in the latter case, we find that a significant proportion of infected hosts would remain unprotected at the end of the pandemic season and should therefore benefit from vaccination. Crucially, we show that failing to account for these unprotected individuals can lead to large underestimation of the magnitude of the first post-pandemic season. These results are relevant in the context of the 2009 A/H1N1 influenza post-pandemic era. PMID:24267875

  15. Bäcklund transformations of Zn-sine-Gordon systems

    NASA Astrophysics Data System (ADS)

    Yang, Xueping; Li, Chuanzhong

    2017-06-01

    In this paper, from the algebraic reductions from the Lie algebra gl(n, ℂ) to its commutative subalgebra Zn, we construct the general Zn-sine-Gordon and Zn-sinh-Gordon systems which contain many multi-component sine-Gordon type and sinh-Gordon type equations. Meanwhile, we give the Bäcklund transformations of the Zn-sine-Gordon and Zn-sinh-Gordon equations which can generate new solutions from seed solutions. To see the Zn-systems clearly, we consider the Z2-sine-Gordon and Z3-sine-Gordon equations explicitly including their Bäcklund transformations, the nonlinear superposition formula and Lax pairs.

  16. Origin and evolution of SINEs in eukaryotic genomes.

    PubMed

    Kramerov, D A; Vassetzky, N S

    2011-12-01

    Short interspersed elements (SINEs) are one of the two most prolific mobile genomic elements in most of the higher eukaryotes. Although their biology is still not thoroughly understood, unusual life cycle of these simple elements amplified as genomic parasites makes their evolution unique in many ways. In contrast to most genetic elements including other transposons, SINEs emerged de novo many times in evolution from available molecules (for example, tRNA). The involvement of reverse transcription in their amplification cycle, huge number of genomic copies and modular structure allow variation mechanisms in SINEs uncommon or rare in other genetic elements (module exchange between SINE families, dimerization, and so on.). Overall, SINE evolution includes their emergence, progressive optimization and counteraction to the cell's defense against mobile genetic elements.

  17. Origin and evolution of SINEs in eukaryotic genomes

    PubMed Central

    Kramerov, D A; Vassetzky, N S

    2011-01-01

    Short interspersed elements (SINEs) are one of the two most prolific mobile genomic elements in most of the higher eukaryotes. Although their biology is still not thoroughly understood, unusual life cycle of these simple elements amplified as genomic parasites makes their evolution unique in many ways. In contrast to most genetic elements including other transposons, SINEs emerged de novo many times in evolution from available molecules (for example, tRNA). The involvement of reverse transcription in their amplification cycle, huge number of genomic copies and modular structure allow variation mechanisms in SINEs uncommon or rare in other genetic elements (module exchange between SINE families, dimerization, and so on.). Overall, SINE evolution includes their emergence, progressive optimization and counteraction to the cell's defense against mobile genetic elements. PMID:21673742

  18. Optimized {gamma}-Multiplicity Based Spin Assignments of s-Wave Neutron Resonances

    SciTech Connect

    Becvar, F.; Koehler, Paul Edward; Krticka, Milan; Mitchell, G. E.; Ullmann, J. L.

    2011-01-01

    The multiplicity of -ray emission following neutron capture at isolated resonances carries valuable information on the resonance spin. Several methods utilizing this information have been developed. The latest method was recently introduced for analyzing the data from time-of-flight measurements with 4 -calorimetric detection systems. The present paper describes a generalization of this method. The goal is the separation of the -emission yields belonging to the two neutron capturing state spins of isolated (or even unresolved) s-wave neutron resonances on targets with non-zero spin. The formalism for performing this separation is described and then tested on artificially generated data. This new method was applied to the -multiplicity data obtained for the 147Sm(n, )148Sm reaction using the DANCE detector system at the LANSCE facility at Los Alamos National Laboratory. The analyzing power of the upgraded method is supported by combined dicebox and geant4 simulations of the fluctuation properties of the multiplicity distributions.

  19. Statistical Analysis of EMIC Waves in Multiple Component Plasma Including Heavy Ions

    NASA Astrophysics Data System (ADS)

    Matsuda, S.; Kasahara, Y.; Goto, Y.

    2013-12-01

    It is well known that Earth's radiation belts are located around geomagnetic equator, where wide ranges of energetic particles from several hundred keV to several tens MeV are contained. According to the recent study, it is suggested that ELF/VLF waves such as EMIC waves and chorus emissions deeply contribute to the generation and loss mechanism of relativistic electrons in the radiation belt. The ERG mission[1] is expected to provide important clues for solving plasma dynamics in the Earth's radiation belts by means of integrated observation of wide energy range of plasma particles and high resolution plasma waves. On the other hand, long-term observation data which covers over 2 cycles of solar activity obtained by the Akebono satellite is very valuable to work out the strategy of the ERG mission. The ELF receiver, which is a sub-system of the VLF instruments onboard Akebono, measures waveforms below 50 Hz for one component of electric field and three components of magnetic field, or waveforms below 100 Hz for one component of electric and magnetic field, respectively. It was reported that ion cyclotron waves were observed near magnetic equator by the receiver[2]. In our previous study[3], we introduced four events of characteristic EMIC waves observed by Akebono in April, 1989. These waves have sudden decrease of intensity just above half of proton cyclotron frequency changing along the trajectories of Akebono. Comparing the observed data with the dispersion relation in multiple species of ions under cold plasma approximation, we demonstrate that a few percent of 'M / Z = 2 ions (M = mass of ions, Z = charge of ions)' such as alpha particles (He++) or deuterons (D+) cause such characteristic attenuation of EMIC at lower hybrid frequency. In the present study, we performed polarization analysis and direction finding of the waves. It was found that these EMIC waves were left-handed polarized in the higher frequency part, while the polarization gradually changes to

  20. Novel SINE families from salmons validate Parahucho (Salmonidae) as a distinct genus and give evidence that SINEs can incorporate LINE-related 3'-tails of other SINEs.

    PubMed

    Matveev, Vitaliy; Nishihara, Hidenori; Okada, Norihiro

    2007-08-01

    Short interspersed elements (SINEs) constitute a group of retroposons propagating in the genome via a mechanism of reverse transcription, in which they depend on the enzymatic machinery of long retroposons (LINEs). Over 70 SINE families have been described to date from the genomes of various eukaryotes. Here, we characterize two novel SINEs from salmons (Actinopterygii: Salmonoidei). The first family, termed SlmI, was shown to be widespread among all genera of the suborder. These SINEs have a tRNA(Leu)-related promoter region at their 5'-end, a unique central conserved domain with a subfamily-specific region, and an end with RSg-1-LINE-derived 3'-terminus preceding the A/T-rich tail. The same LINE-related segment is also shared by two other salmonid SINEs: HpaI and OS-SINE1. The structural peculiarities and overall sequence identity of the SlmI 3'-terminus suggest that it has been acquired from HpaI SINEs but not directly from the partner LINE. This region plays a crucial role in the process of retrotransposition of short interspersed elements, and the case of its SINE-to-SINE transmission is the first recorded to date. Possible scenarios and potential evolutionary implications of the observed interaction between short retroposons are discussed. Apart from the above, we found a copy of the SlmI SINE in the GenBank entry for the blood fluke, Schistosoma japonicum (Trematoda: Strigeiformes) -- a trematode causing one of the most important human helminth infections, with its genome known to host other groups of salmonoid retroposons. In the present article, we suggest our views with regard to possible ways in which such an intensive horizontal transfer of salmonoid retroposons to the schistosomal genome occurs. The second novel SINE family, termed SlmII, originates from one of the SlmI subfamilies, with which it shares the same tRNA-related region, central domain, and a part of RSg-1-derived segment, but has a different 3'-tail of unidentified origin. Its distribution

  1. Characterization of multiple spiral wave dynamics as a stochastic predator-prey system

    NASA Astrophysics Data System (ADS)

    Otani, Niels F.; Mo, Alisa; Mannava, Sandeep; Fenton, Flavio H.; Cherry, Elizabeth M.; Luther, Stefan; Gilmour, Robert F., Jr.

    2008-08-01

    A perspective on systems containing many action potential waves that, individually, are prone to spiral wave breakup is proposed. The perspective is based on two quantities, “predator” and “prey,” which we define as the fraction of the system in the excited state and in the excitable but unexcited state, respectively. These quantities exhibited a number of properties in both simulations and fibrillating canine cardiac tissue that were found to be consistent with a proposed theory that assumes the existence of regions we call “domains of influence,” each of which is associated with the activity of one action potential wave. The properties include (i) a propensity to rotate in phase space in the same sense as would be predicted by the standard Volterra-Lotka predator-prey equations, (ii) temporal behavior ranging from near periodic oscillation at a frequency close to the spiral wave rotation frequency (“type-1” behavior) to more complex oscillatory behavior whose power spectrum is composed of a range of frequencies both above and, especially, below the spiral wave rotation frequency (“type-2” behavior), and (iii) a strong positive correlation between the periods and amplitudes of the oscillations of these quantities. In particular, a rapid measure of the amplitude was found to scale consistently as the square root of the period in data taken from both simulations and optical mapping experiments. Global quantities such as predator and prey thus appear to be useful in the study of multiple spiral wave systems, facilitating the posing of new questions, which in turn may help to provide greater understanding of clinically important phenomena such as ventricular fibrillation.

  2. Multiple scattering dynamics of fermions at an isolated p-wave resonance

    NASA Astrophysics Data System (ADS)

    Thomas, R.; Roberts, K. O.; Tiesinga, E.; Wade, A. C. J.; Blakie, P. B.; Deb, A. B.; Kjærgaard, N.

    2016-07-01

    The wavefunction for indistinguishable fermions is anti-symmetric under particle exchange, which directly leads to the Pauli exclusion principle, and hence underlies the structure of atoms and the properties of almost all materials. In the dynamics of collisions between two indistinguishable fermions, this requirement strictly prohibits scattering into 90° angles. Here we experimentally investigate the collisions of ultracold clouds fermionic 40K atoms by directly measuring scattering distributions. With increasing collision energy we identify the Wigner threshold for p-wave scattering with its tell-tale dumb-bell shape and no 90° yield. Above this threshold, effects of multiple scattering become manifest as deviations from the underlying binary p-wave shape, adding particles either isotropically or axially. A shape resonance for 40K facilitates the separate observation of these two processes. The isotropically enhanced multiple scattering mode is a generic p-wave threshold phenomenon, whereas the axially enhanced mode should occur in any colliding particle system with an elastic scattering resonance.

  3. Multiple scattering dynamics of fermions at an isolated p-wave resonance

    PubMed Central

    Thomas, R.; Roberts, K. O.; Tiesinga, E.; Wade, A. C. J.; Blakie, P. B.; Deb, A. B.; Kjærgaard, N.

    2016-01-01

    The wavefunction for indistinguishable fermions is anti-symmetric under particle exchange, which directly leads to the Pauli exclusion principle, and hence underlies the structure of atoms and the properties of almost all materials. In the dynamics of collisions between two indistinguishable fermions, this requirement strictly prohibits scattering into 90° angles. Here we experimentally investigate the collisions of ultracold clouds fermionic 40K atoms by directly measuring scattering distributions. With increasing collision energy we identify the Wigner threshold for p-wave scattering with its tell-tale dumb-bell shape and no 90° yield. Above this threshold, effects of multiple scattering become manifest as deviations from the underlying binary p-wave shape, adding particles either isotropically or axially. A shape resonance for 40K facilitates the separate observation of these two processes. The isotropically enhanced multiple scattering mode is a generic p-wave threshold phenomenon, whereas the axially enhanced mode should occur in any colliding particle system with an elastic scattering resonance. PMID:27396294

  4. Multiple-frequency continuous wave ultrasonic system for accurate distance measurement

    NASA Astrophysics Data System (ADS)

    Huang, C. F.; Young, M. S.; Li, Y. C.

    1999-02-01

    A highly accurate multiple-frequency continuous wave ultrasonic range-measuring system for use in air is described. The proposed system uses a method heretofore applied to radio frequency distance measurement but not to air-based ultrasonic systems. The method presented here is based upon the comparative phase shifts generated by three continuous ultrasonic waves of different but closely spaced frequencies. In the test embodiment to confirm concept feasibility, two low cost 40 kHz ultrasonic transducers are set face to face and used to transmit and receive ultrasound. Individual frequencies are transmitted serially, each generating its own phase shift. For any given frequency, the transmitter/receiver distance modulates the phase shift between the transmitted and received signals. Comparison of the phase shifts allows a highly accurate evaluation of target distance. A single-chip microcomputer-based multiple-frequency continuous wave generator and phase detector was designed to record and compute the phase shift information and the resulting distance, which is then sent to either a LCD or a PC. The PC is necessary only for calibration of the system, which can be run independently after calibration. Experiments were conducted to test the performance of the whole system. Experimentally, ranging accuracy was found to be within ±0.05 mm, with a range of over 1.5 m. The main advantages of this ultrasonic range measurement system are high resolution, low cost, narrow bandwidth requirements, and ease of implementation.

  5. Spatially Extended Relativistic Particles Out of Traveling Front Solutions of Sine-Gordon Equation in (1+2) Dimensions

    PubMed Central

    Zarmi, Yair

    2016-01-01

    Slower-than-light multi-front solutions of the Sine-Gordon in (1+2) dimensions, constructed through the Hirota algorithm, are mapped onto spatially localized structures, which emulate free, spatially extended, massive relativistic particles. A localized structure is an image of the junctions at which the fronts intersect. It propagates together with the multi-front solution at the velocity of the latter. The profile of the localized structure obeys the linear wave equation in (1+2) dimensions, to which a term that represents interaction with a slower-than-light, Sine-Gordon-multi-front solution has been added. This result can be also formulated in terms of a (1+2)-dimensional Lagrangian system, in which the Sine-Gordon and wave equations are coupled. Expanding the Euler-Lagrange equations in powers of the coupling constant, the zero-order part of the solution reproduces the (1+2)-dimensional Sine-Gordon fronts. The first-order part is the spatially localized structure. PACS: 02.30.Ik, 03.65.Pm, 05.45.Yv, 02.30.Ik. PMID:26930077

  6. Spatially Extended Relativistic Particles Out of Traveling Front Solutions of Sine-Gordon Equation in (1+2) Dimensions.

    PubMed

    Zarmi, Yair

    2016-01-01

    Slower-than-light multi-front solutions of the Sine-Gordon in (1+2) dimensions, constructed through the Hirota algorithm, are mapped onto spatially localized structures, which emulate free, spatially extended, massive relativistic particles. A localized structure is an image of the junctions at which the fronts intersect. It propagates together with the multi-front solution at the velocity of the latter. The profile of the localized structure obeys the linear wave equation in (1+2) dimensions, to which a term that represents interaction with a slower-than-light, Sine-Gordon-multi-front solution has been added. This result can be also formulated in terms of a (1+2)-dimensional Lagrangian system, in which the Sine-Gordon and wave equations are coupled. Expanding the Euler-Lagrange equations in powers of the coupling constant, the zero-order part of the solution reproduces the (1+2)-dimensional Sine-Gordon fronts. The first-order part is the spatially localized structure. 02.30.Ik, 03.65.Pm, 05.45.Yv, 02.30.Ik.

  7. A multiple flux boundary element method applied to the description of surface water waves

    NASA Astrophysics Data System (ADS)

    Hague, C. H.; Swan, C.

    2009-08-01

    This paper concerns a two dimensional numerical model based on a high-order boundary element method with fully nonlinear free surface boundary conditions. Multiple fluxes are applied as a method of removing the so-called “corner problem”, whereby the direction of the outward normal at geometric discontinuities is ill-defined. In the present method, both fluxes associated with differing directions of the outward normal at a corner are considered, allowing a single node to be placed at that position. This prevents any loss of information at what can be an important part of the boundary, especially if considering simulations of wave reflection and wave run-up. The method is compared to both the double node approach and the use of discontinuous elements and is shown to be a more accurate technique. The success of the method is further demonstrated by its ability to accurately simulate various problems involving wave transmission and wave-structure interactions at domain corners; the results being achieved without the need for filtering, smoothing or re-gridding of any kind.

  8. Guided wave-based identification of multiple cracks in beams using a Bayesian approach

    NASA Astrophysics Data System (ADS)

    He, Shuai; Ng, Ching-Tai

    2017-02-01

    A guided wave damage identification method using a model-based approach is proposed to identify multiple cracks in beam-like structures. The guided wave propagation is simulated using spectral finite element method and a crack element is proposed to take into account the mode conversion effect. The Bayesian model class selection algorithm is employed to determine the crack number and then the Bayesian statistical framework is used to identify the crack parameters and the associated uncertainties. In order to improve the efficiency and ensure the reliability of identification, the Transitional Markov Chain Monte Carlo (TMCMC) method is implemented in the Bayesian approach. A series of numerical case studies are carried out to assess the performance of the proposed method, in which the sensitivity of different guided wave modes and effect of different levels of measurement noise in identifying different numbers of cracks is studied in detail. The proposed method is also experimentally verified using guided wave data obtained from laser vibrometer. The results show that the proposed method is able to accurately identify the number, locations and sizes of the cracks, and also quantify the associated uncertainties. In addition the proposed method is robust under measurement noise and different situations of the cracks.

  9. Numerical investigation of interactions of multiple spherical shock waves between themselves and with the underlying surface

    NASA Astrophysics Data System (ADS)

    Andrushchenko, V. A.; Murashkin, I. V.; Shevelev, Yu. D.

    2016-06-01

    Within the investigation of various aspects of asteroid and comet danger and, in particular, the explosion of several fragments of meteoroids in the atmosphere above the Earth surface, the toy problem about four point explosions in the case of their special arrangement above the underlying surface is numerically solved. Complex interactions of primary and secondary shock waves between themselves, with the hard surface, and with tangential discontinuities are examined. The structure of flow inside gas regions disturbed by the explosions—the occurrence of eddy structures in them and the influence of reflected shocks waves on them—are investigated. The tendency of the external wave fronts of each explosion to form a unified front and the tendency of their internal hot domains to merge into a joined configuration (where the second process proceeds a little later than the first one) is revealed. This unified front and joined configuration are qualitatively identical to the external internal structure for the solitary explosion. The specially arranged explosions are chosen because the effects of multiple diffraction, interference, and, the main thing, cumulation of spherical waves are manifested more clearly in this caseTwo variants with different altitude of the explosions above the surface are calculated.

  10. A pulse coding and decoding strategy to perform Lamb wave inspections using simultaneously multiple actuators

    NASA Astrophysics Data System (ADS)

    De Marchi, Luca; Marzani, Alessandro; Moll, Jochen; Kudela, Paweł; Radzieński, Maciej; Ostachowicz, Wiesław

    2017-07-01

    The performance of Lamb wave based monitoring systems, both in terms of diagnosis time and data complexity, can be enhanced by increasing the number of transducers used to actuate simultaneously the guided waves in the inspected medium. However, in case of multiple simultaneously-operated actuators the interference among the excited wave modes within the acquired signals has to be considered for the further processing. To this aim, in this work a code division strategy based on the Warped Frequency Transform is presented. At first, the proposed procedure encodes actuation pulses using Gold sequences. Next, for each considered actuator the acquired signals are compensated from dispersion by cross correlating the warped version of the actuated and received signals. Compensated signals form the base for a final wavenumber imaging meant at emphasizing defects and or anomalies by removing incident wavefield and edge reflections. The proposed strategy is tested numerically, and validated through an experiment in which guided waves are actuated in a plate by four piezoelectric transducers operating simultaneously.

  11. Mechanical waves conceptual survey: Its modification and conversion to a standard multiple-choice test

    NASA Astrophysics Data System (ADS)

    Barniol, Pablo; Zavala, Genaro

    2016-06-01

    In this article we present several modifications of the mechanical waves conceptual survey, the most important test to date that has been designed to evaluate university students' understanding of four main topics in mechanical waves: propagation, superposition, reflection, and standing waves. The most significant changes are (i) modification of several test questions that had some problems in their original design, (ii) standardization of the number of options for each question to five, (iii) conversion of the two-tier questions to multiple-choice questions, and (iv) modification of some questions to make them independent of others. To obtain a final version of the test, we administered both the original and modified versions several times to students at a large private university in Mexico. These students were completing a course that covers the topics tested by the survey. The final modified version of the test was administered to 234 students. In this study we present the modifications for each question, and discuss the reasons behind them. We also analyze the results obtained by the final modified version and offer a comparison between the original and modified versions. In the Supplemental Material we present the final modified version of the test. It can be used by teachers and researchers to assess students' understanding of, and learning about, mechanical waves.

  12. Numerical and Experimental Investigation of Multiple Shock Wave/Turbulent Boundary Layer Interactions in a Rectangular Duct

    DTIC Science & Technology

    1988-01-06

    variety of devices including scramjet inlets, gas ejector and supersonic wind tunnels. For sufficiently high duct exit pressures, a multiple shock wave...devices including scramijet inlets, gas ejectors , and supersonic wind tunnels. For sufficiently high duct exit pressures, a * multiple shock wave...gas ejectors , supersonic wind tunnel diffusers, and scramjet (supersonic combustion ramjet) inlets. Ejectors are used to both -- pump and mix fluids and

  13. Traveling waves and worms in ac-driven electroconvection under external multiplicative noise

    NASA Astrophysics Data System (ADS)

    Huh, Jong-Hoon

    2017-04-01

    In the presence of external multiplicative noise, ac-driven electroconvection (EC) in a nematic liquid crystal is investigated. Noise-induced traveling waves (TWs) including localized ones (worms) are found with a typical, stationary wave. Three kinds of TWs are classified by their dynamic features (e.g., noise-intensity-dependent Hopf frequency and space-time map). Moreover, ac frequency-dependent threshold voltages of EC are examined in high noise intensities causing abnormal charge redistribution of the EC cell, and the roles of ac and noise fields with respect to TWs are elucidated in successive pattern evolutions. The mechanism of TWs is discussed in terms of a locally perturbed dynamic conductivity due to the noise field additionally applied to the EC; such a conductivity can be related to a weak-electrolyte model for a Hopf bifurcation to a TW.

  14. Multiple Scattering of Seismic Waves from Ensembles of Upwardly Lossy Thin Flux Tubes

    NASA Astrophysics Data System (ADS)

    Hanson, Chris S.; Cally, Paul S.

    2015-07-01

    Our previous semi-analytic treatment of - and -mode multiple scattering from ensembles of thin flux tubes (Hanson and Cally, Astrophys. J. 781, 125, 2014a; 791, 129, 2014b) is extended by allowing both sausage and kink waves to freely escape at the top of the model using a radiative boundary condition there. As expected, this additional avenue of escape, supplementing downward loss into the deep solar interior, results in substantially greater absorption of incident - and -modes. However, less intuitively, it also yields mildly to substantially smaller phase shifts in waves emerging from the ensemble. This may have implications for the interpretation of seismic data for solar plage regions, and in particular their small measured phase shifts.

  15. Can we explain the Jovian decametric arc pattern with the multiple reflection Alfven wave model?

    NASA Astrophysics Data System (ADS)

    Leblanc, Y.; Bagenal, F.

    The pattern of arcs made by bursts of Io-modulated dkm-band emission in frequency time spectrograms has been examined for the A and B sources and compared with predictions of the Alfven-wave model. Planetary Radio Astronomy data from the Voyager 1 and 2 Jupiter encounters are employed, and the observations of the A and B sources are organized with respect to the Io phase for fixed 30-deg longitude intervals. A clear pattern of regions of strong emission separated by holes (regions with weak or no emission) is found. This preliminary study suggests the bunching of dkm arcs matches the Alfven wave pattern generated by Io. This implies that each Alfven current generates multiple beams of dkm emission.

  16. Traveling waves and worms in ac-driven electroconvection under external multiplicative noise.

    PubMed

    Huh, Jong-Hoon

    2017-04-01

    In the presence of external multiplicative noise, ac-driven electroconvection (EC) in a nematic liquid crystal is investigated. Noise-induced traveling waves (TWs) including localized ones (worms) are found with a typical, stationary wave. Three kinds of TWs are classified by their dynamic features (e.g., noise-intensity-dependent Hopf frequency and space-time map). Moreover, ac frequency-dependent threshold voltages of EC are examined in high noise intensities causing abnormal charge redistribution of the EC cell, and the roles of ac and noise fields with respect to TWs are elucidated in successive pattern evolutions. The mechanism of TWs is discussed in terms of a locally perturbed dynamic conductivity due to the noise field additionally applied to the EC; such a conductivity can be related to a weak-electrolyte model for a Hopf bifurcation to a TW.

  17. New calibration technique for multiple-component stress wave force balances

    SciTech Connect

    Abdel-jawad, Madhat M.; Mee, David J.; Morgan, Richard G.

    2007-06-15

    The measurement of forces in hypervelocity expansion tubes is not possible using conventional techniques. The stress wave force balance technique can be applied in expansion tubes to measure forces despite the short test times involved. This article presents a new calibration technique for multiple-component stress wave force balances where an impulse response created using a load distribution is required and no orthogonal surfaces on the model exist. This new technique relies on the tensorial superposition of single-component impulse responses analogous to the vectorial superposition of the calibration loads. The example presented here is that of a scale model of the Mars Pathfinder, but the technique is applicable to any geometry and may be useful for cases where orthogonal loads cannot be applied.

  18. Critical immune and vaccination thresholds for determining multiple influenza epidemic waves.

    PubMed

    Matrajt, Laura; Longini, Ira M

    2012-03-01

    Previous influenza pandemics (1918, 1957, and 1968) have all had multiple waves. The 2009 pandemic influenza A (H1N1) (pandemic H1N1) started in April 2009 and was followed, in the United States (US) and temperate Northern Hemisphere, by a second wave during the fall of 2009. The ratio of susceptible and immune individuals in a population at the end of a wave determines the potential and magnitude of a subsequent wave. As influenza vaccines are not completely protective, there was a combined immunity in the population at the beginning of 2010 (due to vaccination and due to previous natural infection), and it was uncertain if this mixture of herd immunity was enough to prevent a third wave of pandemic influenza during the winter of 2010. Motivated by this problem, we developed a mathematical deterministic two-group epidemic model with vaccination and calibrated it for the 2009 pandemic H1N1. Then, applying methods from mathematical epidemiology we developed a scheme that allowed us to determine critical thresholds for vaccine-induced and natural immunity that would prevent the spread of influenza. Finally, we estimated the level of combined immunity in the US during winter 2010. Our results suggest that a third wave was unlikely if the basic reproduction number R(0) were below 1.6, plausible if the original R(0) was 1.6, and likely if the original R(0) was 1.8 or higher. Given that the estimates for the basic reproduction number for pandemic influenza place it in the range between 1.4 and 1.6 (Bacaer and Ait Dads, 2011; Fraser et al., 2009; Munayco et al., 2009; Pourbohloul et al., 2009; Tuite et al., 2010; White et al., 2009; Yang et al., 2009), our approach accurately predicted the absence of a third wave of influenza in the US during the winter of 2010. We also used this scheme to accurately predict the second wave of pandemic influenza in London and the West Midlands, UK during the fall of 2009.

  19. Bayesian reconstruction of gravitational wave bursts using chirplets

    NASA Astrophysics Data System (ADS)

    Millhouse, Margaret; Cornish, Neil; Littenberg, Tyson

    2017-01-01

    The BayesWave algorithm has been shown to accurately reconstruct unmodeled short duration gravitational wave bursts and to distinguish between astrophysical signals and transient noise events. BayesWave does this by using a variable number of sine-Gaussian (Morlet) wavelets to reconstruct data in multiple interferometers. While the Morlet wavelets can be summed together to produce any possible waveform, there could be other wavelet functions that improve the performance. Because we expect most astrophysical gravitational wave signals to evolve in frequency, modified Morlet wavelets with linear frequency evolution - called chirplets - may better reconstruct signals with fewer wavelets. We compare the performance of BayesWave using Morlet wavelets and chirplets on a variety of simulated signals.

  20. Formation of multiple shocklets in a transonic diffuser flow

    NASA Astrophysics Data System (ADS)

    Handa, T.; Miyazato, Y.; Masuda, M.; Matsuo, K.

    Multiple shocklets are frequently generated in transonic diffuser flows. The present paper investigates the formation of these shocklets with a high-speed CCD camera combined with the schlieren method. It is observed that compression waves steepen while propagating upstream, and eventually become new shock waves. The ordinary shock wave is found to move upstream beyond the nozzle throat or to disappear while moving downstream depending on the pressure ratio across the nozzle. This phenomenon is also analyzed with the one-dimensional Euler equations by assuming a pressure disturbance given by the sine function at the channel exit. The calculated results are found to reproduce quite well the experimental behavior of the shocklets. The effect of the frequency of disturbance is also studied numerically, and it is shown that the multiple shocklet pattern appears when the amplitude of disturbance is not large and the diverging part of the channel downstream of the ordinary shock wave is long.

  1. Multiple harmonic ULF waves in the plasma sheet boundary layer: Instability analysis

    NASA Astrophysics Data System (ADS)

    Denton, R. E.; Engebretson, M. J.; Keiling, A.; Walsh, A. P.; Gary, S. P.; DéCréAu, P. M. E.; Cattell, C. A.; RèMe, H.

    2010-12-01

    Multiple-harmonic electromagnetic waves in the ULF band have occasionally been observed in Earth's magnetosphere, both near the magnetic equator in the outer plasmasphere and in the plasma sheet boundary layer (PSBL) in Earth's magnetotail. Observations by the Cluster spacecraft of multiple-harmonic electromagnetic waves with fundamental frequency near the local proton cyclotron frequency, Ωcp, were recently reported in the plasma sheet boundary layer by Broughton et al. (2008). A companion paper surveys the entire magnetotail passage of Cluster during 2003, and reports 35 such events, all in the PSBL, and all associated with elevated fluxes of counterstreaming ions and electrons. In this study we use observed pitch angle distributions of ions and electrons during a wave event observed by Cluster on 9 September 2003 to perform an instability analysis. We use a semiautomatic procedure for developing model distributions composed of bi-Maxwellian components that minimizes the difference between modeled and observed distribution functions. Analysis of wave instability using the WHAMP electromagnetic plasma wave dispersion code and these model distributions reveals an instability near Ωcp and its harmonics. The observed and model ion distributions exhibit both beam-like and ring-like features which might lead to instability. Further instability analysis with simple beam-like and ring-like model distribution functions indicates that the instability is due to the ring-like feature. Our analysis indicates that this instability persists over an enormous range in the effective ion beta (based on a best fit for the observed distribution function using a single Maxwellian distribution), β', but that the character of the instability changes with β'. For β' of order unity (for instance, the observed case with β' ˜ 0.4), the instability is predominantly electromagnetic; the fluctuating magnetic field has components in both the perpendicular and parallel directions, but the

  2. Possible involvement of SINEs in mammalian-specific brain formation.

    PubMed

    Sasaki, Takeshi; Nishihara, Hidenori; Hirakawa, Mika; Fujimura, Koji; Tanaka, Mikiko; Kokubo, Nobuhiro; Kimura-Yoshida, Chiharu; Matsuo, Isao; Sumiyama, Kenta; Saitou, Naruya; Shimogori, Tomomi; Okada, Norihiro

    2008-03-18

    Retroposons, such as short interspersed elements (SINEs) and long interspersed elements (LINEs), are the major constituents of higher vertebrate genomes. Although there are many examples of retroposons' acquiring function, none has been implicated in the morphological innovations specific to a certain taxonomic group. We previously characterized a SINE family, AmnSINE1, members of which constitute a part of conserved noncoding elements (CNEs) in mammalian genomes. We proposed that this family acquired genomic functionality or was exapted after retropositioning in a mammalian ancestor. Here we identified 53 new AmnSINE1 loci and refined 124 total loci, two of which were further analyzed. Using a mouse enhancer assay, we demonstrate that one SINE locus, AS071, 178 kbp from the gene FGF8 (fibroblast growth factor 8), is an enhancer that recapitulates FGF8 expression in two regions of the developing forebrain, namely the diencephalon and the hypothalamus. Our gain-of-function analysis revealed that FGF8 expression in the diencephalon controls patterning of thalamic nuclei, which act as a relay center of the neocortex, suggesting a role for FGF8 in mammalian-specific forebrain patterning. Furthermore, we demonstrated that the locus, AS021, 392 kbp from the gene SATB2, controls gene expression in the lateral telencephalon, which is thought to be a signaling center during development. These results suggest important roles for SINEs in the development of the mammalian neuronal network, a part of which was initiated with the exaptation of AmnSINE1 in a common mammalian ancestor.

  3. Multiple extracorporeal shock wave therapy degrades capsular fibrosis after insertion of silicone implants.

    PubMed

    Fischer, Sebastian; Mueller, Wolf; Schulte, Matthias; Kiefer, Jurij; Hirche, Christoph; Heimer, Sina; Köllensperger, Eva; Germann, Günter; Reichenberger, Matthias A

    2015-03-01

    Capsular fibrosis is the most frequent long-term complication after insertion of silicone devices. Today, mainly direct immunostimulation and subclinical infection are held responsible for inducing and maintaining inflammatory reactions, which lead to overwhelming extracellular matrix formation. Extracorporeal shock waves (ESWs) are capable of inhibiting inflammatory processes and revealing antibacterial capacity. In our previous study, we observed decelerated capsule development after application of a single shock wave immediately after surgery. The purpose of this study was to evaluate the effects of multiple ESWT after insertion of silicone implants in the same rodent model. Therefore, silicone prostheses were inserted into a submuscular pocket in 12 additional male Lewis rats, and shock waves were administered over a 14-d interval. At 35 d (n = 6) and 100 d (n = 6) after insertion, silicone implants and surrounding capsule tissue were removed and prepared for histologic and immunohistochemical analysis, as well as polymerase chain reaction (Ccl2, CD68, transforming growth factor β1, matrix metalloproteinase 2). Compared with the control group, multiple ESWT had no effect on day 35, but resulted in a significantly thinner capsule on day 100 (825.8 ± 313.2 vs. 813.3 ± 47.9, p = 0.759, and 1062.3 ± 151.9 vs. 495.4 ± 220.4, p < 0.001, respectively). The capsule was even thinner than after a single shock wave application, which had been found to result in thinner capsules at every time point in our previous study. This active degradation of the fibrous envelope caused by multiple ESWs was accompanied by synergistic alterations in pro- and anti-fibrotic proteins (transforming growth factor β1 and matrix metalloproteinase 2, respectively). In conclusion, after insertion of silicone devices, single ESWT is capable of decelerating capsule formation in contrast to multiple ESWT, which degrades fibrotic tissue. These findings seem to be associated with inhibition of

  4. Surface Acoustic Wave Multiple Phase Shift Keying Modulator-Demodulator Circuits

    NASA Astrophysics Data System (ADS)

    Araki, Nobushige; Komine, Kenji; Hara, Motoaki; Ueno, Hiroaki; Hohkawa, Kohji

    1994-05-01

    Multiple phase shift keying technology is effectively used in various communication systems because of its high-capacity data transmission capability along a restricted passband. This-paper proposes a high-performance offset quadri-pulse shift keying modulator and demodulator with a new simple circuit configuration employing surface acoustic wave (SAW) devices. We propose two types of modulators (modulation and pulse pattern generation method) and a demodulator with a differential-operation SAW device. A fundamental experiment verified the feasibility of the circuits.

  5. Wave field reconstruction from multiple plane intensity-only data: augmented lagrangian algorithm.

    PubMed

    Migukin, Artem; Katkovnik, Vladimir; Astola, Jaakko

    2011-06-01

    A complex-valued wave field is reconstructed from intensity-only measurements given at multiple observation planes parallel to the object plane. The phase-retrieval algorithm is obtained from the constrained maximum likelihood approach provided that the additive noise is gaussian. The forward propagation from the object plane to the measurement plane is treated as a constraint in the proposed variational setting of reconstruction. The developed iterative algorithm is based on an augmented lagrangian technique. An advanced performance of the algorithm is demonstrated by numerical simulations.

  6. Energy in a String Wave

    ERIC Educational Resources Information Center

    Ng, Chiu-king

    2010-01-01

    When one end of a taut horizontal elastic string is shaken repeatedly up and down, a transverse wave (assume sine waveform) will be produced and travel along it. College students know this type of wave motion well. They know when the wave passes by, each element of the string will perform an oscillating up-down motion, which in mechanics is termed…

  7. Energy in a String Wave

    ERIC Educational Resources Information Center

    Ng, Chiu-king

    2010-01-01

    When one end of a taut horizontal elastic string is shaken repeatedly up and down, a transverse wave (assume sine waveform) will be produced and travel along it. College students know this type of wave motion well. They know when the wave passes by, each element of the string will perform an oscillating up-down motion, which in mechanics is termed…

  8. Comparative evolution history of SINEs in Arabidopsis thaliana and Brassica oleracea: evidence for a high rate of SINE loss.

    PubMed

    Lenoir, A; Pélissier, T; Bousquet-Antonelli, C; Deragon, J M

    2005-01-01

    Brassica oleracea and Arabidopsis thaliana belong to the Brassicaceae(Cruciferae) family and diverged 16 to 19 million years ago. Although the genome size of B. oleracea (approximately 600 million base pairs) is more than four times that of A. thaliana (approximately 130 million base pairs), their gene content is believed to be very similar with more than 85% sequence identity in the coding region. Therefore, this important difference in genome size is likely to reflect a different rate of non-coding DNA accumulation. Transposable elements (TEs) constitute a major fraction of non-coding DNA in plant species. A different rate in TE accumulation between two closely related species can result in significant genome size variations in a short evolutionary period. Short interspersed elements (SINEs) are non-autonomous retroposons that have invaded the genome of most eukaryote species. Several SINE families are present in B. oleracea and A. thaliana and we found that two of them (called RathE1 and RathE2) are present in both species. In this study, the tempo of evolution of RathE1 and RathE2 SINE families in both species was compared. We observed that most B. oleracea RathE2 SINEs are "young" (close to the consensus sequence) and abundant while elements from this family are more degenerated and much less abundant in A. thaliana. However, the situation is different for the RathE1 SINE family for which the youngest elements are found in A. thaliana. Surprisingly, no SINE was found to occupy the same (orthologous) genomic locus in both species suggesting that either these SINE families were not amplified at a significant rate in the common ancestor of the two species or that older elements were lost and only the recent (lineage-specific) insertions remain. To test this latter hypothesis, loci containing a recently inserted SINE in the A. thaliana col-0 ecotype were selected and characterized in several other A. thaliana ecotypes. In addition to the expected SINE containing

  9. SINEs, evolution and genome structure in the opossum.

    PubMed

    Gu, Wanjun; Ray, David A; Walker, Jerilyn A; Barnes, Erin W; Gentles, Andrew J; Samollow, Paul B; Jurka, Jerzy; Batzer, Mark A; Pollock, David D

    2007-07-01

    Short INterspersed Elements (SINEs) are non-autonomous retrotransposons, usually between 100 and 500 base pairs (bp) in length, which are ubiquitous components of eukaryotic genomes. Their activity, distribution, and evolution can be highly informative on genomic structure and evolutionary processes. To determine recent activity, we amplified more than one hundred SINE1 loci in a panel of 43 M. domestica individuals derived from five diverse geographic locations. The SINE1 family has expanded recently enough that many loci were polymorphic, and the SINE1 insertion-based genetic distances among populations reflected geographic distance. Genome-wide comparisons of SINE1 densities and GC content revealed that high SINE1 density is associated with high GC content in a few long and many short spans. Young SINE1s, whether fixed or polymorphic, showed an unbiased GC content preference for insertion, indicating that the GC preference accumulates over long time periods, possibly in periodic bursts. SINE1 evolution is thus broadly similar to human Alu evolution, although it has an independent origin. High GC content adjacent to SINE1s is strongly correlated with bias towards higher AT to GC substitutions and lower GC to AT substitutions. This is consistent with biased gene conversion, and also indicates that like chickens, but unlike eutherian mammals, GC content heterogeneity (isochore structure) is reinforced by substitution processes in the M. domestica genome. Nevertheless, both high and low GC content regions are apparently headed towards lower GC content equilibria, possibly due to a relative shift to lower recombination rates in the recent Monodelphis ancestral lineage. Like eutherians, metatherian (marsupial) mammals have evolved high CpG substitution rates, but this is apparently a convergence in process rather than a shared ancestral state.

  10. Feedback sine wave driver design for ultrasonic transducers

    NASA Astrophysics Data System (ADS)

    Schweitzer, P.; Tisserand, E.; Hamed, A.; Andréa, J.; Coutard, F.

    2009-07-01

    The optimal sinusoidal excitation of an ultrasonic transducer requests a knowledge of the frequency and the impedance of the used ceramic. These parameters, that vary during the application, depend on the characteristics of the transducer but also on the acoustic load of the propagation medium. In the search for an adaptive excitation, we propose the design of a digital generator assuring the functions of automatic tuning and impedance matching. The design uses the Butterworth-Van Dycke model of pizoelectric ceramics. The method of determination and identification of the model parameters is presented and applied on three different transducers. The negative feedback of the generator is carried out by the signal measured on the transducers. The dynamic voltage being very variable, the output resistor of the driver is controlled by transducer impedance. This feedback control allows the stability of the output voltage to a constant value whatever the frequency and the medium is. A Simulink^circledR model of the regulation loop shows that the frequency tuning could be realized by exploiting the command signal of the driver resistance. The precision and the stability of the feedback system are tested for frequencies between 1 to 3 MHz.

  11. Low-frequency sine wave hard-limiting technique

    NASA Technical Reports Server (NTRS)

    Anderson, T. O.

    1977-01-01

    Circuit includes serial-in/parallel-out shift register and weighting network that are used to eliminate effects of noise and other nonrepetitive circuit transients. Register and weighting network average decisions from section of signal where decisions are more dependable or where differences between two consecutive samples are larger.

  12. Multiple scales analysis and travelling wave solutions for KdV type nonlinear evolution equations

    NASA Astrophysics Data System (ADS)

    Ayhan, Burcu; Ozer, M. Naci; Bekir, Ahmet

    2017-01-01

    Nonlinear evolution equations are the mathematical models of problems that arise in many field of science. These equations has become an important field of study in applied mathematics in recent years. We apply exact solution methods and multiple scale method which is known as a perturbation method to nonlinear evolution equations. Using exact solution methods we get travelling wave solutions expressed by hyperbolic functions, trigonometric functions and rational functions. Also we derive Nonlinear Schrödinger (NLS) type equations from Korteweg-de Vries (KdV) type nonlinear evolution equations and we get approximate solutions for KdV type equations using multiple scale method. The proposed methods are direct and effective and can be used for many nonlinear evolution equations. It is shown that these methods provide a powerful mathematical tool to solve nonlinear evolution equations in mathematical physics.

  13. Continuous Measurement of Multiple Gases Using Ball Surface Acoustic Wave Gas Chromatograph

    NASA Astrophysics Data System (ADS)

    Sakamoto, Toshihiro; Akao, Shingo; Iwaya, Takamitsu; Tsuji, Toshihiro; Nakaso, Noritaka; Yamanaka, Kazushi

    2012-07-01

    Although portable gas chromatographs (GCs) have been developed for the monitoring of volatile organic compounds (VOCs) in working environments, they still need high power consumption for the heating column. Thus, we previously developed a portable surface acoustic wave (SAW) GC equipped with a ball SAW sensor and a micro-electromechanical-system column (ball SAW GC) and proved the usefulness of the forward flush (FF) method for realizing the fast analysis of multiple gases without a heater. However, its ability to measure ten kinds of VOCs at ppm order and automatic continuous measurement were not demonstrated. In this study, a ball SAW GC employing the FF method and equipped with a gas sampler for continuous injection was developed. Then, the performance of monitoring multiple gases in working environments was verified by measuring ten kinds of VOCs with maximum acceptable concentrations. Moreover, real-time monitoring of seven kinds of VOCs with a linear change in the response value to concentration changes was demonstrated.

  14. Broadband Lamb Wave Trapping in Cellular Metamaterial Plates with Multiple Local Resonances

    PubMed Central

    Zhao, De-Gang; Li, Yong; Zhu, Xue-Feng

    2015-01-01

    We have investigated the Lamb wave propagation in cellular metamaterial plates constructed by bending-dominated and stretch-dominated unit-cells with the stiffness differed by orders of magnitude at an ultralow density. The simulation results show that ultralight metamaterial plates with textured stubs deposited on the surface can support strong local resonances for both symmetric and anti-symmetric modes at low frequencies, where Lamb waves at the resonance frequencies are highly localized in the vibrating stubs. The resonance frequency is very sensitive to the geometry of textured stubs. By reasonable design of the geometry of resonant elements, we establish a simple loaded-bar model with the array of oscillators having a gradient relative density (or weight) that can support multiple local resonances, which permits the feasibility of a broadband Lamb wave trapping. Our study could be potentially significant in designing ingenious weight-efficient acoustic devices for practical applications, such as shock absorption, cushioning, and vibrations traffic, etc. PMID:25790858

  15. Use of multiple acoustic wave modes for assessment of long bones: Model study

    PubMed Central

    Tatarinov, Alexey; Sarvazyan, Noune; Sarvazyan, Armen

    2010-01-01

    Multiple acoustic wave mode method has been proposed as a new modality in axial bone QUS. The new method is based on measurement of ultrasound velocity at different ratio of wavelength to the bone thickness, and taking into account both bulk and guided waves. It allows assessment of changes in both the material properties related to porosity and mineralization as well as the cortical thickness influenced by resorption from inner layers, which are equally important in diagnostics of osteoporosis and other bone osteopenia. Developed method was validated in model studies using a dual-frequency (100 and 500 kHz) ultrasound device. Three types of bone phantoms for long bones were developed and tested: (1) tubular specimens from polymer materials to model combined changes of material stiffness and cortical wall thickness; (2) layered specimens to model porosity in compact bone progressing from endosteum towards periosteum; (3) animal bone specimens with both cortical and trabecular components. Observed changes of the ultrasound velocity of guided waves at 100 kHz followed gradual changes in the thickness of the intact cortical layer. On the other hand, the bulk velocity at 500 kHz remained nearly constant at the different cortical layer thickness but was affected by the material stiffness. Similar trends were observed in phantoms and in fragments of animal bones. PMID:15982472

  16. Optical interference-based multiple-image encryption using spherical wave illumination and gyrator transform.

    PubMed

    Abuturab, Muhammad Rafiq

    2014-10-10

    A new optical interference-based multiple-image encryption using spherical wave illumination and gyrator transform is proposed. In this proposal, each secret color image is divided into normalized red, green, and blue component images and independently encoded into corresponding phase-only component images. Then each phase-only component image of all the images are combined together to produce a single-phase-only component image as an input component image, which is bounded with a random phase mask to form a complex image. The two phase-only masks are analytically obtained from the inverse Fourier transformation of the complex image. The host image is chosen as the first phase-only mask, and the complex image hidden in the host image is regarded as the second phase-only mask. The spherical wave is generated to simultaneously illuminate phase-only masks. Then two modulated masks are gyrator transformed. The corresponding transformed images are phase truncated to obtain encrypted images and amplitude truncated to construct decryption keys. The decryption keys, angles of gyrator transform, wavelength and radius of the spherical wave, and individual decryption keys for authorized users are sensitive keys, which enhance the security layers of the system. The proposed system can be implemented by using optoelectronic architecture. Numerical simulation results demonstrate the flexibility of the system.

  17. Oblique wave motion over multiple submerged porous bars near a vertical wall

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Liu, Yong; Li, Huajun; Chang, Anteng

    2017-08-01

    This study examines oblique wave motion over multiple submerged porous bars in front of a vertical wall. Based on linear potential theory, an analytical solution for the present problem is developed using matched eigenfunction expansions. A complex dispersion relation is adopted to describe the wave elevation and energy dissipation over submerged porous bars. In the analytical solution, no limitations on the bar number, bar size, and spacing between adjacent bars are set. The convergence of the analytical solution is satisfactory, and the correctness of the analytical solution is confirmed by an independently developed multi-domain BEM (boundary element method) solution. Numerical examples are presented to examine the reflection and transmission coefficients of porous bars, C R and C T , respectively, for engineering applications. The calculation results show that when the sum of widths for all the porous bars is fixed, increasing the bar number can significantly improve the sheltering function of the bars. Increasing the bar height can cause more wave energy dissipation and lower C R and C T . The spacing between adjacent bars and the spacing between the last bar and the vertical wall are the key parameters affecting C R and C T . The proposed analytical method may be used to analyze the hydrodynamic performance of submerged porous bars in preliminary engineering designs.

  18. Stirring Coronal Spaghetti: Exploring Multiple Interactions Between MHD Waves and Density Fluctuations

    NASA Astrophysics Data System (ADS)

    Cranmer, Steven R.

    2016-05-01

    The solar corona has been revealed in the past few decades to be a highly dynamic nonequilibrium plasma environment. Both the loop-filled coronal base and the extended acceleration region of the solar wind appear to be strongly turbulent, and models that invoke the dissipation of incompressible Alfvenic fluctuations have had some success in explaining the heating. However, many of these models neglect the mounting evidence that density and pressure variations may play an important role in the mass and energy balance of this system. In this presentation I will briefly review observations of both compressible and incompressible MHD fluctuations in the corona and solar wind, and discuss future prospects with DKIST. I will also attempt to outline the many ways that these different fluctuation modes have been proposed to interact with one another -- usually with an eye on finding ways to enhance their dissipation and heating. One under-appreciated type of interaction is the fact that Alfven waves will undergo multiple reflections and refractions in a "background plasma" filled with localized density fluctuations. It is becoming increasingly clear that models must not only include the effects of longitudinal variability (e.g., magnetoacoustic waves and pulse-like jets) but also transverse "striations" that appear naturally in a structured magnetic field with small-scale footpoint variability. Future off-limb observations, such as those with DKIST's Cryo-NIRSP instrument, will be crucial for providing us with a detailed census of MHD waves and their mutual interactions in the corona.

  19. Stopping rules for surveys with multiple waves of nonrespondent follow-up.

    PubMed

    Rao, R Sowmya; Glickman, Mark E; Glynn, Robert J

    2008-05-30

    In surveys with multiple waves of follow-up, nonrespondents to the first wave are sometimes followed intensively but this does not guarantee an increase in the response rate or an appreciable change in the estimate of interest. Most prior research has focused on stopping rules for Phase I clinical trials. To our knowledge there are no standard methods to stop follow-up in observational studies. Previous research suggests optimal stopping strategies where decisions are based on achieving a given precision for minimum cost or reducing cost for a given precision. In this paper, we propose three stopping rules that are based on assessing whether successive waves of sampling provide evidence that the parameter of interest is changing. Two of the rules rely on examining patterns of observed responses while the third rule uses missing data methods to multiply impute missing responses. We also present results from a simulation study to evaluate our proposed methods. Our simulations suggest that rules that adjust for nonresponse are preferred for decisions to discontinue follow-up since they reduce bias in the estimate of interest. The rules are not complicated and may be applied in a straightforward manner. Discontinuing follow-up would save time and possibly resources, and adjusting for the nonresponse in the analysis would reduce the impact of nonresponse bias.

  20. Microgenetic patterns of children's multiplication learning: confirming the overlapping waves model by latent growth modeling.

    PubMed

    van der Ven, Sanne H G; Boom, Jan; Kroesbergen, Evelyn H; Leseman, Paul P M

    2012-09-01

    Variability in strategy selection is an important characteristic of learning new skills such as mathematical skills. Strategies gradually come and go during this development. In 1996, Siegler described this phenomenon as "overlapping waves." In the current microgenetic study, we attempted to model these overlapping waves statistically. In addition, we investigated whether development in strategy selection is related to development in accuracy and to what degree working memory is related to both. We expected that children with poor working memory are limited in their possibilities to make the associations that are necessary to progress to more mature strategies. This limitation would explain the often-found relationship between working memory and mathematical abilities. To this aim, the strategy selection and accuracy of 98 children who were learning single-digit multiplication was assessed eight times on a weekly basis. Using latent growth modeling for categorical data, we confirmed Siegler's hypothesis of overlapping waves. Moreover, both the intercepts and the slopes of strategy selection and accuracy were strongly interrelated. Finally, working memory predicted both strategy selection and accuracy, confirming that working memory is related to mathematical problem solving in two ways because it influences both the maturity of strategy choice and the probability of making procedural mistakes. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Measurement of the viscosity-density product using multiple reflections of ultrasonic shear horizontal waves.

    PubMed

    Greenwood, Margaret S; Adamson, Justus D; Bond, Leonard J

    2006-12-22

    We have developed an on-line computer-controlled sensor, based on ultrasound reflection measurements, to determine the product of the viscosity and density of a liquid or slurry for Newtonian fluids and the shear impedance of the liquid for non-Newtonian fluids. A 14 MHz shear wave transducer is bonded to one side of a 45-90 degrees fused silica wedge and the base is in contract with the liquid. Twenty-eight echoes were observed due to the multiple reflections of an ultrasonic shear horizontal (SH) wave within the wedge. The fast Fourier transform of each echo was obtained for a liquid and for water, which serves as the calibration fluid, and the reflection coefficient at the solid-liquid interface was obtained. Data were obtained for 11 sugar water solutions ranging in concentration from 10% to 66% by weight. The viscosity values are shown to be in good agreement with those obtained independently using a laboratory viscometer. The data acquisition time is 14s and this can be reduced by judicious selection of the echoes for determining the reflection coefficient. The measurement of the density results in a determination of the viscosity for Newtonian fluids or the shear wave velocity for non-Newtonian fluids. The sensor can be deployed for process control in a pipeline, with the base of the wedge as part of the pipeline wall, or immersed in a tank.

  2. Multiple scattering effects in quasifree scattering from halo nuclei: A test of the distorted-wave impulse approximation

    SciTech Connect

    Crespo, R.; Deltuva, A.; Cravo, E.; Rodriguez-Gallardo, M.; Fonseca, A. C.

    2008-02-15

    Full Faddeev-type calculations are performed for {sup 11}Be breakup on a proton target at 38.4, 100, and 200 MeV/u incident energies. The convergence of the multiple scattering expansion is investigated. The results are compared with those of other frameworks like distorted-wave impulse approximation that are based on an incomplete and truncated multiple scattering expansion.

  3. Wave field autofocusing and applications to multidimensional deconvolution and imaging with internal multiples

    NASA Astrophysics Data System (ADS)

    Broggini, Filippo

    One of the most challenging tasks of exploration geophysics is to build a quantitatively accurate image of the structures inside the Earth from reflection data measured at the Earth's surface. When the subsurface is structurally complicated, accurate images are needed to locate energy sources, such as hydrocarbon reservoirs. Conventional migration algorithms rely on the single-scattering assumption. This restrictive assumption requires that the recorded data do not include waves that have bounced multiple times between layers before reaching the receivers. Standard imaging algorithms incorrectly image the multiple reflections as ghost reflectors and these artifacts can mislead the interpreters in locating potential energy sources. The objective of this thesis is to investigate a new method in reflection seismology for building ghost-free images of the subsurface. The goal is to take advantage of multiply-scattered waves in order to produce more correct images in complicated geological subsurface environments. The method I propose, defined as wave field autofocusing, is based on inverse methods originally used in quantum scattering. The first part of this thesis presents the connection between such inverse methods and Green's function retrieval for a one-dimensional medium. I emphasize that the importance of these inversion methods is linked to the retrieval of the wave field propagating in an unknown medium and not to the retrieval of the impedance profile of the same medium. Based on this connection, I extend the method to two-dimensional media and apply it to multidimensional deconvolution to obtain a ghost-free image, hence presenting ad advantage over standard imaging techniques. Then, using the unitarity of the scattering matrix, I show the consistency between the new approach (requiring data on only one side of the medium) and existing methods that require measurement on a closed boundary, such as seismic interferometry. In the last part of this thesis, I

  4. Multiple phase screen calculation of two-way spherical wave propagation in the ionosphere

    NASA Astrophysics Data System (ADS)

    Knepp, Dennis L.

    2016-04-01

    This paper presents a numerical solution to the parabolic wave equation for spherical wave propagation in a disturbed ionosphere. The solution uses the Fourier/split step approach where the propagation medium is modeled using multiple phase-changing screens separated by free space. The phase screens can consist of deterministic or random components describing spatial scales of any size. This solution consists of realizations of the signal (i.e., the ionospheric transfer function) after two-way propagation from a transmitter, through the medium to a target, and back. The transmitter and target can be comprised of multiple, independent point scatterers. The solution is applicable to many propagation problems including synthetic aperture radar and is not subject to the small-scene limitation, where all scatterers in the scene experience identical propagation conditions. Several examples are given illustrating some features of the solution including reciprocity, relationship between one- and two-way (monostatic and bistatic) scintillation index, and reflection from a large target.

  5. A doubly-fed induction generator-based wind generation system with quasi-sine rotor injection

    NASA Astrophysics Data System (ADS)

    Yuvarajan, S.; Fan, Lingling

    Wind generating systems use doubly-fed induction generators (DFIGs) to achieve high conversion efficiency and to reduce the installation cost. The paper proposes and analyzes a simple DFIG-based wind generation system in which the excitation power is obtained from a photovoltaic (PV) panel and battery. The proposed scheme is suitable for small wind power systems for which a complex field orientation control is not justified. It can be used for stand-alone operation and also grid-tied operation. The rotor of the DFIG is applied with a quasi-sine wave instead of a sine wave. The operation and harmonic characteristics of the scheme are established using analysis, simulation, and experimentation. The details of the control circuit are given along with the experimental waveforms of voltages and currents and frequency spectra. The total harmonic distortion in the output current is found to be around 8%.

  6. Bubblelike structures generated by activation of internal shape modes in two-dimensional sine-Gordon line solitons.

    PubMed

    García-Ñustes, Mónica A; Marín, Juan F; González, Jorge A

    2017-03-01

    Nonlinear waves that collide with localized defects exhibit complex behavior. Apart from reflection, transmission, and annihilation of an incident wave, a local inhomogeneity can activate internal modes of solitons, producing many impressive phenomena. In this work we investigate a two-dimensional sine-Gordon model perturbed by a family of localized forces. We observed the formation of bubblelike and droplike structures due to local internal shape mode instabilities. We describe the formation of such structures on the basis of a one-dimensional theory of activation of internal modes of sine-Gordon solitons. An interpretation of the observed phenomena, in the context of phase transition theory, is given. Implications in Josephson junctions with a current dipole device are discussed.

  7. Observations and modeling of EMIC wave properties in the presence of multiple ion species as function of magnetic local time

    NASA Astrophysics Data System (ADS)

    Lee, Justin H.; Angelopoulos, Vassilis

    2014-11-01

    Electromagnetic ion cyclotron (EMIC) wave generation and propagation in Earth's magnetosphere depend on readily measurable hot (a few to tens of keV) plasma sheet ions, elusive plasmaspheric or ionospheric cold (sub-eV to a few eV) ions, and partially heated warm ions (tens to hundreds of eV). Previous work has assumed all low-energy ions are cold and not considered possible effects of warm ions. Using measurements by multiple Time History of Events and Macroscale Interactions during Substorms spacecraft, we analyze four typical EMIC wave events in the four magnetic local time sectors and consider the properties of both cold and warm ions supplied from previous statistical studies to interpret the wave observations using linear theory. As expected, we find that dusk EMIC waves grow due to the presence of drifting hot anisotropic protons and cold plasmaspheric ions with a dominant cold proton component. Near midnight, EMIC waves are less common because warm heavy ions that suppress wave growth are more abundant there. The waves can grow when cold, plume-like density enhancements are present, however. Dawn EMIC waves, known for their peculiar properties, are generated away from the equator and change polarization during propagation through the warm plasma cloak. Noon EMIC waves can also be generated nonlocally and their properties modified during propagation by a plasmaspheric plume combined with low-energy ions from solar and terrestrial sources. Accounting for multiple ion species, measured wave dispersion, and propagation characteristics can explain previously elusive EMIC wave properties and are therefore important for future studies of EMIC wave effects on energetic particle depletion.

  8. Chaos Suppression in a Sine Square Map through Nonlinear Coupling

    NASA Astrophysics Data System (ADS)

    Eduardo, L. Brugnago; Paulo, C. Rech

    2011-11-01

    We study a pair of nonlinearly coupled identical chaotic sine square maps. More specifically, we investigate the chaos suppression associated with the variation of two parameters. Two-dimensional parameter-space regions where the chaotic dynamics of the individual chaotic sine square map is driven towards regular dynamics are delimited. Additionally, the dynamics of the coupled system is numerically characterized as the parameters are changed.

  9. Short interspersed elements (SINEs) are a major source of canine genomic diversity.

    PubMed

    Wang, Wei; Kirkness, Ewen F

    2005-12-01

    SINEs are retrotransposons that have enjoyed remarkable reproductive success during the course of mammalian evolution, and have played a major role in shaping mammalian genomes. Previously, an analysis of survey-sequence data from an individual dog (a poodle) indicated that canine genomes harbor a high frequency of alleles that differ only by the absence or presence of a SINEC_Cf repeat. Comparison of this survey-sequence data with a draft genome sequence of a distinct dog (a boxer) has confirmed this prediction, and revealed the chromosomal coordinates for >10,000 loci that are bimorphic for SINEC_Cf insertions. Analysis of SINE insertion sites from the genomes of nine additional dogs indicates that 3%-5% are absent from either the poodle or boxer genome sequences--suggesting that an additional 10,000 bimorphic loci could be readily identified in the general dog population. We describe a methodology that can be used to identify these loci, and could be adapted to exploit these bimorphic loci for genotyping purposes. Approximately half of all annotated canine genes contain SINEC_Cf repeats, and these elements are occasionally transcribed. When transcribed in the antisense orientation, they provide splice acceptor sites that can result in incorporation of novel exons. The high frequency of bimorphic SINE insertions in the dog population is predicted to provide numerous examples of allele-specific transcription patterns that will be valuable for the study of differential gene expression among multiple dog breeds.

  10. Square or Sine: Finding a Waveform with High Success Rate of Eliciting SSVEP

    PubMed Central

    Teng, Fei; Chen, Yixin; Choong, Aik Min; Gustafson, Scott; Reichley, Christopher; Lawhead, Pamela; Waddell, Dwight

    2011-01-01

    Steady state visual evoked potential (SSVEP) is the brain's natural electrical potential response for visual stimuli at specific frequencies. Using a visual stimulus flashing at some given frequency will entrain the SSVEP at the same frequency, thereby allowing determination of the subject's visual focus. The faster an SSVEP is identified, the higher information transmission rate the system achieves. Thus, an effective stimulus, defined as one with high success rate of eliciting SSVEP and high signal-noise ratio, is desired. Also, researchers observed that harmonic frequencies often appear in the SSVEP at a reduced magnitude. Are the harmonics in the SSVEP elicited by the fundamental stimulating frequency or by the artifacts of the stimuli? In this paper, we compare the SSVEP responses of three periodic stimuli: square wave (with different duty cycles), triangle wave, and sine wave to find an effective stimulus. We also demonstrate the connection between the strength of the harmonics in SSVEP and the type of stimulus. PMID:21941529

  11. Energy conservative solutions to the system of full variational sine-Gordon equations in a unit sphere

    NASA Astrophysics Data System (ADS)

    Wang, Qin; Song, Kyungwoo

    2016-02-01

    We establish the global existence of a conservative weak solution to the Cauchy problem for a complete system of variational sine-Gordon equations, which models the motion of long waves on a neutral dipole chain in the continuum limit in a unit sphere. Although singularities may develop in finite time, the energy of the solution is conserved across singular times. We also obtain the continuous dependence of solutions on the given initial data.

  12. SINEs and LINEs: symbionts of eukaryotic genomes with a common tail.

    PubMed

    Ohshima, K; Okada, N

    2005-01-01

    Many SINEs and LINEs have been characterized to date, and examples of the SINE and LINE pair that have the same 3' end sequence have also increased. We report the phylogenetic relationships of nearly all known LINEs from which SINEs are derived, including a new example of a SINE/LINE pair identified in the salmon genome. We also use several biological examples to discuss the impact and significance of SINEs and LINEs in the evolution of vertebrate genomes.

  13. High Similarity between Distantly Related Species of a Plant SINE Family Is Consistent with a Scenario of Vertical Transmission without Horizontal Transfers.

    PubMed

    Fawcett, Jeffrey A; Innan, Hideki

    2016-10-01

    Many transposable element (TE) families show surprisingly high levels of similarity between distantly related species. This high similarity, coupled with a "patchy" phylogenetic distribution, has often been attributed to frequent horizontal transfers of TEs between species, even though the mechanistic basis tends to be speculative. Here, we studied the evolution of the Au SINE (Short INterspersed Element) family, in which high similarity between distantly related plant species has been reported. We were able to identify several copies present in orthologous regions of various species, including species that diverged ∼90 Ma, thereby confirming the presence of Au SINE at multiple evolutionary time points. We also found that the Au SINE has been degenerating and is en route to disappearing in many species, indicating that the loss of Au SINE is common. Our results suggest that the evolution of the Au SINE can be readily explained by a scenario of vertical transmission without having to invoke hypothetical scenarios of rampant horizontal transfers. The Au SINE was likely present in the common ancestor of all angiosperms and was retained in some lineages while lost from others. The high level of conservation is probably because the sequences were important for ensuring their transpositional activity. This model of TE evolution should provide a basic framework for understanding the evolution of TEs in general. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Multiple Scattering of Sound by Internal Waves and Acoustic Characterization of Internal Wave Fields in Deep and Shallow Water

    DTIC Science & Technology

    2005-09-30

    approximation in many practical situations. The equation for the average acoustic field in the statistically homogeneous in horizontal plane stratified...using diagrammatic technique similar to the one used in the theory of wave propagation in the homogeneous medium. The mass operator was calculated...perturbations on various eigenrays due to the horizontal refraction induced by internal waves with the Garrett-Munk spectrum: rigorous internal wave model

  15. In vitro ultrasound experiments: Standing wave and multiple reflections influence on the outcome.

    PubMed

    Secomski, Wojciech; Bilmin, Krzysztof; Kujawska, Tamara; Nowicki, Andrzej; Grieb, Paweł; Lewin, Peter A

    2017-05-01

    The purpose of this work was to determine the influence of standing waves and possible multiple reflections under the conditions often encountered in examining the effects of ultrasound exposure on the cell cultures in vitro. More specifically, the goal was to quantitatively ascertain the influence of ultrasound exposure under free field (FF) and standing waves (SW) and multiple reflections (MR) conditions (SWMR) on the biological endpoint (50% cell necrosis). Such information would help in designing the experiments, in which the geometry of the container with biological tissue may prevent FF conditions to be established and in which the ultrasound generated temperature elevation is undesirable. This goal was accomplished by performing systematic, side-by-side experiments in vitro with C6 rat glioma cancer cells using 12 well and 96 well plates. It was determined that to obtain 50% of cell viability using the 12 well plates, the spatial average, temporal average (ISATA) intensities of 0.32W/cm(2) and 5.89W/cm(2) were needed under SWMR and FF conditions, respectively. For 96 well plates the results were 0.80W/cm(2) and 2.86W/cm(2) respectively. The corresponding, hydrophone measured pRMS maximum pressure amplitude values, were 0.71MPa, 0.75MPa, 0.75MPa and 0.73MPa, respectively. These results suggest that pRMS pressure amplitude was independent of the measurement set-up geometry and hence could be used to predict the cells' mortality threshold under any in vitro experimental conditions or even as a starting point for (pre-clinical) in vivo tests. The described procedure of the hydrophone measurements of the pRMS maximum pressure amplitude at the λ/2 distance (here 0.75mm) from the cell's level at the bottom of the dish or plate provides the guideline allowing the difference between the FF and SWMR conditions to be determined in any experimental setup. The outcome of the measurements also indicates that SWMR exposure might be useful at any ultrasound assisted

  16. Comparison of the efficacy of defibrillation with the damped sine and constant-tilt current waveforms in the intact animal.

    PubMed

    Hinds, M; Ayers, G M; Bourland, J D; Geddes, L A; Tacker, W A; Fearnot, N

    1987-04-01

    The efficacy of defibrillation using the damped sine and constant-tile (60%) truncated exponential waveforms was determined in each of nine dogs. Two measures of efficacy were used to compare the two waveforms: 1) threshold defibrillation current and 2) percent successful defibrillation. For both measures of efficacy, shock strength was expressed in terms of delivered energy. Mean threshold energy was 0.98 J/kg for the damped sine wave and it was 1.24 J/kg for the truncated exponential waveform. Percent successful defibrillation versus energy/kg curves were constructed for each of the waveforms and were found to be essentially the same. Percent successful defibrillation increased with increasing shock intensity. For 50% success, the energy for the damped sine wave was 1.16 J/kg; for the truncated exponential wave, the corresponding value was 1.15 J/kg. A shock of threshold intensity successfully defibrillated in approximately 50% of the defibrillation attempts, i.e., defibrillation threshold corresponds to about 50% successful defibrillation.

  17. Short interspersed elements (SINEs) from insectivores. Two classes of mammalian SINEs distinguished by A-rich tail structure.

    PubMed

    Borodulina, O R; Kramerov, D A

    2001-10-01

    Four tRNA-related SINE families were isolated from the genome of the shrew Sorex araneus (SOR element), mole Mogera robusta (TAL element), and hedgehog Mesechinus dauuricus (ERI-1 and ERI-2 elements). Each of these SINEs families is specific for a single Insectivora family: SOR, for Soricidae (shrews); TAL, for Talpidae (moles and desmans); ERI-1 and ERI-2, for Erinaceidae (hedgehogs). There is a long polypyrimidine region (TC-motif) in TAL, ERI-1, and ERI-2 elements located immediately upstream of an A-rich tail with polyadenylation signals (AATAAA) and an RNA polymerase III terminator (T(4-6)) or TCT(3-4)). Ten out of 14 analyzed mammalian tRNA-related SINE families have an A-rich tail similar to that of TAL, ERI-1, and ERI-2 elements. These elements were assigned to class T+. The other four SINEs including SOR element have no polyadenylation signal and transcription terminator in their A-rich tail and were assigned to class T-. Class T+ SINEs occur only in mammals, and most of them have a long polypyrimidine region. Possible models of retroposition of class T+ and T- SINEs are discussed.

  18. On the multiple scattering of VHF/UHF waves in the equatorial ionosphere

    NASA Technical Reports Server (NTRS)

    Vats, H. O.

    1981-01-01

    Using amplitude data of radio beacons at 40, 140, and 360 MHz from ATS 6 (phase II), an attempt has been made to study scattering of these waves in the equatorial ionosphere. A comparison of observed scintillation index S sub 4 with the theoretical results of the multiple scattering approach and variation of autocorrelation time with frequency indicates that this theory explains the results to a large extent. A comparison of power spectra of amplitude records with the ionograms of a nearby equatorial station has led to the following conclusions: the change from a weak scattering regime to a strong scattering regime is gradual and occurs because of the gradual decrease in the scale size of the irregularities (i.e., broadening of the spectra) and the gradual increase in the thickness of the irregular region.

  19. Acoustically mediated long-range interaction among multiple spherical particles exposed to a plane standing wave

    NASA Astrophysics Data System (ADS)

    Zhang, Shenwei; Qiu, Chunyin; Wang, Mudi; Ke, Manzhu; Liu, Zhengyou

    2016-11-01

    In this work, we study the acoustically mediated interaction forces among multiple well-separated spherical particles trapped in the same node or antinode plane of a standing wave. An analytical expression of the acoustic interaction force is derived, which is accurate even for the particles beyond the Rayleigh limit. Interestingly, the multi-particle system can be decomposed into a series of independent two-particle systems described by pairwise interactions. Each pairwise interaction is a long-range interaction, as characterized by a soft oscillatory attenuation (at the power exponent of n = -1 or -2). The vector additivity of the acoustic interaction force, which is not well expected considering the nonlinear nature of the acoustic radiation force, is greatly useful for exploring a system consisting of a large number of particles. The capability of self-organizing a big particle cluster can be anticipated through such acoustically controllable long-range interaction.

  20. Measurement of the Viscosity-Density Product Using Multiple Reflections of Ultrasonic Shear Horizontal Waves

    SciTech Connect

    Greenwood, Margaret S.; Adamson, Justus D.; Bond, Leonard J.

    2006-12-22

    We have developed an on-line computer-controlled sensor, based on ultrasound reflection measurements, to determine the product of the viscosity and density of a liquid or slurry for Newtonian fluids and the shear impedance of the liquid for non-Newtonian fluids. A 14-MHz shear wave transducer is bonded to one side of a 45°-90° fused silica wedge and the base is in contract with the liquid. Twenty-eight echoes were observed due to the multiple reflections of an ultrasonic shear horizontal (SH) wave within the wedge. The fast Fourier transform of each echo is obtained for a liquid and for water, which serves as the calibration fluid. The reflection coefficient at the solid-liquid interface is obtained by plotting the natural logarithm of the ratio (amplitude for liquid/amplitude for water) versus the echo number and determining the slope. Because the slope of this line is not affected by changes in the pulser voltage and/or system electronics, the sensor is self-calibrating and a very accurate measurement of the reflection coefficient results. Data were obtained for 11 sugar water solutions ranging in concentration from 10% to 66% by weight. Since these solutions are Newtonian fluids, the data obtained from reflection coefficient measurements yield a value of the viscosity-density product. In tests, the viscosity values are shown to be in good agreement with those obtained independently using a laboratory viscometer. The data acquisition time is 14 seconds and this can be reduced by judicious selection of the echoes for determining the reflection coefficient. The measurement of the density results in a determination of the viscosity for Newtonian fluids or the shear wave velocity for non-Newtonian fluids. The sensor can be deployed for process control in a pipeline, with the base of the wedge as part of the pipeline wall, or immersed in a tank.

  1. Concentration gradient limiter designs for incident plane waves and multiple chromophores

    NASA Astrophysics Data System (ADS)

    McLean, Daniel G.

    1998-10-01

    A design method for reverse saturable absorbing (RSA) dye concentration gradient limiters, termed here the Absorption Diffraction Balance (ADB) design method, is used to produce designs for multiple chromophores and is extended to allow incident plane waves. The ADB design method is reviewed for Gaussian beams applied to a constant fluence design and a linear fluence design. These two designs are combined to allow different dyes to be used in different portions of the limiter. It is found that this hybrid design significantly enhances performance under some circumstances. It is also shown to reduce the probability of dye photodegradation. The ADB design method is extended to allow for incident plane waves or a top-hat beam profile. The field at the geometric shadow edge, expressed in terms of Lommel functions, is shown to closely match the Gaussian field when the incident irradiance, power, and second moments are the same. Since the irradiance distribution is not monotonically increasing in the focal region, the required concentration distribution has regions of negative concentration, i.e. gain regions. These designs are useful for initiating numerical nonlinear beam propagation studies.

  2. Monte Carlo wave packet approach to dissociative multiple ionization in diatomic molecules

    NASA Astrophysics Data System (ADS)

    Leth, Henriette Astrup; Madsen, Lars Bojer; Mølmer, Klaus

    2010-05-01

    A detailed description of the Monte Carlo wave packet technique applied to dissociative multiple ionization of diatomic molecules in short intense laser pulses is presented. The Monte Carlo wave packet technique relies on the Born-Oppenheimer separation of electronic and nuclear dynamics and provides a consistent theoretical framework for treating simultaneously both ionization and dissociation. By simulating the detection of continuum electrons and collapsing the system onto either the neutral, singly ionized or doubly ionized states in every time step the nuclear dynamics can be solved separately for each molecular charge state. Our model circumvents the solution of a multiparticle Schrödinger equation and makes it possible to extract the kinetic energy release spectrum via the Coulomb explosion channel as well as the physical origin of the different structures in the spectrum. The computational effort is restricted and the model is applicable to any molecular system where electronic Born-Oppenheimer curves, dipole moment functions, and ionization rates as a function of nuclear coordinates can be determined.

  3. Continuous and multiple waves of emotional responses: Mother's experience with a premature infant

    PubMed Central

    Valizadeh, Laila; Zamanzadeh, Vahid; Mohammadi, Easa; Arzani, Afsaneh

    2014-01-01

    Background: In recent years, there has been a rise in the number of premature births. Mothers of these newborns experience a high degree of stress over time. Since a more comprehensive understanding of this phenomenon can help the healthcare teams in detecting the deficiencies and needs of such newborns’ mothers for a better and more effective intervention, the present study was carried out to describe the mothers’ experiences in the area of premature birth. Materials and Methods: The present study is a qualitative study with a content analysis approach. The data collection process included 15 semi-structured and in-depth interviews with the mothers delivering premature babies during 2012-2013 in the medical educational centers of north and northwest of Iran. A purposive sampling method was used. All the interviews were recorded, typed, and finally analyzed using a qualitative content analysis with a conventional method. Results: Data analysis led to the extraction of continuous and multiple waves of emotional responses in mothers with premature birth. This has been revealed in mothers by the different categories of affective reactions, symptoms of anxiety, and mood disturbances including decline in performance, individual shortcomings, and mental irritation. Conclusions: Mothers’ unpreparedness and unexpected childbirth make them encounter the multiple and continuous waves of emotional responses, which will consequently lead to decline in performance, individual shortcomings, and mental irritation among them. Therefore, in order to prevent the negative and long-term consequences of such reactions, it is recommended that more attention should be given to support these mothers as the main caregivers of such infants. PMID:25183972

  4. Multiple channels for horizontal, but only one for vertical corrugations? A new look at the stereo anisotropy.

    PubMed

    Serrano-Pedraza, Ignacio; Read, Jenny C A

    2010-10-01

    Stereo vision displays a well-known anisotropy: disparity-defined slant is easier to detect for rotations about a horizontal axis than about a vertical axis, and low-frequency sinusoidal depth corrugations are easier to detect when the corrugations are horizontal than when they are vertical. Here, we determined disparity thresholds for vertically and horizontally oriented depth corrugations with both sinusoidal and square-wave profiles. We found that the orientation anisotropy for square waves is much weaker than for sine waves and is almost independent of frequency. This weaker anisotropy for square waves can be explained by considering the Fourier harmonics present in the stimulus. Using linear models imported from the luminance and texture perception domain, the disparity thresholds for square waves can be very well predicted from those for sine waves, for both horizontally and vertically oriented corrugations. For horizontally oriented corrugations, models based on the root mean square of the output of a single linear channel or the output of multiple linear channels worked equally well. This is consistent with previous evidence suggesting that stereo vision has multiple channels tuned to different spatial frequencies of horizontally oriented disparity modulations. However, for vertically oriented corrugations, only the root mean squared output of a single linear channel explained the data. We suggest that the stereo anisotropy may arise because the stereo system possesses multiple spatial frequency channels for detecting horizontally oriented modulations in horizontal disparity, but only one for vertically oriented modulations.

  5. Suppression of stimulated Brillouin instability of a beat-wave of two lasers in multiple-ion-species plasmas

    SciTech Connect

    Yadav, Pinki; Gupta, D. N. Avinash, K.

    2016-01-15

    Stimulated Brillouin instability of a beat-wave of two lasers in plasmas with multiple-ion-species (negative-ions) was studied. The inclusion of negative-ions affects the growth of ion-acoustic wave in Brillouin scattering. Thus, the growth rate of instability is suppressed significantly by the density of negative-ions. To obey the phase-matching condition, the growth rate of the instability attains a maxima for an appropriate scattering angle (angle between the pump and scattered sideband waves). This study would be technologically important to have diagnostics in low-temperature plasmas.

  6. Possible involvement of SINEs in mammalian-specific brain formation

    PubMed Central

    Sasaki, Takeshi; Nishihara, Hidenori; Hirakawa, Mika; Fujimura, Koji; Tanaka, Mikiko; Kokubo, Nobuhiro; Kimura-Yoshida, Chiharu; Matsuo, Isao; Sumiyama, Kenta; Saitou, Naruya; Shimogori, Tomomi; Okada, Norihiro

    2008-01-01

    Retroposons, such as short interspersed elements (SINEs) and long interspersed elements (LINEs), are the major constituents of higher vertebrate genomes. Although there are many examples of retroposons' acquiring function, none has been implicated in the morphological innovations specific to a certain taxonomic group. We previously characterized a SINE family, AmnSINE1, members of which constitute a part of conserved noncoding elements (CNEs) in mammalian genomes. We proposed that this family acquired genomic functionality or was exapted after retropositioning in a mammalian ancestor. Here we identified 53 new AmnSINE1 loci and refined 124 total loci, two of which were further analyzed. Using a mouse enhancer assay, we demonstrate that one SINE locus, AS071, 178 kbp from the gene FGF8 (fibroblast growth factor 8), is an enhancer that recapitulates FGF8 expression in two regions of the developing forebrain, namely the diencephalon and the hypothalamus. Our gain-of-function analysis revealed that FGF8 expression in the diencephalon controls patterning of thalamic nuclei, which act as a relay center of the neocortex, suggesting a role for FGF8 in mammalian-specific forebrain patterning. Furthermore, we demonstrated that the locus, AS021, 392 kbp from the gene SATB2, controls gene expression in the lateral telencephalon, which is thought to be a signaling center during development. These results suggest important roles for SINEs in the development of the mammalian neuronal network, a part of which was initiated with the exaptation of AmnSINE1 in a common mammalian ancestor. PMID:18334644

  7. Guinea Pig ID-Like Families of SINEs

    PubMed Central

    Kass, David H.; Schaetz, Brian A.; Beitler, Lindsey; Bonney, Kevin M.; Jamison, Nicole; Wiesner, Cathy

    2009-01-01

    Previous studies have indicated a paucity of SINEs within the genomes of the guinea pig and nutria, representatives of the Hystricognathi suborder of rodents. More recent work has shown that the guinea pig genome contains a large number of B1 elements, expanding to various levels among different rodents. In this work we utilized A–B PCR and screened GenBank with sequences from isolated clones to identify potentially uncharacterized SINEs within the guinea pig genome, and identified numerous sequences with a high degree of similarity (>92%) specific to the guinea pig. The presence of A-tails and flanking direct repeats associated with these sequences supported the identification of a full-length SINE, with a consensus sequence notably distinct from other rodent SINEs. Although most similar to the ID SINE, it clearly was not derived from the known ID master gene (BC1), hence we refer to this element as guinea pig ID-like (GPIDL). Using the consensus to screen the guinea pig genomic database (Assembly CavPor2) with Ensembl BlastView, we estimated at least 100,000 copies, which contrasts markedly to just over 100 copies of ID elements. Additionally we provided evidence of recent integrations of GPIDL as two of seven analyzed conserved GPIDL-containing loci demonstrated presence/absence variants in Cavia porcellus and C. aperea. Using intra-IDL PCR and sequence analyses we also provide evidence that GPIDL is derived from a hystricognath-specific SINE family. These results demonstrate that this SINE family continues to contribute to the dynamics of genomes of hystricognath rodents. PMID:19232383

  8. Guinea pig ID-like families of SINEs.

    PubMed

    Kass, David H; Schaetz, Brian A; Beitler, Lindsey; Bonney, Kevin M; Jamison, Nicole; Wiesner, Cathy

    2009-05-01

    Previous studies have indicated a paucity of SINEs within the genomes of the guinea pig and nutria, representatives of the Hystricognathi suborder of rodents. More recent work has shown that the guinea pig genome contains a large number of B1 elements, expanding to various levels among different rodents. In this work we utilized A-B PCR and screened GenBank with sequences from isolated clones to identify potentially uncharacterized SINEs within the guinea pig genome, and identified numerous sequences with a high degree of similarity (>92%) specific to the guinea pig. The presence of A-tails and flanking direct repeats associated with these sequences supported the identification of a full-length SINE, with a consensus sequence notably distinct from other rodent SINEs. Although most similar to the ID SINE, it clearly was not derived from the known ID master gene (BC1), hence we refer to this element as guinea pig ID-like (GPIDL). Using the consensus to screen the guinea pig genomic database (Assembly CavPor2) with Ensembl BlastView, we estimated at least 100,000 copies, which contrasts markedly to just over 100 copies of ID elements. Additionally we provided evidence of recent integrations of GPIDL as two of seven analyzed conserved GPIDL-containing loci demonstrated presence/absence variants in Cavia porcellus and C. aperea. Using intra-IDL PCR and sequence analyses we also provide evidence that GPIDL is derived from a hystricognath-specific SINE family. These results demonstrate that this SINE family continues to contribute to the dynamics of genomes of hystricognath rodents.

  9. Recombinant SINEs are formed at high frequency during induced retrotransposition in vivo.

    PubMed

    Yadav, Vijay Pal; Mandal, Prabhat Kumar; Bhattacharya, Alok; Bhattacharya, Sudha

    2012-05-22

    Non-long terminal repeat Retrotransposons are referred to as long interspersed nuclear elements (LINEs) and their non-autonomous partners are short interspersed nuclear elements (SINEs). It is believed that an active SINE copy, upon retrotransposition, generates near identical copies of itself, which subsequently accumulate mutations resulting in sequence polymorphism. Here we show that when a retrotransposition-competent cell line of the parasitic protist Entamoeba histolytica, transfected with a marked SINE copy, is induced to retrotranspose, >20% of the newly retrotransposed copies are neither identical to the marked SINE nor to the mobilized resident SINEs. Rather they are recombinants of resident SINEs and the marked SINE. They are a consequence of retrotransposition and not DNA recombination, as they are absent in cells not expressing the retrotransposition functions. This high-frequency recombination provides a new explanation for the existence of mosaic SINEs, which may impact on genetic analysis of SINE lineages, and measurement of phylogenetic distances.

  10. Ground-based low-frequency gravitational-wave detector with multiple outputs

    NASA Astrophysics Data System (ADS)

    Shoda, Ayaka; Kuwahara, Yuya; Ando, Masaki; Eda, Kazunari; Tejima, Kodai; Aso, Yoichi; Itoh, Yousuke

    2017-04-01

    We have developed a new gravitational-wave (GW) detector, TOrsion-Bar Antenna (TOBA), which has a multiple-output configuration. TOBA is a detector with bar-shaped test masses that are rotated by the tidal force of the GWs. In our detector, three independent signals can be derived from the GW by monitoring multiple rotational degrees of freedom, i.e., the horizontal rotations and vertical rotations of the bars. Since the three outputs have different antenna pattern functions, the multioutput system improves the detection rate and the parameter estimation accuracy. This is useful for obtaining further details about the GW sources, such as population and directions. We successfully operated the multioutput detector continuously for more than 24 hours with stable data quality. The GW equivalent strain noise in one of the signals has been reduced to 1 ×10-10 Hz-1 /2 at 3 Hz by a combination of passive and active vibration isolation systems, while the sensitivities to possible GW signals derived from the vertical rotations are worse than that from the horizontal rotation.

  11. The Construction of a 'Relativistic' Wave-Particle: The Soliton.

    ERIC Educational Resources Information Center

    Isenberg, Cyril

    1982-01-01

    Although most waves studied by students satisfy the linear equation, particle physicists have become interested in nonlinear waves--those not satisfying the superposition principle. A mechanical wave system, satisfying the sine-Gordon equation, can be constructed using a modified transverse wave system to demonstrate nonlinear wave-particle…

  12. 2D numerical modeling of ultrasonic wave propagation in concrete: A parameterization study in a multiple-scattering medium

    NASA Astrophysics Data System (ADS)

    Yu, Ting; Chaix, Jean-François; Komatitsch, Dimitri; Garnier, Vincent; Audibert, Lorenzo; Henault, Jean-Marie

    2017-02-01

    Multiple scattering is important when ultrasounds propagate in a heterogeneous medium such as concrete, the scatterer size of which is in the order of the wavelength. The aim of this work is to build a 2D numerical model of ultrasonic wave propagation integrating the multiple scattering phenomena in SPECFEM software. The coherent field of multiple scattering could be obtained by averaging numerical wave fields, and it is used to determine the effective phase velocity and attenuation corresponding to an equivalent homogeneous medium. After the creation of numerical model under several assumptions, its validation is completed in a case of scattering by one cylinder through the comparison with analytical solution. Two cases of multiple scattering by a set of cylinders at different concentrations are simulated to perform a parametric study (of frequency, scatterer concentration, scatterer size). The effective properties are compared with the predictions of Waterman-Truell model as well, to verify its validity.

  13. Role of Multiple Soliton Interactions in the Generation of Rogue Waves: The Modified Korteweg-de Vries Framework.

    PubMed

    Slunyaev, A V; Pelinovsky, E N

    2016-11-18

    The role of multiple soliton and breather interactions in the formation of very high waves is disclosed within the framework of the integrable modified Korteweg-de Vries (MKdV) equation. Optimal conditions for the focusing of many solitons are formulated explicitly. Namely, trains of ordered solitons with alternate polarities evolve to huge strongly localized transient waves. The focused wave amplitude is exactly the sum of the focusing soliton heights; the maximum wave inherits the polarity of the fastest soliton in the train. The focusing of several solitary waves or/and breathers may naturally occur in a soliton gas and will lead to rogue-wave-type dynamics; hence, it represents a new nonlinear mechanism of rogue wave generation. The discovered scenario depends crucially on the soliton polarities (phases), and is not taken into account by existing kinetic theories. The performance of the soliton mechanism of rogue wave generation is shown for the example of the focusing MKdV equation, when solitons possess "frozen" phases (certain polarities), though the approach is efficient in some other integrable systems which admit soliton and breather solutions.

  14. Role of Multiple Soliton Interactions in the Generation of Rogue Waves: The Modified Korteweg-de Vries Framework

    NASA Astrophysics Data System (ADS)

    Slunyaev, A. V.; Pelinovsky, E. N.

    2016-11-01

    The role of multiple soliton and breather interactions in the formation of very high waves is disclosed within the framework of the integrable modified Korteweg-de Vries (MKdV) equation. Optimal conditions for the focusing of many solitons are formulated explicitly. Namely, trains of ordered solitons with alternate polarities evolve to huge strongly localized transient waves. The focused wave amplitude is exactly the sum of the focusing soliton heights; the maximum wave inherits the polarity of the fastest soliton in the train. The focusing of several solitary waves or/and breathers may naturally occur in a soliton gas and will lead to rogue-wave-type dynamics; hence, it represents a new nonlinear mechanism of rogue wave generation. The discovered scenario depends crucially on the soliton polarities (phases), and is not taken into account by existing kinetic theories. The performance of the soliton mechanism of rogue wave generation is shown for the example of the focusing MKdV equation, when solitons possess "frozen" phases (certain polarities), though the approach is efficient in some other integrable systems which admit soliton and breather solutions.

  15. Stochastic D-bifurcation for a damped sine-Gordon equation with noise

    SciTech Connect

    Huang, Qiongwei; Xue, Changfeng; Tang, Jiashi

    2015-04-15

    We investigate the stochastic bifurcation of a damped sine-Gordon equation with Dirichlet boundary conditions under the influence of multiplicative Gaussian white noise. Introducing a slow time scale, we derive the amplitude equations near the trivial solution by multiscale analysis. And the stationary probability density functions are formulated analytically using the stochastic averaging of energy envelope. The numerical calculations show that the system undergoes a stochastic D-bifurcation of energy envelope from a delta measure to new stationary measures when the control parameter crosses a critical point.

  16. Maternal caffeine consumption and sine causa recurrent miscarriage.

    PubMed

    Stefanidou, Erato M; Caramellino, Laura; Patriarca, Ambra; Menato, Guido

    2011-10-01

    The objective of this study was to examine whether the risk of sine causa recurrent miscarriage is associated with caffeine consumption during the periconceptional period and early gestation after controlling for pregnancy-related symptoms. A retrospective case-control study was conducted in the Department of Obstetrics and Gynecology, University of Turin between 2008 and 2009. Fifty-two sine causa recurrent miscarriers and 260 healthy pregnant women were assessed. Data were analyzed using SPSS 17 for Windows. Caffeine consumption during the periconceptional period and early gestation was higher in sine causa recurrent miscarriers compared to healthy pregnant women. Moreover, each caffeine intake of 100mg/day was associated with an increased odds ratio for sine causa recurrent miscarriage of 2724 (p for trend 0.001; 95% confidence interval [CI], 2.715-2.733), after adjusting for relevant confounding covariates. Caffeine intake may increase the risk of sine causa recurrent miscarriage regardless of pregnancy-related symptoms and relevant covariates (such as age and tobacco use). Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. Nonlinear Fourier analysis with cnoidal waves

    SciTech Connect

    Osborne, A.R.

    1996-12-31

    Fourier analysis is one of the most useful tools to the ocean engineer. The approach allows one to analyze wave data and thereby to describe a dynamical motion in terms of a linear superposition of ordinary sine waves. Furthermore, the Fourier technique allows one to compute the response function of a fixed or floating structure: each sine wave in the wave or force spectrum yields a sine wave in the response spectrum. The counting of fatigue cycles is another area where the predictable oscillations of sine waves yield procedures for the estimation of the fatigue life of structures. The ocean environment, however, is a source of a number of nonlinear effects which must also be included in structure design. Nonlinearities in ocean waves deform the sinusoidal shapes into other kinds of waves such as the Stokes wave, cnoidal wave or solitary wave. A key question is: Does there exist a generalization of linear Fourier analysis which uses nonlinear basis functions rather than the familiar sine waves? Herein addresses the dynamics of nonlinear wave motion in shallow water where the basis functions are cnoidal waves and discuss nonlinear Fourier analysis in terms of a linear superposition of cnoidal waves plus their mutual nonlinear interactions. He gives a number of simple examples of nonlinear Fourier wave motion and then analyzes an actual surface-wave time series obtained on an offshore platform in the Adriatic Sea. Finally, he briefly discusses application of the cnoidal wave spectral approach to the computation of the frequency response function of a floating vessel. The results given herein will prove useful in future engineering studies for the design of fixed, floating and complaint offshore structures.

  18. Experimental measurements of the coherent field resulting from the interaction of an ultrasonic shock wave with a multiple scattering medium

    NASA Astrophysics Data System (ADS)

    Viard, Nicolas; Gianmarinaro, Bruno; Derode, Arnaud; Barrière, Christophe

    2014-04-01

    Whereas multiple scattering and shock wave formation are known to be antagonistic phenomena, this work concentrates on the interaction of an ultrasonic shock wave with a random multiple scattering medium. The shock wave is generated by long distance propagation of a short pulse (4 periods at a 3.5 MHz central frequency) in water before it encounters the scattering medium (a slab-shaped random set of parallel metallic rods). Transmitted waves are recorded over hundreds of positions along the lateral dimension of the slab to estimate the ensemble-averaged transmitted field langlephi(t)rangle, also known as the coherent wave. Experiments are repeated for different thicknesses L of the slab and different emission amplitudes. The elastic mean free path le (i.e the typical distance for the decreasing of the coherent intensity |langlephi(t)rangle|2 due to scattering) is determined as well as the harmonic rate of the averaged transmitted wave. Experimental results are discussed and compared to the linear case.

  19. A Journey Through the Mantle Transition Zone Under Western US From Single and Multiple Scattered Waves

    NASA Astrophysics Data System (ADS)

    Tauzin, B.; Trampert, J.; van der Hilst, R.; Wittlinger, G.; Vergne, J.

    2011-12-01

    Using data from the US Transportable Array, we combine observations of P-to-S single and multiple scattered waves to constrain the transition zone (TZ) structure beneath the Western US. From stacking the data by common conversion points along profiles, we produce depth images of seismic discontinuities. Systematic depth and amplitude measurements are performed for the '410', the '660', and some other minor seismic discontinuities identified as sharp reductions of wave velocities at ˜350 km depth (the '350') and ˜590 km depth (the '590'). The Gorda plate, subducted under Northern California, is traced back to the TZ where it seems to flatten and induces, due to cold temperatures or a high water content, a significant uplift of the '410' under Northern Nevada. The geographical maps of the '410'/'660' amplitude/topography reveal an anomalous TZ at the borders between Washington, Oregon and Idaho with: (i) a thickened TZ, (ii) a sharp jump in the topography of the '660' both in a South-North and West-East direction, and (iii) reduced '410' amplitudes at the North. Such anomalous structure might be inherited from the past history of plate subduction/accretion. A thinned TZ under the Yellowstone is likely the result of a deep hot thermal plume. Both the '350' and the '590' negative discontinuities extend over very large areas. They might be related either to an increased water content in the TZ and/or significant amount of oceanic material accumulated through the past 100 My. An estimation of the TZ water content is now possible based on observation of PPS reverberated phases on the '410' and '660' interfaces.

  20. Genealogy of families of SINEs in cetaceans and artiodactyls: the presence of a huge superfamily of tRNA(Glu)-derived families of SINEs.

    PubMed

    Shimamura, M; Abe, H; Nikaido, M; Ohshima, K; Okada, N

    1999-08-01

    Several novel (sub)families of SINEs were isolated from the genomes of cetaceans and artiodactyls, and their sequences were determined. From comparisons of diagnostic nucleotides among the short interspersed repetitive elements (SINEs) in these (sub)families, we were able to draw the following conclusions. (1) After the divergence of the suborder Tylopoda (camels), the CHRS family of SINEs was newly created from tRNA(Glu) in a common ancestor of the lineages of the Suina (pigs and peccaries), Ruminantia (cows and deer), and Cetacea (whales and dolphins). (2) After divergence of the Suina lineage, the CHR-1 SINE and the CHR-2 SINE were generated successively in a common ancestor of ruminants, hippopotamuses, and cetaceans. (3) In the Ruminantia lineage, the Bov-tA SINE was generated by recombination between the CHR-2 SINE and Bov-A. (4) In the Suina lineage, the CHRS-S SINE was generated from the CHRS SINE. (5) In this latter lineage, the PRE-1 family of SINEs was created by insertion of part of the gene for tRNA(Arg) into the 5' region of the CHRS-S family. The distribution of a particular family of SINEs among species of artiodactyls and cetaceans confirmed the most recent conclusion for paraphyly of the order Artiodactyla. The present study also revealed that a newly created tRNA(Glu)-derived family of SINEs was subjected both to recombination with different units and to duplication of an internal sequence within a SINE unit to generate, during evolution, a huge superfamily of tRNA(Glu)-related families of SINEs that are now found in the genomes of artiodactyls and cetaceans.

  1. A real case comparison between surface-related multiple elimination and other wave equation-based techniques

    SciTech Connect

    Jugla, F.; Julien, P.; Groot, P.F. de; Verschuur, E.

    1994-12-31

    A new antimultiple software has been developed by E. Verschuur (1991) and industrialized by TNO and TOTAL. This is a surface related multiple elimination technique which uses the seismic data itself to predict and subtract all the multiples related to the free reflecting surface. A benchmark test was performed to compare five contractors wave equation based antimultiples with the new technique. The benchmark has shown that this new technique has effectively attenuated numerous strong peg-leg multiples in the interval of interest (2.0--3.5 sec) where it compares favorably with the other methods results. The water bottom multiples and the deep multiples (below 3.5 sec) have only been slightly attacked. Some tests have shown that the present results can be improved by applying a refined near offsets data interpolation and an XT least squares filtering that ameliorates the adaptative multiple subtraction.

  2. Selective inhibitors of nuclear export (SINE) in hematological malignancies.

    PubMed

    Das, Arundhati; Wei, Guoqing; Parikh, Kaushal; Liu, Delong

    2015-01-01

    Regulated nucleo-cytoplasmic transport plays a major role in maintaining cellular homeostasis. CRM1 (chromosome region maintenance 1 or exportin 1 or XPO 1) is responsible for the nucleo-cytoplasmic transport of more than 200 proteins, including most of the tumor suppressor proteins (TSP). CRM1 is overexpressed in pancreatic cancer, osteosarcoma, glioma, cervical and hematological malignancies. This inspired the development of novel agents that selectively inhibit nuclear exportins (SINEs). In this review we focus on the significance of CRM1 in carcinogenesis and review the new development of SINE inhibitiors in hematological malignancies. Selinexor (KPT-330) as the first-in-human SINE agent represents this novel class of anti-cancer agents.

  3. On integrability aspects of the supersymmetric sine-Gordon equation

    NASA Astrophysics Data System (ADS)

    Bertrand, S.

    2017-04-01

    In this paper we study certain integrability properties of the supersymmetric sine-Gordon equation. We construct Lax pairs with their zero-curvature representations which are equivalent to the supersymmetric sine-Gordon equation. From the fermionic linear spectral problem, we derive coupled sets of super Riccati equations and the auto-Bäcklund transformation of the supersymmetric sine-Gordon equation. In addition, a detailed description of the associated Darboux transformation is presented and non-trivial super multisoliton solutions are constructed. These integrability properties allow us to provide new explicit geometric characterizations of the bosonic supersymmetric version of the Sym–Tafel formula for the immersion of surfaces in a Lie superalgebra. These characterizations are expressed only in terms of the independent bosonic and fermionic variables.

  4. A case of sine scleroderma with parenchymal lung disease.

    PubMed

    Karimifar, Mansoor; Hashemi, Hourosadat; Karimifar, Mozhgan; Kazizadeh, Amir

    2014-01-01

    Systemic sclerosis sine scleroderma is a subtype of scleroderma, which is characterized by involvement of visceral organs, but no characteristic skin alteration. The involved organs could be kidneys, heart, gastrointestinal system, and lungs. Interstitial lung disease (ILD) is one of the pulmonary manifestations of sine scleroderma. We report a 38-year-old woman presenting with chill, fever, generalized malaise, dyspnea on exertion, and dry cough with a history of Raynaud's phenomenon, who was evaluated by physical examination, spirometry, and computed tomography scan, that all lead to the diagnosis of ILD. Combination of high-titer positive anti-nuclear antibody, high erythrocyte sedimentation rate, positive C-reactive protein, and ILD could be explained by sine scleroderma.

  5. Short interspersed elements (SINEs) in plants: origin, classification, and use as phylogenetic markers.

    PubMed

    Deragon, Jean-Marc; Zhang, Xiaoyu

    2006-12-01

    Short interspersed elements (SINEs) are a class of dispersed mobile sequences that use RNA as an intermediate in an amplification process called retroposition. The presence-absence of a SINE at a given locus has been used as a meaningful classification criterion to evaluate phylogenetic relations among species. We review here recent developments in the characterisation of plant SINEs and their use as molecular makers to retrace phylogenetic relations among wild and cultivated Oryza and Brassica species. In Brassicaceae, further use of SINE markers is limited by our partial knowledge of endogenous SINE families (their origin and evolution histories) and by the absence of a clear classification. To solve this problem, phylogenetic relations among all known Brassicaceae SINEs were analyzed and a new classification, grouping SINEs in 15 different families, is proposed. The relative age and size of each Brassicaceae SINE family was evaluated and new phylogenetically supported subfamilies were described. We also present evidence suggesting that new potentially active SINEs recently emerged in Brassica oleracea from the shuffling of preexisting SINE portions. Finally, the comparative evolution history of SINE families present in Arabidopsis thaliana and Brassica oleracea revealed that SINEs were in general more active in the Brassica lineage. The importance of these new data for the use of Brassicaceae SINEs as molecular markers in future applications is discussed.

  6. SINE retrotransposons cause epigenetic reprogramming of adjacent gene promoters.

    PubMed

    Estécio, Marcos R H; Gallegos, Juan; Dekmezian, Mhair; Lu, Yue; Liang, Shoudan; Issa, Jean-Pierre J

    2012-10-01

    Almost half of the human genome and as much as 40% of the mouse genome is composed of repetitive DNA sequences. The majority of these repeats are retrotransposons of the SINE and LINE families, and such repeats are generally repressed by epigenetic mechanisms. It has been proposed that these elements can act as methylation centers from which DNA methylation spreads into gene promoters in cancer. Contradictory to a methylation center function, we have found that retrotransposons are enriched near promoter CpG islands that stay methylation-free in cancer. Clearly, it is important to determine which influence, if any, these repetitive elements have on nearby gene promoters. Using an in vitro system, we confirm here that SINE B1 elements can influence the activity of downstream gene promoters, with acquisition of DNA methylation and loss of activating histone marks, thus resulting in a repressed state. SINE sequences themselves did not immediately acquire DNA methylation but were marked by H3K9me2 and H3K27me3. Moreover, our bisulfite sequencing data did not support that gain of DNA methylation in gene promoters occurred by methylation spreading from SINE B1 repeats. Genome-wide analysis of SINE repeats distribution showed that their enrichment is directly correlated with the presence of USF1, USF2, and CTCF binding, proteins with insulator function. In summary, our work supports the concept that SINE repeats interfere negatively with gene expression and that their presence near gene promoters is counter-selected, except when the promoter is protected by an insulator element.

  7. Inference of magnetic field in the coronal streamer invoking kink wave motions generated by multiple EUV waves

    NASA Astrophysics Data System (ADS)

    Srivastava, A. K.; Singh, Talwinder; Ofman, Leon; Dwivedi, Bhola N.

    2016-12-01

    We analyse the observations from Solar TErrestrial RElations Observatory (STEREO) of an oscillating coronal streamer. STEREO-B Extreme Ultraviolet Imaging (EUVI) temporal data on 2012 March 7 show an evolution of two consecutive EUV waves that interact with footpoint of a coronal streamer clearly evident in the co-spatial and co-temporal STEREO-B/COR-1 observations. The waves are observed in the STEREO-B/EUVI too, and its apparent energy exchange with coronal streamer generates kink oscillations. We apply the methodology of magnetohydrodynamic (MHD) seismology of the observed waves and determine the magnetic field profile of the coronal streamer. In particular, we estimate the phase velocities of the kink wave perturbations by tracking them at different heights. We also estimate electron densities inside and outside the streamer using spherically symmetric inversion of polarized brightness images in STEREO-B/COR-1. We detect two large-scale kink wave oscillations that diagnose exponentially decaying radial profiles of magnetic field in streamer up to 3 solar radii. Within the limit of observational and systematic uncertainties, we find that magnetic field of streamer varies slowly at various heights, although its nature always remains exponentially decaying with height. It is seen that during evolution of second kink motion in streamer, it increases in brightness (thus mass density), and also in areal extent slightly, which may be associated with decreased photospheric magnetic flux at footpoint of streamer. As a result, magnetic field profile produced by second kink wave is reduced within streamer compared to the one diagnosed by the first one.

  8. CAN--a pan-carnivore SINE family.

    PubMed

    Vassetzky, Nikita S; Kramerov, Dmitri A

    2002-01-01

    Short retroposons or short interspersed elements (SINEs) constituting 5-10% genome have been isolated from various organisms. CAN SINEs initially found in American mink were named after dogs (Canis), and the range of their distribution in the genomes of carnivores and mammals in general remained topical. Here we demonstrate CAN sequences in representatives of all carnivore families, but not beyond carnivores, on the basis of sequence bank search and genomic PCR. Analysis of their distribution supports division of carnivores into caniform (dogs, mustelids, raccoons, bears, and pinnipeds) and feliform (cats, civets, and hyenas) lineages. CAN structure is considered in the context of their function and evolution.

  9. Dispersion-Tolerant Multiple WDM Channel Millimeter-Wave Signal Generation Using a Single Monolithic Mode-Locked Semiconductor Laser

    NASA Astrophysics Data System (ADS)

    Attygalle, M.; Lim, C.; Nirmalathas, A.

    2005-01-01

    This paper presents a scheme by which multiple wavelength-division-multiplexed millimeter-wave (mm-wave) signals in the range of 30 GHz can be generated from a single monolithic semiconductor laser for applications in optically fed mm-wave networks or fiber radio networks. The mm-wave signals are generated using dual optical modes separated by a mm-wave frequency, obtained from spectrum slicing the output from a stable multimode hybrid mode-locked semiconductor laser. In this scheme, self-heterodyne detection at a high-speed photodetector achieves the photonic upconversion of low-data-rate signals to mm-wave frequencies without the need for electronic mixing. Experimental results show the generation of up to 14 WDM channels using a single laser. The phase noise of electrical signals generated by photonic upconversion of these signals is less than -94 dBc/Hz at 100-kHz offset frequency across the wavelengths. Also presented is the transmission of 155-Mb/s binary-phase-shift-keyed data signals at 30-GHz frequency over 10 km of single-mode fiber at different wavelengths using dual-mode signals. The results confirm that a bit-error rate of 10-^9 can be easily achieved. The dispersion tolerance of the dual-mode signals is evaluated using simulation and an analytical model and compared with other mm-wave signal generation techniques.

  10. Multiple damage identification and imaging in an aluminum plate using effective Lamb wave response automatic extraction technology

    NASA Astrophysics Data System (ADS)

    Ouyang, Qinghua; Zhou, Li; Liu, Xiaotong

    2016-04-01

    In order to identify multiple damage in the structure, a method of multiple damage identification and imaging based on the effective Lamb wave response automatic extraction algorithm is proposed. In this method, the detected key area in the structure is divided into a number of subregions, and then, the effective response signals including the structural damage information are automatically extracted from the entire Lamb wave responses which are received by the piezoelectric sensors. Further, the damage index values of every subregion based on the correlation coefficient are calculated using the effective response signals. Finally, the damage identification and imaging are performed using the reconstruction algorithm for probabilistic inspection of damage (RAPID) technique. The experimental research was conducted using an aluminum plate. The experimental results show that the method proposed in this research can quickly and effectively identify the single damage or multiple damage and image the damages clearly in detected area.

  11. Mechanical Waves Conceptual Survey: Its Modification and Conversion to a Standard Multiple-Choice Test

    ERIC Educational Resources Information Center

    Barniol, Pablo; Zavala, Genaro

    2016-01-01

    In this article we present several modifications of the mechanical waves conceptual survey, the most important test to date that has been designed to evaluate university students' understanding of four main topics in mechanical waves: propagation, superposition, reflection, and standing waves. The most significant changes are (i) modification of…

  12. Mechanical Waves Conceptual Survey: Its Modification and Conversion to a Standard Multiple-Choice Test

    ERIC Educational Resources Information Center

    Barniol, Pablo; Zavala, Genaro

    2016-01-01

    In this article we present several modifications of the mechanical waves conceptual survey, the most important test to date that has been designed to evaluate university students' understanding of four main topics in mechanical waves: propagation, superposition, reflection, and standing waves. The most significant changes are (i) modification of…

  13. 5S rRNA-derived and tRNA-derived SINEs in fruit bats.

    PubMed

    Gogolevsky, Konstantin P; Vassetzky, Nikita S; Kramerov, Dmitri A

    2009-05-01

    Most short retroposons (SINEs) descend from cellular tRNA of 7SL RNA. Here, four new SINEs were found in megabats (Megachiroptera) but neither in microbats nor in other mammals. Two of them, MEG-RS and MEG-RL, descend from another cellular RNA, 5S rRNA; one (MEG-T2) is a tRNA-derived SINE; and MEG-TR is a hybrid tRNA/5S rRNA SINE. Insertion locus analysis suggests that these SINEs were active in the recent fruit bat evolution. Analysis of MEG-RS and MEG-RL in comparison with other few 5S rRNA-derived SINEs demonstrates that the internal RNA polymerase III promoter is their most invariant region, while the secondary structure is more variable. The mechanisms underlying the modular structure of these and other SINEs as well as their variation are discussed. The scenario of evolution of MEG SINEs is proposed.

  14. Micro-Doppler analysis of multiple frequency continuous wave radar signatures

    NASA Astrophysics Data System (ADS)

    Anderson, Michael G.; Rogers, Robert L.

    2007-04-01

    Micro-Doppler refers to Doppler scattering returns produced by non rigid-body motion. Micro-Doppler gives rise to many detailed radar image features in addition to those associated with bulk target motion. Targets of different classes (for example, humans, animals, and vehicles) produce micro-Doppler images that are often distinguishable even by nonexpert observers. Micro-Doppler features have great potential for use in automatic target classification algorithms. Although the potential benefit of using micro-Doppler in classification algorithms is high, relatively little experimental (non-synthetic) micro-Doppler data exists. Much of the existing experimental data comes from highly cooperative targets (human or vehicle targets directly approaching the radar). This research involved field data collection and analysis of micro-Doppler radar signatures from non-cooperative targets. The data was collected using a low cost Xband multiple frequency continuous wave (MFCW) radar with three transmit frequencies. The collected MFCW radar signatures contain data from humans, vehicles, and animals. The presented data includes micro-Doppler signatures previously unavailable in the literature such as crawling humans and various animal species. The animal micro-Doppler signatures include deer, dog, and goat datasets. This research focuses on the analysis of micro-Doppler from noncooperative targets approaching the radar at various angles, maneuvers, and postures.

  15. Reconstruction of multiple gastric electrical wave fronts using potential based inverse methods

    PubMed Central

    Kim, J HK; Pullan, A J; Cheng, L K

    2012-01-01

    One approach, commonly used in the field of electrocardiography, involves solving an inverse problem whereby electrical potentials on the stomach surface are directly reconstructed from dense potential measurements on the skin surface. To investigate this problem, an anatomically realistic torso model and an electrical stomach model were used to simulate potentials on stomach and skin surfaces arising from normal gastric electrical activity. The effectiveness of the Greensite-Tikhonov or the Tikhonov inverse methods were compared under the presence of 10% Gaussian noise with either 84 or 204 body surface electrodes. The stability and accuracy of the Greensite-Tikhonov method was further investigated by introducing varying levels of Gaussian signal noise or by increasing or decreasing the size of the stomach by 10%. Results showed that the reconstructed solutions were able to represent the presence of propagating multiple wave fronts and the Greensite-Tikhonov method with 204 electrodes performed best (Correlation coefficients of activation time: 90%; Pacemaker localization error: 3 cm). The Greensite-Tikhonov method was stable with Gaussian noise levels up to 20% and 10% change in stomach size. The use of 204 rather than 84 body surface electrodes improved the performance; however, for all investigated cases, the Greensite-Tikhonov method outperformed the Tikhonov method. PMID:22842812

  16. Reconstruction of multiple gastric electrical wave fronts using potential-based inverse methods.

    PubMed

    Kim, J H K; Pullan, A J; Cheng, L K

    2012-08-21

    One approach for non-invasively characterizing gastric electrical activity, commonly used in the field of electrocardiography, involves solving an inverse problem whereby electrical potentials on the stomach surface are directly reconstructed from dense potential measurements on the skin surface. To investigate this problem, an anatomically realistic torso model and an electrical stomach model were used to simulate potentials on stomach and skin surfaces arising from normal gastric electrical activity. The effectiveness of the Greensite-Tikhonov or the Tikhonov inverse methods were compared under the presence of 10% Gaussian noise with either 84 or 204 body surface electrodes. The stability and accuracy of the Greensite-Tikhonov method were further investigated by introducing varying levels of Gaussian signal noise or by increasing or decreasing the size of the stomach by 10%. Results showed that the reconstructed solutions were able to represent the presence of propagating multiple wave fronts and the Greensite-Tikhonov method with 204 electrodes performed best (correlation coefficients of activation time: 90%; pacemaker localization error: 3 cm). The Greensite-Tikhonov method was stable with Gaussian noise levels up to 20% and 10% change in stomach size. The use of 204 rather than 84 body surface electrodes improved the performance; however, for all investigated cases, the Greensite-Tikhonov method outperformed the Tikhonov method.

  17. Reconstruction of multiple gastric electrical wave fronts using potential-based inverse methods

    NASA Astrophysics Data System (ADS)

    Kim, J. H. K.; Pullan, A. J.; Cheng, L. K.

    2012-08-01

    One approach for non-invasively characterizing gastric electrical activity, commonly used in the field of electrocardiography, involves solving an inverse problem whereby electrical potentials on the stomach surface are directly reconstructed from dense potential measurements on the skin surface. To investigate this problem, an anatomically realistic torso model and an electrical stomach model were used to simulate potentials on stomach and skin surfaces arising from normal gastric electrical activity. The effectiveness of the Greensite-Tikhonov or the Tikhonov inverse methods were compared under the presence of 10% Gaussian noise with either 84 or 204 body surface electrodes. The stability and accuracy of the Greensite-Tikhonov method were further investigated by introducing varying levels of Gaussian signal noise or by increasing or decreasing the size of the stomach by 10%. Results showed that the reconstructed solutions were able to represent the presence of propagating multiple wave fronts and the Greensite-Tikhonov method with 204 electrodes performed best (correlation coefficients of activation time: 90%; pacemaker localization error: 3 cm). The Greensite-Tikhonov method was stable with Gaussian noise levels up to 20% and 10% change in stomach size. The use of 204 rather than 84 body surface electrodes improved the performance; however, for all investigated cases, the Greensite-Tikhonov method outperformed the Tikhonov method.

  18. The mean drift forces and yaw moment on multiple-cylinders in waves and current

    SciTech Connect

    Kinoshita, Takeshi; Bao, Weiguang; Sunahara, Shunji

    1996-12-31

    In the present work, the interaction of an assembly of circular cylinders with regular waves and slow current is considered. The interaction among cylinders is represented by additional waves emitting from adjacent cylinders towards the cylinders under consideration. By means of eigenfunction expansion, drift forces, as well as yaw moment, are evaluated by the far field method and the wave drift damping is deduced from these results semi-analytically. The contribution from the second order steady potential which is quadratic in wave amplitude is also considered. Calculated examples are presented in various wave direction. Those results are also compared with experimental measurements to verify the present theory.

  19. Generation of multiple stress waves in silica glass in high fluence femtosecond laser ablation

    SciTech Connect

    Hu Haofeng; Wang Xiaolei; Zhai Hongchen; Zhang Nan; Wang Pan

    2010-08-09

    Shadowgraphs of dynamic processes outside and inside transparent target during the intense femtosecond laser ablation of silica glass are recorded. Two material ejections outside the target and two corresponding stress waves inside the target are observed at different energy fluences. In particular, a third stress wave can be observed at energy fluence as high as 40 J/cm{sup 2}. The first wave is a thermoelastic wave, while the second and the third may be generated subsequently by the mechanical expansions. In addition, the magnitudes of the three stress waves decrease sequentially based on our analysis.

  20. Evaluation of quasi-square wave inverter as a power source for induction motors

    NASA Technical Reports Server (NTRS)

    Guynes, B. V.; Haggard, R. L.; Lanier, J. R., Jr.

    1977-01-01

    The relative merits of quasi-square wave inverter-motor technology versus a sine wave inverter-motor system were investigated. The empirical results of several tests on various sizes of wye-wound induction motors are presented with mathematical analysis to support the conclusions of the study. It was concluded that, within the limitations presented, the quasi-square wave inverter-motor system is superior to the more complex sine wave system for most induction motor applications in space.

  1. A new compound control method for sine-on-random mixed vibration test

    NASA Astrophysics Data System (ADS)

    Zhang, Buyun; Wang, Ruochen; Zeng, Falin

    2017-09-01

    Vibration environmental test (VET) is one of the important and effective methods to provide supports for the strength design, reliability and durability test of mechanical products. A new separation control strategy was proposed to apply in multiple-input multiple-output (MIMO) sine on random (SOR) mixed mode vibration test, which is the advanced and intensive test type of VET. As the key problem of the strategy, correlation integral method was applied to separate the mixed signals which included random and sinusoidal components. The feedback control formula of MIMO linear random vibration system was systematically deduced in frequency domain, and Jacobi control algorithm was proposed in view of the elements, such as self-spectrum, coherence, and phase of power spectral density (PSD) matrix. Based on the excessive correction of excitation in sine vibration test, compression factor was introduced to reduce the excitation correction, avoiding the destruction to vibration table or other devices. The two methods were synthesized to be applied in MIMO SOR vibration test system. In the final, verification test system with the vibration of a cantilever beam as the control object was established to verify the reliability and effectiveness of the methods proposed in the paper. The test results show that the exceeding values can be controlled in the tolerance range of references accurately, and the method can supply theory and application supports for mechanical engineering.

  2. Quantum sine-Gordon dynamics on analogue curved spacetime in a weakly imperfect scalar Bose gas

    NASA Astrophysics Data System (ADS)

    Volkoff, T. J.; Fischer, Uwe R.

    2016-07-01

    Using the coherent state functional integral expression of the partition function, we show that the sine-Gordon model on an analogue curved spacetime arises as the effective quantum field theory for phase fluctuations of a weakly imperfect Bose gas on an incompressible background superfluid flow when these fluctuations are restricted to a subspace of the single-particle Hilbert space. We consider bipartitions of the single-particle Hilbert space relevant to experiments on ultracold bosonic atomic or molecular gases, including, e.g., restriction to high- or low-energy sectors of the dynamics and spatial bipartition corresponding to tunnel-coupled planar Bose gases. By assuming full unitary quantum control in the low-energy subspace of a trapped gas, we show that (1) appropriately tuning the particle number statistics of the lowest-energy mode partially decouples the low- and high-energy sectors, allowing any low-energy single-particle wave function to define a background for sine-Gordon dynamics on curved spacetime and (2) macroscopic occupation of a quantum superposition of two states of the lowest two modes produces an analogue curved spacetime depending on two background flows, with respective weights continuously dependent on the corresponding weights of the superposed quantum states.

  3. Multiple Scattering of Sound by Internal Waves and Acoustic Characterization of Internal Wave Fields in Deep and Shallow Water

    DTIC Science & Technology

    2007-09-30

    less pronounced for steeper and shallower rays (Figs. 2 - 4). Results obtained with eigenrays and unconstrained rays are similar as long as the...intervals of the launch angle (yellow), and averages over the internal wave field realizations for eigenrays with additional averaging over 0.5º...realizations for eigenrays with additional averaging over 0.5º (magenta dots) and 2º (magenta line) intervals of the launch angle. Propagation range r

  4. Generalized universality in the massive sine-Gordon model

    SciTech Connect

    Nagy, S.; Sailer, K.; Nandori, I.; Polonyi, J.

    2008-01-15

    A nontrivial interplay of the UV and IR scaling laws, a generalization of the universality is demonstrated in the framework of the massive sine-Gordon model, as a result of a detailed study of the global behavior of the renormalization group flow and the phase structure.

  5. A SINE-based dichotomous key for primate identification.

    PubMed

    Herke, Scott W; Xing, Jinchuan; Ray, David A; Zimmerman, Jacquelyn W; Cordaux, Richard; Batzer, Mark A

    2007-04-01

    For DNA samples or 'divorced' tissues, identifying the organism from which they were taken generally requires some type of analytical method. The ideal approach would be robust even in the hands of a novice, requiring minimal equipment, time, and effort. Genotyping SINEs (Short INterspersed Elements) is such an approach as it requires only PCR-related equipment, and the analysis consists solely of interpreting fragment sizes in agarose gels. Modern primate genomes are known to contain lineage-specific insertions of Alu elements (a primate-specific SINE); thus, to demonstrate the utility of this approach, we used members of the Alu family to identify DNA samples from evolutionarily divergent primate species. For each node of a combined phylogenetic tree (56 species; n=8 [Hominids]; 11 [New World monkeys]; 21 [Old World monkeys]; 2 [Tarsiformes]; and, 14 [Strepsirrhines]), we tested loci (>400 in total) from prior phylogenetic studies as well as newly identified elements for their ability to amplify in all 56 species. Ultimately, 195 loci were selected for inclusion in this Alu-based key for primate identification. This dichotomous SINE-based key is best used through hierarchical amplification, with the starting point determined by the level of initial uncertainty regarding sample origin. With newly emerging genome databases, finding informative retrotransposon insertions is becoming much more rapid; thus, the general principle of using SINEs to identify organisms is broadly applicable.

  6. Silk worm Bm1 SINE RNA increases following cellular insults.

    PubMed

    Kimura, R H; Choudary, P V; Schmid, C W

    1999-08-15

    The effect of cell stresses upon the expression of the Bm1 short interspersed element (SINE) family in cultured silk worm cells is examined. Primer extension analysis shows that Bm1 repeats are transcribed by RNA polymerase III (Pol III) into cytoplasmic RNAs. Five consecutive T residues, which would normally terminate Pol III transcription, occur within the Bm1 consensus and are included within cDNA sequences representing these transcripts. In analogy to mammalian SINEs, the level of the Bm1 transcripts increases in response to either heat shock, inhibiting protein synthesis by cycloheximide or viral infection. The lifetime of Bm1 RNA increases following cell insults so that post-transcriptional events partially account for stress induced increases in its abundance. In the case of heat shock, the increase in Bm1 RNA follows the transient increase in hsp70 mRNA indicating that this response is temporally regulated to occur later in heat shock recovery. These results support the proposal that SINE RNAs serve a role in the cell stress response that predates the divergence of insects and mammals implying that SINEs are essentially a class of cell stress genes.

  7. Explicitly solvable complex Chebyshev approximation problems related to sine polynomials

    NASA Technical Reports Server (NTRS)

    Freund, Roland

    1989-01-01

    Explicitly solvable real Chebyshev approximation problems on the unit interval are typically characterized by simple error curves. A similar principle is presented for complex approximation problems with error curves induced by sine polynomials. As an application, some new explicit formulae for complex best approximations are derived.

  8. Prediction and phylogenetic analysis of mammalian short interspersed elements (SINEs).

    PubMed

    Rogozin, I B; Mayorov, V I; Lavrentieva, M V; Milanesi, L; Adkison, L R

    2000-09-01

    The presence of repetitive elements can create serious problems for sequence analysis, especially in the case of homology searches in nucleotide sequence databases. Repetitive elements should be treated carefully by using special programs and databases. In this paper, various aspects of SINE (short interspersed repetitive element) identification, analysis and evolution are discussed.

  9. Long-life electromechanical sine-cosine generator

    NASA Technical Reports Server (NTRS)

    Flagge, B.

    1971-01-01

    Sine-cosine generator with no sliding parts is capable of withstanding a 20 Hz oscillation for more than 14 hours. Tests show that generator is electrically equal to potentiometer and that it has excellent dynamic characteristics. Generator shows promise of higher-speed applications than was previously possible.

  10. The Sine Method: An Alternative Height Measurement Technique

    Treesearch

    Don C. Bragg; Lee E. Frelich; Robert T. Leverett; Will Blozan; Dale J. Luthringer

    2011-01-01

    Height is one of the most important dimensions of trees, but few observers are fully aware of the consequences of the misapplication of conventional height measurement techniques. A new approach, the sine method, can improve height measurement by being less sensitive to the requirements of conventional techniques (similar triangles and the tangent method). We studied...

  11. New waves at multiples of the plasma frequency upstream of the earth's bow shock

    NASA Technical Reports Server (NTRS)

    Cairns, I. H.

    1986-01-01

    The first observations of waves at harmonics higher than the second of the electron plasma frequency are reported. The observations were made by the ISEE 1 spacecraft upstream of the earth's bow shock. The waves are interpreted as electromagnetic radiation at the fundamental and up to the fifth harmonic of the plasma frequency, with effective temperatures decreasing from 5 x 10 to the 17th K to 10 billion K over this range. Two models are proposed for the emission of the waves.

  12. Hierarchical Search Strategy for Detecting Gravitational waves from Inspiraling Compact Binaries with Multiple Interferometers

    NASA Astrophysics Data System (ADS)

    Seader, Shawn; Bose, Sukanta

    2004-05-01

    Perhaps the most promising gravitational-wave source for detection with Earth-based interferometers is the compact binary system, such as a binary neutron star. For these sources, the inspiral waveform is well-known in the sensitive frequency band of the interferometers. This allows one to match-filter the output of the interferometer with many different templates of the pre-calculated waveforms. While operating, each interferometer takes strain data at a rate of several gigabytes per day. Matched filtering the outputs from multiple detectors, such as in a multi-detector coherent search, becomes very demanding computationally not only due to the enormous amount of data, but also due to the size of the parameter space that is accessible to a network of detectors. Indeed, the non-spinning binary waveform depends on a total of nine parameters, namely, the luminosity distance to the source, the time of arrival, the initial phase, the orbital inclination, the polarization angle, the two sky-position angles, and the two binary masses. Fortunately, it is possible to maximize a network's matched-filter output analytically over the first five parameters. Thus, a GW astronomer need search numerically only over a four-dimensional parameter space for a signal in the data. A "brute force" implementation of such a search is still not practicable. A promising strategy to make the search computationally viable is to perform it in multiple relatively inexpensive steps, i.e., implement it hierarchically. In a two-step hierarchical search, the data is filtered first with a bank of templates that are spaced coarsely on the parameter space. If any of these templates find a signal at or above a pre-set threshold on the signal-to-noise ratio (SNR), then that part of the data is filtered a second time with a more finely spaced bank of templates, centered around the filter that recorded the high SNR in the first, coarse bank. In this work we show how by setting the detection thresholds and

  13. Applicability of the Multiple-event Stacking Technique for Shear-wave Splitting Analysis

    NASA Astrophysics Data System (ADS)

    Kong, F.; Gao, S. S.; Liu, K. H.

    2015-12-01

    For several decades, shear wave splitting (SWS) parameters (fast polarization orientations and splitting times) have been widely measured to reveal the orientation and strength of mantle anisotropy. One of the most popularly used techniques for obtaining station averaged SWS parameters is the multiple-event stacking technique (MES). Results from previous studies suggest that the splitting times obtained using MES are frequently smaller than those derived from simple averaging of splitting times obtained using the event-specific technique of Silver and Chan (1991) (SC). To confirm such apparent discrepancies between the two popularly used methods and to explore the causes, we conduct numerical experiments using both synthetic and observed data. The results show that when the anisotropic structure can be represented by a horizontal single layer of anisotropy with constant or spatially varying splitting times, MES can accurately retrieve the splitting parameters. However, when the fast orientations or both splitting parameters vary azimuthally due to lateral heterogeneities or double-layer anisotropy, the station averaged fast orientations from MES and SC are mostly comparable, but the splitting times obtained using MES are underestimated. For laterally varying fast orientations in the vicinity of a station, the magnitude of the underestimation is dependent on the arriving azimuth of the events participated in the stacking; for two-layer models of anisotropy, the resulting splitting parameters using MES are biased towards those of the top layer, due to the dominance of events with a back azimuth parallel or orthogonal to the fast orientation of the lower layer. Obviously, MES can still be applied in areas with complex or spatially varying anisotropy to obtain reliable results by stacking events from narrow back-azimuthal windows, especially when limited amounts of high-quality data are present.

  14. High-power free-electron maser with frequency multiplication operating in a shortwave part of the millimeter wave range

    NASA Astrophysics Data System (ADS)

    Bandurkin, I. V.; Kaminsky, A. K.; Perelstein, E. A.; Peskov, N. Yu.; Savilov, A. V.; Sedykh, S. N.

    2012-08-01

    The possibility of using frequency multiplication in order to obtain high-power short-wavelength radiation from a free-electron maser (FEM) with a Bragg resonator has been studied. Preliminary experiments with an LIU-3000 (JINR) linear induction accelerator demonstrate the operation of a frequency-multiplying FEM at megawatt power in the 6- and 4-mm wave bands on the second and third harmonic, respectively.

  15. A new approach to sparse decomposition of nonstationary signals with multiple scale structures using self-consistent nonlinear waves

    NASA Astrophysics Data System (ADS)

    Young, Hsu-Wen Vincent; Hsu, Ke-Hsin; Pham, Van-Truong; Tran, Thi-Thao; Lo, Men-Tzung

    2017-09-01

    A new method for signal decomposition is proposed and tested. Based on self-consistent nonlinear wave equations with self-sustaining physical mechanisms in mind, the new method is adaptive and particularly effective for dealing with synthetic signals consisting of components of multiple time scales. By formulating the method into an optimization problem and developing the corresponding algorithm and tool, we have proved its usefulness not only for analyzing simulated signals, but, more importantly, also for real clinical data.

  16. Microgenetic Patterns of Children's Multiplication Learning: Confirming the Overlapping Waves Model by Latent Growth Modeling

    ERIC Educational Resources Information Center

    van der Ven, Sanne H. G.; Boom, Jan; Kroesbergen, Evelyn H.; Leseman, Paul P. M.

    2012-01-01

    Variability in strategy selection is an important characteristic of learning new skills such as mathematical skills. Strategies gradually come and go during this development. In 1996, Siegler described this phenomenon as ''overlapping waves.'' In the current microgenetic study, we attempted to model these overlapping waves statistically. In…

  17. Spectral collocation methods using sine functions for a rotating Bose-Einstein condensation in optical lattices

    NASA Astrophysics Data System (ADS)

    Chen, Huei-Shuang; Chang, Shing-Lin; Chien, Cheng-Sheng

    2012-02-01

    We study spectral-Galerkin methods (SGM) and spectral collocation methods (SCM) for parameter-dependent problems, where the Fourier sine functions are used as the basis functions. When the SGM and the SCM are incorporated in the context of a Taylor predictor-inexact Newton corrector continuation algorithm for tracing solution curves of the Gross-Pitaevskii equation (GPE), they can efficiently provide accurate numerical solutions for the GPE. We show how the inexact Newton method outperforms the classical Newton method in the continuation algorithm. In our numerical experiments, the centered difference method (CDM), the SGM and SCM are exploited to compute energy levels and wave functions of a rotating Bose-Einstein condensation (BEC) and a rotating BEC in optical lattices in 2D. Sample numerical results are reported.

  18. Sauria SINEs: Novel short interspersed retroposable elements that are widespread in reptile genomes.

    PubMed

    Piskurek, Oliver; Austin, Christopher C; Okada, Norihiro

    2006-05-01

    SINEs are short interspersed retrotransposable elements that invade new genomic sites. Their retrotransposition depends on reverse transcriptase and endonuclease activities encoded by partner LINEs (long interspersed elements). Recent genomic research has demonstrated that retroposons account for at least 40% of the human genome. Hitherto, more than 30 families of SINEs have been characterized in mammalian genomes, comprising approximately 4600 extant species; the distribution and extent of SINEs in reptilian genomes, however, are poorly documented. With more than 7400 species of lizards and snakes, Squamata constitutes the largest and most diverse group of living reptiles. We have discovered and characterized a novel SINE family, Sauria SINEs, whose members are widely distributed among genomes of lizards, snakes, and tuataras. Sauria SINEs comprise a 5' tRNA-related region, a tRNA-unrelated region, and a 3' tail region (containing short tandem repeats) derived from LINEs. We distinguished eight Sauria SINE subfamilies in genomes of four major squamate lineages and investigated their evolutionary relationships. Our data illustrate the overall efficacy of Sauria SINEs as novel retrotransposable markers for elucidation of squamate evolutionary history. We show that all Sauria SINEs share an identical 3' sequence with Bov-B LINEs and propose that they utilize the enzymatic machinery of Bov-B LINEs for their own retrotransposition. This finding, along with the ubiquity of Bov-B LINEs previously demonstrated in squamate genomes, suggests that these LINEs have been an active partner of Sauria SINEs since this SINE family was generated more than 200 million years ago.

  19. SINE transcription by RNA polymerase III is suppressed by histone methylation but not by DNA methylation.

    PubMed

    Varshney, Dhaval; Vavrova-Anderson, Jana; Oler, Andrew J; Cowling, Victoria H; Cairns, Bradley R; White, Robert J

    2015-03-23

    Short interspersed nuclear elements (SINEs), such as Alu, spread by retrotransposition, which requires their transcripts to be copied into DNA and then inserted into new chromosomal sites. This can lead to genetic damage through insertional mutagenesis and chromosomal rearrangements between non-allelic SINEs at distinct loci. SINE DNA is heavily methylated and this was thought to suppress its accessibility and transcription, thereby protecting against retrotransposition. Here we provide several lines of evidence that methylated SINE DNA is occupied by RNA polymerase III, including the use of high-throughput bisulphite sequencing of ChIP DNA. We find that loss of DNA methylation has little effect on accessibility of SINEs to transcription machinery or their expression in vivo. In contrast, a histone methyltransferase inhibitor selectively promotes SINE expression and occupancy by RNA polymerase III. The data suggest that methylation of histones rather than DNA plays a dominant role in suppressing SINE transcription.

  20. SINE transcription by RNA polymerase III is suppressed by histone methylation but not by DNA methylation

    PubMed Central

    Varshney, Dhaval; Vavrova-Anderson, Jana; Oler, Andrew J.; Cowling, Victoria H.; Cairns, Bradley R.; White, Robert J.

    2015-01-01

    Short interspersed nuclear elements (SINEs), such as Alu, spread by retrotransposition, which requires their transcripts to be copied into DNA and then inserted into new chromosomal sites. This can lead to genetic damage through insertional mutagenesis and chromosomal rearrangements between non-allelic SINEs at distinct loci. SINE DNA is heavily methylated and this was thought to suppress its accessibility and transcription, thereby protecting against retrotransposition. Here we provide several lines of evidence that methylated SINE DNA is occupied by RNA polymerase III, including the use of high-throughput bisulphite sequencing of ChIP DNA. We find that loss of DNA methylation has little effect on accessibility of SINEs to transcription machinery or their expression in vivo. In contrast, a histone methyltransferase inhibitor selectively promotes SINE expression and occupancy by RNA polymerase III. The data suggest that methylation of histones rather than DNA plays a dominant role in suppressing SINE transcription. PMID:25798578

  1. Observation of multiple mechanisms for stimulating ion waves in ignition scale plasmas. Revision 1

    SciTech Connect

    Kirkwood, R.K.; MacGowan, B.J.; Montgomery, D.S.

    1997-03-03

    The laser and plasma conditions expected in ignition experiments using indirect drive inertial confinement have been studied experimentally. It has been shown that there are at least three ways in which ion waves can be stimulated in these plasmas and have significant effect on the energy balance and distribution in the target. First ion waves can be stimulated by a single laser beam by the process of Stimulated Brillouin Scattering (SBS) in which an ion acoustic and a scattered electromagnetic wave grow from noise. Second, in a plasma where more than one beam intersect, ion waves can Lie excited at the `beat` frequency and wave number of the intersecting beams,, causing the side scatter instability to be seeded, and substantial energy to be transferred between the beams [R. K. Kirkwood et. al. Phys. Rev. Lett. 76, 2065 (1996)]. And third, ion waves may be stimulated by the decay of electron plasma waves produced by Stimulated Raman Scattering (SRS), thereby inhibiting the SRS process [R. K. Kirkwood et. al. Phys. Rev. Lett. 77, 2706 (1996)].

  2. Energy propagation by transverse waves in multiple flux tube systems using filling factors

    SciTech Connect

    Van Doorsselaere, T.; Gijsen, S. E.; Andries, J.; Verth, G. E-mail: stief.gijsen@wis.kuleuven.be E-mail: g.verth@sheffield.ac.uk

    2014-11-01

    In the last few years, it has been found that transverse waves are present at all times in coronal loops or spicules. Their energy has been estimated with an expression derived for bulk Alfvén waves in homogeneous media, with correspondingly uniform wave energy density and flux. The kink mode, however, is localized in space with the energy density and flux dependent on the position in the cross-sectional plane. The more relevant quantities for the kink mode are the integrals of the energy density and flux over the cross-sectional plane. The present paper provides an approximation to the energy propagated by kink modes in an ensemble of flux tubes by means of combining the analysis of single flux tube kink oscillations with a filling factor for the tube cross-sectional area. This finally allows one to compare the expressions for energy flux of Alfvén waves with an ensemble of kink waves. We find that the correction factor for the energy in kink waves, compared to the bulk Alfvén waves, is between f and 2f, where f is the density filling factor of the ensemble of flux tubes.

  3. Experimental Evidence of the Collective Brillouin Scattering of Multiple Laser Beams Sharing Acoustic Waves

    NASA Astrophysics Data System (ADS)

    Neuville, C.; Tassin, V.; Pesme, D.; Monteil, M.-C.; Masson-Laborde, P.-E.; Baccou, C.; Fremerye, P.; Philippe, F.; Seytor, P.; Teychenné, D.; Seka, W.; Katz, J.; Bahr, R.; Depierreux, S.

    2016-06-01

    The indirect-drive scheme to inertial confinement fusion uses a large number of laser beams arranged in a symmetric angular distribution. Collective laser plasma instabilities can therefore develop that couple all the incident laser waves located in a cone to the daughter wave growing along the cone symmetry axis [D. F. DuBois et al., Phys. Fluids B 4, 241 (1992)]. With complementary diagnostics of Thomson scattering and of the scattered light, we demonstrate the occurrence of collective stimulated Brillouin sidescattering driving collective acoustic waves in indirect-drive experiments.

  4. Combined effects of ULF, VLF, and EMIC Waves, Substorms, and Solar Wind Parameters on Relativistic Electron Flux: Multiple Regression Analysis

    NASA Astrophysics Data System (ADS)

    Simms, L. E.; Engebretson, M. J.; Rodger, C. J.; Gjerloev, J. W.; Lessard, M.; Clilverd, M. A.; Pilipenko, V.; Reeves, G. D.

    2016-12-01

    Relativistic electron flux may be influenced by energy inputs from the solar wind (velocity, number density, and IMF Bz), substorm activity, source and seed electron populations (tens of keV and hundreds of keV, respectively), as well as by the ULF, VLF, and EMIC waves triggered by these factors. As all these variables are intercorrelated, we use multiple regression analyses to determine which are most influential when other factors are controlled. For the years 2005-2011, we use daily averages of LANL geostationary orbit electron data (three high energy channels, as well as source and seed electrons), number of substorms per day from the SUPERMAG substorm list, a ULF index from ground magnetometers, lower band whistler mode chorus power (VLF) observed by the DEMETER satellite, and EMIC (< 1 Hz) wave data from the Halley ground station. The correlations found in the linear multiple regression support several hypotheses. ULF and VLF waves enhance the 1.8-3.5 MeV electron flux but their effect falls off (or becomes negative) on higher energy fluxes (3.5-6.0 and 6.0-7.8 MeV). EMIC waves reduce high energy electron flux mainly in the highest energy channel (6.0-7.8 MeV); their effect on the lower 1.8-3.5 MeV channel is minimal. A higher number of substorms in a day also enhance relativistic electron flux, with more impact at higher energy channels. We explore the relations between these parameters using path analysis to determine the mechanisms driving wave power which subsequently impact flux levels. We also assess the predictive ability of these models in forecasting flux.

  5. Invariant solutions of the supersymmetric sine-Gordon equation

    NASA Astrophysics Data System (ADS)

    Grundland, A. M.; Hariton, A. J.; Šnobl, L.

    2009-08-01

    A comprehensive symmetry analysis of the {\\cal N}=1 supersymmetric sine-Gordon equation is performed. Two different forms of the supersymmetric system are considered. We begin by studying a system of partial differential equations corresponding to the coefficients of the various powers of the anticommuting independent variables. Next, we consider the super-sine-Gordon equation expressed in terms of a bosonic superfield involving anticommuting independent variables. In each case, a Lie (super)algebra of symmetries is determined and a classification of all subgroups having generic orbits of codimension 1 in the space of independent variables is performed. The method of symmetry reduction is systematically applied in order to derive invariant solutions of the supersymmetric model. Several types of algebraic, hyperbolic and doubly periodic solutions are obtained in explicit form.

  6. Zoster sine herpete, vertebral artery stenosis, and ischemic stroke.

    PubMed

    Chen, Wei-Hsi; Chui, Chi; Yin, Hsin-Ling

    2013-10-01

    Although a previous or recent history of varicella-zoster virus (VZV) infection is known to increase the risk of stroke in both children and adults, the influence of zoster sine herpetic remains unclear. We report an immunocompetent man with common cold symptoms and conjunctivitis, followed by an acute onset of bulbar weakness and hemihypesthesia without preceding skin rash. Acute medullary infarction and left vertebral artery stenosis were detected. VZV infection was finally identified. Zoster sine herpetic interferes with accurate diagnosis of infectious stroke, and vertebral artery involvement is unusual in ischemic stroke in this situation. An unexplained course of ischemic stroke event should be suspected in patients with VZV cerebrovasculopathy, especially in those without conventional stroke risk factors and those exhibiting concomitant infectious complications. Copyright © 2013 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  7. Perspective on classical strings from complex sine-Gordon solitons

    SciTech Connect

    Okamura, Keisuke; Suzuki, Ryo

    2007-02-15

    We study a family of classical string solutions with large spins on R{sub t}xS{sup 3} subspace of AdS{sub 5}xS{sup 5} background, which are related to Complex sine-Gordon solitons via Pohlmeyer's reduction. The equations of motion for the classical strings are cast into Lame equations and Complex sine-Gordon equations. We solve them under periodic boundary conditions, and obtain analytic profiles for the closed strings. They interpolate two kinds of known rigid configurations with two spins: on one hand, they reduce to folded or circular spinning/rotating strings in the limit where a soliton velocity goes to zero, while on the other hand, the dyonic giant magnons are reproduced in the limit where the period of a kink-array goes to infinity.

  8. A fully integrated CMOS inverse sine circuit for computational systems

    NASA Astrophysics Data System (ADS)

    Seon, Jong-Kug

    2010-08-01

    An inverse trigonometric function generator using CMOS technology is presented and implemented. The development and synthesis of inverse trigonometric functional circuits based on the simple approximation equations are also introduced. The proposed inverse sine function generator has the infinite input range and can be used in many measurement and instrumentation systems. The nonlinearity of less than 2.8% for the entire input range of 0.5 Vp-p with a small-signal bandwidth of 3.2 MHz is achieved. The chip implemented in 0.25 μm CMOS process operates from a single 1.8 V supply. The measured power consumption and the active chip area of the inverse sine function circuit are 350 μW and 0.15 mm2, respectively.

  9. Direction dependent Love and Rayleigh wave noise characteristics using multiple arrays across Europe

    NASA Astrophysics Data System (ADS)

    Juretzek, Carina; Perleth, Magdalena; Hadziioannou, Celine

    2016-04-01

    Seismic noise has become an important signal source for tomography and monitoring purposes. Better understanding of the noise field characteristics is crucial to further improve noise applications. Our knowledge about common and different origins of Love and Rayleigh waves in the microseism band is still limited. This applies in particular for constraints on source locations and source mechanisms of Love waves. Here, 3-component beamforming is used to distinguish between the different polarized wave types in the primary and secondary microseism noise field recorded at several arrays across Europe. We compare characteristics of Love and Rayleigh wave noise, such as source directions and frequency content. Further, Love to Rayleigh wave ratios are measured and a dependence on direction is found, especially in the primary microseism band. Estimates of the kinetic energy density ratios propose a dominance of coherent Love waves in the primary, but not in the secondary microseism band. The seasonality of the noise field characteristics is examined by using a full year of data in 2013 and is found to be stable.

  10. Variations in mesospheric gravity waves observed in multiple airglow layers, and filtered temporal spectra studies

    NASA Astrophysics Data System (ADS)

    Mangognia, T.; Swenson, G. R.; Vargas, F.

    2013-12-01

    The Andes Lidar Observatory (ALO) at Cerro Pachon, Chile (Lat= 30.25 S, Long = 70.74 W) is equipped with an all-sky OH and O(1S) airglow imager, OH temperature mapper, OH IR imager, multichannel photometer, meteor radar, and a Na wind/temperature lidar. Spectral analysis of airglow photometry data of OH Meinel (5-1),(6-2); O2 (b) (0,1); and O(1S) emissions reveals varying gravity wave periods over time. Variations in period of high frequency waves are often observed. Studies of frequency variability with the background atmospheric temperature and the effect on the Brunt-Vaisala frequency will be described. Additionally, the vertical separation of the respective layers of a few km offers information regarding wave damping and reflection as the amplitude often changes with altitude. The nature of wave damping is primarily noted to be constant with altitude as a saturated wave spectrum indicates. The correlative nature of the data provides verification of optical methods in characterizing wave attributes. These studies will be described in this presentation.

  11. Multiple Directions of Shear-wave Splitting in the 2005 Alpha, Idaho Earthquake Swarm

    NASA Astrophysics Data System (ADS)

    Zollweg, J. E.; Radenz-Benoit, A. M.

    2014-12-01

    Most studies of shear-wave splitting identify one dominant fast direction. Two directions of splitting were observed for events in the 2005 Alpha, Idaho earthquake swarm. This tectonic sequence was particularly shallow (most depths < 4 km). S-wave recordings are unusually complex. Identification of S-wave onsets is usually very difficult, even at distances less than 6 km. The shear-wave window for observing S-wave splitting from shallow events is very short, but at least one station was usually within that distance. Horizontal hodograms indicate that two non-orthogonal directions of splitting exist. Comparison with local topography, mapped faults, earthquake T-axes, and local surface joint azimuths leads to two potential correlations. One direction of splitting may correspond to an older stress direction matching local topography and one peak in joint azimuths. The other may be aligned with the current stress direction, nearby Tertiary faults, and another peak in joint azimuths. The two directions differ by about 45 degrees, in approximate agreement with the hodograms. The two splitting directions qualitatively support the seismogram complexity. Each leads to a fast and a slow S-wave pulse. The shallowness of the sources is already likely to result in seismograms rich in reflections, and two splitting directions will double the number of S arrivals. At short distances the energy distribution among increased numbers of arrivals is likely to decrease peak ground motions derived from simple models that do not take anisotropy into account.

  12. Systemic Sclerosis Sine Scleroderma in Mexican Patients. Case Reports.

    PubMed

    Vera-Lastra, Olga; Sauceda-Casas, Christian Alexis; Domínguez, María Del Pilar Cruz; Alvarez, Sergio Alberto Mendoza; Sepulceda-Delgado, Jesús

    2017-01-03

    Systemic sclerosis sine scleroderma (ssSSc) is a form of systemic sclerosis that is characterized by Raynaud's phenomenon (RP), visceral involvement without thickening of skin and anticentromere antibodies (ACA). We studied 10 ssSsc patients with a prevalence of 2%. The clinical signs were: RP 9/10, esophageal manifestations 8/10, pulmonary arterial hypertension 4/10, interstitial lung disease 4/10, cardiac signs 3/10 and ACA 8/10.

  13. The Quantum Sine-Gordon Model in Perturbative AQFT

    NASA Astrophysics Data System (ADS)

    Bahns, Dorothea; Rejzner, Kasia

    2017-08-01

    We study the Sine-Gordon model with Minkowski signature in the framework of perturbative algebraic quantum field theory. We calculate the vertex operator algebra braiding property. We prove that in the finite regime of the model, the expectation value—with respect to the vacuum or a Hadamard state—of the Epstein Glaser S-matrix and the interacting current or the field respectively converge, both given as formal power series.

  14. Comparison of sine dwell and broadband methods for modal testing

    NASA Technical Reports Server (NTRS)

    Chen, Jay-Chung

    1989-01-01

    The objectives of modal tests for large complex spacecraft structural systems are outlined. The comparison criteria for the modal test methods, namely, the broadband excitation and the sine dwell methods, are established. Using the Galileo spacecraft modal test and the Centaur G Prime upper stage vehicle modal test as examples, the relative advantage or disadvantage of each method is examined. The usefulness or shortcomings of the methods are given from a practical engineering viewpoint.

  15. On sine dwell or broadband methods for modal testing

    NASA Technical Reports Server (NTRS)

    Chen, Jay-Chung; Wada, Ben K.

    1987-01-01

    For large, complex spacecraft structural systems, the objectives of the modal test are outlined. Based on these objectives, the comparison criteria for the modal test methods, namely, the broadband excitation and the sine dwell methods are established. Using the Galileo spacecraft modal test and the Centaur G Prime upper stage vehicle modal test as examples, the relative advantages or disadvantages of each method are examined. The usefulness or shortcoming of the methods are given from a practicing engineer's view point.

  16. [Non-LTR retrotransposons: LINEs and SINEs in plant genome].

    PubMed

    Cheng, Xu-Dong; Ling, Hong-Qing

    2006-06-01

    Retrotransposons are one of the drivers of genome evolution. They include LTR (long terminal repeat) retrotransposons, which widespread in Eukaryotagenomes, show structural similarity to retroviruses. Non-LTR retrotransposons were first discovered in animal genomes and then identified as ubiquitous components of nuclear genomes in many species across the plant kingdom. They constitute a large fraction of the repetitive DNA. Non-LTR retrotransposons are divided into LINEs (long interspersed nuclear elements) and SINEs (short interspersed nuclear elements). Transposition of non-LTR retrotransposons is rarely observed in plants indicating that most of them are inactive and/or under regulation of the host genome. Transposition is poorly understood, but experimental evidence from other genetic systems shows that LINEs are able to transpose autonomously while non-autonomous SINEs depend on the reverse transcription machinery of other retrotransposons. Phylogenic analysis shows LINEs are probably the most ancient class of retrotransposons in plant genomes, while the origin of SINEs is unknown. This review sums up the above data and wants to show readers a clear picture of non-LTR retrotransposons.

  17. Polypteridae (Actinopterygii: Cladistia) and DANA-SINEs insertions.

    PubMed

    Morescalchi, Maria Alessandra; Barucca, Marco; Stingo, Vincenzo; Capriglione, Teresa

    2010-06-01

    SINE sequences are interspersed throughout virtually all eukaryotic genomes and greatly outnumber the other repetitive elements. These sequences are of increasing interest for phylogenetic studies because of their diagnostic power for establishing common ancestry among taxa, once properly characterized. We identified and characterized a peculiar family of composite tRNA-derived short interspersed SINEs, DANA-SINEs, associated with mutational activities in Danio rerio, in a group of species belonging to one of the most basal bony fish families, the Polypteridae, in order to investigate their own inner specific phylogenetic relationships. DANA sequences were identified, sequenced and then localized, by means of fluorescent in situ hybridization (FISH), in six Polypteridae species (Polypterus delhezi, P. ornatipinnis, P. palmas, P. buettikoferi P. senegalus and Erpetoichthys calabaricus) After cloning, the sequences obtained were aligned for phylogenetic analysis, comparing them with three Dipnoan lungfish species (Protopterus annectens, P. aethiopicus, Lepidosiren paradoxa), and Lethenteron reissneri (Petromyzontidae)was used as outgroup. The obtained overlapping MP, ML and NJ tree clustered together the species belonging to the two taxonomically different Osteichthyans groups: the Polypteridae, by one side, and the Protopteridae by the other, with the monotypic genus Erpetoichthys more distantly related to the Polypterus genus comprising three distinct groups: P. palmas and P. buettikoferi, P. delhezi and P. ornatipinnis and P. senegalus. In situ hybridization with DANA probes marked along the whole chromosome arms in the metaphases of all the Polypteridae species examined. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. V-SINEs: a new superfamily of vertebrate SINEs that are widespread in vertebrate genomes and retain a strongly conserved segment within each repetitive unit.

    PubMed

    Ogiwara, Ikuo; Miya, Masaki; Ohshima, Kazuhiko; Okada, Norihiro

    2002-02-01

    We have identified a new superfamily of vertebrate short interspersed repetitive elements (SINEs), designated V-SINEs, that are widespread in fishes and frogs. Each V-SINE includes a central conserved domain preceded by a 5'-end tRNA-related region and followed by a potentially recombinogenic (TG)(n) tract, with a 3' tail derived from the 3' untranslated region (UTR) of the corresponding partner long interspersed repetitive element (LINE) that encodes a functional reverse transcriptase. The central domain is strongly conserved and is even found in SINEs in the lamprey genome, suggesting that V-SINEs might be approximately 550 Myr old or older in view of the timing of divergence of the lamprey lineage from the bony fish lineage. The central conserved domain might have been subject to some form of positive selection. Although the contemporary 3' tails of V-SINEs differ from one another, it is possible that the original 3' tail might have been replaced, via recombination, by the 3' tails of more active partner LINEs, thereby retaining retropositional activity and the ability to survive for long periods on the evolutionary time scale. It seems plausible that V-SINEs may have some function(s) that have been maintained by the coevolution of SINEs and LINEs during the evolution of vertebrates.

  19. Magnetic and charge structures in itinerant-electron magnets: Coexistence of multiple spin-density and charge-density waves

    NASA Astrophysics Data System (ADS)

    Ohkawa, Fusayoshi J.

    2002-06-01

    A theory of Kondo lattices is applied to studying possible magnetic and charge structures of itinerant-electron antiferromagnets. Even helical spin structures can be stabilized when the nesting of the Fermi surface is not sharp and the superexchange interaction, which arises from the virtual exchange of pair excitations across the Mott-Hubbard gap, is mainly responsible for magnetic instability. Sinusoidal spin structures or spin-density waves (SDW's) are only stabilized when the nesting of the Fermi surface is sharp enough or when an exchange interaction arising from that of pair excitations of quasiparticles is mainly responsible for magnetic instability. In particular, multiple SDW's are stabilized when their incommensurate ordering wave numbers +/-Q are multiple; magnetizations of different +/-Q components are orthogonal to each other in double and triple SDW's when magnetic anisotropy is weak enough. Unless +/-2Q are commensurate, charge-density waves (CDW's) with +/-2Q coexist with SDW's with +/-Q. Because the quenching of magnetic moments by the Kondo effect or local quantum spin fluctuations depends on local numbers of electrons, the phase of CDW's or electron densities is such that magnetic moments are large where the quenching is weak. It is proposed that the so-called stripe order must be the coexisting state of double incommensurate SDW's and CDW's in tetragonal cuprate-oxide high temperature superconductors, in particular, those with the square CuO2 lattices.

  20. Isolation and characterization of active LINE and SINEs from the eel.

    PubMed

    Kajikawa, Masaki; Ichiyanagi, Kenji; Tanaka, Nozomu; Okada, Norihiro

    2005-03-01

    Long interspersed elements (LINEs) and short interspersed elements (SINEs) are retrotransposons. These elements can mobilize by the "copy-and-paste" mechanism, in which their own RNA is reverse-transcribed into complementary DNA (cDNA). LINEs and SINEs not only are components of eukaryotic genomes but also drivers of genomic evolution. Thus, studies of the amplification mechanism of LINEs and SINEs are important for understanding eukaryotic genome evolution. Here we report the characterization of one LINE family (UnaL2) and two SINE families (UnaSINE1 and UnaSINE2) from the eel (Anguilla japonica) genome. UnaL2 is approximately 3.6 kilobases (kb) and encodes only one open reading frame (ORF). UnaL2 belongs to the stringent type--thought to be a major group of LINEs--and can mobilize in HeLa cells. We also show that UnaL2 and the two UnaSINEs have similar 3' tails, and that both UnaSINE1 and UnaSINE2 can be mobilized by UnaL2 in HeLa cells. These elements are thus useful for delineating the amplification mechanism of stringent type LINEs as well as that of SINEs.

  1. Location of high-frequency P wave microseismic noise in the Pacific Ocean using multiple small aperture arrays

    DOE PAGES

    Pyle, Moira L.; Koper, Keith D.; Euler, Garrett G.; ...

    2015-04-20

    We investigate source locations of P-wave microseisms within a narrow frequency band (0.67–1.33 Hz) that is significantly higher than the classic microseism band (~0.05–0.3 Hz). Employing a backprojection method, we analyze data recorded during January 2010 from five International Monitoring System arrays that border the Pacific Ocean. We develop a ranking scheme that allows us to combine beam power from multiple arrays to obtain robust locations of the microseisms. Some individual arrays exhibit a strong regional component, but results from the combination of all arrays show high-frequency P wave energy emanating from the North Pacific basin, in general agreement withmore » previous observations in the double-frequency (DF) microseism band (~0.1–0.3 Hz). This suggests that the North Pacific source of ambient P noise covers a broad range of frequencies and that the wave-wave interaction model is likely valid at shorter periods.« less

  2. Structure of North American mantle constrained by simultaneous inversion of multiple-frequency SH, SS, and Love waves

    NASA Astrophysics Data System (ADS)

    Tian, Yue; Zhou, Ying; Sigloch, Karin; Nolet, Guust; Laske, Gabi

    2011-02-01

    We simultaneously invert for the velocity and attenuation structure of the North American mantle from a mixed data set: SH wave traveltime and amplitude anomalies, SS wave differential traveltime anomalies, and Love wave fundamental mode phase delays. All data are measured for multiple frequency bands, and finite frequency sensitivity kernels are used to explain the observations. In the resulting SH velocity model, a lower mantle plume is observed to originate at about 1500 km depth beneath the Yellowstone area, tilting about 40° from vertical. The plume rises up through a gap in the subducting Farallon slab. The SH velocity model confirms high-level segmentation of the Farallon slab, which was observed in the recent P velocity model. Attenuation structure is resolvable in the upper mantle and transition zone; in estimating it, we correct for focusing. High-correlation coefficients between δlnVS and δlnQS under the central and eastern United States suggest one main physical source, most likely temperature. The smaller correlation coefficients and larger slopes of the δlnQS - δlnVS relationship under the western United States suggest an influence of nonthermal factors such as the existence of water and partial melt. Finally, we analyze the influence of the different components of our data set. The addition of Love wave phase delays helps to improve the resolution of both velocity and attenuation, and the effect is noticeable even in the lower mantle.

  3. A real-time plane-wave decomposition algorithm for characterizing perforated liners damping at multiple mode frequencies.

    PubMed

    Zhao, Dan

    2011-03-01

    Perforated liners with a narrow frequency range are widely used as acoustic dampers to stabilize combustion systems. When the frequency of unstable modes present in the combustion system is within the effective frequency range, the liners can efficiently dissipate acoustic waves. The fraction of the incident waves being absorbed (known as power absorption coefficient) is generally used to characterize the liners damping. To estimate it, plane waves either side of the liners need to be decomposed and characterized. For this, a real-time algorithm is developed. Emphasis is being placed on its ability to online decompose plane waves at multiple mode frequencies. The performance of the algorithm is evaluated first in a numerical model with two unstable modes. It is then experimentally implemented in an acoustically driven pipe system with a lined section attached. The acoustic damping of perforated liners is continuously characterized in real-time. Comparison is then made between the results from the algorithm and those from the short-time fast Fourier transform (FFT)-based techniques, which are typically used in industry. It was found that the real-time algorithm allows faster tracking of the liners damping, even when the forcing frequency was suddenly changed.

  4. Interplanetary shock wave extent in the inner heliosphere as observed by multiple spacecraft

    NASA Astrophysics Data System (ADS)

    de Lucas, A.; Schwenn, R.; dal Lago, A.; Marsch, E.; Clúa de Gonzalez, A. L.

    2011-06-01

    For over an entire solar cycle, from the end of 1974 until the beginning of 1986, the twin Helios spacecraft explored the inner heliosphere. These in situ, high-resolution plasma and magnetic field measurements covered heliocentric distances between 0.3 and 1 AU from the Sun and are of particular interest to studies of space weather phenomena. During this period the two spacecraft detected 395 ICME-driven shocks and these waves were found to be driven by interplanetary coronal mass ejections (ICMEs). Based on these multi-spacecraft measurements, which include a third vantage point with the observations from ISEE-3/IMP-8, the longitudinal extent of the shock waves were measured in the inner heliosphere. It was found that shock waves have about a 50% chance to be observed by two different locations separated by 90°. In practice, one can expect with about a 50% chance that the shock driven by a limb coronal mass ejections (CMEs) will hit the Earth, considering the expansion in longitude of shock waves driven by their associated ICMEs. For a larger separation the uncertainty increases, as only a few cases could be observed. With the absence of simultaneous solar disk observations one can then no longer unequivocally identify the shock waves observed at each spacecraft.

  5. Single- and Multiple- Track Location Shear Wave and Acoustic Radiation Force Impulse Imaging: Matched Comparison of Contrast, CNR, and Resolution

    PubMed Central

    Hollender, Peter J.; Rosenzweig, Stephen J.; Nightingale, Kathryn R.; Trahey, Gregg E.

    2014-01-01

    Acoustic radiation force impulse (ARFI) imaging and shear wave elasticity imaging (SWEI) use the dynamic response of tissue to impulsive mechanical stimulus to characterize local elasticity. A variant of conventional, multiple track location SWEI (MTL-SWEI), denoted single track location SWEI (STL-SWEI) offers the promise of creating speckle-free shear wave images. This work compares the three imaging modalities using a high push and track beam density combined acquisition sequence to image inclusions of different sizes and contrasts. STL-SWEI is shown to have significantly higher CNR than MTL-SWEI, allowing for operation at higher resolution. ARFI and STL-SWEI perform similarly in the larger inclusions, with STL-SWEI providing better visualization of small targets ≤2.5 mm in diameter. The processing of each modality introduces different trade-offs between smoothness and resolution of edges and structures; these are discussed in detail. PMID:25701531

  6. Analysis and experimental verification of multiple scattering of acoustoelastic waves in thin plates for enhanced energy harvesting

    NASA Astrophysics Data System (ADS)

    Darabi, Amir; Leamy, Michael J.

    2017-08-01

    Acoustoelastic wave energy harvesting in thin plates and other structures has recently gained attention from the energy harvesting research community. Metamaterial-inspired concepts for enhancing wave power generation have been investigated, including metamaterial funnels, mirrors, and defect-based resonators. In support of such concepts, this paper presents an electromechanically coupled, multiple scattering formulation for accurately modeling, exploring, and optimizing metamaterial-based harvesting systems incorporating scatterers (e.g., cylindrical inclusions and voids). Following development, the formulation is applied to determining optimal arrangements of scatterers, nominally in a semi-elliptical path, which maximize electrical power harvested, This is done, in part, by diminishing side lobes resulting from ellipse truncation. Optimization results exhibit minimized side lobes and harvester power nearly ten times that of the non-optimized case. Finally, an experimental study is presented which confirms many of the model predictions.

  7. Spatial gravity wave characteristics obtained from multiple OH(3-1) airglow temperature time series

    NASA Astrophysics Data System (ADS)

    Wachter, Paul; Schmidt, Carsten; Wüst, Sabine; Bittner, Michael

    2015-12-01

    We present a new approach for the detection of gravity waves in OH-airglow observations at the measurement site Oberpfaffenhofen (11.27°E, 48.08°N), Germany. The measurements were performed at the German Remote Sensing Data Center (DFD) of the German Aerospace Center (DLR) during the period from February 4th, 2011 to July 6th, 2011. In this case study the observations were carried out by three identical Ground-based Infrared P-branch Spectrometers (GRIPS). These instruments provide OH(3-1) rotational temperature time series, which enable spatio-temporal investigations of gravity wave characteristics in the mesopause region. The instruments were aligned in such a way that their fields of view (FOV) formed an equilateral triangle in the OH-emission layer at a height of 87 km. The Harmonic Analysis is applied in order to identify joint temperature oscillations in the three individual datasets. Dependent on the specific gravity wave activity in a single night, it is possible to detect up to four different wave patterns with this method. The values obtained for the waves' periods and phases are then used to derive further parameters, such as horizontal wavelength, phase velocity and the direction of propagation. We identify systematic relationships between periods and amplitudes as well as between periods and horizontal wavelengths. A predominant propagation direction towards the East and North-North-East characterizes the waves during the observation period. There are also indications of seasonal effects in the temporal development of the horizontal wavelength and the phase velocity. During late winter and early spring the derived horizontal wavelengths and the phase velocities are smaller than in the subsequent period from early April to July 2011.

  8. Comparative analysis of fourth-harmonic multiplying gyrotron traveling-wave amplifiers operating at different frequency multiplications

    NASA Astrophysics Data System (ADS)

    Yeh, Y. S.; Kao, W. J.; Li, L. J.; Guo, Y. W.

    2017-01-01

    The harmonic multiplying operation in a gyrotron traveling-wave amplifier (gyro-TWA) permits magnetic field reduction and frequency multiplication. This study presents a comparative analysis of fourth-harmonic multiplying gyro-TWAs with three schemes of operation. An improved mode-selective circuit using circular waveguides with various radii provides the rejection points within the range of operating frequencies to suppress the competing modes of gyro-TWAs. The simulated results reveal that gyro-TWAs are the most susceptible to the fundamental-harmonic TE11 competing mode, regardless of the operating scheme, and that the mode-selective circuit can provide an attenuation of more than 20 dB to suppress the competing modes. The amplification of the waves in a gyro-TWA depends on the lengths of the sections, and the simulated results show that the gain increases for all schemes, as the length of the lossy section or the length of the copper section increases. All schemes exhibit nearly the same saturated output powers and bandwidths; however, the saturated gain of the scheme at a high frequency multiplication ratio is less than that of the scheme at a low frequency multiplication ratio. Extensive numerical calculations of power and gain scaling are conducted for all schemes.

  9. Tidal waves in 102Pd: a rotating condensate of multiple d bosons.

    PubMed

    Ayangeakaa, A D; Garg, U; Caprio, M A; Carpenter, M P; Ghugre, S S; Janssens, R V F; Kondev, F G; Matta, J T; Mukhopadhyay, S; Patel, D; Seweryniak, D; Sun, J; Zhu, S; Frauendorf, S

    2013-03-08

    Low-lying collective excitations in even-even vibrational and transitional nuclei may be described semiclassically as quadrupole running waves on the surface of the nucleus ("tidal waves"), and the observed vibrational-rotational behavior can be thought of as resulting from a rotating condensate of interacting d bosons. These concepts have been investigated by measuring lifetimes of the levels in the yrast band of the (102)Pd nucleus with the Doppler shift attenuation method. The extracted B(E2) reduced transition probabilities for the yrast band display a monotonic increase with spin, in agreement with the interpretation based on rotation-induced condensation of aligned d bosons.

  10. Analytical investigation of the Brillouin interaction between multiple pulsed pump tones and probe waves

    NASA Astrophysics Data System (ADS)

    Voskoboinik, Asher; Willner, Alan E.; Tur, Moshe

    2013-05-01

    We analytically investigate the case of the Brillouin interaction between probe waves propagating against two modulated pump waves. This investigation is motivated by the sweep-free BOTDA technique, where, to increase the BOTDR sensing speed, the Brillouin gain spectrum is simultaneously interrogated by many probe-pump pairs. It is shown both analytically and experimentally that the Brillouin interaction between a probe and its corresponding pump is negligibly affected by a neighboring pump only when the pump tones separation is much larger than the width of the Brillouin gain spectrum.

  11. The dynamic proliferation of CanSINEs mirrors the complex evolution of Feliforms.

    PubMed

    Walters-Conte, Kathryn B; Johnson, Diana L E; Johnson, Warren E; O'Brien, Stephen J; Pecon-Slattery, Jill

    2014-06-20

    Repetitive short interspersed elements (SINEs) are retrotransposons ubiquitous in mammalian genomes and are highly informative markers to identify species and phylogenetic associations. Of these, SINEs unique to the order Carnivora (CanSINEs) yield novel insights on genome evolution in domestic dogs and cats, but less is known about their role in related carnivores. In particular, genome-wide assessment of CanSINE evolution has yet to be completed across the Feliformia (cat-like) suborder of Carnivora. Within Feliformia, the cat family Felidae is composed of 37 species and numerous subspecies organized into eight monophyletic lineages that likely arose 10 million years ago. Using the Felidae family as a reference phylogeny, along with representative taxa from other families of Feliformia, the origin, proliferation and evolution of CanSINEs within the suborder were assessed. We identified 93 novel intergenic CanSINE loci in Feliformia. Sequence analyses separated Feliform CanSINEs into two subfamilies, each characterized by distinct RNA polymerase binding motifs and phylogenetic associations. Subfamily I CanSINEs arose early within Feliformia but are no longer under active proliferation. Subfamily II loci are more recent, exclusive to Felidae and show evidence for adaptation to extant RNA polymerase activity. Further, presence/absence distributions of CanSINE loci are largely congruent with taxonomic expectations within Feliformia and the less resolved nodes in the Felidae reference phylogeny present equally ambiguous CanSINE data. SINEs are thought to be nearly impervious to excision from the genome. However, we observed a nearly complete excision of a CanSINEs locus in puma (Puma concolor). In addition, we found that CanSINE proliferation in Felidae frequently targeted existing CanSINE loci for insertion sites, resulting in tandem arrays. We demonstrate the existence of at least two SINE families within the Feliformia suborder, one of which is actively involved in

  12. Genomic distribution of SINEs in Entamoeba histolytica strains: implication for genotyping

    PubMed Central

    2013-01-01

    Background The major clinical manifestations of Entamoeba histolytica infection include amebic colitis and liver abscess. However the majority of infections remain asymptomatic. Earlier reports have shown that some E. histolytica isolates are more virulent than others, suggesting that virulence may be linked to genotype. Here we have looked at the genomic distribution of the retrotransposable short interspersed nuclear elements EhSINE1 and EhSINE2. Due to their mobile nature, some EhSINE copies may occupy different genomic locations among isolates of E. histolytica possibly affecting adjacent gene expression; this variability in location can be exploited to differentiate strains. Results We have looked for EhSINE1- and EhSINE2-occupied loci in the genome sequence of Entamoeba histolytica HM-1:IMSS and searched for homologous loci in other strains to determine the insertion status of these elements. A total of 393 EhSINE1 and 119 EhSINE2 loci were analyzed in the available sequenced strains (Rahman, DS4-868, HM1:CA, KU48, KU50, KU27 and MS96-3382. Seventeen loci (13 EhSINE1 and 4 EhSINE2) were identified where a EhSINE1/EhSINE2 sequence was missing from the corresponding locus of other strains. Most of these loci were unoccupied in more than one strain. Some of the loci were analyzed experimentally for SINE occupancy using DNA from strain Rahman. These data helped to correctly assemble the nucleotide sequence at three loci in Rahman. SINE occupancy was also checked at these three loci in 7 other axenically cultivated E. histolytica strains and 16 clinical isolates. Each locus gave a single, specific amplicon with the primer sets used, making this a suitable method for strain typing. Based on presence/absence of SINE and amplification with locus-specific primers, the 23 strains could be divided into eleven genotypes. The results obtained by our method correlated with the data from other typing methods. We also report a bioinformatic analysis of EhSINE2 copies

  13. The dynamic proliferation of CanSINEs mirrors the complex evolution of Feliforms

    PubMed Central

    2014-01-01

    Background Repetitive short interspersed elements (SINEs) are retrotransposons ubiquitous in mammalian genomes and are highly informative markers to identify species and phylogenetic associations. Of these, SINEs unique to the order Carnivora (CanSINEs) yield novel insights on genome evolution in domestic dogs and cats, but less is known about their role in related carnivores. In particular, genome-wide assessment of CanSINE evolution has yet to be completed across the Feliformia (cat-like) suborder of Carnivora. Within Feliformia, the cat family Felidae is composed of 37 species and numerous subspecies organized into eight monophyletic lineages that likely arose 10 million years ago. Using the Felidae family as a reference phylogeny, along with representative taxa from other families of Feliformia, the origin, proliferation and evolution of CanSINEs within the suborder were assessed. Results We identified 93 novel intergenic CanSINE loci in Feliformia. Sequence analyses separated Feliform CanSINEs into two subfamilies, each characterized by distinct RNA polymerase binding motifs and phylogenetic associations. Subfamily I CanSINEs arose early within Feliformia but are no longer under active proliferation. Subfamily II loci are more recent, exclusive to Felidae and show evidence for adaptation to extant RNA polymerase activity. Further, presence/absence distributions of CanSINE loci are largely congruent with taxonomic expectations within Feliformia and the less resolved nodes in the Felidae reference phylogeny present equally ambiguous CanSINE data. SINEs are thought to be nearly impervious to excision from the genome. However, we observed a nearly complete excision of a CanSINEs locus in puma (Puma concolor). In addition, we found that CanSINE proliferation in Felidae frequently targeted existing CanSINE loci for insertion sites, resulting in tandem arrays. Conclusions We demonstrate the existence of at least two SINE families within the Feliformia suborder, one

  14. Multiple charge density wave states at the surface of TbT e3

    NASA Astrophysics Data System (ADS)

    Fu, Ling; Kraft, Aaron M.; Sharma, Bishnu; Singh, Manoj; Walmsley, Philip; Fisher, Ian R.; Boyer, Michael C.

    2016-11-01

    We studied TbT e3 using scanning tunneling microscopy (STM) in the temperature range of 298-355 K. Our measurements detect a unidirectional charge density wave (CDW) state in the surface Te layer with a wave vector consistent with that of the bulk qCDW=0.30 ±0.01 c* . However, unlike previous STM measurements, and differing from measurements probing the bulk, we detect two perpendicular orientations for the unidirectional CDW with no directional preference for the in-plane crystal axes (a or c axis) and no noticeable difference in wave vector magnitude. In addition, we find regions in which the bidirectional CDW states coexist. We propose that observation of two unidirectional CDW states indicates a decoupling of the surface Te layer from the rare-earth block layer below, and that strain variations in the Te surface layer drive the local CDW direction to the specific unidirectional or, in rare occurrences, bidirectional CDW orders observed. This indicates that similar driving mechanisms for CDW formation in the bulk, where anisotropic lattice strain energy is important, are at play at the surface. Furthermore, the wave vectors for the bidirectional order we observe differ from those theoretically predicted for checkerboard order competing with stripe order in a Fermi-surface nesting scenario, suggesting that factors beyond Fermi-surface nesting drive CDW order in TbT e3 . Finally, our temperature-dependent measurements provide evidence for localized CDW formation above the bulk transition temperature TCDW.

  15. When Measures Change over Time: A Workable Solution for Analysing Change and Growth across Multiple Waves

    ERIC Educational Resources Information Center

    Lloyd, Jennifer E. V.; Zumbo, Bruno D.; Siegel, Linda S.

    2009-01-01

    In the past 20 years, the analysis of individual change has become a key focus in educational research. There are several parametric analyses that centre upon quantifying change. Some researchers state that such analyses should only occur if the measure itself remains completely unchanged across waves, arguing that it is not possible to link or…

  16. Mode structure in the far field radiation of a leaky-wave multiple quantum well laser

    SciTech Connect

    Nekorkin, S M; Zvonkov, B N; Karzanova, Maria V; Dikareva, Natalia V; Aleshkin, V Ya; Dubinov, A A

    2012-10-31

    The radiation patterns of a leaky-wave InGaAs/GaAs/InGaP laser are studied. In the subthreshold regime, several peaks are found, corresponding to the emission of fundamental and excited modes. The dependences of the amplitude, position and width of the peaks on the pump current are investigated and explained. (measurement of laser radiation parameters)

  17. New acoustic wave therapy improves quality of life in patients with multiple sclerosis and chronic cerebrospinal venous insufficiency.

    PubMed

    d'Alessandro, Aldo; Niglio, Tarcisio; Desogus, Antonello; d'Alessandro, Alessandro; Mandolesi, Dimitri

    2015-01-01

    A Multiple Sclerosis patient with chronic cerebrospinal venous insufficiency (CCSVI) treated by acoustic waves, modulated in frequency and power of the Dreno-MAM® device, showed a progressive improvement in motor coordination, resistance to work, muscular power and rigidity, and distal microcirculation. Life quality, chronic fatigue, and clinical severity questionnaires EDSS show marked improvements with a follow-up of two years. We suggest that the method could be also used in the chronic fatigue syndrome and other neurological diseases such as Parkinson or Meniere syndrome. Analyses on statistically robust samples are in progress to validate such impressive result obtained by this nonpharmacological and non-invasive treatment.

  18. Characterization of Pairwise Correlations from Multiple Quantum Correlated Beams Generated from Cascaded Four-Wave Mixing Processes

    PubMed Central

    Wang, Hailong; Cao, Leiming; Jing, Jietai

    2017-01-01

    We theoretically characterize the performance of the pairwise correlations (PCs) from multiple quantum correlated beams based on the cascaded four-wave mixing (FWM) processes. The presence of the PCs with quantum corre- lation in these systems can be verified by calculating the degree of intensity difference squeezing for any pair of all the output fields. The quantum correlation characteristics of all the PCs under different cascaded schemes are also discussed in detail and the repulsion effect between PCs in these cascaded FWM processes is theoretically predicted. Our results open the way for the classification and application of quantum states generated from the cascaded FWM processes. PMID:28071759

  19. Multiple mechanisms of spiral wave breakup in a model of cardiac electrical activity

    NASA Astrophysics Data System (ADS)

    Fenton, Flavio H.; Cherry, Elizabeth M.; Hastings, Harold M.; Evans, Steven J.

    2002-09-01

    It has become widely accepted that the most dangerous cardiac arrhythmias are due to reentrant waves, i.e., electrical wave(s) that recirculate repeatedly throughout the tissue at a higher frequency than the waves produced by the heart's natural pacemaker (sinoatrial node). However, the complicated structure of cardiac tissue, as well as the complex ionic currents in the cell, have made it extremely difficult to pinpoint the detailed dynamics of these life-threatening reentrant arrhythmias. A simplified ionic model of the cardiac action potential (AP), which can be fitted to a wide variety of experimentally and numerically obtained mesoscopic characteristics of cardiac tissue such as AP shape and restitution of AP duration and conduction velocity, is used to explain many different mechanisms of spiral wave breakup which in principle can occur in cardiac tissue. Some, but not all, of these mechanisms have been observed before using other models; therefore, the purpose of this paper is to demonstrate them using just one framework model and to explain the different parameter regimes or physiological properties necessary for each mechanism (such as high or low excitability, corresponding to normal or ischemic tissue, spiral tip trajectory types, and tissue structures such as rotational anisotropy and periodic boundary conditions). Each mechanism is compared with data from other ionic models or experiments to illustrate that they are not model-specific phenomena. Movies showing all the breakup mechanisms are available at http://arrhythmia.hofstra.edu/breakup and at ftp://ftp.aip.org/epaps/chaos/E-CHAOEH-12-039203/ INDEX.html. The fact that many different breakup mechanisms exist has important implications for antiarrhythmic drug design and for comparisons of fibrillation experiments using different species, electromechanical uncoupling drugs, and initiation protocols.

  20. Experimental Analysis of a Piezoelectric Energy Harvesting System for Harmonic, Random, and Sine on Random Vibration

    SciTech Connect

    Cryns, Jackson W.; Hatchell, Brian K.; Santiago-Rojas, Emiliano; Silvers, Kurt L.

    2013-07-01

    Formal journal article Experimental analysis of a piezoelectric energy harvesting system for harmonic, random, and sine on random vibration Abstract: Harvesting power with a piezoelectric vibration powered generator using a full-wave rectifier conditioning circuit is experimentally compared for varying sinusoidal, random and sine on random (SOR) input vibration scenarios. Additionally, the implications of source vibration characteristics on harvester design are discussed. Studies in vibration harvesting have yielded numerous alternatives for harvesting electrical energy from vibrations but piezoceramics arose as the most compact, energy dense means of energy transduction. The rise in popularity of harvesting energy from ambient vibrations has made piezoelectric generators commercially available. Much of the available literature focuses on maximizing harvested power through nonlinear processing circuits that require accurate knowledge of generator internal mechanical and electrical characteristics and idealization of the input vibration source, which cannot be assumed in general application. In this manuscript, variations in source vibration and load resistance are explored for a commercially available piezoelectric generator. We characterize the source vibration by its acceleration response for repeatability and transcription to general application. The results agree with numerical and theoretical predictions for in previous literature that load optimal resistance varies with transducer natural frequency and source type, and the findings demonstrate that significant gains are seen with lower tuned transducer natural frequencies for similar source amplitudes. Going beyond idealized steady state sinusoidal and simplified random vibration input, SOR testing allows for more accurate representation of real world ambient vibration. It is shown that characteristic interactions from more complex vibrational sources significantly alter power generation and power processing

  1. Liouville Correspondence Between the Short-Pulse Hierarchy and the Sine-Gordon Hierarchy

    NASA Astrophysics Data System (ADS)

    Kang, Jing; Liu, Xiaochuan; Qu, Changzheng

    2016-12-01

    The Liouville correspondence between the short-pulse integrable hierarchy and the sine-Gordon integrable hierarchy is studied. It is shown that the transformation relating the short-pulse equation with the sine-Gordon equation also establishes the correspondence between their flows and Hamiltonian conservation laws in respective hierarchy. This proposes an alternative approach to derive the Hamiltonian conservation laws of the short-pulse equation from the known ones of the classical sine-Gordon equation.

  2. The Role of Pulse Shape in Motor Cortex Transcranial Magnetic Stimulation Using Full-Sine Stimuli

    PubMed Central

    Delvendahl, Igor; Gattinger, Norbert; Berger, Thomas; Gleich, Bernhard; Siebner, Hartwig R.; Mall, Volker

    2014-01-01

    A full-sine (biphasic) pulse waveform is most commonly used for repetitive transcranial magnetic stimulation (TMS), but little is known about how variations in duration or amplitude of distinct pulse segments influence the effectiveness of a single TMS pulse to elicit a corticomotor response. Using a novel TMS device, we systematically varied the configuration of full-sine pulses to assess the impact of configuration changes on resting motor threshold (RMT) as measure of stimulation effectiveness with single-pulse TMS of the non-dominant motor hand area (M1). In young healthy volunteers, we (i) compared monophasic, half-sine, and full-sine pulses, (ii) applied two-segment pulses consisting of two identical half-sines, and (iii) manipulated amplitude, duration, and current direction of the first or second full-sine pulse half-segments. RMT was significantly higher using half-sine or monophasic pulses compared with full-sine. Pulses combining two half-sines of identical polarity and duration were also characterized by higher RMT than full-sine stimuli resulting. For full-sine stimuli, decreasing the amplitude of the half-segment inducing posterior-anterior oriented current in M1 resulted in considerably higher RMT, whereas varying the amplitude of the half-segment inducing anterior-posterior current had a smaller effect. These findings provide direct experimental evidence that the pulse segment inducing a posterior-anterior directed current in M1 contributes most to corticospinal pathway excitation. Preferential excitation of neuronal target cells in the posterior-anterior segment or targeting of different neuronal structures by the two half-segments can explain this result. Thus, our findings help understanding the mechanisms of neural stimulation by full-sine TMS. PMID:25514673

  3. The role of pulse shape in motor cortex transcranial magnetic stimulation using full-sine stimuli.

    PubMed

    Delvendahl, Igor; Gattinger, Norbert; Berger, Thomas; Gleich, Bernhard; Siebner, Hartwig R; Mall, Volker

    2014-01-01

    A full-sine (biphasic) pulse waveform is most commonly used for repetitive transcranial magnetic stimulation (TMS), but little is known about how variations in duration or amplitude of distinct pulse segments influence the effectiveness of a single TMS pulse to elicit a corticomotor response. Using a novel TMS device, we systematically varied the configuration of full-sine pulses to assess the impact of configuration changes on resting motor threshold (RMT) as measure of stimulation effectiveness with single-pulse TMS of the non-dominant motor hand area (M1). In young healthy volunteers, we (i) compared monophasic, half-sine, and full-sine pulses, (ii) applied two-segment pulses consisting of two identical half-sines, and (iii) manipulated amplitude, duration, and current direction of the first or second full-sine pulse half-segments. RMT was significantly higher using half-sine or monophasic pulses compared with full-sine. Pulses combining two half-sines of identical polarity and duration were also characterized by higher RMT than full-sine stimuli resulting. For full-sine stimuli, decreasing the amplitude of the half-segment inducing posterior-anterior oriented current in M1 resulted in considerably higher RMT, whereas varying the amplitude of the half-segment inducing anterior-posterior current had a smaller effect. These findings provide direct experimental evidence that the pulse segment inducing a posterior-anterior directed current in M1 contributes most to corticospinal pathway excitation. Preferential excitation of neuronal target cells in the posterior-anterior segment or targeting of different neuronal structures by the two half-segments can explain this result. Thus, our findings help understanding the mechanisms of neural stimulation by full-sine TMS.

  4. Evolutionary history of 7SL RNA-derived SINEs in Supraprimates.

    PubMed

    Kriegs, Jan Ole; Churakov, Gennady; Jurka, Jerzy; Brosius, Jürgen; Schmitz, Jürgen

    2007-04-01

    The evolutionary relationships of 7SL RNA-derived SINEs such as the primate Alu or the rodent B1 elements have hitherto been obscure. We established an unambiguous phylogenetic tree for Supraprimates, and derived intraordinal relationships of the 7SL RNA-derived SINEs. As well as new elements in Tupaia and primates, we also found that the purported ancestral fossil Alu monomer was restricted to Primates, and provide here the first description of a potential chimeric promoter box region in SINEs.

  5. Wave of a Planet

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This plot tells astronomers that a fifth planet is in orbit around the star 55 Cancri, making the star the record-holder for hosting the most known exoplanets.

    As planets circle around their stars, they cause the stars to wobble back and forth in a regular pattern. By looking for this motion in a star, scientists can find planets that can't be seen with telescopes.

    The wobble caused by the fifth planet discovered around 55 Cancri is represented here by the sinuous line in blue. The actual data points are yellow and error bars are the lines above and below the yellow dots. The cycle of the wobble indicates that the planet circles around its star about every 260 days. The amplitude of the wobble indicates that the planet is a giant at least 45 times the mass of Earth.

    The wobbles caused by the other four planets has been removed from this plot, to reveal that caused by the fifth. The departure from a perfect sine wave suggests the planet's orbit is not perfectly circular.

    Because 55 Cancri has multiple planets, the star had to be observed for a long time before astronomers could find and confirm its fifth planet. These data were collected over a period of 18 years using both the Lick Observatory near San Jose, Calif., and the W.M. Keck Observatory in Hawaii.

  6. Separable-spherical-wave approximation: Application to x-ray-absorption fine-structure multiple scattering in ReO3

    NASA Astrophysics Data System (ADS)

    Houser, B.; Ingalls, R.; Rehr, J. J.

    1992-04-01

    Rehr and Albers have shown that the exact x-ray-absorption fine-structure (XAFS) propagator may be expanded in a separable matrix form, and that the lowest-order term in the expansion yields XAFS formulas that contain spherical-wave corrections, yet retain the simplicity of the plane-wave approximation. This separable-spherical-wave approximation was used to model the multiple-scattering contributions to the XAFS spectrum of rhenium trioxide. We report a modest improvement over the plane-wave approximation.

  7. RetroPred: A tool for prediction, classification and extraction of non-LTR retrotransposons (LINEs & SINEs) from the genome by integrating PALS, PILER, MEME and ANN.

    PubMed

    Naik, Pradeep Kumar; Mittal, Vinay Kumar; Gupta, Sumit

    2008-01-27

    The problem of predicting non-long terminal repeats (LTR) like long interspersed nuclear elements (LINEs) and short interspersed nuclear elements (SINEs) from the DNA sequence is still an open problem in bioinformatics. To elevate the quality of annotations of LINES and SINEs an automated tool "RetroPred" was developed. The pipeline allowed rapid and thorough annotation of non-LTR retrotransposons. The non-LTR retrotransposable elements were initially predicted by Pairwise Aligner for Long Sequences (PALS) and Parsimonious Inference of a Library of Elementary Repeats (PILER). Predicted non-LTR elements were automatically classified into LINEs and SINEs using ANN based on the position specific probability matrix (PSPM) generated by Multiple EM for Motif Elicitation (MEME). The ANN model revealed a superior model (accuracy = 78.79 +/- 6.86 %, Q(pred) = 74.734 +/- 17.08 %, sensitivity = 84.48 +/- 6.73 %, specificity = 77.13 +/- 13.39 %) using four-fold cross validation. As proof of principle, we have thoroughly annotated the location of LINEs and SINEs in rice and Arabidopsis genome using the tool and is proved to be very useful with good accuracy. Our tool is accessible at http://www.juit.ac.in/RepeatPred/home.html.

  8. Distribution, Diversity, and Long-Term Retention of Grass Short Interspersed Nuclear Elements (SINEs)

    PubMed Central

    Mao, Hongliang

    2017-01-01

    Abstract Instances of highly conserved plant short interspersed nuclear element (SINE) families and their enrichment near genes have been well documented, but little is known about the general patterns of such conservation and enrichment and underlying mechanisms. Here, we perform a comprehensive investigation of the structure, distribution, and evolution of SINEs in the grass family by analyzing 14 grass and 5 other flowering plant genomes using comparative genomics methods. We identify 61 SINE families composed of 29,572 copies, in which 46 families are first described. We find that comparing with other grass TEs, grass SINEs show much higher level of conservation in terms of genomic retention: The origin of at least 26% families can be traced to early grass diversification and these families are among most abundant SINE families in 86% species. We find that these families show much higher level of enrichment near protein coding genes than families of relatively recent origin (51%:28%), and that 40% of all grass SINEs are near gene and the percentage is higher than other types of grass TEs. The pattern of enrichment suggests that differential removal of SINE copies in gene-poor regions plays an important role in shaping the genomic distribution of these elements. We also identify a sequence motif located at 3′ SINE end which is shared in 17 families. In short, this study provides insights into structure and evolution of SINEs in the grass family. PMID:28903462

  9. SINE Retrotransposition: Evaluation of Alu Activity and Recovery of De Novo Inserts.

    PubMed

    Ade, Catherine; Roy-Engel, Astrid M

    2016-01-01

    Mobile element activity is of great interest due to its impact on genomes. However, the types of mobile elements that inhabit any given genome are remarkably varied. Among the different varieties of mobile elements, the Short Interspersed Elements (SINEs) populate many genomes, including many mammalian species. Although SINEs are parasites of Long Interspersed Elements (LINEs), SINEs have been highly successful in both the primate and rodent genomes. When comparing copy numbers in mammals, SINEs have been vastly more successful than other nonautonomous elements, such as the retropseudogenes and SVA. Interestingly, in the human genome the copy number of Alu (a primate SINE) outnumbers LINE-1 (L1) copies 2 to 1. Estimates suggest that the retrotransposition rate for Alu is tenfold higher than LINE-1 with about 1 insert in every twenty births. Furthermore, Alu-induced mutagenesis is responsible for the majority of the documented instances of human retroelement insertion-induced disease. However, little is known on what contributes to these observed differences between SINEs and LINEs. The development of an assay to monitor SINE retrotransposition in culture has become an important tool for the elucidation of some of these differences. In this chapter, we present details of the SINE retrotransposition assay and the recovery of de novo inserts. We also focus on the nuances that are unique to the SINE assay.

  10. Multiple charge density wave states at the surface of TbTe3

    DOE PAGES

    Fu, Ling; Kraft, Aaron M.; Sharma, Bishnu; ...

    2016-11-01

    We studied TbTe3 using scanning tunneling microscopy (STM) in the temperature range of 298–355 K. Our measurements detect a unidirectional charge density wave (CDW) state in the surface Te layer with a wave vector consistent with that of the bulk qCDW = 0.30 ± 0.01c*. However, unlike previous STM measurements, and differing from measurements probing the bulk, we detect two perpendicular orientations for the unidirectional CDW with no directional preference for the in-plane crystal axes (a or c axis) and no noticeable difference in wave vector magnitude. In addition, we find regions in which the bidirectional CDW states coexist. Wemore » propose that observation of two unidirectional CDW states indicates a decoupling of the surface Te layer from the rare-earth block layer below, and that strain variations in the Te surface layer drive the local CDW direction to the specific unidirectional or, in rare occurrences, bidirectional CDW orders observed. This indicates that similar driving mechanisms for CDW formation in the bulk, where anisotropic lattice strain energy is important, are at play at the surface. Furthermore, the wave vectors for the bidirectional order we observe differ from those theoretically predicted for checkerboard order competing with stripe order in a Fermi-surface nesting scenario, suggesting that factors beyond Fermi-surface nesting drive CDW order in TbTe3. As a result, our temperature-dependent measurements provide evidence for localized CDW formation above the bulk transition temperature TCDW.« less

  11. Evidence for a Peierls phase-transition in a three-dimensional multiple charge-density waves solid.

    PubMed

    Mansart, Barbara; Cottet, Mathieu J G; Penfold, Thomas J; Dugdale, Stephen B; Tediosi, Riccardo; Chergui, Majed; Carbone, Fabrizio

    2012-04-10

    The effect of dimensionality on materials properties has become strikingly evident with the recent discovery of graphene. Charge ordering phenomena can be induced in one dimension by periodic distortions of a material's crystal structure, termed Peierls ordering transition. Charge-density waves can also be induced in solids by strong coulomb repulsion between carriers, and at the extreme limit, Wigner predicted that crystallization itself can be induced in an electrons gas in free space close to the absolute zero of temperature. Similar phenomena are observed also in higher dimensions, but the microscopic description of the corresponding phase transition is often controversial, and remains an open field of research for fundamental physics. Here, we photoinduce the melting of the charge ordering in a complex three-dimensional solid and monitor the consequent charge redistribution by probing the optical response over a broad spectral range with ultrashort laser pulses. Although the photoinduced electronic temperature far exceeds the critical value, the charge-density wave is preserved until the lattice is sufficiently distorted to induce the phase transition. Combining this result with ab initio electronic structure calculations, we identified the Peierls origin of multiple charge-density waves in a three-dimensional system for the first time.

  12. A coupled wave-3-D hydrodynamics model of the Taranto Sea (Italy): a multiple-nesting approach

    NASA Astrophysics Data System (ADS)

    Gaeta, Maria Gabriella; Samaras, Achilleas G.; Federico, Ivan; Archetti, Renata; Maicu, Francesco; Lorenzetti, Giuliano

    2016-09-01

    The present work describes an operational strategy for the development of a multiscale modeling system, based on a multiple-nesting approach and open-source numerical models. The strategy was applied and validated for the Gulf of Taranto in southern Italy, scaling large-scale oceanographic model results to high-resolution coupled wave-3-D hydrodynamics simulations for the area of Mar Grande in the Taranto Sea. The spatial and temporal high-resolution simulations were performed using the open-source TELEMAC suite, forced by wind data from the COSMO-ME database, boundary wave spectra from the RON buoy at Crotone and results from the Southern Adriatic Northern Ionian coastal Forecasting System (SANIFS) regarding sea levels and current fields. Model validation was carried out using data collected in the Mar Grande basin from a fixed monitoring station and during an oceanographic campaign in October 2014. The overall agreement between measurements and model results in terms of waves, sea levels, surface currents, circulation patterns and vertical velocity profiles is deemed to be satisfactory, and the methodology followed in the process can constitute a useful tool for both research and operational applications in the same field and as support of decisions for management and design of infrastructures.

  13. Broadband light absorption with multiple surface plasmon polariton waves excited at the interface of a metallic grating and photonic crystal.

    PubMed

    Hall, Anthony Shoji; Faryad, Muhammad; Barber, Greg D; Liu, Liu; Erten, Sema; Mayer, Theresa S; Lakhtakia, Akhlesh; Mallouk, Thomas E

    2013-06-25

    Light incident upon a periodically corrugated metal/dielectric interface can generate surface plasmon polariton (SPP) waves. This effect is used in many sensing applications. Similar metallodielectric nanostructures are used for light trapping in solar cells, but the gains are modest because SPP waves can be excited only at specific angles and with one linear polarization state of incident light. Here we report the optical absorptance of a metallic grating coupled to silicon oxide/oxynitride layers with a periodically varying refractive index, i.e., a 1D photonic crystal. These structures show a dramatic enhancement relative to those employing a homogeneous dielectric material. Multiple SPP waves can be activated, and both s- and p-polarized incident light can be efficiently trapped. Many SPP modes are weakly bound and display field enhancements that extend throughout the dielectric layers. These modes have significantly longer propagation lengths than the single SPP modes excited at the interface of a metallic grating and a uniform dielectric. These results suggest that metallic gratings coupled to photonic crystals could have utility for light trapping in photovoltaics, sensing, and other applications.

  14. The effect of sine-Wiener noises on transition in a genotype selection model with time delays

    NASA Astrophysics Data System (ADS)

    Ning, Li Juan; Liu, Pei

    2016-09-01

    A genotype selection system interplay with sine-Wiener noises and time delays is investigated. Stationary probability distribution function is obtained by numerical simulations. Results show that the multiplicative bounded noise can facilitate the gene separation, while the additive bounded noise suppresses the gene separation. Besides, local time delays α and β, being in gene transformation and gene heredity progress respectively, play opposite roles in the gene selection process. What is more interesting is that there is no transition during the process of gene select when time delays α = β (i.e., the system is subjected to global time delay).

  15. The effect of sine-Wiener noises on transition in a genotype selection model with time delays

    NASA Astrophysics Data System (ADS)

    Juan Ning, Li; Liu, Pei

    2016-09-01

    A genotype selection system interplay with sine-Wiener noises and time delays is investigated. Stationary probability distribution function is obtained by numerical simulations. Results show that the multiplicative bounded noise can facilitate the gene separation, while the additive bounded noise suppresses the gene separation. Besides, local time delays α and β, being in gene transformation and gene heredity progress respectively, play opposite roles in the gene selection process. What is more interesting is that there is no transition during the process of gene select when time delays α = β (i.e., the system is subjected to global time delay).

  16. Retinitis pigmentosa sine pigmenti. Debut with macular oedema.

    PubMed

    de la Mata Pérez, G; Ruiz-Moreno, O; Fernández-Pérez, S; Torrón Fernández-Blanco, C; Pablo-Júlvez, L

    2014-09-01

    A 25-year-old woman, with metamorphopsia in her left eye of one year onset. The examination revealed a bilateral cystoid macular oedema (CME) and vascular attenuation. We describe the diagnostic tests, as well as differential diagnosis and treatment response with carbonic anhydrase inhibitors. The retinitis pigmentosa sine pigment is a subtype of atypical retinitis pigmentosa characterised by the absence of pigment deposits. The night blindness is milder, and perimetric and electroretinographic impairment is lower. CME is an important cause of central vision loss, and responds to anhydrase carbonic inhibitors. Copyright © 2012 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  17. Overlaps after quantum quenches in the sine-Gordon model

    NASA Astrophysics Data System (ADS)

    Horváth, D. X.; Takács, G.

    2017-08-01

    We present a numerical computation of overlaps in mass quenches in sine-Gordon quantum field theory using truncated conformal space approach (TCSA). To improve the cut-off dependence of the method, we use a novel running coupling definition which has a general applicability in free boson TCSA. The numerical results for the first breather overlaps are compared with the analytic continuation of a previously proposed analytical Ansatz for the initial state in a related sinh-Gordon quench, and good agreement is found between the numerical data and the analytical prediction in a large energy range.

  18. Modulational instability in nonlocal Kerr media with a sine-oscillatory response

    NASA Astrophysics Data System (ADS)

    Wang, Zhuo; Guo, Qi; Hong, Weiyi; Hu, Wei

    2017-07-01

    We discuss modulational instability (MI) in nonlocal optical Kerr media with a sine-oscillatory response which can model nematic liquid crystals with negative dielectric anisotropy. In the framework of nonlocal nonlinear Schrödinger equation, MI in this type of media is found to have two unique properties different from those in other media discussed previously. First, MI exists both when the Kerr coefficient is positive and when it is negative. Second, the maximum gain points of MI do not shift with light intensity. We also explore the physical mechanism behind MI in local and nonlocal optical Kerr media by utilizing the theory of four-wave mixing. Through introducing a phase mismatch term (Δk) and a growth factor (γ), we deduce that the necessary and sufficient condition for MI to occur is that the phase mismatching during the four-wave-mixing process should be small enough such that | Δk | < 2 | γ | . Based on this condition, we can uniformly and consistently explain the results of MI in optical Kerr media obtained in the current work as well as those presented in previous work by others.

  19. Polyadenylation of RNA transcribed from mammalian SINEs by RNA polymerase III: Complex requirements for nucleotide sequences.

    PubMed

    Borodulina, Olga R; Golubchikova, Julia S; Ustyantsev, Ilia G; Kramerov, Dmitri A

    2016-02-01

    It is generally accepted that only transcripts synthesized by RNA polymerase II (e.g., mRNA) were subject to AAUAAA-dependent polyadenylation. However, we previously showed that RNA transcribed by RNA polymerase III (pol III) from mouse B2 SINE could be polyadenylated in an AAUAAA-dependent manner. Many species of mammalian SINEs end with the pol III transcriptional terminator (TTTTT) and contain hexamers AATAAA in their A-rich tail. Such SINEs were united into Class T(+), whereas SINEs lacking the terminator and AATAAA sequences were classified as T(-). Here we studied the structural features of SINE pol III transcripts that are necessary for their polyadenylation. Eight and six SINE families from classes T(+) and T(-), respectively, were analyzed. The replacement of AATAAA with AACAAA in T(+) SINEs abolished the RNA polyadenylation. Interestingly, insertion of the polyadenylation signal (AATAAA) and pol III transcription terminator in T(-) SINEs did not result in polyadenylation. The detailed analysis of three T(+) SINEs (B2, DIP, and VES) revealed areas important for the polyadenylation of their pol III transcripts: the polyadenylation signal and terminator in A-rich tail, β region positioned immediately downstream of the box B of pol III promoter, and τ region located upstream of the tail. In DIP and VES (but not in B2), the τ region is a polypyrimidine motif which is also characteristic of many other T(+) SINEs. Most likely, SINEs of different mammals acquired these structural features independently as a result of parallel evolution. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Bilayer honeycomb lattice with ultracold atoms: Multiple Fermi surfaces and incommensurate spin density wave instability

    NASA Astrophysics Data System (ADS)

    Dey, Santanu; Sensarma, Rajdeep

    2016-12-01

    We propose an experimental setup using ultracold atoms to implement a bilayer honeycomb lattice with Bernal stacking. In the presence of a potential bias between the layers and at low densities, fermions placed in this lattice form an annular Fermi sea. The presence of two Fermi surfaces leads to interesting patterns in Friedel oscillations and RKKY interactions in the presence of impurities. Furthermore, a repulsive fermion-fermion interaction leads to a Stoner instability towards an incommensurate spin density wave order with a wave vector equal to the thickness of the Fermi sea. The instability occurs at a critical interaction strength which goes down with the density of the fermions. We find that the instability survives interaction renormalization due to vertex corrections and discuss how this can be seen in experiments. We also track the renormalization group flows of the different couplings between the fermionic degrees of freedom, and find that there are no perturbative instabilities, and that Stoner instability is the strongest instability which occurs at a critical threshold value of the interaction. The critical interaction goes to zero as the chemical potential is tuned towards the band bottom.

  1. Breather-like structures in modified sine-Gordon models

    NASA Astrophysics Data System (ADS)

    Ferreira, L. A.; Zakrzewski, Wojtek J.

    2016-05-01

    We report analytical and numerical results on breather-like field configurations in a theory which is a deformation of the integrable sine-Gordon model in (1  +  1) dimensions. The main motivation of our study is to test the ideas behind the recently proposed concept of quasi-integrability, which emerged from the observation that some field theories possess an infinite number of quantities which are asymptotically conserved in the scattering of solitons, and periodic in time in the case of breather-like configurations. Even though the mechanism responsible for such phenomena is not well understood yet, it is clear that special properties of the solutions under a space-time parity transformation play a crucial role. The numerical results of the present paper give support for the ideas on quasi-integrability, as it is found that extremely long-lived breather configurations satisfy these parity properties. We also report on a mechanism, particular to the theory studied here, that favours the existence of long lived breathers even in cases of significant deformations of the sine-Gordon potential. We also find numerically that our breather-like configurations decay through the gradual increase of their frequency of oscillations.

  2. V-SINEs: A New Superfamily of Vertebrate SINEs That Are Widespread in Vertebrate Genomes and Retain a Strongly Conserved Segment within Each Repetitive Unit

    PubMed Central

    Ogiwara, Ikuo; Miya, Masaki; Ohshima, Kazuhiko; Okada, Norihiro

    2002-01-01

    We have identified a new superfamily of vertebrate short interspersed repetitive elements (SINEs), designated V-SINEs, that are widespread in fishes and frogs. Each V-SINE includes a central conserved domain preceded by a 5′-end tRNA-related region and followed by a potentially recombinogenic (TG)n tract, with a 3′ tail derived from the 3′ untranslated region (UTR) of the corresponding partner long interspersed repetitive element (LINE) that encodes a functional reverse transcriptase. The central domain is strongly conserved and is even found in SINEs in the lamprey genome, suggesting that V-SINEs might be ∼550 Myr old or older in view of the timing of divergence of the lamprey lineage from the bony fish lineage. The central conserved domain might have been subject to some form of positive selection. Although the contemporary 3′ tails of V-SINEs differ from one another, it is possible that the original 3′ tail might have been replaced, via recombination, by the 3′ tails of more active partner LINEs, thereby retaining retropositional activity and the ability to survive for long periods on the evolutionary time scale. It seems plausible that V-SINEs may have some function(s) that have been maintained by the coevolution of SINEs and LINEs during the evolution of vertebrates. [The sequences reported in this paper have been deposited in the DDBJ/GenBank database under accession nos. AB072981–AB073004. Supplemental figures are available online at http://www.genome.org.] PMID:11827951

  3. Frequency-controlable sine signal based on PWM and its implementation on FPGA

    NASA Astrophysics Data System (ADS)

    Huang, Lianzhen; Li, Jiangang; Zhang, Dongjun

    2012-09-01

    A sine generation method that the different frequent sine signals can be generated by the different Pulse-Width Modulation (PWM) signals generated by Field-Programmable Gate Array (FPGA) through low-pass filter of fixed parameters was proposed. The method just takes a few FPGA resources and was proved feasible by the theory. The experiment results and theory analysis tally.

  4. RUDI, a short interspersed element of the V-SINE superfamily widespread in molluscan genomes.

    PubMed

    Luchetti, Andrea; Šatović, Eva; Mantovani, Barbara; Plohl, Miroslav

    2016-06-01

    Short interspersed elements (SINEs) are non-autonomous retrotransposons that are widespread in eukaryotic genomes. They exhibit a chimeric sequence structure consisting of a small RNA-related head, an anonymous body and an AT-rich tail. Although their turnover and de novo emergence is rapid, some SINE elements found in distantly related species retain similarity in certain core segments (or highly conserved domains, HCD). We have characterized a new SINE element named RUDI in the bivalve molluscs Ruditapes decussatus and R. philippinarum and found this element to be widely distributed in the genomes of a number of mollusc species. An unexpected structural feature of RUDI is the HCD domain type V, which was first found in non-amniote vertebrate SINEs and in the SINE from one cnidarian species. In addition to the V domain, the overall sequence conservation pattern of RUDI elements resembles that found in ancient AmnSINE (~310 Myr old) and Au SINE (~320 Myr old) families, suggesting that RUDI might be among the most ancient SINE families. Sequence conservation suggests a monophyletic origin of RUDI. Nucleotide variability and phylogenetic analyses suggest long-term vertical inheritance combined with at least one horizontal transfer event as the most parsimonious explanation for the observed taxonomic distribution.

  5. Novel SINEs families in Medicago truncatula and Lotus japonicus: bioinformatic analysis.

    PubMed

    Gadzalski, Marek; Sakowicz, Tomasz

    2011-07-01

    Although short interspersed elements (SINEs) were discovered nearly 30 years ago, the studies of these genomic repeats were mostly limited to animal genomes. Very little is known about SINEs in legumes--one of the most important plant families. Here we report identification, genomic distribution and molecular features of six novel SINE elements in Lotus japonicus (named LJ_SINE-1, -2, -3) and Medicago truncatula (MT_SINE-1, -2, -3), model species of legume. They possess all the structural features commonly found in short interspersed elements including RNA polymerase III promoter, polyA tail and flanking repeats. SINEs described here are present in low to moderate copy numbers from 150 to 3000. Bioinformatic analyses were used to searched public databases, we have shown that three of new SINE elements from M. truncatula seem to be characteristic of Medicago and Trifolium genera. Two SINE families have been found in L. japonicus and one is present in both M. truncatula and L. japonicus. In addition, we are discussing potential activities of the described elements. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Inverse PCR-based method for isolating novel SINEs from genome.

    PubMed

    Han, Yawei; Chen, Liping; Guan, Lihong; He, Shunping

    2014-04-01

    Short interspersed elements (SINEs) are moderately repetitive DNA sequences in eukaryotic genomes. Although eukaryotic genomes contain numerous SINEs copy, it is very difficult and laborious to isolate and identify them by the reported methods. In this study, the inverse PCR was successfully applied to isolate SINEs from Opsariichthys bidens genome in Eastern Asian Cyprinid. A group of SINEs derived from tRNA(Ala) molecular had been identified, which were named Opsar according to Opsariichthys. SINEs characteristics were exhibited in Opsar, which contained a tRNA(Ala)-derived region at the 5' end, a tRNA-unrelated region, and AT-rich region at the 3' end. The tRNA-derived region of Opsar shared 76 % sequence similarity with tRNA(Ala) gene. This result indicated that Opsar could derive from the inactive or pseudogene of tRNA(Ala). The reliability of method was tested by obtaining C-SINE, Ct-SINE, and M-SINEs from Ctenopharyngodon idellus, Megalobrama amblycephala, and Cyprinus carpio genomes. This method is simpler than the previously reported, which successfully omitted many steps, such as preparation of probes, construction of genomic libraries, and hybridization.

  7. Mobile Element Evolution Playing Jigsaw - SINEs in Gastropod and Bivalve Mollusks.

    PubMed

    Matetovici, Irina; Sajgo, Szilard; Ianc, Bianca; Ochis, Cornelia; Bulzu, Paul; Popescu, Octavian; Damert, Annette

    2016-01-06

    SINEs (Short INterspersed Elements) are widely distributed among eukaryotes. Some SINE families are organized in superfamilies characterized by a shared central domain. These central domains are conserved across species, classes, and even phyla. Here we report the identification of two novel such superfamilies in the genomes of gastropod and bivalve mollusks. The central conserved domain of the first superfamily is present in SINEs in Caenogastropoda and Vetigastropoda as well as in all four subclasses of Bivalvia. We designated the domain MESC (Romanian for MElc-snail and SCoica-mussel) because it appears to be restricted to snails and mussels. The second superfamily is restricted to Caenogastropoda. Its central conserved domain-Snail-is related to the Nin-DC domain. Furthermore, we provide evidence that a 40-bp subdomain of the SINE V-domain is conserved in SINEs in mollusks and arthropods. It is predicted to form a stable stem-loop structure that is preserved in the context of the overall SINE RNA secondary structure in invertebrates. Our analysis also recovered short retrotransposons with a Long INterspersed Element (LINE)-derived 5' end. These share the body and/or the tail with transfer RNA (tRNA)-derived SINEs within and across species. Finally, we identified CORE SINEs in gastropods and bivalves-extending the distribution range of this superfamily. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  8. Mobile Element Evolution Playing Jigsaw—SINEs in Gastropod and Bivalve Mollusks

    PubMed Central

    Matetovici, Irina; Sajgo, Szilard; Ianc, Bianca; Ochis, Cornelia; Bulzu, Paul; Popescu, Octavian; Damert, Annette

    2016-01-01

    SINEs (Short INterspersed Elements) are widely distributed among eukaryotes. Some SINE families are organized in superfamilies characterized by a shared central domain. These central domains are conserved across species, classes, and even phyla. Here we report the identification of two novel such superfamilies in the genomes of gastropod and bivalve mollusks. The central conserved domain of the first superfamily is present in SINEs in Caenogastropoda and Vetigastropoda as well as in all four subclasses of Bivalvia. We designated the domain MESC (Romanian for MElc—snail and SCoica—mussel) because it appears to be restricted to snails and mussels. The second superfamily is restricted to Caenogastropoda. Its central conserved domain—Snail—is related to the Nin-DC domain. Furthermore, we provide evidence that a 40-bp subdomain of the SINE V-domain is conserved in SINEs in mollusks and arthropods. It is predicted to form a stable stem-loop structure that is preserved in the context of the overall SINE RNA secondary structure in invertebrates. Our analysis also recovered short retrotransposons with a Long INterspersed Element (LINE)-derived 5′ end. These share the body and/or the tail with transfer RNA (tRNA)-derived SINEs within and across species. Finally, we identified CORE SINEs in gastropods and bivalves—extending the distribution range of this superfamily. PMID:26739168

  9. Optical study of the multiple charge-density-wave transitions in ErTe3

    NASA Astrophysics Data System (ADS)

    Hu, B. F.; Cheng, B.; Yuan, R. H.; Dong, T.; Fang, A. F.; Guo, W. T.; Chen, Z. G.; Zheng, P.; Shi, Y. G.; Wang, N. L.

    2011-10-01

    We present an optical spectroscopy study on singe crystalline ErTe3, a rare-earth-element tritelluride, which experiences two successive charge-density wave (CDW) transitions at Tc1=267 K and Tc2=150 K. Two corresponding gap features, centered at 2770 cm-1 (˜343 meV) and 890 cm-1 (˜110 meV), respectively, are clearly seen in ordered state. A pronounced Drude component, which exists at all measurement temperatures, demonstrates the partial gap character of both CDW orders. About half of the unmodulated Fermi surface (FS) remains in the CDW state at the lowest measurement temperature. The study also indicates that fluctuation effect may be still prominent in this two-dimensional material.

  10. Seismic‐wave attenuation determined from tectonic tremor in multiple subduction zones

    USGS Publications Warehouse

    Yabe, Suguru; Baltay, Annemarie S.; Ide, Satoshi; Beroza, Gregory C.

    2014-01-01

    Tectonic tremor provides a new source of observations that can be used to constrain the seismic attenuation parameter for ground‐motion prediction and hazard mapping. Traditionally, recorded earthquakes of magnitude ∼3–8 are used to develop ground‐motion prediction equations; however, typical earthquake records may be sparse in areas of high hazard. In this study, we constrain the distance decay of seismic waves using measurements of the amplitude decay of tectonic tremor, which is plentiful in some regions. Tectonic tremor occurs in the frequency band of interest for ground‐motion prediction (i.e., ∼2–8  Hz) and is located on the subducting plate interface, at the lower boundary of where future large earthquakes are expected. We empirically fit the distance decay of peak ground velocity from tremor to determine the attenuation parameter in four subduction zones: Nankai, Japan; Cascadia, United States–Canada; Jalisco, Mexico; and southern Chile. With the large amount of data available from tremor, we show that in the upper plate, the lower crust is less attenuating than the upper crust. We apply the same analysis to intraslab events in Nankai and show the possibility that waves traveling from deeper intraslab events experience more attenuation than those from the shallower tremor due to ray paths that pass through the subducting and highly attenuating oceanic crust. This suggests that high pore‐fluid pressure is present in the tremor source region. These differences imply that the attenuation parameter determined from intraslab earthquakes may underestimate ground motion for future large earthquakes on the plate interface.

  11. Comparison of renormalization group schemes for sine-Gordon-type models

    SciTech Connect

    Nandori, I.; Nagy, S.; Sailer, K.; Trombettoni, A.

    2009-07-15

    The scheme dependence of the renormalization group (RG) flow has been investigated in the local potential approximation for two-dimensional periodic, sine-Gordon type field-theoretic models discussing the applicability of various functional RG methods in detail. It was shown that scheme-independent determination of such physical parameters is possible as the critical frequency (temperature) at which Kosterlitz-Thouless-Berezinskii type phase transition takes place in the sine-Gordon and the layered sine-Gordon models, and the critical ratio characterizing the Ising-type phase transition of the massive sine-Gordon model. For the latter case, the Maxwell construction represents a strong constraint on the RG flow, which results in a scheme-independent infrared value for the critical ratio. For the massive sine-Gordon model also the shrinking of the domain of the phase with spontaneously broken periodicity is shown to take place due to the quantum fluctuations.

  12. Computer modeling of multiple-channel input signals and intermodulation losses caused by nonlinear traveling wave tube amplifiers

    NASA Technical Reports Server (NTRS)

    Stankiewicz, N.

    1982-01-01

    The multiple channel input signal to a soft limiter amplifier as a traveling wave tube is represented as a finite, linear sum of Gaussian functions in the frequency domain. Linear regression is used to fit the channel shapes to a least squares residual error. Distortions in output signal, namely intermodulation products, are produced by the nonlinear gain characteristic of the amplifier and constitute the principal noise analyzed in this study. The signal to noise ratios are calculated for various input powers from saturation to 10 dB below saturation for two specific distributions of channels. A criterion for the truncation of the series expansion of the nonlinear transfer characteristic is given. It is found that he signal to noise ratios are very sensitive to the coefficients used in this expansion. Improper or incorrect truncation of the series leads to ambiguous results in the signal to noise ratios.

  13. Hybrid functional for correlated electrons in the projector augmented-wave formalism: Study of multiple minima for actinide oxides

    NASA Astrophysics Data System (ADS)

    Jollet, F.; Jomard, G.; Amadon, B.; Crocombette, J. P.; Torumba, D.

    2009-12-01

    Exact (Hartree-Fock) exchange for correlated electrons is implemented to describe correlated orbitals in the projector augmented-waves (PAW) framework, as suggested recently in another context [P. Novák , Phys. Status Solidi B 243, 563 (2006)]. Hartree-Fock exchange energy is applied to strongly correlated electrons only inside the PAW atomic spheres. This allows the use of PBE0 hybrid exchange-correlation functional for correlated electrons. This method is tested on NiO and results agree well with already published results and generalized gradient approximation, GGA+U calculations. It is then applied to plutonium oxides and UO2 for which the results are comparable with the ones of GGA+U calculations but without adjustable parameter. As evidenced in the uranium oxide case, the occurrence of multiple energy minima may lead to very different results depending on the initial electronic configurations and on the symmetries taken into account in the calculation.

  14. Degenerate four-wave mixing in room-temperature GaAs/GaAlAs multiple quantum well structures

    NASA Astrophysics Data System (ADS)

    Miller, D. A. B.; Chemla, D. S.; Eilenberger, D. J.; Smith, P. W.; Gossard, A. C.; Wiegman, W.

    1983-06-01

    Degenerate four-wave mixing (DFWM) is of current interest both for practical applications (e.g., phase conjugation) and as a physical probe. DFWM makes it possible to detect very small nonlinear changes in refraction. In connection with the present investigation, the first observations of DFWM in GaAs/GaAlAs multiple quantum well structures (MQW's) at room temperature are reported. By combining DFWM and nonlinear absorption results, a direct measurement of the nonlinear refraction near the band gap of the MQW is conducted. The obtained value is compared with previous estimates. The measurements are of practical importance for possible low-power optical devices compatible with laser diodes based either on DFWM, nonlinear refraction (such as optical bistability) of nonlinear absorption. The MQW samples were grown by molecular beam epitaxy (MBE) on GaAs substrates, with the MQW layers sandwiched between GaAlAs cap layers which are transparent at the considered wavelengths.

  15. Segmentation of holter ECG waves via analysis of a discrete wavelet-derived multiple skewness-kurtosis based metric.

    PubMed

    Ghaffari, A; Homaeinezhad, M R; Khazraee, M; Daevaeiha, M M

    2010-04-01

    In this study, a simple mathematical-statistical based metric called Multiple Higher Order Moments (MHOM) is introduced enabling the electrocardiogram (ECG) detection-delineation algorithm to yield acceptable results in the cases of ambulatory holter ECG including strong noise, motion artifacts, and severe arrhythmia(s). In the MHOM measure, important geometric characteristics such as maximum value to minimum value ratio, area, extent of smoothness or being impulsive and distribution skewness degree (asymmetry), occult. In the proposed method, first three leads of high resolution 24-h holter data are extracted and preprocessed using Discrete Wavelet Transform (DWT). Next, a sample to sample sliding window is applied to preprocessed sequence and in each slid, mean value, variance, skewness, and kurtosis of the excerpted segment are superimposed called MHOM. The MHOM metric is then used as decision statistic to detect and delineate ECG events. To show advantages of the presented method, it is applied to MIT-BIH Arrhythmia Database, QT Database, and T-Wave Alternans Database and as a result, the average values of sensitivity and positive predictivity Se = 99.95% and P+ = 99.94% are obtained for the detection of QRS complexes, with the average maximum delineation error of 6.1, 4.1, and 6.5 ms for P-wave, QRS complex, and T-wave, respectively showing marginal improvement of detection-delineation performance. In the next step, the proposed method is applied to DAY hospital high resolution holter data (more than 1,500,000 beats including Bundle Branch Blocks--BBB, Premature Ventricular Complex--PVC, and Premature Atrial Complex-PAC) and average values of Se = 99.97% and P+ = 99.95% are obtained for QRS detection. In summary, marginal performance improvement of ECG events detection-delineation process, reliable robustness against strong noise, artifacts, and probable severe arrhythmia(s) of high resolution holter data can be mentioned as important merits and capabilities

  16. Low-frequency guided waves in a fluid-filled borehole: Simultaneous effects of generation and scattering due to multiple fractures

    NASA Astrophysics Data System (ADS)

    Minato, Shohei; Ghose, Ranajit

    2017-03-01

    Low-frequency, axially-symmetric guided waves which propagate along a fluid-filled borehole (tube waves) are studied in order to characterize the hydraulic fractures intersecting the borehole. We formulate a new equation for the total tube wavefield, which includes simultaneous effects of (1) tube-wave scattering (reflection and transmission) due to wave propagation across hydraulic fractures, and (2) tube-wave generation due to incident plane P waves. The fracture is represented by the nonwelded interface boundary conditions. We use an appropriate form of the representation theorem in order to correctly handle the multiple scattering due to nonwelded interfaces. Our approach can implement any model that has so far been developed. We consider a recent model which includes simultaneous effects of fluid viscosity, dynamic fluid flow, and fracture compliance. The derived equation offers a number of important insights. We recognize that the effective generation amplitude contains the simultaneous effect of both tube-wave generation and scattering. This leads to a new physical understanding indicating that the tube waves are scattered immediately after generation. We show that this scattering is nonlinear with respect to interface compliance. This physical mechanism can be implicitly accounted for by considering more realistic boundary conditions. We also illustrate the application of the new equation in order to predict the complex signature of the total tube wavefield, including generation and scattering at multiple hydraulic fractures. A new formulation for focusing analyses is also derived in order to image and characterize the hydraulic fractures. The obtained results and discussions are important for interpretation, modeling, and imaging using low-frequency guided waves, in the presence of multiple fractures along a cylindrical inclusion.

  17. Electron transport in graphene/graphene side-contact junction by plane-wave multiple-scattering method

    SciTech Connect

    Li, Xiang-Guo; Chu, Iek-Heng; Zhang, X. -G.; Cheng, Hai-Ping

    2015-05-28

    Electron transport in graphene is along the sheet but junction devices are often made by stacking different sheets together in a “side-contact” geometry which causes the current to flow perpendicular to the sheets within the device. Such geometry presents a challenge to first-principles transport methods. We solve this problem by implementing a plane-wave-based multiple-scattering theory for electron transport. In this study, this implementation improves the computational efficiency over the existing plane-wave transport code, scales better for parallelization over large number of nodes, and does not require the current direction to be along a lattice axis. As a first application, we calculate the tunneling current through a side-contact graphene junction formed by two separate graphene sheets with the edges overlapping each other. We find that transport properties of this junction depend strongly on the AA or AB stacking within the overlapping region as well as the vacuum gap between two graphene sheets. Finally, such transport behaviors are explained in terms of carbon orbital orientation, hybridization, and delocalization as the geometry is varied.

  18. Three-dimensional, prestack, plane wave migration of teleseismic P-to-S converted phases: 2. Stacking multiple events

    NASA Astrophysics Data System (ADS)

    Poppeliers, Christian; Pavlis, Gary L.

    2003-05-01

    In part 1 we developed the theoretical foundations of a prestack migration procedure to image forward scattered P to S (PdS) converted waves in the coda of teleseismic P waves. This paper addresses the issue of how to optimally stack data from multiple events migrated by this procedure. We apply matrix perturbation theory to develop an objective way to quantify noise in deconvolved PdS data. Application of the theory demonstrates that an optimal stack requires weighting the migrated data from each event by a signal-to-noise ratio criterion. We also find that the migrated PdS images have to be binned by back azimuth and balanced prior to the final stack. This is necessary to mitigate coherent noise that results from aliased microseism noise that is enhanced by our processing method. We processed 23 events recorded by the Lodore array in northwestern Colorado with our procedure. The results indicate the presence of a major, lithospheric scale discontinuity defined by a south dipping boundary within the crust that we interpret as the subsurface expression of the Cheyenne Belt. The suture is also marked by a transition in crustal thickness from 35 km on the Archean side to over 40 km on the Colorado Plateau side. We also observe a strong difference in the lithospheric mantle PdS conversion signature on opposite sides of the suture that suggests delamination and northward convergence of the Colorado lithosphere beneath the Wyoming province.

  19. On the propagation and multiple reflections of a blast wave travelling through a dusty gas in a closed box

    NASA Astrophysics Data System (ADS)

    Lappa, Marcello; Drikakis, Dimitris; Kokkinakis, Ioannis

    2017-03-01

    This paper concerns the propagation of shock waves in an enclosure filled with dusty gas. The main motivation for this problem is to probe the effect on such dynamics of solid particles dispersed in the fluid medium. This subject, which has attracted so much attention over recent years given its important implications in the study of the structural stability of systems exposed to high-energy internal detonations, is approached here in the framework of a hybrid numerical two-way coupled Eulerian-Lagrangian methodology. In particular, insights are sought by considering a relatively simple archetypal setting corresponding to a shock wave originating from a small spherical region initialized on the basis of available analytic solutions. The response of the system is explored numerically with respect to several parameters, including the blast intensity (via the related value of the initial shock Mach number), the solid mass fraction (mass load), and the particle size (Stokes number). Results are presented in terms of pressure-load diagrams. Beyond practical applications, it is shown that a kaleidoscope of fascinating patterns is produced by the "triadic" relationships among multiple shock reflection events and particle-fluid and particle-wall interaction dynamics. These would be of great interest to researchers and scientists interested in fundamental problems relating to the general theory of pattern formation in complex nonlinear multiphase systems.

  20. Electron transport in graphene/graphene side-contact junction by plane-wave multiple-scattering method

    DOE PAGES

    Li, Xiang-Guo; Chu, Iek-Heng; Zhang, X. -G.; ...

    2015-05-28

    Electron transport in graphene is along the sheet but junction devices are often made by stacking different sheets together in a “side-contact” geometry which causes the current to flow perpendicular to the sheets within the device. Such geometry presents a challenge to first-principles transport methods. We solve this problem by implementing a plane-wave-based multiple-scattering theory for electron transport. In this study, this implementation improves the computational efficiency over the existing plane-wave transport code, scales better for parallelization over large number of nodes, and does not require the current direction to be along a lattice axis. As a first application, wemore » calculate the tunneling current through a side-contact graphene junction formed by two separate graphene sheets with the edges overlapping each other. We find that transport properties of this junction depend strongly on the AA or AB stacking within the overlapping region as well as the vacuum gap between two graphene sheets. Finally, such transport behaviors are explained in terms of carbon orbital orientation, hybridization, and delocalization as the geometry is varied.« less

  1. Multiple Andreev reflections in s -wave superconductor-quantum dot-topological superconductor tunnel junctions and Majorana bound states

    NASA Astrophysics Data System (ADS)

    Golub, Anatoly

    2015-05-01

    We calculate the current as a function of applied voltage in a nontopological s -wave superconductor-quantum dot-topological superconductor (TS) tunnel junction. We consider the type of TS which hosts two Majorana bound states (MBSs) at the ends of a semiconductor quantum wire or of a chain of magnetic atoms in the proximity with an s -wave superconductor. We find that the I -V characteristic of such a system in the regime of big voltages has a typical two-dot shape and is ornamented by peaks of multiple Andreev reflections. We also consider the other options when the zero-energy states are created by disorder (hereby Shiba states) or by Andreev zero-energy bound states at the surface of a quantum dot and a superconductor. The later are obtained by tuning the magnetic field to a specific value. Unlike the last two cases the MBS I -V curves are robust to change the magnetic field. Therefore, the magnetic-field dependence of the tunneling current can serve as a unique signature for the presence of a MBS.

  2. Evolutionary modes of emergence of short interspersed nuclear element (SINE) families in grasses.

    PubMed

    Kögler, Anja; Schmidt, Thomas; Wenke, Torsten

    2017-08-30

    Short interspersed nuclear elements (SINEs) are non-autonomous transposable elements which are propagated by retrotransposition and constitute an inherent part of the genome of most eukaryotic species. Knowledge of heterogeneous and highly abundant SINEs is crucial for de novo (or improvement of) annotation of whole genome sequences. We scanned Poaceae genome sequences of six important cereals (Oryza sativa, Triticum aestivum, Hordeum vulgare, Panicum virgatum, Sorghum bicolor, Zea mays) and Brachypodium distachyon to examine the diversity and evolution of SINE populations. We comparatively analyzed the structural features, distribution, evolutionary relation and abundance of 32 SINE families and subfamilies within grasses, comprising 11 052 individual copies. The investigation of activity profiles within the Poaceae provides insights into their species-specific diversification and amplification. We found that Poaceae SINEs (PoaS) fall into two length categories: simple SINEs of up to 180 bp and dimeric SINEs larger than 240 bp. Detailed analysis at the nucleotide level revealed that multimerization of related and unrelated SINE copies is an important evolutionary mechanism of SINE formation. We conclude that PoaS families diversify by massive reshuffling between SINE families, likely caused by insertion of truncated copies, and provide a model for this evolutionary scenario. Twenty-eight of 32 PoaS families and subfamilies show significant conservation, in particular either in the 5' or 3' regions, across Poaceae species and share large sequence stretches with one or more other PoaS families. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  3. Early modern human dispersal from Africa: genomic evidence for multiple waves of migration.

    PubMed

    Tassi, Francesca; Ghirotto, Silvia; Mezzavilla, Massimo; Vilaça, Sibelle Torres; De Santi, Lisa; Barbujani, Guido

    2015-01-01

    Anthropological and genetic data agree in indicating the African continent as the main place of origin for anatomically modern humans. However, it is unclear whether early modern humans left Africa through a single, major process, dispersing simultaneously over Asia and Europe, or in two main waves, first through the Arab Peninsula into southern Asia and Oceania, and later through a northern route crossing the Levant. Here, we show that accurate genomic estimates of the divergence times between European and African populations are more recent than those between Australo-Melanesia and Africa and incompatible with the effects of a single dispersal. This difference cannot possibly be accounted for by the effects of either hybridization with archaic human forms in Australo-Melanesia or back migration from Europe into Africa. Furthermore, in several populations of Asia we found evidence for relatively recent genetic admixture events, which could have obscured the signatures of the earliest processes. We conclude that the hypothesis of a single major human dispersal from Africa appears hardly compatible with the observed historical and geographical patterns of genome diversity and that Australo-Melanesian populations seem still to retain a genomic signature of a more ancient divergence from Africa.

  4. Design and Synthesis of Antiblinking and Antibleaching Quantum Dots in Multiple Colors via Wave Function Confinement.

    PubMed

    Cao, Hujia; Ma, Junliang; Huang, Lin; Qin, Haiyan; Meng, Renyang; Li, Yang; Peng, Xiaogang

    2016-12-07

    Single-molecular spectroscopy reveals that photoluminescence (PL) of a single quantum dot blinks, randomly switching between bright and dim/dark states under constant photoexcitation, and quantum dots photobleach readily. These facts cast great doubts on potential applications of these promising emitters. After ∼20 years of efforts, synthesis of nonblinking quantum dots is still challenging, with nonblinking quantum dots only available in red-emitting window. Here we report synthesis of nonblinking quantum dots covering most part of the visible window using a new synthetic strategy, i.e., confining the excited-state wave functions of the core/shell quantum dots within the core quantum dot and its inner shells (≤ ∼5 monolayers). For the red-emitting ones, the new synthetic strategy yields nonblinking quantum dots with small sizes (∼8 nm in diameter) and improved nonblinking properties. These new nonblinking quantum dots are found to be antibleaching. Results further imply that the PL blinking and photobleaching of quantum dots are likely related to each other.

  5. A comparison of heat wave climatologies and trends in China based on multiple definitions

    NASA Astrophysics Data System (ADS)

    You, Qinglong; Jiang, Zhihong; Kong, Lei; Wu, Zhiwei; Bao, Yutao; Kang, Shichang; Pepin, Nick

    2017-06-01

    Heat waves (HWs) can have disastrous impacts on human activities and natural systems, and are one of the current foci of scientific research, particularly in the context of global warming. However, there is no standard definition of a HW, which makes assessment of temporal trends a challenge. In this study, based on daily mean, maximum and minimum temperature, and relative humidity datasets from China Meteorological Administration, the patterns, trends and variations of HW in China during 1961-2014 are investigated. Sixteen previously published HW indices (HIs) are calculated, which are divided into two types using relative and absolute threshold temperatures, respectively. During 1961-2014, both relative and absolute threshold HIs show the highest number of HW in Jianghua and South China, geographically consistent with the climate characteristics of China. The majority of HIs shows negative/positive trends of HW days before/after 1990 over the whole of China, but especially in Jianghua and South China, which reflects rapid warming since 1990. There are significant correlations among different HIs in the same type (both absolute and relative), but correlations are weak between relative and absolute threshold HIs. Because relative and absolute HIs show contrasting trends, the choice of HI is therefore critical for future analysis

  6. Neocortical dynamics at multiple scales: EEG standing waves, statistical mechanics, and physical analogs.

    PubMed

    Ingber, Lester; Nunez, Paul L

    2011-02-01

    The dynamic behavior of scalp potentials (EEG) is apparently due to some combination of global and local processes with important top-down and bottom-up interactions across spatial scales. In treating global mechanisms, we stress the importance of myelinated axon propagation delays and periodic boundary conditions in the cortical-white matter system, which is topologically close to a spherical shell. By contrast, the proposed local mechanisms are multiscale interactions between cortical columns via short-ranged non-myelinated fibers. A mechanical model consisting of a stretched string with attached nonlinear springs demonstrates the general idea. The string produces standing waves analogous to large-scale coherent EEG observed in some brain states. The attached springs are analogous to the smaller (mesoscopic) scale columnar dynamics. Generally, we expect string displacement and EEG at all scales to result from both global and local phenomena. A statistical mechanics of neocortical interactions (SMNI) calculates oscillatory behavior consistent with typical EEG, within columns, between neighboring columns via short-ranged non-myelinated fibers, across cortical regions via myelinated fibers, and also derives a string equation consistent with the global EEG model. Copyright © 2010 Elsevier Inc. All rights reserved.

  7. A comparison of heat wave climatologies and trends in China based on multiple definitions

    NASA Astrophysics Data System (ADS)

    You, Qinglong; Jiang, Zhihong; Kong, Lei; Wu, Zhiwei; Bao, Yutao; Kang, Shichang; Pepin, Nick

    2016-08-01

    Heat waves (HWs) can have disastrous impacts on human activities and natural systems, and are one of the current foci of scientific research, particularly in the context of global warming. However, there is no standard definition of a HW, which makes assessment of temporal trends a challenge. In this study, based on daily mean, maximum and minimum temperature, and relative humidity datasets from China Meteorological Administration, the patterns, trends and variations of HW in China during 1961-2014 are investigated. Sixteen previously published HW indices (HIs) are calculated, which are divided into two types using relative and absolute threshold temperatures, respectively. During 1961-2014, both relative and absolute threshold HIs show the highest number of HW in Jianghua and South China, geographically consistent with the climate characteristics of China. The majority of HIs shows negative/positive trends of HW days before/after 1990 over the whole of China, but especially in Jianghua and South China, which reflects rapid warming since 1990. There are significant correlations among different HIs in the same type (both absolute and relative), but correlations are weak between relative and absolute threshold HIs. Because relative and absolute HIs show contrasting trends, the choice of HI is therefore critical for future analysis

  8. New infinite-dimensional algebras, sine brackets, and SU (infinity)

    SciTech Connect

    Zachos, C.K.; Fairlie, D.B.

    1989-01-01

    We investigate the infinite dimensional algebras we have previously introduced, which involve trigonometric functions in their structure constants. We find a realization for them which provides a basis-independent formulation, identified with the algebra of sine brackets. A special family of them, the cyclotomic ones, contain SU(N) as invariant subalgebras. In this basis, it is evident by inspection that the algebra of SU(infinity) is equivalent to the centerless algebra of SDiff/sub 0/ on two-dimensional manifolds. Gauge theories of SU(infinity) are thus simply reformulated in terms of surface (sheet) coordinates. Spacetime-independent configurations of their gauge fields describe strings through the quadratic Schild action. 11 refs.

  9. Revisiting The Effect Of Sine Sweep Rate On Modal Identification

    NASA Astrophysics Data System (ADS)

    Roy, Nicolas; Girard, Alain

    2012-07-01

    Sine-sweep base excitation vibration tests are performed to qualify spacecraft structures in the low-frequency environment where the dynamic behavior can be characterized by a small number of modes. These modes can be extracted from the measured frequency response functions (FRF) by various modal identification methods, and then used for model validation purposes. If the sweep rate is too high, the steady-state response is not reached and the resulting FRF profile will be modified by the presence of transients. This has a direct effect on the modal parameters extracted from the FRF.Several authors have examined the effect of the sweep rate based on the response of a one-degree-of-freedom system. The goal of this paper is to adapt the approach to base-excitation vibration tests. Both increasing and decreasing exponential sweep rates are considered. The effect on the three principal modal parameters (natural frequency, damping and modal effective parameters) is examined.

  10. Langevin simulation of the chirally decomposed sine-Gordon model

    SciTech Connect

    Moriconi, L.; Moriconi, M.

    2005-07-01

    A large class of quantum and statistical field theoretical models, encompassing relevant condensed matter and non-Abelian gauge systems, are defined in terms of complex actions. As the ordinary Monte Carlo methods are useless in dealing with these models, alternative computational strategies have been proposed along the years. The Langevin technique, in particular, is known to be frequently plagued with difficulties such as strong numerical instabilities or subtle ergodic behavior. Regarding the chirally decomposed version of the sine-Gordon model as a prototypical case for the failure of the Langevin approach, we devise a truncation prescription in the stochastic differential equations which yields numerical stability and is assumed not to spoil the Berezinskii-Kosterlitz-Thouless transition. This conjecture is supported by a finite size scaling analysis, whereby a massive phase ending at a line of critical points is clearly observed for the truncated stochastic model.

  11. Zero temperature landscape of the random sine-Gordon model

    SciTech Connect

    Sanchez, A.; Bishop, A.R.; Cai, D.

    1997-04-01

    We present a preliminary summary of the zero temperature properties of the two-dimensional random sine-Gordon model of surface growth on disordered substrates. We found that the properties of this model can be accurately computed by using lattices of moderate size as the behavior of the model turns out to be independent of the size above certain length ({approx} 128 x 128 lattices). Subsequently, we show that the behavior of the height difference correlation function is of (log r){sup 2} type up to a certain correlation length ({xi} {approx} 20), which rules out predictions of log r behavior for all temperatures obtained by replica-variational techniques. Our results open the way to a better understanding of the complex landscape presented by this system, which has been the subject of very many (contradictory) analysis.

  12. SINEs of progress: Mobile element applications to molecular ecology.

    PubMed

    Ray, David A

    2007-01-01

    Mobile elements represent a unique and under-utilized set of tools for molecular ecologists. They are essentially homoplasy-free characters with the ability to be genotyped in a simple and efficient manner. Interpretation of the data generated using mobile elements can be simple compared to other genetic markers. They exist in a wide variety of taxa and are useful over a wide selection of temporal ranges within those taxa. Furthermore, their mode of evolution instills them with another advantage over other types of multilocus genotype data: the ability to determine loci applicable to a range of time spans in the history of a taxon. In this review, I discuss the application of mobile element markers, especially short interspersed elements (SINEs), to phylogenetic and population data, with an emphasis on potential applications to molecular ecology.

  13. Matrix formalism of electromagnetic wave propagation through multiple layers in the near-field region: application to the flat panel display.

    PubMed

    Lee, C Y; Lee, D E; Hong, Y K; Shim, J H; Jeong, C K; Joo, J; Zang, D S; Shim, M G; Lee, J J; Cha, J K; Yang, H G

    2003-04-01

    We have developed an electromagnetic (EM) wave propagation theory through a single layer and multiple layers in the near-field and far-field regions, and have constructed a matrix formalism in terms of the boundary conditions of the EM waves. From the shielding efficiency (SE) against EM radiation in the near-field region calculated by using the matrix formalism, we propose that the effect of multiple layers yields enhanced shielding capability compared to a single layer with the same total thickness in conducting layers as the multiple layers. We compare the intensities of an EM wave propagating through glass coated with conducting indium tin oxide (ITO) on one side and on both sides, applying it to the electromagnetic interference (EMI) shielding filter in a flat panel display such as a plasma display panel (PDP). From the measured intensities of EMI noise generated by a PDP loaded with ITO coated glass samples, the two-side coated glass shows a lower intensity of EMI noise compared to the one-side coated glass. The result confirms the enhancement of the SE due to the effect of multiple layers, as expected in the matrix formalism of EM wave propagation in the near-field region. In the far-field region, the two-side coated glass with ITO in multiple layers has a higher SE than the one-side coated glass with ITO, when the total thickness of ITO in both cases is the same.

  14. Multiple charge density wave transitions in the antiferromagnets R NiC2 (R =Gd ,Tb)

    NASA Astrophysics Data System (ADS)

    Shimomura, S.; Hayashi, C.; Hanasaki, N.; Ohnuma, K.; Kobayashi, Y.; Nakao, H.; Mizumaki, M.; Onodera, H.

    2016-04-01

    X-ray scattering and electrical resistivity measurements were performed on GdNiC2 and TbNiC2. We found a set of satellite peaks characterized by q1=(0.5 ,η ,0 ) below T1, at which the resistivity shows a sharp inflection, suggesting the charge density wave (CDW) formation. The value of η decreases with decreasing temperature below T1, and then a transition to a commensurate phase with q1 C=(0.5 ,0.5 ,0 ) takes place. The diffuse scattering observed above T1 indicates the presence of soft phonon modes associated with CDW instabilities at q1 and q2=(0.5 ,0.5 ,0.5 ) . The long-range order given by q2 is developed in addition to that given by q1 C in TbNiC2, while the short-range correlation with q2 persists even at 6 K in GdNiC2. The amplitude of the q1 C lattice modulation is anomalously reduced below an antiferromagnetic transition temperature TN in GdNiC2. In contrast, the q2 order vanishes below TN in TbNiC2. We demonstrate that R NiC2 (R = rare earth) compounds exhibit similarities with respect to their CDW phenomena, and discuss the effects of magnetic transitions on CDWs. We offer a possible displacement pattern of the modulated structure characterized by q1 C and q2 in terms of frustration.

  15. Accelerating the discontinuous Galerkin method for seismic wave propagation simulations using multiple GPUs with CUDA and MPI

    NASA Astrophysics Data System (ADS)

    Mu, Dawei; Chen, Po; Wang, Liqiang

    2013-12-01

    We have successfully ported an arbitrary high-order discontinuous Galerkin method for solving the three-dimensional isotropic elastic wave equation on unstructured tetrahedral meshes to multiple Graphic Processing Units (GPUs) using the Compute Unified Device Architecture (CUDA) of NVIDIA and Message Passing Interface (MPI) and obtained a speedup factor of about 28.3 for the single-precision version of our codes and a speedup factor of about 14.9 for the double-precision version. The GPU used in the comparisons is NVIDIA Tesla C2070 Fermi, and the CPU used is Intel Xeon W5660. To effectively overlap inter-process communication with computation, we separate the elements on each subdomain into inner and outer elements and complete the computation on outer elements and fill the MPI buffer first. While the MPI messages travel across the network, the GPU performs computation on inner elements, and all other calculations that do not use information of outer elements from neighboring subdomains. A significant portion of the speedup also comes from a customized matrix-matrix multiplication kernel, which is used extensively throughout our program. Preliminary performance analysis on our parallel GPU codes shows favorable strong and weak scalabilities.

  16. Reconstruction of the first-derivative EPR spectrum from multiple harmonics of the field-modulated continuous wave signal.

    PubMed

    Tseitlin, Mark; Eaton, Sandra S; Eaton, Gareth R

    2011-04-01

    Selection of the amplitude of magnetic field modulation for continuous wave electron paramagnetic resonance (EPR) often is a trade-off between sensitivity and resolution. Increasing the modulation amplitude improves the signal-to-noise ratio, S/N, at the expense of broadening the signal. Combining information from multiple harmonics of the field-modulated signal is proposed as a method to obtain the first derivative spectrum with minimal broadening and improved signal-to-noise. The harmonics are obtained by digital phase-sensitive detection of the signal at the modulation frequency and its integer multiples. Reconstruction of the first-derivative EPR line is done in the Fourier conjugate domain where each harmonic can be represented as the product of the Fourier transform of the 1st derivative signal with an analytical function. The analytical function for each harmonic can be viewed as a filter. The Fourier transform of the 1st derivative spectrum can be calculated from all available harmonics by solving an optimization problem with the goal of maximizing the S/N. Inverse Fourier transformation of the result produces the 1st derivative EPR line in the magnetic field domain. The use of modulation amplitude greater than linewidth improves the S/N, but does not broaden the reconstructed spectrum. The method works for an arbitrary EPR line shape, but is limited to the case when magnetization instantaneously follows the modulation field, which is known as the adiabatic approximation. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Reconstruction of the first derivative EPR spectrum from multiple harmonics of the field-modulated continuous wave signal

    PubMed Central

    Tseitlin, Mark; Eaton, Sandra S.; Eaton, Gareth R.

    2011-01-01

    Selection of the amplitude of magnetic field modulation for continuous wave electron paramagnetic resonance (EPR) often is a trade-off between sensitivity and resolution. Increasing the modulation amplitude improves the signal-to-noise ratio, S/N, at the expense of broadening the signal. Combining information from multiple harmonics of the field-modulated signal is proposed as a method to obtain the first derivative spectrum with minimal broadening and improved signal-to-noise. The harmonics are obtained by digital phase-sensitive detection of the signal at the modulation frequency and its integer multiples. Reconstruction of the first derivative EPR line is done in the Fourier conjugate domain where each harmonic can be represented as the product of the Fourier transform of the 1st derivative signal with an analytical function. The analytical function for each harmonic can be viewed as a filter. The Fourier transform of the 1st derivative spectrum can be calculated from all available harmonics by solving an optimization problem with the goal of maximizing the S/N. Inverse Fourier transformation of the result produces the 1st derivative EPR line in the magnetic field domain. The use of modulation amplitude greater than linewidth improves the S/N, but does not broaden the reconstructed spectrum. The method works for an arbitrary EPR line shape, but is limited to the case when magnetization instantaneously follows the modulation field, which is known as the adiabatic approximation. PMID:21349750

  18. P-wave travel-time tomography reveals multiple mantle upwellings beneath the northern East-Africa Rift

    NASA Astrophysics Data System (ADS)

    Hammond, J. O. S.; Civiero, C.; Goes, S. D. B.; Ahmed, A.; Ayele, A.; Doubre, C.; Goitom, B.; Keir, D.; Kendall, M.; Leroy, S. D.; Ogubazghi, G.; Rumpker, G.; Stuart, G. W.

    2014-12-01

    The East African Rift (EAR) shows evidence for active magmatism from the eruption of flood basalts 30 Ma to active volcanism associated with rifting today. Mantle plumes have been invoked as the likely cause. However, the nature of mantle upwelling is debated, with proposed models ranging from a single broad plume, the African Superplume, connected to the LLSVP beneath Southern Africa, to multiple distinct sources of upwelling along the East-Africa Rift. We present a new relative travel-time tomography model that images detailed P-wave velocities below the northern East-African rift from the surface to lower mantle depths. Data comes from 439 stations that cover the area from Tanzania to Saudi Arabia. The aperture of the integrated dataset allows us to image for the first time low-velocity structures of ~ 100-km length scales down to depths of 900 km beneath this region. Our images provide evidence of at least two separate low-velocity structures with a diameter of ~200 km that continue through the transition zone and into the lower mantle: the first, and most pronounced, is beneath the Afar Depression, which extends to at least 900 km depth and a second is located beneath the Main Ethiopian Rift that extends to at least 750 km. Taking into account seismic sensitivity to temperature and thermally controlled phase boundary topography, we interpret these features as multiple focused upwellings from below the transition zone with excess temperatures of ~ 100-150 K. Such temperatures are also fully consistent with previous petrological and other geophysical estimates. Furthermore, the separate structures could explain differences in geochemistry of erupted magmas along the rift zone, as well as the dynamic topography seen at the surface. Our findings thus support the involvement of multiple plumes in the evolution of the EAR and a direct connection between lower mantle features and the volcanism at the surface.

  19. Detection of briefly flashed sine-gratings in dark-adapted vision.

    PubMed

    Hofmann, M I; Barnes, C S; Hallett, P E

    1990-01-01

    Scotopic contrast sensitivity was measured near 20 deg retinal eccentricity for briefly flashed (10 or 20 msec) sine-wave gratings presented in darkness to dark-adapted subjects. For very low spatial frequencies (0.2-0.5 c/deg), curves of contrast sensitivity vs luminous energy show evidence of a low rod plateau and a high scotopic region, with an intervening transition at around -2 to -2.5 log scot td sec. Similar measurements made using long flashed or flickering gratings do not show a plateau. The results suggest that vision in the low rod region is impaired for brief flashes. For the briefly flashed stimuli, curves of contrast sensitivity versus spatial frequency in the low region were best fit by simple Gaussian functions with a variable centre size (sigma c = 0.5----0.25 deg), size decreasing with increasing flash energy. Difference-of-Gaussian functions with constant centre size (sigma c = 0.25 deg) provided the best fit in the high region. Overt input from the cones and grating area artefacts are excluded by appropriate tests. Calculation of photon flux into the receptive field centres suggests that signal compression in P alpha ganglion cells contributes to the low rod plateau.

  20. Sine-Gordon modulation solutions: Application to macroscopic non-lubricant friction

    NASA Astrophysics Data System (ADS)

    Gershenzon, Naum I.; Bambakidis, Gust; Skinner, Thomas E.

    2016-10-01

    The Frenkel-Kontorova (FK) model and its continuum approximation, the sine-Gordon (SG) equation, are widely used to model a variety of important nonlinear physical systems. Many practical applications require the wave-train solution, which includes many solitons. In such cases, an important and relevant extension of these models applies Whitham's averaging procedure to the SG equation. The resulting SG modulation equations describe the behavior of important measurable system parameters that are the average of the small-scale solutions given by the SG equation. A fundamental problem of modern physics that is the topic of this paper is the description of the transitional process from a static to a dynamic frictional regime. We have shown that the SG modulation equations are a suitable apparatus for describing this transition. The model provides relations between kinematic (rupture and slip velocities) and dynamic (shear and normal stresses) parameters of the transition process. A particular advantage of the model is its ability to describe frictional processes over a wide range of rupture and slip velocities covering seismic events ranging from regular earthquakes, with rupture velocities on the order of a few km/s, to slow slip events, with rupture velocities on the order of a few km/day.

  1. MULTIPLE SCATTERING OF WAVES BY A PAIR OF GRAVITATIONALLY STRATIFIED FLUX TUBES

    SciTech Connect

    Hanasoge, Shravan M.; Cally, Paul S.

    2009-05-20

    We study the near-field coupling of a pair of flux tubes embedded in a gravitationally stratified environment. The mutual induction of the near-field jackets of the two flux tubes can considerably alter the scattering properties of the system, resulting in sizable changes in the magnitudes of scattering coefficients and bizarre trends in the phases. The dominant length scale governing the induction zone turns out to be approximately half the horizontal wavelength of the incident mode, a result that fits in quite pleasantly with extant theories of scattering. Higher-{beta} flux tubes are more strongly coupled than weaker ones, a consequence of the greater role that the near-field jacket modes play in such tubes. We also comment on the importance of incorporating the effects of multiple scattering when studying the effects of mode absorption in plage and interpreting related scattering measurements. That the near field plays such an important role in the scattering process lends encouragement to the eventual goal of observationally resolving subwavelength features of flux tubes using techniques of helioseismology.

  2. Can SINEs: a family of tRNA-derived retroposons specific to the superfamily Canoidea.

    PubMed Central

    Coltman, D W; Wright, J M

    1994-01-01

    A repetitive element of approximately 200 bp was cloned from harbour seal (Phoca vitulina concolour) genomic DNA. The sequence of the element revealed putative RNA polymerase III control boxes, a poly A tail and direct terminal repeats characteristic of SINEs. Sequence and secondary structural similarities suggest that the SINE is derived from a tRNA, possibly tRNA-alanine. Southern blot analysis indicated that the element is predominately dispersed in unique regions of the seal genome, but may also be present in other repetitive sequences, such as tandemly arrayed satellite DNA. Based on slot-blot hybridization analysis, we estimate that 1.3 x 10(6) copies of the SINE are present in the harbour seal genome; SINE copy number based on the number of clones isolated from a size-selected library, however, is an order of magnitude lower (1-3 x 10(5) copies), an estimate consistent with the abundance of SINEs in other mammalian genomes. Database searches found similar sequences have been isolated from dog (Canis familiaris) and mink (Mustela vison). These, and the seal SINE sequences are characterized by an internal CT dinucleotide microsatellite in the tRNA-unrelated region. Hybridization of genomic DNA from representative species of a wide range of mammalian orders to an oligonucleotide (30mer) probe complementary to a conserved region of the SINE confirmed that the element is unique to carnivores of the superfamily Canoidea. Images PMID:8052527

  3. Selective inhibitors of nuclear export (SINE) as novel therapeutics for prostate cancer

    PubMed Central

    Kim, Hae-Soo; Hammers, Hans; Meeker, Alan; De Marzo, Angelo; Carducci, Michael; Kauffman, Michael; Shacham, Sharon; Kachhap, Sushant

    2014-01-01

    Mislocalization of proteins is a common feature of cancer cells. Since localization of proteins is tightly linked to its function, cancer cells can inactivate function of a tumor suppressor protein through mislocalization. The nuclear exportin CRM1/XPO 1 is upregulated in many cancers. Targeting XPO 1 can lead to nuclear retention of cargo proteins such as p53, Foxo, and BRCA1 leading to cell cycle arrest and apoptosis. We demonstrate that selective inhibitors of nuclear export (SINE) can functionally inactivate XPO 1 in prostate cancer cells. Unlike the potent, but toxic, XPO 1 inhibitor leptomycin B, SINE inhibitors (KPT-185, KPT-330, and KPT-251) cause a decrease in XPO 1 protein level through the proteasomal pathway. Treatment of prostate cancer cells with SINE inhibitors lead to XPO 1 inhibition, as evaluated by RevGFP export assay, leading to nuclear retention of p53 and Foxo proteins, consequently, triggering apoptosis. Our data reveal that treatment with SINE inhibitors at nanomolar concentrations results in decrease in proliferation and colonogenic capacity of prostate cancer cells by triggering apoptosis without causing any cell cycle arrest. We further demonstrate that SINE inhibitors can be combined with other chemotherapeutics like doxorubicin to achieve enhanced growth inhibition of prostate cancer cells. Since SINE inhibitors offer increased bioavailability, reduced toxicity to normal cells, and are orally available they can serve as effective therapeutics against prostate cancer. In conclusion, our data reveals that nucleocytoplasmic transport in prostate cancer can be effectively targeted by SINE inhibitors. PMID:25026284

  4. Selective inhibitors of nuclear export (SINE) as novel therapeutics for prostate cancer.

    PubMed

    Mendonca, Janet; Sharma, Anup; Kim, Hae-Soo; Hammers, Hans; Meeker, Alan; De Marzo, Angelo; Carducci, Michael; Kauffman, Michael; Shacham, Sharon; Kachhap, Sushant

    2014-08-15

    Mislocalization of proteins is a common feature of cancer cells. Since localization of proteins is tightly linked to its function, cancer cells can inactivate function of a tumor suppressor protein through mislocalization. The nuclear exportin CRM1/XPO 1 is upregulated in many cancers. Targeting XPO 1 can lead to nuclear retention of cargo proteins such as p53, Foxo, and BRCA1 leading to cell cycle arrest and apoptosis. We demonstrate that selective inhibitors of nuclear export (SINE) can functionally inactivate XPO 1 in prostate cancer cells. Unlike the potent, but toxic, XPO 1 inhibitor leptomycin B, SINE inhibitors (KPT-185, KPT-330, and KPT-251) cause a decrease in XPO 1 protein level through the proteasomal pathway. Treatment of prostate cancer cells with SINE inhibitors lead to XPO 1 inhibition, as evaluated by RevGFP export assay, leading to nuclear retention of p53 and Foxo proteins, consequently, triggering apoptosis. Our data reveal that treatment with SINE inhibitors at nanomolar concentrations results in decrease in proliferation and colonogenic capacity of prostate cancer cells by triggering apoptosis without causing any cell cycle arrest. We further demonstrate that SINE inhibitors can be combined with other chemotherapeutics like doxorubicin to achieve enhanced growth inhibition of prostate cancer cells. Since SINE inhibitors offer increased bioavailability, reduced toxicity to normal cells, and are orally available they can serve as effective therapeutics against prostate cancer. In conclusion, our data reveals that nucleocytoplasmic transport in prostate cancer can be effectively targeted by SINE inhibitors.

  5. Characterization of Three Novel SINE Families with Unusual Features in Helicoverpa armigera

    PubMed Central

    Wang, Jianjun; Wang, Aina; Han, Zhaojun; Zhang, Zan; Li, Fei; Li, Xianchun

    2012-01-01

    Although more than 120 families of short interspersed nuclear elements (SINEs) have been isolated from the eukaryotic genomes, little is known about SINEs in insects. Here, we characterize three novel SINEs from the cotton bollworm, Helicoverpa armigera. Two of them, HaSE1 and HaSE2, share similar 5′ -structure including a tRNA-related region immediately followed by conserved central domain. The 3′ -tail of HaSE1 is significantly similar to that of one LINE retrotransposon element, HaRTE1.1, in H. armigera genome. The 3′ -region of HaSE2 showed high identity with one mariner-like element in H. armigera. The third family, termed HaSE3, is a 5S rRNA-derived SINE and shares both body part and 3′-tail with HaSE1, thus may represent the first example of a chimera generated by recombination between 5S rRNA and tRNA-derived SINE in insect species. Further database searches revealed the presence of these SINEs in several other related insect species, but not in the silkworm, Bombyx mori, indicating a relatively narrow distribution of these SINEs in Lepidopterans. Apart from above, we found a copy of HaSE2 in the GenBank EST entry for the cotton aphid, Aphis gossypii, suggesting the occurrence of horizontal transfer. PMID:22319625

  6. Short interspersed transposable elements (SINEs) are excluded from imprinted regions in the human genome.

    PubMed

    Greally, John M

    2002-01-08

    To test whether regions undergoing genomic imprinting have unique genomic characteristics, imprinted and nonimprinted human loci were compared for nucleotide and retroelement composition. Maternally and paternally expressed subgroups of imprinted genes were found to differ in terms of guanine and cytosine, CpG, and retroelement content, indicating a segregation into distinct genomic compartments. Imprinted regions have been normally permissive to L1 long interspersed transposable element retroposition during mammalian evolution but universally and significantly lack short interspersed transposable elements (SINEs). The primate-specific Alu SINEs, as well as the more ancient mammalian-wide interspersed repeat SINEs, are found at significantly low densities in imprinted regions. The latter paleogenomic signature indicates that the sequence characteristics of currently imprinted regions existed before the mammalian radiation. Transitions from imprinted to nonimprinted genomic regions in cis are characterized by a sharp inflection in SINE content, demonstrating that this genomic characteristic can help predict the presence and extent of regions undergoing imprinting. During primate evolution, SINE accumulation in imprinted regions occurred at a decreased rate compared with control loci. The constraint on SINE accumulation in imprinted regions may be mediated by an active selection process. This selection could be because of SINEs attracting and spreading methylation, as has been found at other loci. Methylation-induced silencing could lead to deleterious consequences at imprinted loci, where inactivation of one allele is already established, and expression is often essential for embryonic growth and survival.

  7. Epigenetic regulation of transcription and possible functions of mammalian short interspersed elements, SINEs.

    PubMed

    Ichiyanagi, Kenji

    2013-01-01

    Short interspersed elements (SINEs) are a class of retrotransposons, which amplify their copy numbers in their host genomes by retrotransposition. More than a million copies of SINEs are present in a mammalian genome, constituting over 10% of the total genomic sequence. In contrast to the other two classes of retrotransposons, long interspersed elements (LINEs) and long terminal repeat (LTR) elements, SINEs are transcribed by RNA polymerase III. However, like LINEs and LTR elements, the SINE transcription is likely regulated by epigenetic mechanisms such as DNA methylation, at least for human Alu and mouse B1. Whereas SINEs and other transposable elements have long been thought as selfish or junk DNA, recent studies have revealed that they play functional roles at their genomic locations, for example, as distal enhancers, chromatin boundaries and binding sites of many transcription factors. These activities imply that SINE retrotransposition has shaped the regulatory network and chromatin landscape of their hosts. Whereas it is thought that the epigenetic mechanisms were originated as a host defense system against proliferation of parasitic elements, this review discusses a possibility that the same mechanisms are also used to regulate the SINE-derived functions.

  8. Short interspersed transposable elements (SINEs) are excluded from imprinted regions in the human genome

    PubMed Central

    Greally, John M.

    2002-01-01

    To test whether regions undergoing genomic imprinting have unique genomic characteristics, imprinted and nonimprinted human loci were compared for nucleotide and retroelement composition. Maternally and paternally expressed subgroups of imprinted genes were found to differ in terms of guanine and cytosine, CpG, and retroelement content, indicating a segregation into distinct genomic compartments. Imprinted regions have been normally permissive to L1 long interspersed transposable element retroposition during mammalian evolution but universally and significantly lack short interspersed transposable elements (SINEs). The primate-specific Alu SINEs, as well as the more ancient mammalian-wide interspersed repeat SINEs, are found at significantly low densities in imprinted regions. The latter paleogenomic signature indicates that the sequence characteristics of currently imprinted regions existed before the mammalian radiation. Transitions from imprinted to nonimprinted genomic regions in cis are characterized by a sharp inflection in SINE content, demonstrating that this genomic characteristic can help predict the presence and extent of regions undergoing imprinting. During primate evolution, SINE accumulation in imprinted regions occurred at a decreased rate compared with control loci. The constraint on SINE accumulation in imprinted regions may be mediated by an active selection process. This selection could be because of SINEs attracting and spreading methylation, as has been found at other loci. Methylation-induced silencing could lead to deleterious consequences at imprinted loci, where inactivation of one allele is already established, and expression is often essential for embryonic growth and survival. PMID:11756672

  9. Multiplicity

    DTIC Science & Technology

    1991-04-01

    practice as a "[descent] into that inner circle of the Inferno where the damned endlessly degate multiplicity for sentencing." United States v. Barnard...select the charges to be brought in a particular case"). 19 Brown v. Ohio, 432 U.S. 161, 165 (1977). 20 Whalen v. United States, 445 U.S. at 689. 21...parte Lange, 8-5 U.S. (19 Wall.) 163 (1874). Cf. Brown v. Ohio, 432 U.S. at 165 ("once the legislature has acted courts may not impose more than one

  10. Core-SINE blocks comprise a large fraction of monotreme genomes; implications for vertebrate chromosome evolution.

    PubMed

    Kirby, Patrick J; Greaves, Ian K; Koina, Edda; Waters, Paul D; Marshall Graves, Jennifer A

    2007-01-01

    The genomes of the egg-laying platypus and echidna are of particular interest because monotremes are the most basal mammal group. The chromosomal distribution of an ancient family of short interspersed repeats (SINEs), the core-SINEs, was investigated to better understand monotreme genome organization and evolution. Previous studies have identified the core-SINE as the predominant SINE in the platypus genome, and in this study we quantified, characterized and localized subfamilies. Dot blot analysis suggested that a very large fraction (32% of the platypus and 16% of the echidna genome) is composed of Mon core-SINEs. Core-SINE-specific primers were used to amplify PCR products from platypus and echidna genomic DNA. Sequence analysis suggests a common consensus sequence Mon 1-B, shared by platypus and echidna, as well as platypus-specific Mon 1-C and echidna specific Mon 1-D consensus sequences. FISH mapping of the Mon core-SINE products to platypus metaphase spreads demonstrates that the Mon-1C subfamily is responsible for the striking Mon core-SINE accumulation in the distal regions of the six large autosomal pairs and the largest X chromosome. This unusual distribution highlights the dichotomy between the seven large chromosome pairs and the 19 smaller pairs in the monotreme karyotype, which has some similarity to the macro- and micro-chromosomes of birds and reptiles, and suggests that accumulation of repetitive sequences may have enlarged small chromosomes in an ancestral vertebrate. In the forthcoming sequence of the platypus genome there are still large gaps, and the extensive Mon core-SINE accumulation on the distal regions of the six large autosomal pairs may provide one explanation for this missing sequence.

  11. Occurrence of Can-SINEs and intron sequence evolution supports robust phylogeny of pinniped carnivores and their terrestrial relatives.

    PubMed

    Schröder, Christiane; Bleidorn, Christoph; Hartmann, Stefanie; Tiedemann, Ralph

    2009-12-15

    Investigating the dog genome we found 178965 introns with a moderate length of 200-1000 bp. A screening of these sequences against 23 different repeat libraries to find insertions of short interspersed elements (SINEs) detected 45276 SINEs. Virtually all of these SINEs (98%) belong to the tRNA-derived Can-SINE family. Can-SINEs arose about 55 million years ago before Carnivora split into two basal groups, the Caniformia (dog-like carnivores) and the Feliformia (cat-like carnivores). Genome comparisons of dog and cat recovered 506 putatively informative SINE loci for caniformian phylogeny. In this study we show how to use such genome information of model organisms to research the phylogeny of related non-model species of interest. Investigating a dataset including representatives of all major caniformian lineages, we analysed 24 randomly chosen loci for 22 taxa. All loci were amplifiable and revealed 17 parsimony-informative SINE insertions. The screening for informative SINE insertions yields a large amount of sequence information, in particular of introns, which contain reliable phylogenetic information as well. A phylogenetic analysis of intron- and SINE sequence data provided a statistically robust phylogeny which is congruent with the absence/presence pattern of our SINE markers. This phylogeny strongly supports a sistergroup relationship of Musteloidea and Pinnipedia. Within Pinnipedia, we see strong support from bootstrapping and the presence of a SINE insertion for a sistergroup relationship of the walrus with the Otariidae.

  12. Sand ripples under water with complex wave motion.

    PubMed

    Scheibye-Knudsen, K; Ellegaard, C; Bundgaard, F; Sams, Thomas

    2005-07-01

    Experiments studying ripple formation under water have usually used sinusoidal driving force. Here an experiment is presented where the driving force can be an arbitrary wave form, thus trying to mimic the realistic wave motion in shallow water coastal zones. We study a simple modulated sine wave and more complicated wave forms with several superposed harmonics. In particular we demonstrate how a small higher order harmonic can have a dramatic effect on the wavelength of the ripple pattern.

  13. Mixed simulation of the multiple elastic scattering of electrons and positrons using partial-wave differential cross-sections

    NASA Astrophysics Data System (ADS)

    Benedito, E.; Fernández-Varea, J. M.; Salvat, F.

    2001-03-01

    We describe an algorithm for mixed (class II) simulation of electron multiple elastic scattering using numerical differential cross-sections (DCS), which is applicable in a wide energy range, from ˜100 eV to ˜1 GeV. DCSs are calculated by partial-wave analysis, or from a suitable high-energy approximation, and tabulated on a grid of scattering angles and electron energies. The size of the required DCS table is substantially reduced by means of a change of variable that absorbs most of the energy dependence of the DCS. That is, the scattering angle θ is replaced by a variable u, whose probability distribution function varies smoothly with the kinetic energy of the electron. A fast procedure to generate random values of u in restricted intervals is described. The algorithm for the simulation of electron transport in pure elastic scattering media (with energy-loss processes switched off) is obtained by combining this sampling procedure with a simple model for space displacements. The accuracy and stability of this algorithm is demonstrated by comparing results with those from detailed, event by event, simulations using the same DCSs. A complete transport code, including energy losses and the production of secondary radiations, is obtained by coupling the present elastic scattering simulation algorithm to the general-purpose Monte Carlo program PENELOPE. Simulated angular distributions of MeV electrons backscattered in aluminium and gold are in good agreement with experimental data.

  14. Sorting photon wave packets using temporal-mode interferometry based on multiple-stage quantum frequency conversion

    NASA Astrophysics Data System (ADS)

    Reddy, D. V.; Raymer, M. G.; McKinstrie, C. J.

    2015-01-01

    All classical and quantum technologies that encode in and retrieve information from optical fields rely on the ability to selectively manipulate orthogonal field modes of light. Such manipulation can be achieved with high selectivity for polarization modes and transverse-spatial modes. For the time-frequency degree of freedom, this could efficiently be achieved for a limited choice of approximately orthogonal modes, i.e., nonoverlapping bins in time or frequency. We recently proposed a method that surmounts the selectivity barrier for sorting arbitrary orthogonal temporal modes [Opt. Lett. 39, 2924 (2014)., 10.1364/OL.39.002924] using cascaded interferometric quantum frequency conversion in nonlinear optical media. We call this method temporal-mode interferometry, as it has a close resemblance to the well-known separated-fields atomic interferometry method introduced by Ramsey. The method has important implications for quantum memories, quantum dense coding, quantum teleportation, and quantum key distribution. Here we explore the inner workings of the method in detail, and extend it to multiple stages with a concurrent asymptotic convergence of temporal-mode selectivity to unity. We also complete our analysis of pump-chirp compensation to counter pump-induced nonlinear phase modulation in four-wave mixing implementations.

  15. Development of a multi-frequency diffuse photon density wave device for the characterization of tissue damage at multiple depths

    NASA Astrophysics Data System (ADS)

    Diaz, David; Weingarten, Michael S.; Neidrauer, Michael T.; Samuels, Joshua A.; Huneke, Richard B.; Kuzmin, Vladimir L.; Lewin, Peter A.; Zubkov, Leonid A.

    2014-02-01

    The ability to determine the depth and degree of cutaneous and subcutaneous tissue damage is critical for medical applications such as burns and pressure ulcers. The Diffuse Photon Density Wave (DPDW) methodology at near infrared wavelengths can be used to non-invasively measure the optical absorption and reduced scattering coefficients of tissue at depths of several millimeters. A multi-frequency DPDW system with one light source and one detector was constructed so that light is focused onto the tissue surface using an optical fiber and lens mounted to a digitally-controlled actuator which changes the distance between light source and detector. A variable RF generator enables the modulation frequency to be selected between 50 to 400MHz. The ability to digitally control both source-detector separation distance and modulation frequency allows for virtually unlimited number of data points, enabling precise selection of the volume and depth of tissue that will be characterized. Suspensions of Intralipid and india ink with known absorption and reduced scattering coefficients were used as optical phantoms to assess device accuracy. Solid silicon phantoms were formulated for stability testing. Standard deviations for amplitude and phase shift readings were found to be 0.9% and 0.2 degrees respectively, over a one hour period. The ability of the system to quantify tissue damage in vivo at multiple depths was tested in a porcine burn model.

  16. SINE polymorphism reveals distinct strains of Entamoeba histolytica from North India.

    PubMed

    Sharma, Shraddha; Banyal, Neha; Singh, Mukul; Mandal, A K; Bhattacharya, Sudha; Paul, Jaishree

    2017-04-01

    Entamoeba histolytica is an intestinal parasite causing significant morbidity and mortality in the developing world. More tools are needed to understand the epidemiology and molecular pathogenesis of amebiasis. Virulence pattern of E. histolytica could be linked with the genotype of a strain. Several loci showing insertion polymorphism of retrotransposable short interspersed nuclear elements EhSINE1 and EhSINE2 have been reported among laboratory strains of E. histolytica. The present study was undertaken to validate this observation in clinical isolates from north India. Our results indicate that the Indian samples show a different propensity of SINE retention or loss at two of the polymorphic loci compared with non-Indian samples. Statistical analysis of different loci revealed Locus 17 of EhSINE1as a potential geographical marker for distinguishing Indian isolates from non Indian isolates. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Sine Rotation Vector Method for Attitude Estimation of an Underwater Robot

    PubMed Central

    Ko, Nak Yong; Jeong, Seokki; Bae, Youngchul

    2016-01-01

    This paper describes a method for estimating the attitude of an underwater robot. The method employs a new concept of sine rotation vector and uses both an attitude heading and reference system (AHRS) and a Doppler velocity log (DVL) for the purpose of measurement. First, the acceleration and magnetic-field measurements are transformed into sine rotation vectors and combined. The combined sine rotation vector is then transformed into the differences between the Euler angles of the measured attitude and the predicted attitude; the differences are used to correct the predicted attitude. The method was evaluated according to field-test data and simulation data and compared to existing methods that calculate angular differences directly without a preceding sine rotation vector transformation. The comparison verifies that the proposed method improves the attitude estimation performance. PMID:27490549

  18. Perish, then publish: Thomas Harriot and the sine law of refraction.

    PubMed

    Fishman, R S

    2000-03-01

    A talented young scientist, Thomas Harriot, wrote the first English account of the New World, "A Briefe and True Report of the New Found Land of Virginia," distinguished by its serious effort to describe and understand the American Indian. Harriot went on to make innovations in mathematics and was one of the first astronomers to use the telescope. His largely unappreciated contribution to the history of ophthalmology was the first formulation of the sine law of refraction of light, found in his unpublished papers long after his death in 1621. Willebrord Snell discovered the sine law in Holland in 1621 but also died without formally publishing it. Rene Descartes first published the sine law in 1637. The sine law of refraction became not only the prime law of all lens systems but ushered in a new world of physical laws.

  19. RNA-Seq Analysis to Measure the Expression of SINE Retroelements.

    PubMed

    Román, Ángel Carlos; Morales-Hernández, Antonio; Fernández-Salguero, Pedro M

    2016-01-01

    The intrinsic features of retroelements, like their repetitive nature and disseminated presence in their host genomes, demand the use of advanced methodologies for their bioinformatic and functional study. The short length of SINE (short interspersed elements) retrotransposons makes such analyses even more complex. Next-generation sequencing (NGS) technologies are currently one of the most widely used tools to characterize the whole repertoire of gene expression in a specific tissue. In this chapter, we will review the molecular and computational methods needed to perform NGS analyses on SINE elements. We will also describe new methods of potential interest for researchers studying repetitive elements. We intend to outline the general ideas behind the computational analyses of NGS data obtained from SINE elements, and to stimulate other scientists to expand our current knowledge on SINE biology using RNA-seq and other NGS tools.

  20. Sine Rotation Vector Method for Attitude Estimation of an Underwater Robot.

    PubMed

    Ko, Nak Yong; Jeong, Seokki; Bae, Youngchul

    2016-08-02

    This paper describes a method for estimating the attitude of an underwater robot. The method employs a new concept of sine rotation vector and uses both an attitude heading and reference system (AHRS) and a Doppler velocity log (DVL) for the purpose of measurement. First, the acceleration and magnetic-field measurements are transformed into sine rotation vectors and combined. The combined sine rotation vector is then transformed into the differences between the Euler angles of the measured attitude and the predicted attitude; the differences are used to correct the predicted attitude. The method was evaluated according to field-test data and simulation data and compared to existing methods that calculate angular differences directly without a preceding sine rotation vector transformation. The comparison verifies that the proposed method improves the attitude estimation performance.

  1. Engineering chiral density waves and topological band structures by multiple-Q superpositions of collinear up-up-down-down orders

    NASA Astrophysics Data System (ADS)

    Hayami, Satoru; Ozawa, Ryo; Motome, Yukitoshi

    2016-07-01

    Magnetic orders characterized by multiple ordering vectors harbor noncollinear and noncoplanar spin textures and can be a source of unusual electronic properties through the spin Berry phase mechanism. We theoretically show that such multiple-Q states are stabilized in itinerant magnets in the form of superpositions of collinear up-up-down-down (UUDD) spin states, which accompany the density waves of vector and scalar chirality. The result is drawn by examining the ground state of the Kondo lattice model with classical localized moments, especially when the Fermi surface is tuned to be partially nested by the symmetry-related commensurate vectors. We unveil the instability toward a double-Q UUDD state with vector chirality density waves on the square lattice and a triple-Q UUDD state with scalar chirality density waves on the triangular lattice, using the perturbative theory and variational calculations. The former double-Q state is also confirmed by large-scale Langevin dynamics simulations. We also show that, for a sufficiently large exchange coupling, the chirality density waves can induce rich nontrivial topology of electronic structures, such as the massless Dirac semimetal, Chern insulator with quantized topological Hall response, and peculiar edge states which depend on the phase of chirality density waves at the edges.

  2. Mapping the sources of the seismic wave field at Kilauea volcano, Hawaii, using data recorded on multiple seismic Antennas

    USGS Publications Warehouse

    Almendros, J.; Chouet, B.; Dawson, P.; Huber, Caleb G.

    2002-01-01

    Seismic antennas constitute a powerful tool for the analysis of complex wave fields. Well-designed antennas can identify and separate components of a complex wave field based on their distinct propagation properties. The combination of several antennas provides the basis for a more complete understanding of volcanic wave fields, including an estimate of the location of each individual wave-field component identified simultaneously by at least two antennas. We used frequency-slowness analyses of data from three antennas to identify and locate the different components contributing to the wave fields recorded at Kilauea volcano, Hawaii, in February 1997. The wave-field components identified are (1) a sustained background volcanic tremor in the form of body waves generated in a shallow hydrothermal system located below the northeastern edge of the Halemaumau pit crater; (2) surface waves generated along the path between this hydrothermal source and the antennas; (3) back-scattered surface wave energy from a shallow reflector located near the southeastern rim of Kilauea caldera; (4) evidence for diffracted wave components originating at the southeastern edge of Halemaumau; and (5) body waves reflecting the activation of a deeper tremor source between 02 hr 00 min and 16 hr 00 min Hawaii Standard Time on 11 February.

  3. Sine oculis homeobox homolog 1 promotes DNA replication and cell proliferation in cervical cancer.

    PubMed

    Liu, Dan; Zhang, Xiao-Xue; Xi, Bi-Xin; Wan, Dong-Yi; Li, Li; Zhou, Jin; Wang, Wei; Ma, Ding; Wang, Hui; Gao, Qing-Lei

    2014-09-01

    Malignant proliferation is the fundamental trait of tumor cells. The initiation of DNA replication represents a key process for cell proliferation, and has a marked impact on tumorigenesis and progression. Here we report that Sine oculis homeobox homolog 1 (SIX1) functions as a master regulator in DNA replication of cervical cancer cells. The expression of SIX1 was induced by the E7 oncoprotein of human papillomaviruses in cervical intraepithelial neoplasia and cervical cancer. The increase of SIX1 expression resulted in the upregulation of multiple genes related to the initiation of DNA replication, including the genes coding for the proteins in minichromosome maintenance complex (MCM2, MCM3, MCM6), DNA polymerase α-primase complex (POLA1, PRIM1, PRIM2), clamp loader (RFC3, RFC4, RFC5), DNA polymerase δ complex (POLD3) and DNA polymerase ε complex (POLE2). In line with this, the increase of SIX1 expression enhanced DNA synthesis, accelerated G1 to S phase progression, and promoted the proliferation of cervical cancer cells and the growth of cervical cancer. Consistently, knockdown of SIX1 could hamper DNA synthesis, slow down G1 to S phase progression, and suppress tumor cell proliferation and tumor growth. Importantly, SIX1 could more efficiently promote anchorage-independent cell growth. These results suggest that the increase of SIX1 expression could promote tumorigenesis, progression and invasive growth of cervical cancer by promoting DNA replication, and that targeting SIX1 may have significant therapeutic value in cervical cancer treatment.

  4. Systemic sclerosis sine scleroderma: a case report of anterior uveitis.

    PubMed

    Borges, T; Vilaça, J; Ferreira, S; Chora, I; Silva, S; Dias, C

    2015-06-30

    Systemic sclerosis (SSc) sine scleroderma (ssSSc) is characterized by the absence of skin involvement, despite other manifestations of systemic sclerosis are present. It is not known whether sSSc represents a forme fruste of limited cutaneous SSc or a distinct entity, but the 2013 American College of Rheumatology/European League Against Rheumatism criteria for the classification of SSc have considered SSc without skin involvement to be a distinct subset. The authors present the case of a 70-year old female that was referred for a consultation for Raynaud's phenomenon and a chronic anterior uveitis (CAU). She had a history of dysphagia, diffuse pulmonary emphysema and a biopsy-documented fibrosis of the upper lobes, and an idiopathic non-ischemic dilated cardiomyopathy with severe left ventricle systolic dysfunction and left bundle branch block. Anti-nuclear and anti-centromere antibodies were positive, while manometry revealed distal esophageal hypomotility. After establishing the diagnosis of ssSSc and starting immunosuppression, the ocular disease improved, while the lung and heart diseases remained stable. This case underlines that it is very important to suspect SSc when CAU is present and/or skin thickening is absent. To our knowledge, this is the first report of CAU in a patient with ssSSc.

  5. Lateral sinus thrombosis associated with zoster sine herpete.

    PubMed

    Chan, James; Bergstrom, Richard T; Lanza, Donald C; Oas, John G

    2004-01-01

    Herpes zoster results from reactivation of the varicella zoster virus (VZV). Zoster sine herpete (ZSH) is an uncommon manifestation of VZV infection and presents with similar symptoms but without the vesicular rash. We describe an unusual case of lateral sinus thrombosis (LST) that developed during the clinical course of ZSH in the C2 distribution. A 55-year-old woman presented with a 3-day history of left temporal and postauricular pain, nausea, vomiting, and mild photophobia. She denied otalgia, otorrhea, and hearing loss. Examination revealed hyperesthesia in the left C2 nerve root distribution without evidence of herpetic rash. A computed tomography scan showed minimal fluid in the left mastoid cavity (not mastoiditis) and thrombus within the left lateral and sigmoid dural sinus. Magnetic resonance imaging and magnetic resonance angiogram confirmed these findings. Laboratory studies revealed elevated neurotrophic immunoglobulin G levels to VZV. Hypercoagulable studies were normal. She was subsequently treated with Neurontin, acyclovir, and anticoagulation. Her symptoms improved, and she was discharged 3 days later. LST is generally a complication of middle ear infection. Nonseptic LST, however, may result from dehydration, oral contraceptive use, coagulopathy, or thyroid disease. This unusual case raises the suspicion that thrombosis resulted from VZV associated thrombophlebitis in the ipsilateral cerebral venous sinuses along the second cervical nerve root distribution. A high index of suspicion is necessary in such cases so that a different treatment course can be identified and antiviral medication initiated promptly.

  6. Twisted hierarchies associated with the generalized sine-Gordon equation

    NASA Astrophysics Data System (ADS)

    Ma, Hui; Wu, Derchyi

    2011-09-01

    Twisted U- and twisted U/K-hierarchies are soliton hierarchies introduced by Terng to find higher flows of the generalized sine-Gordon equation. Twisted O(J,J)/O(J)× O(J)-hierarchies are among the most important classes of twisted hierarchies. In this paper, we derive explicit interesting first and higher flows of twisted O(J,J)/O(J)× O(J)-hierarchies, justify that the one-dimensional systems of twisted O(J,J)/O(J)× O(J)-hierarchies for J = Iq, n - q(1 ⩽ q ⩽ n - 1), called the generalized sinh-Gordon equations, are the Gauss-Codazzi equations for n-dimensional timelike submanifolds with constant sectional curvature 1 and index q in pseudo-Euclidean (2n - 1)-dimensional space {R}^{2n-1}_{2q-1} with index 2q - 1. Furthermore, a unified treatment of the inverse scattering theory for twisted O(J,J)/O(J)× O(J)-hierarchies is provided.

  7. Effects of envelope bandwidth on the intelligibility of sine- and noise-vocoded speech

    PubMed Central

    Souza, Pamela; Rosen, Stuart

    2009-01-01

    The choice of processing parameters for vocoded signals may have an important effect on the availability of various auditory features. Experiment 1 varied envelope cutoff frequency (30 and 300 Hz), carrier type (sine and noise), and number of bands (2–5) for vocoded speech presented to normal-hearing listeners. Performance was better with a high cutoff for sine-vocoding, with no effect of cutoff for noise-vocoding. With a low cutoff, performance was better for noise-vocoding than for sine-vocoding. With a high cutoff, performance was better for sine-vocoding. Experiment 2 measured perceptibility of cues to voice pitch variations. A noise carrier combined with a high cutoff allowed intonation to be perceived to some degree but performance was best in high-cutoff sine conditions. A low cutoff led to poorest performance, regardless of carrier. Experiment 3 tested the relative contributions of comodulation across bands and spectral density to improved performance with a sine carrier and high cutoff. Comodulation across bands had no effect so it appears that sidebands providing a denser spectrum improved performance. These results indicate that carrier type in combination with envelope cutoff can alter the available cues in vocoded speech, factors which must be considered in interpreting results with vocoded signals. PMID:19640044

  8. Effects of envelope bandwidth on the intelligibility of sine- and noise-vocoded speech.

    PubMed

    Souza, Pamela; Rosen, Stuart

    2009-08-01

    The choice of processing parameters for vocoded signals may have an important effect on the availability of various auditory features. Experiment 1 varied envelope cutoff frequency (30 and 300 Hz), carrier type (sine and noise), and number of bands (2-5) for vocoded speech presented to normal-hearing listeners. Performance was better with a high cutoff for sine-vocoding, with no effect of cutoff for noise-vocoding. With a low cutoff, performance was better for noise-vocoding than for sine-vocoding. With a high cutoff, performance was better for sine-vocoding. Experiment 2 measured perceptibility of cues to voice pitch variations. A noise carrier combined with a high cutoff allowed intonation to be perceived to some degree but performance was best in high-cutoff sine conditions. A low cutoff led to poorest performance, regardless of carrier. Experiment 3 tested the relative contributions of co-modulation across bands and spectral density to improved performance with a sine carrier and high cutoff. Co-modulation across bands had no effect so it appears that sidebands providing a denser spectrum improved performance. These results indicate that carrier type in combination with envelope cutoff can alter the available cues in vocoded speech, factors which must be considered in interpreting results with vocoded signals.

  9. A New Class of SINEs with snRNA Gene-Derived Heads.

    PubMed

    Kojima, Kenji K

    2015-05-27

    Eukaryotic genomes are colonized by various transposons including short interspersed elements (SINEs). The 5' region (head) of the majority of SINEs is derived from one of the three types of RNA genes--7SL RNA, transfer RNA (tRNA), or 5S ribosomal RNA (rRNA)--and the internal promoter inside the head promotes the transcription of the entire SINEs. Here I report a new group of SINEs whose heads originate from either the U1 or U2 small nuclear RNA gene. These SINEs, named SINEU, are distributed among crocodilians and classified into three families. The structures of the SINEU-1 subfamilies indicate the recurrent addition of a U1- or U2-derived sequence onto the 5' end of SINEU-1 elements. SINEU-1 and SINEU-3 are ancient and shared among alligators, crocodiles, and gharials, while SINEU-2 is absent in the alligator genome. SINEU-2 is the only SINE family that was active after the split of crocodiles and gharials. All SINEU families, especially SINEU-3, are preferentially inserted into a family of Mariner DNA transposon, Mariner-N4_AMi. A group of Tx1 non-long terminal repeat retrotransposons designated Tx1-Mar also show target preference for Mariner-N4_AMi, indicating that SINEU was mobilized by Tx1-Mar. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  10. A New Class of SINEs with snRNA Gene-Derived Heads

    PubMed Central

    Kojima, Kenji K.

    2015-01-01

    Eukaryotic genomes are colonized by various transposons including short interspersed elements (SINEs). The 5′ region (head) of the majority of SINEs is derived from one of the three types of RNA genes—7SL RNA, transfer RNA (tRNA), or 5S ribosomal RNA (rRNA)—and the internal promoter inside the head promotes the transcription of the entire SINEs. Here I report a new group of SINEs whose heads originate from either the U1 or U2 small nuclear RNA gene. These SINEs, named SINEU, are distributed among crocodilians and classified into three families. The structures of the SINEU-1 subfamilies indicate the recurrent addition of a U1- or U2-derived sequence onto the 5′ end of SINEU-1 elements. SINEU-1 and SINEU-3 are ancient and shared among alligators, crocodiles, and gharials, while SINEU-2 is absent in the alligator genome. SINEU-2 is the only SINE family that was active after the split of crocodiles and gharials. All SINEU families, especially SINEU-3, are preferentially inserted into a family of Mariner DNA transposon, Mariner-N4_AMi. A group of Tx1 non-long terminal repeat retrotransposons designated Tx1-Mar also show target preference for Mariner-N4_AMi, indicating that SINEU was mobilized by Tx1-Mar. PMID:26019167

  11. Identification of a Recently Active Mammalian SINE Derived from Ribosomal RNA

    PubMed Central

    Longo, Mark S.; Brown, Judy D.; Zhang, Chu; O’Neill, Michael J.; O’Neill, Rachel J.

    2015-01-01

    Complex eukaryotic genomes are riddled with repeated sequences whose derivation does not coincide with phylogenetic history and thus is often unknown. Among such sequences, the capacity for transcriptional activity coupled with the adaptive use of reverse transcription can lead to a diverse group of genomic elements across taxa, otherwise known as selfish elements or mobile elements. Short interspersed nuclear elements (SINEs) are nonautonomous mobile elements found in eukaryotic genomes, typically derived from cellular RNAs such as tRNAs, 7SL or 5S rRNA. Here, we identify and characterize a previously unknown SINE derived from the 3′-end of the large ribosomal subunit (LSU or 28S rDNA) and transcribed via RNA polymerase III. This new element, SINE28, is represented in low-copy numbers in the human reference genome assembly, wherein we have identified 27 discrete loci. Phylogenetic analysis indicates these elements have been transpositionally active within primate lineages as recently as 6 MYA while modern humans still carry transcriptionally active copies. Moreover, we have identified SINE28s in all currently available assembled mammalian genome sequences. Phylogenetic comparisons indicate that these elements are frequently rederived from the highly conserved LSU rRNA sequences in a lineage-specific manner. We propose that this element has not been previously recognized as a SINE given its high identity to the canonical LSU, and that SINE28 likely represents one of possibly many unidentified, active transposable elements within mammalian genomes. PMID:25637222

  12. RNA-Mediated Gene Duplication and Retroposons: Retrogenes, LINEs, SINEs, and Sequence Specificity

    PubMed Central

    2013-01-01

    A substantial number of “retrogenes” that are derived from the mRNA of various intron-containing genes have been reported. A class of mammalian retroposons, long interspersed element-1 (LINE1, L1), has been shown to be involved in the reverse transcription of retrogenes (or processed pseudogenes) and non-autonomous short interspersed elements (SINEs). The 3′-end sequences of various SINEs originated from a corresponding LINE. As the 3′-untranslated regions of several LINEs are essential for retroposition, these LINEs presumably require “stringent” recognition of the 3′-end sequence of the RNA template. However, the 3′-ends of mammalian L1s do not exhibit any similarity to SINEs, except for the presence of 3′-poly(A) repeats. Since the 3′-poly(A) repeats of L1 and Alu SINE are critical for their retroposition, L1 probably recognizes the poly(A) repeats, thereby mobilizing not only Alu SINE but also cytosolic mRNA. Many flowering plants only harbor L1-clade LINEs and a significant number of SINEs with poly(A) repeats, but no homology to the LINEs. Moreover, processed pseudogenes have also been found in flowering plants. I propose that the ancestral L1-clade LINE in the common ancestor of green plants may have recognized a specific RNA template, with stringent recognition then becoming relaxed during the course of plant evolution. PMID:23984183

  13. Phylogenetic relationships among East African haplochromine fish as revealed by short interspersed elements (SINEs).

    PubMed

    Terai, Yohey; Takezaki, Naoko; Mayer, Werner E; Tichy, Herbert; Takahata, Naoyuki; Klein, Jan; Okada, Norihiro

    2004-01-01

    Genomic DNA libraries were prepared from two endemic species of Lake Victoria haplochromine (cichlid) fish and used to isolate and characterize a set of short interspersed elements (SINEs). The distribution and sequences of the SINEs were used to infer phylogenetic relationships among East African haplochromines. The SINE-based classification divides the fish into four groups, which, in order of their divergence from a stem lineage, are the endemic Lake Tanganyika flock (group 1); fish of the nonendemic, monotypic, widely distributed genus Astatoreochromis (group 2); the endemic Lake Malawi flock (group 3); and group 4, which contains fish from widely dispersed East African localities including Lakes Victoria, Edward, George, Albert, and Rukwa, as well as many rivers. The group 4 haplochromines are characterized by a subset of polymorphic SINEs, each of which is present in some individuals and absent in others of the same population at a given locality, the same morphologically defined species, and the same mtDNA-defined haplogroup. SINE-defined group 4 contains six of the seven previously described mtDNA haplogroups. One of the polymorphic SINEs appears to be fixed in the endemic Lake Victoria flock; four others display the presence-or-absence polymorphism within the species of this flock. These findings have implications for the origin of Lake Victoria cichlids and for their founding population sizes.

  14. Theoretical analysis of interferometer wave front tilt and fringe radiant flux on a rectangular photodetector.

    PubMed

    Smith, Robert; Fuss, Franz Konstantin

    2013-09-06

    This paper is a theoretical analysis of mirror tilt in a Michelson interferometer and its effect on the radiant flux over the active area of a rectangular photodetector or image sensor pixel. It is relevant to sensor applications using homodyne interferometry where these opto-electronic devices are employed for partial fringe counting. Formulas are derived for radiant flux across the detector for variable location within the fringe pattern and with varying wave front angle. The results indicate that the flux is a damped sine function of the wave front angle, with a decay constant of the ratio of wavelength to detector width. The modulation amplitude of the dynamic fringe pattern reduces to zero at wave front angles that are an integer multiple of this ratio and the results show that the polarity of the radiant flux changes exclusively at these multiples. Varying tilt angle causes radiant flux oscillations under an envelope curve, the frequency of which is dependent on the location of the detector with the fringe pattern. It is also shown that a fringe count of zero can be obtained for specific photodetector locations and wave front angles where the combined effect of fringe contraction and fringe tilt can have equal and opposite effects. Fringe tilt as a result of a wave front angle of 0.05° can introduce a phase measurement difference of 16° between a photodetector/pixel located 20 mm and one located 100 mm from the optical origin.

  15. Genome-wide mapping of infection-induced SINE RNAs reveals a role in selective mRNA export

    PubMed Central

    Zhao, Yang; Alla, Ravi

    2017-01-01

    Abstract Short interspersed nuclear elements (SINEs) are retrotransposons evolutionarily derived from endogenous RNA Polymerase III RNAs. Though SINE elements have undergone exaptation into gene regulatory elements, how transcribed SINE RNA impacts transcriptional and post-transcriptional regulation is largely unknown. This is partly due to a lack of information regarding which of the loci have transcriptional potential. Here, we present an approach (short interspersed nuclear element sequencing, SINE-seq), which selectively profiles RNA Polymerase III-derived SINE RNA, thereby identifying transcriptionally active SINE loci. Applying SINE-seq to monitor murine B2 SINE expression during a gammaherpesvirus infection revealed transcription from 28 270 SINE loci, with ∼50% of active SINE elements residing within annotated RNA Polymerase II loci. Furthermore, B2 RNA can form intermolecular RNA–RNA interactions with complementary mRNAs, leading to nuclear retention of the targeted mRNA via a mechanism involving p54nrb. These findings illuminate a pathway for the selective regulation of mRNA export during stress via retrotransposon activation. PMID:28334904

  16. Genome-wide mapping of infection-induced SINE RNAs reveals a role in selective mRNA export.

    PubMed

    Karijolich, John; Zhao, Yang; Alla, Ravi; Glaunsinger, Britt

    2017-06-02

    Short interspersed nuclear elements (SINEs) are retrotransposons evolutionarily derived from endogenous RNA Polymerase III RNAs. Though SINE elements have undergone exaptation into gene regulatory elements, how transcribed SINE RNA impacts transcriptional and post-transcriptional regulation is largely unknown. This is partly due to a lack of information regarding which of the loci have transcriptional potential. Here, we present an approach (short interspersed nuclear element sequencing, SINE-seq), which selectively profiles RNA Polymerase III-derived SINE RNA, thereby identifying transcriptionally active SINE loci. Applying SINE-seq to monitor murine B2 SINE expression during a gammaherpesvirus infection revealed transcription from 28 270 SINE loci, with ∼50% of active SINE elements residing within annotated RNA Polymerase II loci. Furthermore, B2 RNA can form intermolecular RNA-RNA interactions with complementary mRNAs, leading to nuclear retention of the targeted mRNA via a mechanism involving p54nrb. These findings illuminate a pathway for the selective regulation of mRNA export during stress via retrotransposon activation. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  17. Effect of body temperature on visual evoked potential delay and visual perception in multiple sclerosis.

    PubMed Central

    Regan, D; Murray, T J; Silver, R

    1977-01-01

    Seven multiple sclerosis patients were cooled and four heated, but evoked potential delay changed in only five out 11 experiments. Control limits were set by cooling eight and heating four control subjects. One patient gave anomalous results in that although heating degraded perceptual delay and visual acuity, and depressed the sine wave grating MTF, double-flash resolution was improved. An explanation is proposed in terms of the pattern of axonal demyelination. The medium frequency flicker evoked potential test seems to be a less reliable means of monitoring the progress of demyelination in multiple sclerosis patients than is double-flash campimetry or perceptual delay campimetry, although in some situations the objectivity of the evoked potential test would be advantageous. PMID:599356

  18. New SINE families from rice, OsSN, with poly(A) at the 3' ends.

    PubMed

    Tsuchimoto, Suguru; Hirao, Yoshitoshi; Ohtsubo, Eiichi; Ohtsubo, Hisako

    2008-06-01

    A database search of the sequences flanking a member of rice retrotransposon RIRE7 revealed that a 298-bp sequence in the region downstream of the member is a repetitive sequence interspersed in the genome of Oryza sativa cv. Nipponbare. Most of the repetitive sequences were flanked by a direct repeat of a target-site sequence, about 14 bp in length. The consensus sequence, 293 bp in length, had no regions encoding any proteins but had sequence motifs of an internal promoter of RNA polymerase III. These indicate that the sequence is a retroposon SINE, designated OsSN1 (Oryza sativa SINE1). OsSN1 is a new rice SINE, because it has no homology with any of the three p-SINE families previously identified from rice, and because it has a stretch of A at the 3' end, unlike p-SINE and any other Gramineae SINEs which have a stretch of T at the 3' end. The Nipponbare genome was found to have many members related to OsSN1, forming two additional new SINE families (designated OsSN2 and OsSN3). OsSN2 and OsSN3 are highly homologous to the 3' and 5' regions of OsSN1, respectively. This suggests that OsSN1 has a mosaic structure, which is generated by sequence exchange (or shuffling) between ancestral OsSN2 and OsSN3. Despite the absence of homology in the 3' regions between OsSN1 (or OsSN2) and OsSN3, a sequence, 5'-TTCTC-3', is commonly present in the region preceding the A stretch at the 3' end. This sequence together with the A stretch and a stem-loop structure found in the region near the A stretch are assumed to be important for retroposition. OsSN members were present in strains of Oryza species, as were p-SINE members. Some of the members showed insertion polymorphism at the respective loci among the rice strains. p-SINE had such polymorphic members, which are useful for classification and phylogenetic analysis of various strains of Oryza species. The polymorphic members of OsSN were more frequently found than those of p-SINE, and therefore, such members are likely to be

  19. Multiple-Station Observation of Frequency Dependence and Polarization Characteristics of ELF/VLF waves generated via Ionospheric Modification

    NASA Astrophysics Data System (ADS)

    Maxworth, A. S.; Golkowski, M.; Cohen, M.; Moore, R. C.

    2014-12-01

    Generation of Extremely Low Frequency (ELF) and Very Low Frequency (VLF) signals through ionospheric modification has been practiced for many years. Heating the lower ionosphere with high power HF waves allows for modulation of natural current systems. Our experiments were carried out at the High Frequency Active Auroral Research Program (HAARP) facility in Alaska, USA. In this experiment, the ionosphere was heated with a vertical amplitude modulating signal and the modulation frequency was changed sequentially within an array of 40 frequencies followed by a frequency ramp. The observed magnetic field amplitude and polarization of the generated ELF/VLF signals were analyzed for multiple sites and as a function of modulation frequency. Our three observation sites: Chistochina, Paxson and Paradise are located within 36km (azimuth 47.7°), 50.2km (azimuth -20°) and 99km (azimuth 80.3°) respectively. We show that the peak amplitudes observed as a function of frequency result from vertical resonance in the Earth-ionosphere waveguide and can be used to diagnose the D-region profile. Polarization analysis showed that out of the three sites Paxson shows the highest circularity in the magnetic field polarization, compared to Chistochina and Paradise which show highly linear polarizations. The experimental results were compared with a theoretical simulation model results and it was clear that in both cases, the modulated Hall current dominates the observed signals at Chistochina and Paradise sites and at Paxson there is an equal contribution from Hall and Pedersen currents. The Chistochina site shows the highest magnetic field amplitudes in both experimental and simulation environments. Depending upon the experimental and simulation observations at the three sites, a radiation pattern for the HAARP ionospheric heater can be mapped

  20. Tunable focusing of sine-azimuthal wavefront modulated cosh-Gaussian beams by one spiral optical vortex.

    PubMed

    Wang, Wen; Zhang, Dawei; Gao, Xiumin; Hong, Ruijin; Zhuang, Songlin

    2013-09-10

    Optical intensity distributions in the focal region play an important role in many optical systems. In this paper, the tunable focusing properties of linearly polarized hyperbolic-cosine-Gaussian beams with sine-azimuthal variation wavefront were investigated by adding a spiral optical vortex. It was found that the focal patterns can be altered very considerably by changing the charge number of the optical vortex under a different phase parameter that indicates the phase change frequency upon increasing the azimuthal angle. The symmetry of focal patterns also changes remarkably upon increasing the charge number. And some novel focal patterns may appear, including a multiple-peak array, wheel focal pattern, or swallow-tailed focal pattern.